STATE OF FLORIDADEPARTMENT OF NATURAL RESOURCES

Elton J. Gissendanner, Executive Director

DIVISION OF RESOURCE MANAGEMENTArt Wilde, Director

BUREAU OF GEOLOGYWalter Schmidt, Chief

INFORMATION CIRCULAR NO. 104

PART I - 1985 FLORIDA PETROLEUMPRODUCTION AND EXPLORATION

ByJacqueline M. Lloyd

andAlbert V. Applegate

PART II - THE BROWN DOLOMITE ZONE OF THE LEHIGH ACRESFORMATION (APTIAN) IN THE SOUTH FLORIDA BASIN -

A POTENTIALLY PROLIFIC PRODUCING HORIZON OFFSHORE

By

Albert V. Applegate

Tallahassee1987

DEPARTMENTOF

NATURAL RESOURCES

BOB MARTINEZGovernor

GEORGE FIRESTONESecretary of State

BILL GUNTERState Treasurer

BETTY CASTORCommissioner of Education

BOB BUTTERWORTHAttorney General

GERALD LEWISState Comptroller

DOYLE CONNERCommissioner of Agriculture

ELTON J. GISSENDANNERExecutive Director

ii

(-.

LETTER OF TRANSMITTAL

BUREAU OF GEOLOGYTALLAHASSEE

Governor Bob Martinez, ChairmanSj Florida Department of Natural Resources

Tallahassee, Florida 32301

Dear Governor Martinez:

The Florida Geological Survey, Bureau of Geology, Division ofResource Management, Department of Natural Resources, is publishinga two-part report as its Information Circular 104. Part I - "1985 FloridaPetroleum Production and Exploration" discusses 1985 oil and gasproduction, onshore and offshore exploration, and oil production andexploration statistics. This information is useful to the oil and gasindustry and to the state in planning wise development of Florida's oiland gas resources.

Part II of this report-- "The Brown Dolomite Zone of the Lehigh AcresFormation (Aptian) in the south Florida Basin - a potentially prolificproducing horizon offshore" discusses the known extent of the BrownDolomite Zone in the south Florida Basin and its possible future poten-tial for producing oil. This information will be useful in planning futureexploration programs and assessment thereof by the State of Florida.

Respectfully yours,

Walter Schmidt, ChiefBureau of Geology

iii

Printed for the

Florida Geological Survey

Tallahassee1987

ISSN No. 0085-0616

Iv

CONTENTS

Page

Part I - 1985 Florida Petroleum Production and Exploration .... 1

Part II - The Brown Dolomite Zone of the Lehigh Acres Formation(Aptian) in the South Florida Basin-A Potentially ProlificProducing Horizon Offshore.................................. 43

v

PART I

1985 FLORIDA PETROLEUM PRODUCTIONAND

EXPLORATION

ByJacqueline M. Lloyd

andAlbert V. Applegate

vi

TABLE OF CONTENTS

Page

Abstract ...................................................... 11985 Production ............................................... 21985 Driling Activity ......................................... 2

Onshore Exploratory Drilling .............................. 2Offshore Exploratory Driling .............................. 7

1985 Geophysical Exploration Activity ......................... 9Recent Florida Oil Field Discoveries ........................... 11

Corkscrew Field ........................................... 11Discovery ............................................. 11Sunniland History .................... .............. . 16Wells Drilled Near Corkscrew Field .................... 18Stratigraphic Cross Section ........................... 18Conclusion ........................................... 20

Bluff Springs Field ........................................ 20Discovery .......................................... 20Historical and Geological Setting .................... 24Conclusion ........................................... 26

McClellan Field ........................................... 26Summary ..................................................... 26References ................................................... 27Appendices ................................................... 28

I. 1985 and Cumulative Production Data ................. 29

II. 1985 Drilling Activity ..................................... 31Table I. 1985 Field Wells Drilled ................... 32Table II. 1985 Wildcat Wells Drilled ................. 34Table III. Wells Drilled During 1985 in Eastern

Planning Area, Gulf of Mexico............. 36

III. Discovery Well Data ................................ 38

IV. 1985 Geophysical Exploration Activity ................. 40

V. Florida Oil and Gas Geology Related Theses ......... 42

ILLUSTRATIONSFigure 1. Production decline curve for Florida and for Jay field1978 through 1985 .............................................. 3

Figure 2. Cumulative oil production through January 1986 forFlorida oil fields ................................................ 4

Figure 3. Stratigraphic nomenclature, Middle Jurassic to LowerCretaceous, Florida panhandle ................................. 5

vii

Figure 4. Stratigraphic nomenclature, Upper Jurassic to LowerCretaceous, south Florida ...................................... 6

Figure 5. Leases and wells drilled in federal waters, offshoreFlorida ....................................................... 8

Figure 6. 1985 geophysical exploration activity ................. 10

Figure 7. South Florida oil field location map .................. 12

Figure 8. Well location map with Sunniland structure, Corkscrewfield ........................................................... 13

Figure 9. Good porosity map of the Sunniland Formation ........ 14

Figure 10. Isopach of Sunniland dark carbonate ................ 15

Figure 11. Log information, P-314 (Sunoco Felda field; Sun OilCo. Red Cattle No. 30-1) ...................................... 17

Figure 12. Stratigraphic cross section of Lake Trafford and Sun-nilard formations ............................................. 19

Figure 13. North Florida oil field location map .................. 21

Figure 14. Well location map with regional Smackover structure,Bluff Springs field area ........................................ 22

Figure 15. Log information, P-1136 (first offset, dry hole) andP-1125 (Bluff Springs discovery well) .......................... 23

TABLES

Table 1. Production statistics, Bluff Springs fielddiscovery well .............................................. 25

viii

1

1985 FLORIDA PETROLEUMPRODUCTION AND EXPLORATION

By

Jacqueline M. Lloydand

Albert V. Applegate

ABSTRACT

Florida petroleum production declined during 1985, as productionfrom Jay field continued to decline. Onshore drilling activity main-tained a level similar to that of 1984, while drilling in federal waters offFlorida showed an increase, with six wells completed during 1985.This peak in offshore drilling activity was presumably due to the factthat many offshore leases were close to expiration. Geophysical ex-ploration activity also increased during 1985, including new ex-ploration interest in the Apalachicola Embayment area andsignificantly increased exploration interest in south Florida.

Wildcat drilling during 1985 yielded one success in south Floridawith the discovery of Corkscrew field. The field is on the Sunnilandtrend and produces from the Lower Cretaceous Sunniland Limestone.Bluff Springs field in north Florida was actually discovered in 1984 butwas not released from confidential status until December 1985. Pro-duction is from the Jurassic-age Smackover Formation. Drilling beganin December, 1985, for another north Florida discovery, McClellanfield. This field is located in Santa Rosa County and also producesfrom the Smackover Formation. The discovery well was completed onFebruary 28, 1986, and is still confidential with the exception of aminimum of information released in F &A Oil Reports (April, 1986).

Appendices of oil and gas information are presented. These include1985 drilling activity, 1985 and cumulative production data, discoverywell date, and 1985 geophysical exploration activity. In addition, atable listing theses held by the Florida Geological Survey library thatare related to Florida oil and gas geology is presented. This should beof particular interest to those who are researching Florida oil and gasfor academic as well as exploratory purposes.

21985 PRODUCTION

Florida oil production continued to decline in 1985 (figure 1 andAppendix 1). During 1985, Florida produced 11,457,913 barrels of oilcompared to 14,461,969 barrels for 1984. This represents a 21 percentdecrease in production. This is a lower percentage than the corres-ponding decrease for 1983 to 1984 (26 percent, Applegate and Lloyd,1985).

Figure 1 also illustrates the production decline for Jay field, indi-cating Jay Field's dominance in Florida oil performance. Smaller fielddiscoveries continue to keep state-wide decline at a slightly lower ratethan the Jay field decline; however, with Jay field accounting for 71percent of the state's cumulative production through January 1986(figure 2), only a discovery of a relatively large field would reverse thetrend.

1985 DRILLING ACTIVITYOnshore Exploratory Drilling

Thirteen wildcat wells were drilled in Florida in 1985. Six of thesewetls were Smackover-Norphlet tests (stratigraphic nomenclatureshown on figure 3) in Santa Rosa and Escambia counties in westFlorida; all were dry holes. Five wildcat wells were Sunniland tests(stratigraphic nomenclature shown on figure 4) drilled in Collier andLee counties on the Sunniland trend. Four of these wells were dryholes, but R.K. Petroleum discovered the Corkscrew field in CollierCounty. This may well be the best field found in Florida since Exxon'sRaccoon Point field was discovered in 1978. R.K. Petroleum has kindlywaived the confidential status on this well and the Corkscrew field isdiscussed separately.

Palmer Petroleum drilled a Paleozoic wildcat in north Florida onacreage leased by Star Petroleum. Star was one of the large lease-holders who assembled acreage in Madison, Taylor, Lafayette,Suwannee, and surrounding counties in the late 1970's. The well(Florida permit #1181), located in Section 2, T4S, R12E, in SuwanneeCounty was drilled to a total depth of 6,888 feet and abandonedwithout testing.

This is the sixth wildcat drilled to test the Paleozic section in northFlorida since 1980. No shows have been found; as a result, much of theacreage acquired has been dropped. At present there are no out-standing drilling permits. Roy Roundtree (Star geologist, personalcommunication, 1985) stated that Star would probably keep itsacreage position, but that it was extremely doubtful that any furtherdrilling would be done until oil prices rebound.

The Sabine Corporation drilled the Miccosukee No. 32-1 (Floridapermit #1169) in Section 32, T49S, R35E in Broward County. This wasthe first oil well drilled in Broward County and was abandoned June28, 1985, at a depth of 11,604 feet. The well was a Sunniland test wellbut was located approximately 10 miles to the east of the presentproducing trend.

OIL PRODUCTION DECLINE1978 THROUGH 1985

50

45

40-

2 -

15-

10-

5 i I I i I' I

1978 1979 1980 198-1 1982 1983 1984 1985

0 JAY FIELD + STATEWIDE

Figure 1. Production decline curve for Florida and for Jay field 1978 through 1985

CUMULATIVEL PIRODUCTION

THROUGH JANUARY, 108651 (7.8%)

S2 (3.8%)53 2 (23)\8) (N3-5) (0.9%)

S3 (2.3%) \ N2 (10.7%)

S4 (1.9%),(s5-14) (1.5%)

KEY OIL FIELD

NE BlikjWk CreekN3 Nt. Cir 1N4 huMwatar CreekN5 BlIff SpringsB1 Weut Feldae2 Sumiland

93 Sunoco Felda94 bar Island55 Lahigh Park96 Raccoo Point87 Nid-FeldaSB Lake Trafford89 Tomumnd CanalSIG SeminolfeSil Forty Nile Bend *S12 Corkicrme913 BaNtr Island A914 Pepper Hiamock

Nl-NWs North Florida Oil N1 (71.1%)sl-614. South Florida Oil* i Abandoned

Figure 2. Cumulative oil production through January 1986 for Florida oil fields

5

GROUPS ANDSERIES STAGES FORMATIONS

LOWERCRETACEOUS BERRIASIAN

COTTON VALLEY

TITHONIAN GROUP

UPPER HAYNESVILLEKIMMERIDGIAN FORMATION

UPPERJURASSIC OBUCKNER MEMBER

KIMMERIDGIAN (L. HAYNESVILLE)

OXFORDIAN SMACKOVERFORMATION

NORPHLETMIDDLE CALLOVIAN FORMATIQN

JURASSIC BATHONIAN LOUANN SALT

Figure 3. Stratigraphic nomenclature, Middle Jurassic to LowerCretaceous, Florida panhandle

6

SERIES STAGES GROUPS AND FORMATIONS

It RATTLESNAKE HAMMOCK FORMATION

O LAKE TRAFFORD FORMATION

< SUNNILAND FORMATION

O PUNTA GORDA ANHYDRITEZ ( ______

0 wz ABLE MEMBERCr W Z0 0 Cr O

< TWELVE MILE MEMBER

-J

.) 0 uJ WEST FELDA SHALE

O0--I 2 PUMPKIN BAY FORMATION

-J

0BONE ISLAND FORMATION

9-

, < WOOD RIVER FORMATION

Figure 4. Stratigraphic nomenclature, Upper Jurassic to LowerCretaceous, south Florida

7OFFSHORE EXPLORATORY DRILLING

Sale Number 94 was held forthe Eastern Gulf of Mexico in December,1985. Figure 5 shows leases held prior to the bidding and leasesacquired at the sale. It also shows the location of wells drilled in federalwaters offshore Florida during 1985. Appendix II, table III is a review ofthe 1985 offshore drilling activity.

Industry paid over $124 million for 82 leases (nine square miles, 5,760acres per lease) out of total of 2,600tracts available. This marked lack ofinterest in the Eastern Gulf of Mexico was not unexpected, and noresumption of interest in the area is expected in the near future.

Drilling in this area has been disappointing. The Destin Dome, whichwas once considered to be very attractive, was originally drilled in 1975.Over one billion dollars have been spent on leases and drilling and noappreciable reserves have been found. Sohio is rumored to have spentin excess of $20 million drilling their Gainesville lease. Drilling in theCharlotte Harbor area encountered basement at 10,000 to 12,000 feet onthe Sarasota Arch. Drilling in the Pulley Ridge area has been postoneddue to environmental studies, and this area will not be drilled beforelate-1986 at the earliest. In the Destin Dome and Pensacola areas, gasand condensate are the probable hydrocarbons to be encountered.These commodities are in oversupply at the present time. Forthese andother reasons, almost 100 blocks in the Eastern Planning Area expiredin 1985 without being drilled.

In sale no. 94, the highest bids went for tracts located on the DestinDome. These bids were made by Shell Offshore Inc, and Amoco. Shellwas high overall bidder, spending-$30.6 million for its interest in 30tracts. Amoco spent $27.8 million forits. interest in 24 tracts. Both ofthese companies purchased drilling blocks outside of the Destin Domearea.

In the Destin Dome and Pensacola areas, the principal drilling targetsare the Norphlet and Smackover formations of Late Jurassic age. Theformer is capable of high volume gas production in the Mobile Bay areaabout 100 miles to the west, where wildcat and development drilling hasbeen carried out by several companies since the original discovery byMobil in 1979. The Norphlet is as much as 600 feet thick in the MobileBay area; unfortunately, it appears to thin rapidly to the east in Floridawaters. The Smackover Formation is the principal producing formationin the Jay and Blackjack Creek fields which are approximately 100 milesto the northwest of the Destin Dome. In other areas in the EasternPlanning Area, Cretaceous limestones and dolomites are the principalwildcat targets.

The exploratory drilling which took place offshore in 1985 was notencouraging. Four Smackover-Norphlet tests were drilled on the DestinDome. Two of these unsuccessful wildcats were drilled by Shell in Block160. Exxon drilled a Smackover-Norphlet dry hole in Block 284. Chev-ron did likewise in Block 422. It was rumored that Shell's first well inBlock 160 had a good show, but no pipe was run in the well.

In the Gainesville area (figure 5) Sohio is believed to have drilled

84 ove64M 0.0"

8 y .._ ,,,, /[ ..

EASTERN \ RA

a . ----- /innd

S ci. Ri -q #i "MOO,

- Fiaure 5. Leases and wells drilled in federal waters, offshore Florida

9

through a thick Eagle Mills (Triassic) section before abandoning a wellin Block 707 in Paleozoic rocks at 15,994 feet.

Sohio drilled a wildcat in Pensacola Block 948 to a total depth of18,958 feet. The well was drilled to test a Louann high and was locatedon the down-thrown side (southwest) of a regional fault. A seven-inchliner was cemented at 18,956 feet and the Smackover and Norphletformations were tested. Test data are not available but the well wasabandoned.

Drilling in the offshore during 1986 (through June 1986) in the East-ern Planning Area of the Gulf of Mexico has been slow. As concessionsgranted by the federal government last for only five years withouttesting, Shell drilled one wildcat in Block 622 of Charlotte Harbor. Thiswell was drilled to a total depth of 10,500 feet. Shell also drilled a testwell in Block 512 of the DeSoto Canyon area to a total depth of 12,300feet. Both wells were abandoned without testing.

1985 GEOPHYSICAL EXPLORATION ACTIVITY

The implementation of Chapter 377, Part 1, Florida Statutes authoriz-ing the Florida Department of Natural Resources to regulate geophysi-cal activities (Applegate and Lloyd, 1985), gives the Florida GeologicalSurvey the opportunity to monitor not only areas of seismic activity inFlorida, but also areas of interest to industry that, for one reason oranother (i.e. economics, permitting problems, logistical problems) werenot surveyed. Thirty-one applications for geophysical permits werereceived by the Florida Geological Survey during 1985. Of these 34applications, 23 have been permitted, fourwerewithdrawn by the appli-cants, and four are still being processed. The areas covered by thesepermits are shown on figure 6. Only 18 permitted areas were actuallysurveyed during 1985; four permitted surveys were cancelled and theremaining one is "on hold" (presumably awaiting changes in economicconditions).

As was the case in 1984, seismic activity for 1985 was greatest in theFlorida panhandle. However, unlike 1984, panhandle activity was notstrictly concentrated in Escambia and Santa Rosa counties but in-cluded seismic surveys in Liberty, Franklin, and Wakulla counties.Applications were also received which included, in addition to thosecounties listed above, proposed surveys in Okaloosa, Walton, Bay, andCalhoun counties. Surveys in these counties were not run, but theapplications indicate an increased interest in Florida panhandle explo-ration. This apparently increased interest includes the ApalachicolaEmbayment area which was discussed by Applegate, et al. (1978) as anarea with significant Smackover oil potential. The panhandle surveyscompleted in 1985 yielded 243 miles of shot-hole and 276 miles ofVibroseis lines, for a total of 519 miles.

Only one application was received during 1985 for geophysical oper-ations in north peninsular Florida. This application was permitted andthe survey was completed. It included 52 miles of shot-hole lines inMadison County.

10

STATE OF FLORIDA

- - r r -7-f" --, i N-. I_.

F i- 6. 1 S

Figure 6. 1985 geophysical exploration activity

11

Geophysical exploration activity increased by an order of magnitudecompared to 1984 in south Florida. A total of 392.25 miles (330 milesVibroseis; 62.25 miles shot-hole) of seismic surveys were run in southFlorida during 1985, compared to a total of only 22 miles for 1984.Surveys also covered a broader geographic area, including parts ofOkeechobee, Collier, Hendry, Dade, Palm Beach, and Browardcounties.

1985 seismic activity showed a general increase in exploration inFlorida over more extensive geographic areas. The recent discoveries inboth north (panhandle) and south Florida should encourage the con-tinuance of this trend.

RECENT FLORIDA OIL FIELD DISCOVERIES

Corkscrew Field

DISCOVERY

The R. K. Petroleum Corp., Midland, Texas, completed 33-2 RexProperties, the discovery well of the Corkscrew field on November 10,1985.-The completion was made in the Sunniland formation of theLower Cretaceous. The well is in Section 33, T46S, R28E, about 21/2miles north and slightly west of the one-well Lake Trafford field inCollier County (figures 7 and 8). This location is favorable on both theequivalent good porosity map and the isopach of Sunniland dark car-bonate (Applegate and Pontigo, 1984, and figures 9 and 10).

The 6,000 acre driling block was assembled by Len W. Sipple, Naples,Florida, and John C. Sipple, Mobile, Alabama, owners of Southern OilExploration Inc., Mobile. Mike Cheeseman, consulting geologist, Pen-sacola, Florida, prepared geological and structural interpretations ofthe area from subsurface data.

A conventional core was taken in the 11,536-564 feet interval of theSunniland with 26.5 feet recovered. In the 11,550.25-559.5 feet interval(8.75 feet) average porosity was 15.25 percent; permeability, 106.2 milli-darcies (horizontal); water saturation, 37 percent of pore space; and oilsaturation, 11.96 percent of pore space. The Analytical Logging Co.described the porous interval as a "fossil hash" of dolomitic limestone.The bottom 4.5 feet of core was described as an indurated, gray, crystal-line limestone with no permeability. After logging, 7-inch casing wascemented at 11,547 feet, and an open hole completion was made in the11,547-565 feet interval of the Sunniland Formation. Production is fromunit 1 of the Sunniland Formation (figure 11). Units 1 and 2 produce inthe Sunniland field to the southeast (Means, 1977). The Lake Traffordand Sunniland formations were encountered at 11,398 and 11,537 feet(E-log depths), respectively.

A nine-hour swab test of the well produced 163.33 barrels of 260gravity oil (A.P.I. at 60 degrees Fahrenheit) with no water, for a daily rateof 435 barrels. The well was placed on a pump and has produced about

12

OIL FIELDS IN SOUTH FLORIDA

b TOWNSEND CANAL

LEE CO. • -- rD HENDRY CO.PALM BEACH CO.

WE3T 3OCO - FELDA R30 R31E-P- 1170

jO E C CO.RKSCEW FIEL

l r~ LAKE TRAFD1F|P-222 I

AIN, 0 kSEMINOLE£

K " GLAN D -- - T493

PEPPER HMOCK 0 BAXTER ISLAND

%LE3 I BROWARD CO.

COLLIER CO.RACOON PONT

DADE CO.

FORTY MLE BEND

EXPLANATION , MONROE CO.* ACTIE OIL FIELDSINACTNIVE 0O. FELD0

10 KM

S 10 .o E3

SCALE 0

Figure 7. South Florida oil field location map

13

w R27E R28E

\. 1 •L P-1199 »P-t7 °Drakocvrew afrordWld / •

410

.0 2000 4000 6000 8000

FEET

CONTOUR INTERVAL: 20 FT.

O NEW PERMITTED LOCATION, P-1201 Corkscrew and Lake Trafford Fields

* OIL FIELDS-117 nd P-11 CORKSCREW Structure Map Top of SunnlandP-401; LAKE TRAFFORD

ABANDONED WILDCATS(1) P-408 (5) P-853(2) P-1030 (6) P-84913) P-1001 (7) P-477(4) P-1050

Figure 8. Well location map with Sunniland structure, Corkscrewfield

14

CnAlNLOTTI L A K E

- ----- P A L M

L3 EEACH

SFIELD, P-1170

25+

Figure 9. Good porosity map of the Sunnhland Formation

EQUIVALENT -GOOD.-POROSITY *"SUNNILAND FORMATION M

Cl * 5 FEET

to o .,M

Figure 9. Good porosity map of the Sunniland Formation

15

\ ̂ \ "-60-^ -V }--- ^-LA E

C ARLOTTE ' " '

L- Eo9 . 90 P •- - L M

ORKSGBEW 1 60FIELD P 170i

SB OWARD

ISOPACH : oSUNNILAND DARK CARBONATE

C.I. 10 FEET '

20 KM 0 A 0 E

0 80 MILESSCALE

PBi MM Y A.V. a PPLEMT

Figure 10. Isopach of Sunniland dark carbonate

16

220 barrels of oil per day, which is the pump capacity, with no water.Production through February 20, 1986, was 20,231 barrels of oil in 92days, for an average of 220 barrels per day.

Permits were secured to drill a west offset (P-1199) and a north offset(P-1201) to this well. The west offset (32-1) was completed as a pro-ducer with the top of the Sunniland encountered at 11,486 feet(figure 8).

SUNNILAND HISTORY

Sunniland field was discovered by Humble Oil and Refining Corp.(now Exxon) in 1943. Corkscrew field is about 11 miles to the northwestof the Sunniland field. The boulder zone, a cavernous dolostone inTertiary age rocks encountered above 4,000 feet in the subsurface ofsouth Florida, makes seismic interpretation difficult. For this reason,drilling of this trend has been limited even though many wells haveproduced a million or more barrels of oil. The Sunniland field, with atotal of 18 producing wells, has yielded more than 18,300,000 barrels ofoil and is currently producing more than 10,000 barrels/month from sixwells.

J. A. Means (1977) broke the Sunniland Formation into five units(figure 11). Following the end of the Punta Gorda Anhydrite deposition,unit 5, the "Rubble Zone," was deposited as the Sunniland seaadvanced. It is a dark brown to dark gray, argillaceous, micritic limes-tone, which exhibits conchoidal fracturing and normally has a stronglypetroliferous odor on a fresh surface. It is approximately 50 feet thick.

The lower part of unit 4 has been called the "Black Shale." It is a denseargillaceous limestone about 40 feet thick. Directly above the "BlackShale" is a light brown, nonporous, miliolid-rich limestone, which is theupper part of unit 4. Directly above unit 4 are units 1,2, and 3, which areapproximately 100 feet in total thickness, are located on the producingtrend, and are composed of localized buildups of rudistids, algal plates,gastropods, Foraminifera, and other organic debris into mounds or podswhich formed porous grainstones. Dolomitization of these grainstoneshas enhanced their porosity. These grade laterally into nonporous,miliolid-rich limestones. Mitchell-Tapping's 1984 and 1985 publicationsinclude excellent photographs of these carbonates.

During and after deposition of the Sunniland Formation, the grain-stones withstood compaction, and the laterally equivalent miliolid-richlime muds were compacted (Means, 1977). This process began at thetime of deposition, as the overlying Lake Trafford Formation thins overSunniland highs. Additional compaction caused fractures and minorfaulting around the edge of the oil fields. These fractures probably areresponsible for the "Rubble Zone" in the lowermost Sunniland and mayserve as a conduit for oil to migrate from the "Rubble Zone" (unit 5) andthe "Black Shale" (lower part of unit 4) into the porous units 1, 2, and 3.

Punta Gorda fm. Sunniland fm. Lake Trafford fnm.- lower anhydrite' - Unit 5 Unit 4 C Unit 2 Unit 1

I .

S* * * ' g : P3 ( no Felda

field, S O . R d C t No.F 1og1 ior to P3 ( Felda- . Su Oi Co R C l

^M J . - U r=_ Ij M I , .... '

18

WELLS DRILLED NEAR CORKSCREW FIELD

Wells drilled near Corkscrew field, which played a significant role indefining the geology and structure of the field, were the following(figure 8);

1. P-408 (Mobile Oil Henry Sanders Trustee 35-1). A drill stem test ofthe unit 5 "Rubble Zone" between 11,838 and 11,888 feet recovered1,000 feet of water column, 1,166 feet of oil and gas cut water column.

2. P-1030 (NRM Audubon Society 1-1). Upper and Lower Sunnilandhad scattered odors and mineral fluorescence.

3. P-1001 (NRM Alico 31-2). Seventeen feet of good Sunniland "reef"rock (grainstone) encountered.

4. P-1056 (NRM Alico 31-4). This well tested 16 barrels of oil and 195barrels of salt water in eight hours, from the Lake Trafford Formation.Also had good shows of oil in unit 1 of the Sunniland and shows of oil infractures in unit 5 "Rubble Zone." The interval from 12,333 to 12,378feet, units 1 and 2 in a directionally drilled hole, had an average porosityof 13.89 percent and horizontal permeability of 11.69 md.

5. P-853 (Total Bernice D. Pepper 2804). This well had shows of oil inthe 11,555-560 feet interval of the Sunniland unit 1 with 15 percentporosity and horizontal permeability ranging from 0 to 67 md. In the11,594-644 feet interval a core showed good porosity and permeabilitydevelopment in units 2 and 3, with porosity occasionally above 20percent. The unit 5 "Rubble Zone" had excellent shows of oil but almostno porosity or permeability.

6. P-849 (Kanaba Oil and Gas Baron Collier 9-2). This well was drilledas a step-out to P-401, the discovery well of the Lake Trafford field. Onlyscattered porosity and permeability were noted in the upper three Sun-niland units. Unit 5 had many live shows of oil, but poor porosity andpermeability.

7. P-401 (Mobile Oil Baron Collier 1). This well was the discovery wellof the Lake Trafford field, which produces from the unit 5"Rubble Zone."The cumulative production through 1985 is more than 253,000 barrelswith daily production of 34 barrels and no water.

8. P-477 (Exchange Oil & Gas Earl Ball 16-1). This is a south offset tothe Lake Trafford discovery well. Completion was made in unit 5. Thewell produced about eight barrels per day of oil and was abandoned.

STRATIGRAPHIC CROSS SECTION

A stratigraphic cross section of the Sunniland and Lake Traffordformations was constructed from P-130 in Collier County to P-152 inGlades County (figure 12). This cross section was drawn approximatelyperpendicular to the producing trend (figures 7, 9, and 10).

In the down-dip well, P-130, relatively thick Sunniland and LakeTrafford formations are composed principally of dark gray to black,nonporous limestones and anhydrite. In P-103, which is down-dip fromthe producing trend but 18 miles northeast of P-130, the Sunniland

P-190 (tiffs I) P*Ifl (Kft III) P-M5 (09s 41r) P-i 10 Oft 40-) W.I ue is)

6p 191 1 ap R96¶IYTI KP U s*I. Y A14MA MAY g6411mly 4AIft PAY 90A,0V1,MY

UAC N ;,OKP1

11.1648

IK.MMIILAP URI 4 LMMfA

ORAWN SY P411IN~f

Figure 12.L Statg AphiCKcosscino aeTafodadSn adfrain

20

Formation is composed principally of dark micritic limestone andanhydrite.

P-222 is on the producing trend; it produced some oil during a drill-stem test. but was abandoned as noncommercial. The thickening of theSunnitand Formation and the thinning of the Lake Trafford Formationon the producing trend, as well as the development of porosity (anestimated 19 feet of porosity total) in units 1, 2, and 3 are as expected.

Moving updip to P-133 and P-152, the Sunniland Formation hasthinned to 215 feet and 168 feet, respectively. The porous Sunnilandlimestone in P-222 has disappeared, and in its place is chalky, nonper-meable limestone. The dark micritic limestone has thinned and almostdisappeared in P-152 and is partially replaced by dolomite.

CONCLUSION

Corkscrew field is favorably located on both the good porosity andthe dark carbonate Sunniland Formation maps. The location of thediscovery well was based on geological and structural interpretations ofthe area from subsurface data. The discovery is consistent with calcula-tions made by Applegate and Pontigo (1984). These calculationsshowed that 45 barrels of recoverable oil had been found for every footof wildcat drilling between 1943 and 1980 In south Florida, and thesereserve figures are very conservative. Additional calculations indicatethat if drilling had been confined to the area of known porosity in theSunniland Formation, the figure would have been more than 100 barrelsof oil for every foot of wildcat drilling. These figures indicate that moredrilling should be done in the future in south Florida.

Bluff Springs Field

DISCOVERY

Bluff Springs field, a new oil field In the western panhandle of Florida,was discovered on March 25,1984. The discovery well, the Stone Petro-leum Corp. St. Regis Paper Co. No. 29-4 (Florida permit 1125), wasreleased from confidential status in December, 1985. It was a rankwildcat located in Section 29, T5N, R31W, Escambia County, approxi-mately 10 miles west-southwest of Jay field and approximately fourmiles southeast of the nearest previously drilled wildcat, Florida permit1177 (figures 13 and 14). This area, west and southwest of Jay, is knownto be underlain by Louann Salt with seismic studies indicating salt-induced fault structures in the overlying formations.

Production is from Jurassic-age Smackover Formation dolomitesfrom 16,332 to 16,339 feet (16,154 to 16,161 feet below MSL, figure 15).These dolomites are dark brownish-gray to brownish-black, finegrained micro-crystalline, and show evidence of recrystallization fromoriginally oolitic and possibly pelletal facies. Examination of core chipsfrom this interval (at 10x with binocular microscope) reveals primarilyintercrystalline to vuggy porosity. Samples from the top of the produc-

21

NORTH FLORIDA OIL FELD LOCATION MAP

Rw R323w Ri0w R29W_ ra .M27W R26W

DISCOVIE UI .

DI COVERY W=BLUFF «PROGa FW EETWATER 1z

...--.- -. __ --______.___ --- -•- .- i

EPLOC ATIN

SACTIVE O FIELD

SCALE CANTONMENT

. I V OACOLA

Figure 13. North Florida oil field location map

1n.S AmiEA NUT CC*1h')Uh f0

SBLUFF SPRINGSN RN S FIELD - LE AO

AREA OF INTEREST

. BLACKJ K CREEK FIELD

O PERMi L ED LOCATION

Figure 14. Well location map with regional Smackover structure, Bluff Springs field areaFigure 14. Well location map with regional Smackover structure, Bluff springs field area

, 3. ....

BUCKNER ANHYDRITE-1su.342 1 16 MSL..'MSI

5i !* MEAN POROSITY

| .E || g| --SMACKOVER-

Dual induction Focused Log BHC Acoustilog Compensated Neutron Lithe Density

Figure 15. Log information, P-1136 (first offset, dry hole) and P1 125 (Bluff Springs discovery well)

24

ing zone also appear to have retained some oomoldic porosity,although the oolites appear to have been replaced with dark brown,crystalline dolomite. Volumetric calculations based on log analyses byDr. Charle H. Tootle of the Florida Bureau of Geology (personal com-munication, 1985) yielded the following values: pay thickness, 10 feet;mean porosity, 19.6 percent; mean oil saturation, 88 percent; original oilin place estimate, 1.3 million barrels; and recoverable oil estimate,195,067 barrels.

In an initial flowing test (assisted by nitrogen injection) on March 25,1984, by Stone Petroleum Corp., the well produced 59.6 barrels of oil inthree hours for an approximate daily rate of 477 barrels. Saltwaterproduction was 170 barrels per day. Oil gravity was 57.0° A.P.I. at 60degrees Fahrenheit.

The first offset, Florida permit 1136 (the Stone Petroleum Corp. St.Regis Paper Co. No. 29-3), to the discovery well was also drilled byStone Petroleum and is located approximately one-half mile northwestof the discovery well (figure 14). The Smackover was encountered at16,342 feet (16,171 feet below MSL), structurally 17 feet lower than inthe discovery well (figure 14). This is apparently too low on the structureas the well produced only salt water from two thin (three to four-feetthick) zones within the 16,354 to 16,363-foot interval (16,183-16,192 feetbelow MSL) of the upper Smackover. Core analysis by Location SampleService, Inc. (LSS, Jackson, Miss.) yielded mean porosity estimates forthese zones of 11.4 and 8.4 percent. Both zones had low permeability.LSS also found a trace of oil in only one sample from 16,356 feet (16,185feet below MSL).

On June 14th and 15th, 1985, Hughes Eastern Corp. retested thediscovery well with results similar to those of Stone Petroleum's March1984 test: 494 barrels of 54.50 A.P.I. gravity oil per day, 238 barrels ofsaltwater per day. Ownership of the discovery well was transferred fromStone Petroleum to Hughes Eastern following this test. Production fromthe well began in January, 1986. Monthly production reports for Janu-ary through June, 1986, indicate that the well Is producing an average of555 barrels of oil and 221 barrels of water per day (see table 1). Permitshave been issued to Hughes Eastern to drill two offsets, one east andone southeast of the discovery well (permits 1204 and 1205, figure 14).Given the results of the offset to the northwest, presumably HughesEastern expects to encounter the Smackover at structurally higherpositions in these new offsets to the east and southeast.

HISTORICAL AND GEOLOGICAL SETTING

The discovery of Bluff Springs field brings the number of oil fields innorth Florida up to five-four active and one plugged and abandoned(figure 13). The first of the north Florida fields to be discovered was Jayfield in 1970. The discoveries of Mt. Carmel and Blackjack Creek fol-lowed in 1971 and 1972. Since then, a long series of dry wildcats (84total) have been drilled in Florida's panhandle. With the exception of thediscovery of the questionably commercial Sweetwater Creek field in

25

1977, the Bluff Springs discovery represents the first successful wildcatin west Florida in 12 years. Hopefully, renewed interest and improvedtechnology will make this only the first in a series of similar successes.

Table I. Production statistics, Bluff Springs field discovery well.

MONTH OIL OIL WATER WATER GAS(1986) BARRELS BOPD* BARRELS BWPD* MCF

January 18963 612 6466 209 8204February 11945 427 5061 181 4608March 17343 559 7110 229 10347April 18415 614 5770 192 11047May 18277 609 7311 244 12625

June 15319 511 8104 270 11258

*BOPD: Barrels of oil per day.*BWPD: Barrels of water per day.

North Florida (i.e. Florida panhandle) oil fields dominate Florida oilproduction (Applegate and Lloyd, 1985). These fields account forapproximately 83 percent of the state's cumulative production throughJanuary, 1986 (figure 2). Jay field alone is responsible for 71 percent ofthe state's production. In all except Mt. Carmel field, production is fromJurassic-age Smackover dolomites and limestones (figure 3). Mt. Car-mel field produces from both the Smackover and the underlyingJurassic-age Norphlet Sandstone.

Although a mixture of carbonates and clastics can be found within theSmackover, in the western panhandle producing area it is almost purelya sequence of dolomites and limestones. The underlying NorphletSandstone is primarily an arkosic sandstone. The Norphlet is underlainby the Louann Salt which is probably responsible for the structuresfound in the north Florida oil fields (except for Sweetwater Creek fieldwhich is believed to be located on a basement high). The Smackover isoverlain by the Buckner Member of the Haynesville Formation. TheBuckner is composed primarily of evaporites and forms the seal forsome of the Smackover producing zones.

Studies of the Jay field Smackover in Florida reveal complex net-works of producing horizons (Lloyd and Parker, 1985; Lloyd, et al.,1986). Production is from dolomite horizons found at different levels inthe Smackover; it is also from more than one porosity and facies type.Production can be from dolomitized oolitic facies with oomoldic poros-ity. More commonly, it is from dolomitized pelletal facies with intercrys-talline, vuggy, and leached matrix porosity. Although core chip exami-nation is not definitive, Bluff Springs field may be producing from bothfacies types. Florida's Smackover reservoirs appear to be the result ofthe complex interplay of porosity, paleoenvironment, diagenesis (prim-arily dolomitization), and the formation of networks of producinghorizons.

26CONCLUSION

The possible complexity of undiscovered Smackover reservoirslocated in north Florida makes their discovery all the more challenging.The discovery of Bluff Springs indicates that it can be done. Wellcoverage in much of the western Florida panhandle is sparse; there is adefinite need for additional exploration within and adjacent to theknown Smackover producing area in Florida.

McCiellan Fleid

Exxon Corp. spudded a rank wildcat (Exxon Corp. State of Florida33-1, Florida permit #1194) on December 31, 1985, in Section 33, T6N,R26W, Santa Rosa County (figure 13). This is approximately 3.25 milesnorth of the abandoned Sweetwater Creek field and 16 miles east of Mt.Carmel field which produces from both the Smackover Formation andthe Norphlet Sandstone. The well found 152 barrels of 410 A.P.I. gravityoil per day from the Smackover through perforations from 14,072 to14,090 feet (-13,828 to -13,846 feet MSL; F & A Oil Reports, 1986).

Total depth of the discovery is 14,475 feet (-14,231 feet MSL). Twoconventional cores and sidewall samples were taken with no detailsreleased (F & A Oil Reports, 1986). Seven-inch casing was run to 14,473feet (-14,229 feet MSL) for completion on February 28, 1986 (F & A OilReports, 1986).

The Sweetwater Creek field produced from the Houston Oil andMinerals Corp., W. M. Stokes 15-2, No. 1 well in Section 15, T5N, R26W,Santa Rosa County (Florida permit #881). In its initial test the wellproduced 624 barrels of 43.50 A.P.I. oil per day and only atrace of waterfrom a Smackover limestone interval from 14,299 to 14,340 feet (-14,044to -14,085 feet MSL). Hopes for a significant discovery proved falsewhen the well began producing 100 percent water in December, 1980.The field produced a total of 13,695 barrels of oil during its entirelifetime. In its final year of production (1980) the well produced 1,465barrels of oil.

SUMMARY

As Florida oil production continues to decline, successful explorationefforts become more significant. Fortunately, recent oil exploration inFlorida has yielded three new oil fields, two in the western panhandle ofnorth Florida and one in south Florida. Unfortunately, it would requirethe discovery of a great number of such small fields to reverse thedeclining production trend which is primarily the result of decliningproduction at Jay field. Despite this, exploration history indicates thatthere is room for additional discoveries within the known Smackoverand Sunniland producing areas. In addition, although efforts have beenunsuccessful to date, the offshore area and the Apalachicola Embay-ment area are relatively unexplored. The possibility of discovery of anew "Jay" should not be ruled out. Meanwhile, the chances for smallerfield discoveries have been positively affirmed by recent history.

27

REFERENCES

Applegate, Albert V., F. A. Pontigo, Jr., and J. H. Rooke, 1978, JurassicSmackover oil prospects in the Apalachicola embayment: Oil & GasJour., January 23, 1978, p. 80-84.

Applegate, Albert V. and F. A. Pontigo, Jr., 1984, Stratigraphy and oilpotential of the Lower Cretaceous Sunniland Formation in south Flor-ida: Fla. Bur. of Geol. Rep. of Invest. No. 89, 40 p.

Applegate, Albert V. and Jacqueline M. Lloyd, 1985, Summary of Floridapetroleum production and exploration, onshore and offshore, through1984: Fla. Bur. of Geol. Inf. Cir. No. 101, 69 p.

F & A Oil Reports, 1986, Florida, Vol. 13, No. 16, 4-16-86, p. 2.

Lloyd, Jacqueline M. and William C. Parker, 1985, Hydrocarbon reser-voir formation: Paleoenvironment and structural interrelationship in theJurassic Smackover, Jay field, Florida: abstract, Geol. Soc. Amer.Abstracts with Programs, 98th Annual Meeting, Orlando, Florida, p. 645.

Lloyd, Jacqueline M., Paul C. Ragland, Joan M. Ragland,;and William C.Parker, 1986, Diagenesis of the Jurassic Smackoiver Formation, Jayfield, Florida: Gulf Coast Assoc. of Geol. Societies Trans., Vol. 36, inpress.

Means, John A., 1977, Southern Florida needs another look: Oil & GasJour., Vol. 75, No. 5, p. 212-225.

Mitchell-Tapping, H. J., 1984, Petrology and depositional environmentof the Sunniland producing fields of south Florida: Gulf Coast Assoc. ofGeol. Societies Trans., Vol. 34, p. 157-173.

Mitchell-Tapping, H. J., 1985, Petrology of the Sunniland, Forty MileBend and Bear Island fields of south Florida: G u If Coast Assoc. of Geol.Societies Trans., Vol. 35, p. 233-242.

Ottman, R. D., P. L. Keyes, and M. A. Ziegler, 1973, Jay field- a Jurassicstratigraphic trap: Gulf Coast Assoc. of Geol. Societies Trans., Vol. 23,p. 146-157.

Sigsby, R. J., 1976, Paleoenvironmental analysis of the Big EscambiaCreek-Jay-Blackjack Creek field area: Gulf Coast Assoc. of Geol.Societies Trans., Vol. 26, p. 258-278.

28

APPENDIX I

1985 AND CUMULATIVE PRODUCTION DATA

1985 AND CUMULATIVE PRODUCTION DATA-WITH 1984 DATA FOR COMPARISON (1)

FIELD (2) CUMULATIVE-1985 PRODUCTION- PRODUCTION

-Number of Wells- Oil Gas Water Oil GasPRO INJ SI TA TOT (Bbis) (MCF) (BbIs) (MBbls) (MMCF)

NORTHWEST FLORIDABluff Springs 1 0 0 0 1 770 650 600 1 1Jay 53 28 35 0 116 6358259 9440024 53651208 345740 435776Blackjack Creek 9 7 8 0 24 1455467 1845391 8691150 51918 47903Mt. Carmel 1 0 0 0 1 68416 101227 225661 4513 4726Sweetwater Creek (3) 0 0 0 0 0 0 0 0 14 15

Subtotal 64 35 43 0 142 7882912 11387292 62568619 402186 4884211984 Subtotal 60 38 44 0 142 11065623 13685980 55132481

SOUTH FLORIDASunoco Felda 10 6 11 0 27 188532 12253 2233681 11107 955Mid-Felda 2 0 1 0 3 107639 0 234850 933 10Townsend Canal 4 0 0 0 4 99866 0 255510 225 0Lehigh Park 4 0 1 0 5 261720 26562 3526210 4536 457West Felda 28 0 12 3 43 1146947 70630 8156504 38151 3020Corkscrew 1 0 0 0 1 9472 0 0 9 0Lake Trafford 1 0 0 0 1 11710 0 0 254 0Seminole (3) 0 0 0 0 0 0 0 0 85 0Sunniland 7 0 12 0 19 129841 12300 3162564 18327 1815Bear Island 16 5 6 0 27 685248 58306 4274921 9201 721Pepper Hammock 0 0 1 0 1 0 0 0 0 0Baxter Island (3) 0 0 0 0 0 0 0 0 2 0Raccoon Point 12 0 1 0 13 934026 109621 638923 1383 152Forty Mile Bend (3) 0 0 0 0 0 0 0 0 33 2

Subtotal 85 11 45 3 144 3575001 289672 22483163 84246 71321984 Subtotal 84 15 37 2 138 3396346 256784 22228837

(Continued on next page.)

FIELD (2) CUMULATIVE--1985 PRODUCTION-- PRODUCTION

-Number of Wells- Oil Gas Water Oil GasPRO INJ 81 TA TOT (Bbis) (MCF) (Bbls) (MBbis) (MMCF)

STATEWIDE TOTAL 149 46 88 3 286 11457913 11676964 85061782 486432 4965531904 TOTAL 144 53 81 2 280 14481960 13942764 77381318

1. Statistics compiled by Dr. Charles Tootle, Florida Bureau of Geology, Oil and Gas Section.2. Fields are listed In order from north to south.3. Plugged and abandoned oil fields.

Abbreviations: PRO - Producing Wells Bbls - Barrels (42 US Gallons)INJ - Injection Wells MBbls - Thousand BarrelsSI - Shut In Wells MCF - Thousand Cubic FeetTA - Temporarily Abandoned Wells MMFC - Million Cubic FeetTOT - Total No. Wells

31

APPENDIX II

1985 DRILLING ACTIVITY

TABLE 1. 1985 FIELD WELLS DRILLED

Drill FloorWaill and Opwetorf-Wll Completion Ele., Ft. Total1

Permit No. Name A No. Location Date Above M8L Depth. Ft. 8ta1m

JAY FIELD4

Santa Ros W-15713 Exxon Corp.-Lawmon 2273' FNL A 2-26-86 247.5 15,686 Completed a aP-1146 Hawthorne No. 5-7 1606' FWL potential producer.

See. &TSN. R29W

Santa Ros• W-15a06 Exxon Corp.-E. a. 2282 FSL & 11-1445 25.6 15,780 Completed a aP-1180 Jeffreys, et. at 4' FEL (NOVO) potential producer.

No. -4 Sea.TSN. R29W

MT. CARMEL FIELDSanta Rosa W-15734 LL & E-Wolf- 191&2' FNL & 4-5-6 206 15,231 Plugged & abandoned

P-114 Hendrcks No. 3884' FWL me a dry hole. 4-5-85.36-1A Seac 36

T6N. R29W8UNNILAND FIELDCcoger W-15754 Exxon Corp.- 271.4A FNL & 3-15-5 42.5 11,780 Completed a- a

P-1142 Colar Co. No. 2114.36' FWL potential producer.19-2 Sec. 10

T48S, rOEBEAR ISLAND FIELDCollier W-15706 Exxon Corp.- SHLL 12-13-85 366 MD:12,000 Completed as a

P61118A Collier Co. No. 1531.9 FSL & (NGVD) TVD:11,.66 potential producer.2-10A 63&2r FWL

See. 1BHL:

272' FSL &40W FELSac. 2T498, R30E

RACCOON POINT FIELDCollier W-15768 Exxon Corp.- SHL 3-15-85 34 MD:12.712 Completed as a

P-1141 Collier Land & 723' FNL & TVD:11,464 . potential producer.Cattle Corp. 707 FWLNo. 2-1 BHL*

1320' FNL &1320' FELSec. 2,T52S, R34E

Collier W-15718 Exxon Corp.- SHL: 1-3-85 35 MD:12,044 Completed as aP-1149 Collier Land & 1821.9' FSL & TVD:11,500 potential producer.

Cattle Corp. 796.8' FELNo. 27-3 Sec. 28

BHL:1320 FSL &1320' FWLSec. 27,T51S, R34E

Collier No W-no.5 Exxon Corp.- SHL: 11-6-85 34.9 MD:11,654 Completed as aP-1150 Collier Land & 1651' FSL & TVD:11.600 potential producer.

Cattle Corp. 809' FELNo. 28-4 BHL:

1320' FSL &1320' FELSec. 28,T51S, R34E

Collier W-15755 Exxon Corp.- SHL: 5-13-85 35 MD:12,370 Completed as aP-1162 Collier Land & 1985.5' FSL & TVD:11,513 potential producer.

Cattle Corp. 745.1' FELNo. 27-2 Sec. 28

BHL:1320' FNL &1320' FWLSec. 27,T51S. R34E

Collier W-15859 Exxon Corp.- SHL: 12-6-85 35 MD:13,670 Completed as aP-1167 Collier Land & 2843' FNL & TVD:11,800 potential producer.

Cattle Corp. 669 FELNo. 22-3 Sec. 28

BHL:1320' FSL &1320' FWLSec. 22,T51S. R34E

1. Florida Bureau of Geology well number for samples (cuttings or core chips). Ca2. For directionally drilled wells, SHL Is surface hole location. BHL Is bottom hole location.3. MD: measured depth; TVD: true vertical depth (determined by directional survey).4 Fields are listed In order from north to south.5., Well samples have not been submitted yet.

TABLE II. 1985 WILDCAT WELLS DRILLED

Drill FloorWell' and Operator-Well Completion Elev.,. Ft. Total3

County Permit No. Name & No. Location 2 Date Above MSL Depth. Ft. Status

NORTHWEST FLORIDAEscanbla W-15873 Cities Service 1628 FSL & 11-1-85 280 16800 Plugged & abandoned

P-1172 Oil & Gas-Llzenby 1540 FWL (GL) as a dry hole, 11-5-85.No. 5-4 Sec. 5,

TSN, R32WEscamblea W-15843 Primary Fuels, Inc. 1133.3' FNL & 11-8-85 270 16880 Plugged & abandoned

P-1177 Robert O'Farell 1278.7' FWL as a dry hole, 11-8+85.No. 22-2 Sec. 22,

T5N, R32WSanta Rosa W-15746 McMoran Oil & Gas 1032' FNL & 4-19-45 221 16,744 Plugged & abandoned

P-1159 Co.-J. Ed Golden, 1029' FEL as a dry hole, 4-19-85.et al. No. 22-1 Sec. 22.

T3N. R28WSanta Rosa W-15711 Smacko, Ltd.-R.W. 1165' FNL & 2-1-85 271 15.300 Plugged & abandoned

P-1160 Blackmon, Jr. No. 1282' FEL as a dry hole, 2-1-85.16-1 Sec. 16,

TSN, RFl2WSanta Rosa W-15874 Spooner Petroleum 1047.7 FSL & 12-27-85 75 16,580 Plugged & abandoned

P-1178 Co.-Champion Inter- 1083.9 FEL as a dry hole, 12-27-85.national No. 5-4 Sec. 5,

T3N,R28WSanta Rosa W-15865 Tenneco Oil Co.- 1320W FSL & 12-20-85 221 17,050 Plugged & abandoned

P-1185 Champion Interna- 1320' FEL as a dry hole, 12-20-85.tional No. 3-4 Sec. 3,

T3N, R30WNORTH FLORIDASuwannee W-15877 Palmer Petroleum, 563' FNL & 12-13-85 88.8 6,888 Plugged & abandoned

P-1181 Inc.-Vining No. 1 752' FEL as a dry hole, 12-13-85.Sec. 2,T4S, R12E

SOUTH FLORIDABroward W-15765 Sabine Corp.- 1616' FNL & 6-28-85 24 11,604 Plugged & abandoned

P-1169 Miccosukee No. 2310' FEL as a dry hole, 6-28-85.32-1 Sec. 32,

T49S, R35ECollier W-15841 Hughes Eastern 1382' FNL & 9-9-85 30 11,547 Plugged & abandoned

P-1086 Petr., Ltd.-Collier 1567 FWL as a dry hole, 9-9-85.Co. No. 10-2 Sec. 10,

T53S, R34ECollier W-15796 Hughes Eastern SHL: 10-15-85 37 MD:11.,632 Plugged & abandoned

P-1140 Petr., Ltd.-Gerry 1295' FNL & TVD:11,591 as a dry hole, 10-15-85.Brothers No. 33-2 1040' FWL

BHL:695' FNL &1040' FWLSec. 33,T49S, R31E

Collier W-15844 R. K. Petroleum 1440' FNL & 12-6-85 43.4 11,565 Completed as aP-1170 Corp.-Rex Proper- 952' FWL producer.

ties No. 33-2 Sec. 33,T46S, R28E.

Lee W-15756 Exxon Corp.-A. 1412' FNL & 5-19-85 52 11,800 Plugged & abandonedP-1165 Kaplan Trustees, 1208' FEL as a dry hole, 5-19-85.

et al. No. 32-1 Sec. 32,T45S, R27E

Lee W-15845 Hughes Enterprises- SHL: 11-15-85 34 MD:11,778 Plugged & abandonedP-1183 Hughes-Rutledge 1185' FNL & TVD:11,350 as a dry hole, 11-15-85.

No. 9-4 2464' FWLBHL:

1640' FSL &1564' FELSec. 9,T44S, R26E

1. Florida Bureau of Geology well number of samples (cuttings or core chips).2. For directlonally drilled wells, SHL is surface hole location. BHL Is bottom hole location.3. MD: measured depth; TVD: true vertical depth (determined by directional survey).

TABLE III. WELLS DRILLED DURING 1985 IN EASTERN PLANNING AREA, GULF OF MEXICO N

DRILLER'SWELL DEPTH, RTE, 1

AREA NO. OPERATOR LOCATION FEET FT. MSL REMARKS

Destin Dome OCS-G-6417 Shell Block 160 17761 105 Smackover-Norphlet well on Destln Dome.Well No. 1 Rumored to have had goo dahow In Norphlet.

Shell-Amoco bids In sale 94, in December, 1985,support this belief. Set open hole plug.Abandoned 12-85.

Destin Dome OCS-G-6417 Shell Block 160 16993 105 Began drilling 5-9-85. Smackover-NorphletWell No. 2 test. Abandoned 8-21-85 without testing.

Destin Dome OCS-G-6428 Exxon Block 284 17500 73 Began driling 6-28-85. Smackover-Norphlettest drilled on Destin Dome. Abandoned11-85 without testing.

Destin Dome OCS-G-6438 Chevron Block 422 22222 83 Began drilling 7-2-85. Smackover-Norphlettest. Abandoned 12-85 without testing.

Gainesville OCS-G-6456 Sohlo Block 707 15994 100 Began drilling 6-3-85. T.D. In Paleozolcs(?).Well believed to have penetrated thick Eagle Mills(Triaasic) section. Abandoned without testing.

Pensacola Block OSC-G-6391 Sohlo Block 948 18958 85 Began drilling 2-18-85. Well drilled on Louann Saltstructure. Seven Inch liner cemented at 18956feet. Well tested In both Norphlet and Smackover.Abandoned 10-16-85.

1. RTE: Rotary Table Elevation.

37

APPENDIX III

DISCOVERY WELL DATA

FLORIDA OIL FIELD DISCOVERY WELL DATA

Discovery Permit Perforations Total Name of Produc- Discovery Oil Gravity,

Date No. Field County or Open Hole Depth Ing Formation Status Degrees API

9.26-43 42 Sunniland Collier 11,602-11,626 11,626 Sunniland Pumping 26

2-1-54 167 Forty Mile Bend Dade 11,322-11,339 11,577 Sunniland Pumping 21

7-22-64 315 Sunoco Felda Hendry 11,472-11,485 11,485 Sunnlland Pumping 25

6-2-66 371 West Felda Hendry 11,486-11,489 11,675 Sunnlland Pumping 26

3-30-69 401 Lake Trafford Collier 11,870-11,892 11,987 Sunnlland Pumping 26

6-15-70 417 Jay Santa Rosa 15,470-15,524 15,984 Smackover Flowing 51

12-19-71 504 Mt. Carmel Santa Rosa 15,260-15,280 15,399 Smackover Flowing 42& Norphlet

2-14-72 523 Blackjack Creek Santa Rosa 15,790-15,900 16.,235 Smackover Flowing 51& Norphlet

12-6-72 563 Bear Island Collier 11,589-11,595 11,817 Sunniland Pumping 26

11-14-73 662 Seminole Hendry 11,415-11,420 11,6051 Sunniland Pumping 25

7-30-74 712 Lehigh Park Lee 11,389-11,394 11,630 Sunniland Pumping 28

4-22-77 881 Sweetwater Creek Santa Rosa 11,299-14,340 14,611 Smackover Pumping 45

8-11-77 865 Baxter Island Collier 11,512-11,515 11,823 Sunniland Pumping 22

10-13-77 904 Mid-Felda Hendry 11,492-11,496 11,686 Sunniland Pumping 26

6-20-78 829 Raccoon Point Collier 11,410-11,414 11,658 Sunniland Pumping 23

9-28-78 897 Pepper Hammock Collier 11,629-11,633 11,897 Sunniland Pumping 27

6-27-82 1070 Townsend Canal Hendry 11,416-11,421 11,462 Sunniland Pumping 28

3-25-84 1125 Bluff Springs Escambla 16,332-16,339 16,800 Smackover Flowing 57

11-10-85 1170 Corkscrew Collier 11,547-11,565 11,565 Sunniland Swab Test 26

2-28-868 1194 McClellan Santa Rosa 14,072-14,090 14,475 Smackover Flowing 41

39

APPENDIX IV

1985 GEOPHYSICAL EXPLORATION ACTIVITY

1985 GEOPHYSICAL EXPLORATION ACTIVITY

COophysl- Surveyed Permit Expiration Energy Depth, Charge Shot Hole SurveyPermit eel Co. For County Approved Date Status Source Ft. lise. Lbe polng, FPt Length, ml. Comments

0-31-86 Texaco Texaco Collier Application Seismic 10-20 0.25-2.5 220 107Withdrawn Gelatin

G-32-86 Seminole Seminole Collier Application Thumper N.A. N.A. NA. NotExpl. Expl. Pending Stated

0-33-88 Sela Pros Edwin & Collier 10-4-85 4-2-86 Survey Explosives 10-20 1 220 10Berry Cox Cancelled

G0-34-88 GFS Bel North Santa Rosa 3-6-85 9-3-85 Completed Seismic 150-180 10-15 330 7Petrol. Gelatin

0-35-86 Western Western Esc., Sta Ra, Application Airgun N.A. N.A, N.A. 350 OffshoreGeophys. Geophys, Oklsa, Wltn Pending

G-36-88 GFS Inexco Santa Rosa 3-18-85 9-14-85 Completed Seismic 150-180 10-15 330 34.5Gelatin

G-37-88 Geco Geco Collier & 5-17-85 5-12-86 Partially Alrgun or N.A. N.A. N.A. 340 Only 50 milesHendry Completed Vibrator Surveyed

0-38-85 GFS Arco Escamblea 3-27-85 9-23-85 Completed Seismic 80-100 2.5-5 330 57Gelatin 150-180

G-39-85 GFS MC Moran Escambia 3-27-85 9-23-85 Completed Seismic 150-180 10-15 330 5Gelatin

0-40-85 Selecom Arco Santa Rosa 3-29-85 9-25-85 Permit Seismic 80-100 5-10 165 30Delta Untd. Expired Gelatin 150-180

G-41-85 Selscom Arco Santa Rosa 6-17-85 12-14-85 Completed Seismic 80-100 5-10 165 30Delta Untd. Gelatin 150-180

G-42-85 Shell West- Shell West- Hendry 4-9-85 4-4-86 Completed Watergel 110 20 80 14.25ern E & P ern E & P Explosive

G-43-85 Geo Seism. Geo Seism. Walton Application Seismic 150-180 20 330 8Serv. Serv. Withdrawn Gelatin

G-44-85 Geco Geco Collier 9-24-85 3-23-86 Permit Vibrator N.A. N.A. N.A. 45.5 Partly OffshoreExpired Comp. Air

G-45-85 GFS Bel North Escambia Application Seismic 80-100 2.5 440 4.5Petrol. Withdrawn Gelatin 150-180 7.5

G-46-85 GFS Union Oil Santa Rosa 7-19-85 1-15-86 Completed Seismic 80-100 2.5 440 4.5Gelatin 150-180 7.5

G-47-85 Conoco Conoco Santa Rosa 7-12-85 1-8-86 Completed Vibrosels N.A. N.A. N.A. 22Inc. Inc.

G-48-85 Southern Southern Okeechobee 7-19-85 1-15-86 Completed Seismic 10 0.25 220 15Seismic Seismic Gelatin

G-49-85 Western Western Madison 7-10-85 1-7-85 Completed Dynamite 60 10 165 52.Geophys. Geophys.

G-50-85 Shell West- Shell West- Dde, PIm 9-11-85 3-10-86 Completed Vibroseis N.A. N.A. N.A. 280ern E & P ern E & P Bch, Cir, Brwd

G-51-85 Seismic Cities Escambia & 9-24-85 9-19-86 On Hold Dynamite 100 20 440 11.3Experts Service Santa Rosa

G-52-85 J.M. J.M. Glades, 12-20-85 6-18-86 Cancelled Seismic 6 .55 110 66 Mini-holesurveyHuber Huber Highlands Gelatin 10 1.1

80-100 "Small" 5280G-53-85 Western Western Escambia Application Dynamite 120 20 440 6

Geophys Geophys WithdrawnG-54-85 Geco Geco Bay, Calhoun, Application Vibrosels N.A. N.A. N.A. 420

Gulf, Liberty, PendingFranklin

G-55-85 Southern Southern Hendry & Application Seismic 20 1 220 15.5Seismic Seismic Collier Pending Gelatin

G-56-85 Southern Gulf Coast Escambia 11-27-85 5-26-86 Completed Seismic 150 20 161 7.5Seismic Geodata Gelatin

G-57-85 Petty-Ray Petty-Ray Lib, Frank., 11-19-85 5-18-86 Completed Vibroesis N.A. N.A. N.A. 246Geophys Geophys Wakulla

G-58-85 GFS LA.Land Santa Rosa 11-8-85 5-7-86 Completed Vibroseis N.A. N.A. N.A. 8& Expl.

G-59-85 Shell West- Shell West- Hendry & 2-10-86 8-9-86 Completed Seismic 110 20 60 33ern E & P ern E & P Palm Bch Gelatin

G-60-85 GFS Mobil Escambla 12-23-85 6-21-86 Completed Seismic 80-150 10-20 330 22.5Gelatin

G-61-85 Western Tenneco Escambla & 2-4-86 5-5-86 Completed Dynamite 70 5 165 75Geophylcal Oil E&P Santa Rosa

Total Miles In Applications 2327.05Total Actual Surveyed 963.25

In South Florida 392.25In North Florida, Panhandle 519.0In North Florida, Peninsula 52.0

Total Pending 796.8Total Withdrawn, Cancelled, or Expired 567.0

42

APPENDIX V

OIL AND GAS RELATED THESES HELD BYTHE FLORIDA GEOLOGICAL SURVEY LIBRARY

Grinnell, Philip C., Jr., 1976, The Sunniland Limestone within the FortyMile Bend Area, Monroe and Dade Counties, Florida: Tallahassee, FL,Fla. State Univ.

Hearn, Frank P., 1984, Pre-Punta Gorda Sediments from the Bass,Collier Company, 12-2 Well, South Florida: Lafayette, LA, Univ. ofSouthwestern Louisiana.

Heron, Stephan D., III, 1982, Depositional and Diagenetic History ofSelected Mesozoic Sediments of the South Florida Basin: Lafayette, LA,Univ. of Southwestern Louisiana.

Laird, John W., 1985, Diagenetic Controls on Reservoir Characteristicsand Development in the Jurassic Norphlet Formation, EscambiaCounty, Alabama: University, AL, Univ. of Alabama.

Pontigo, Felipe Antonio, Jr., 1982, Pre-Haynesville Stratigraphy andStructural Geology of the Apalachicola Embayment, Petrology andPaleoenvironmental Interpretation of the Smackover Formation: Talla-hassee, FL, Fla.State Univ.

Raasch, Albert C., Jr., 1954, The Sunniland Oil Field of Collier County,Florida: Tallahassee, FL, Fla. State Univ.

Vaughan, R. Lee, 1985, Diagenetic Effects on Reservoir Development inthe Upper Jurassic Norphlet Formation, Mobile and Baldwin Counties,and Offshore Alabama: University, AL, Univ. of Alabama.

43

PART II

THE BROWN DOLOMITE ZONE OF THE LEHIGH ACRESFORMATION (APTIAN) IN THE SOUTH FLORIDA BASIN-

A POTENTIALLY PROLIFIC PRODUCING HORIZON OFFSHORE

By

Albert V. Applegate

44 CONTENTS

Page

Acknowledgements .......................................... 45

Abstract ..................................................... 46

Purpose of study ............................................. 46

Method of study .............................................. 46

Metric conversion factors ..................................... 47

Lithology .............................................. ...... 47

Stratigraphic relationships .................................... 51

Geochemistry ................................................ 54

Structure .................................................... 55

Summary .................................................... 57

References .................................................. 58

Appendix I Summary of well data ............................ 59

Appendix II Drill stem test data from Brown Dolomite Zone ...... 66

ILLUSTRATIONS

Figure1 Isopach of the Brown Dolomite ..................... 482 Structural map of the Brown Dolomite ............... 493 Isopach of the porous Brown Dolomite ............... 504 Generalized geological column Lower Cretaceous-

Jurassic (?) rocks; south Florida Basin ............... 525 Control wells ....................................... 536 Structural features in Florida and offshore ............ 56

45

ACKNOWLEDGEMENTS

Geological Survey staff members reviewed and edited this report. JimJones and Ted Kiper drafted and photographed the figures. GeorgeWinston (consulting geologist, Coral Gables, Florida) provided geo-logic information and advice.

46

THE BROWN DOLOMITE ZONE OF THELEHIGH ACRES FORMATION (APTIAN)

IN THE SOUTH FLORIDA BASIN-A POTENTIALLY PROLIFIC PRODUCING HORIZON OFFSHORE

by

Albert V. Applegate

ABSTRACT

The best development of the Brown Dolomite onshore is in Charlotteand surrounding counties in the northern part of the South FloridaBasin at a depth of approximately 12,000 feet. Here, the Brown Dolomitezone attains a maximum thickness of 100 feet, of which one-half isusually porous and capable of high volume fluid production. Offshore,the maximum thickness occurs near the Marquesas Keys, whereapproximately 400 feet of mostly porous dolomite has been encoun-tered. Although very little oil staining has been found in the CharlotteCounty area, staining has been observed in two Marquesas wells.

The best possibility for finding oil in the Brown Dolomite appears tobe in the offshore portion of the South Florida Basin. Brown Dolomite ispresent in at least three wells on the Sarasota Arch and probably con-tinues around the rim of the basin southeast to the Marquesas wherethick vugular dolomite is present. Stratigraphic and structural trapsassociated with this dolomite, which is capped by dense limestone andanhydrite, may have led to the formation of giant oil fields.

PURPOSE OF STUDY

The potential economic importance of the Brown Dolomite in theoffshore area of the South Florida Basin, as well as in the area where itwas originally described, prompted this study. This information willhelp geologists to decide if the possibility of finding oil in this zone isworth the expense of drilling the additional 1,000 feet below the Sunni-land Formation.

METHOD OF STUDY

Core chips and cuttings of wells drilled through the Brown Dolomitezone were studied using a binocular microscope. Appendix I showsthese wells. Information listed in Appendix I includes formation topsfrom the Punta gorda Anhydrite to total depth, net dolomite, porousdolomite, Jost circulation, and other pertinent data. from these data, anisopach map of the Brown Dolomite (Figure 1) was prepared.

47

Appendix 2 lists data on all drill stem tests. Water recoveries in thesetests show that the wells tested had sufficient porosity and permeabilityto be capable of oil production.

A structural map (Figure 2) using subsea depths to the top of thePunta Gorda Anhydrite was made. Wells penetrating the Punta GordaAnhydrite were used in the preparation of this map.

An isopach map (Figure 3) of the porous interval in the Brown Dolom-ite was prepared, utilizing available data. In early wells where sonic andneutron logs were not available, cores, cuttings, caliper surveys, drillingtime logs, and lost circulation intervals were important factors in arriv-ing at estimates of the thickness of the porous interval as well asestimating the actual porosity. In those wells in which sonic or neutron-density logs were available, porosity calculations were found to be infair agreementw.ith estimates made from cores and cuttings.

METRIC CONVERSION FACTORS

The Florida Bureau of Geology, in order to prevent duplication ofparenthetical conversion units, inserts a tabular listing of conversionfactors to obtain metric units.

Multiply by to obtain

feet 0.0348 metersmiles 1.6090 kilometers

LITHOLOGY

The texture of the Brown Dolomite varies from euhedral to anhedral,and from coarse to very fine grained. It is often vugular near the top ofthe section. Drill stem tests made in the Brown Dolomite show that it iscapable of high fluid production. Much of the Brown Dolomite has fossilghosts and other evidence of secondary origin. In general, the dolomitebecomes less porous from top to bottom which may be partially due toporosity changes in the original limestone.

In the Tribal Exxon Gulf Coast Realties 12-2 well (P-727) a corecutting the Brown Dolomite is predominantly limestone due to itsdowndip location in the basin. In this well the lowermost limestonesexhibit the lowest porosity. Dolomite has an average porosity of ninepercent in contrast to about four percent for the limestone.

Permeability was low or non-existent in both the limestone anddolomite. This particular well was a key well in understanding theBrown Dolomite zone. It was cored through the Brown Dolomite zonewith 100 percent core recovery. An analysis of each foot of the core wasmade by All Points, Inc., of Houston, Texas. Geophysical logs that wererun included gamma ray, sonic, caliper, neutron-density and inductionelectrical.

48

FeO C X-^ OBcoEE S-T LUCIE

L 0.-,, O MARTIN

LEE H Y OKEECHOBEE

!BROWARD 1--"COLLIER

"- too THICKNESS IN FEET D , .

SCALE

Figure 1. Isopach of the Brown Dolomite.

49

/L-'"\ I___

0,00 MANATEE HARDEE HIGHLANDS10,5 I OKEECHOBEE | ST. LUCIE

S 10,000 DEPTH BELDESOTOW MLI

10,900 MARTIN

11SCAE100 PALM BEACH

CHARLOTTE

11,300 HEN LAKE

11,500 LEE OKEECHOBEE

11,700

11,900 1 0 *

12,300

10,000 DEPTH BELOW MSL

-T

gure 2. StructurALE map of the Brown Dolomite.

Figure 2. Structural map of the Brown Dolomite.

50

SMAATMI I| AMDe |HmHLANO YOE I OIa o CMO* -T. LUCIE

GLADES LANE -

Figure he porous Brown Dolomite.

COLLMM - a 0W I

Figure 3. !sopach of the porous Brown Dolomite.

51In wells drilled prior to the introduction of the compensated neutron

density log it is mandatory to have cores or good cuttings in order tomake a reliable estimate of net dolomite. Due to lost circulation in themore porous zones, samples may be of very poor quality, completelymissing, or consist of little but lost circulation material. Another prob-lem in the better porosity zones is washout. When this occurs porositycalculations from geophysical logs are not reliable.

STRATIGRAPHIC RELATIONSHIPS

The term Brown Dolomite, or "CD Dolomite" as it was often called byBanks, was first used in two reports (Banks, 1964a and 1964b). Banksstates (1964a, p. 3) that, "the Brown Dolomite occurs in the first few feetor the first few hundred feet of the Choffatella decipiens zone." In astratigraphic section from Lee to Manatee counties (Banks, 1964b) thetop of the Brown Dolomite lies 300 feet below the base of the PuntaGorda Anhydrite.

The Choffatella decipiens zone was not described by Banks, but invarious cross sections by Paul and Esther Applin (1965, plates 8, 9, 11),it has a thickness of approximately 1,000 feet in the area where theBrown Dolomite is present. The Applins considered the Choffatelladecipiens zone to be lowermost Trinity age (lowermost Comanchean).It lies just above their Fort Pierce Formation of Late Jurassic (?) or EarlyCretaceous age. Choffatella decipiens is a large benthic foraminiferawhich ranges throughout Early Cretaceous (Valanginian to Albian). Ithas been identified in limestone in the Caribbean region (Maync, 1950).The Applins (1965, plate 5) found the Choffatella decipiens in the upper250 feet of the Fort Pierce Formation in their type well, the AmeradaCowles Magazine No. 2well (P-259) in St. Lucie County, Florida, and inseveral other wells penetrating this formation.

A new nomenclature for the pre-Punta Gorda rocks in the SouthFlorida Basin was introduced by Applegate, et al. (1981). In this nomen-clature (Figure 4), the Lehigh Acres, an early Trinity age formation, liesbeneath the Punta Gorda. This formation consists of three members,from youngest to oldest: the Able Member, 290-feet thick, composedprincipally of anhydrite and limestone; the Twelve Mile Member, 320-feet thick predominately limestone and dolomite, and the West FeldaMember, 40-feet thick, composed of calcareous shale and dark gray,argillaceous limestone.

The Brown Dolomite zone, which lies entirely within the Twelve MileMember, is found at a minimum depth of about 50 feet below the top ofthe member. Onshore the Brown Dolomite zone is encountered only inthe up-dip of the South Florida Basin. With the exception of its presencein the two Marquesas wells in the Florida Keys (Figure 5, P-275, P-284) itis not present in the area below the 11,900 foot contour of the PuntaGorda Anhydrite.

The best onshore development of the Brown Dolomite occurs innorthern Lee, northern Hendry, Charlotte, Glades, southeast De Soto

52

TT Tl FORMATION .... ......

SUNNILAND DLMLIMESTONE

PUNTA GORDA600' ANHYDRITE

z . ABLE= m MEMBER <\\\ , LIMESTONE

S c ( 290' - - -. , ANHYDRITE

Z u s < TWELVE BROWN2 z MILE DOLOMITEO O Ja MEMBER ZONE

- ° a ,- ,' U-DOLO___ ITE

0 o 320'0 WEST FELDA SHALE SHALE

ILl LIMESTONE

O PUMPKIN BAY '. . NHYDRITE

1050 DOLOMITE

C T • ANHYDRITE0U BONE ISLAND LIMESTONE

1300 DOLOMITE

• > * ANHYDRITE,n WOOD RIVER ...

0 <\• L\L\< DOLOMITE, 1700ccS LIMESTONE

: .BASAL CLASTICZONE

TRIASSIC - JURASSIC ,*, : ; RHYOLITE,.

N ,.•.,, ., .

112 ,''^^»*^ \ 0 BASALT

Figure 4. Generalized geological column of Lower Cretaceous -Jurassic (?) rocks in the south Florida Basin.

53

MANATEE I HARDEE 1jHILANDS ~ _E H A R D E E I I O K E E C H O B E E S T . L U C IE

*236 1f62 i 259

HoR 7 22* ' 2 - I - M A TIN

TREADWELL I so -JN5 HARLOTTE ULGLADES LAKE

7 750 5t GADE OKEECHOBEE PALM BEACH

031 3 152 47

2 rLEE 2 I HENDRY

V -,_..^-, *7;31423, 161 COI 00R14 076 I3 5 14 4 24 265

5|56B BROWARD "

727

0778 9280 - ----..-S DADE

NO BROWN DOLOMITE MONROENOTED IN THESE WELLSIN LEHIGH ACRES FM. I

148

N1 r 902 0

0 25 milesSCALE

284 5 o n

Figure 5. Location map of control wells.

54

and southwest Highlands counties. The best development encounteredwas in the Humble-Treadwell 1-A well, (Sec. 17, T42S, R23E) in south-ern Charlotte County, where there is at least 100 feet of dolomite. Thethickest offshore section, with the exception of the previously dis-cussed Marquesas wells, is found to the west-southwest in the twoCalifornia-Coastal wells (P-289, P-297) in the FSL 224-B lease offshorefrom Lee County (Figure 5). Offshore the dolomite is known to continueto the west, where it has been found in at least three locations on or nearthe Sarasota Arch.

From the Humble-Treadwell well, the thickest section of the BrownDolomite zone closely follows the 11,600-foot structural contour of thePunta Gorda Anhydrite southeast to the Humble-Lehigh Acres well inLee County, and then turns abruptly to the northeast, where it has anestimated thickness of 70 to 75 feet in southeast DeSoto County andsouthwest Highlands County. The occurrence of the rather thick sec-tion here may have been influenced by the Peninsular Arch.

An estimated 38 feet of the Brown Dolomite zone is present in theMobil-Phillips Seminole "C" well (P-565B) in Hendry County. No deepwells have been drilled to the southeast between this well and theSinclair-Wiliams (P-148) and the Robinson-IIF well, both of which arelocated on Key Largo in eastern'Monroe County. Twenty-eight feet ofvery fine-grained anhydriticdolomite was found in the Sinclair-Williamswell (P-148).

Two wells in the Marquesas Keys which have a thick porous dolomitesection are the Gulf-FSL 826Y well (P-275) and the Gulf-California OCSBlock 28 well (P-284). Dolomite found in the Gulf 826Y well is highlyporous and was considered by Banks (1964a and 1964b) to be the sameBrown Dolomite which he had studied in Lee, Charlotte and Sarasotacounties. The Gulf-California Block 28 well was found to have a consid-erably thinner dolomite section than the 826Y well.

George Winston (personal communication, 1984) also believes thatthis dolomite is in the Twelve Mile Member of the Lehigh Acres Forma-tion. It is doubtful that a definitive correlation can be made until moredeep control is available between the Florida Keys and the mainland.

GEOCHEMISTRY

The petroleum source rock study by Palacas (Palacas, et al., 1981) ofpre-Punta Gorda rocks from widely scattered boreholes in the SouthFlorida Basin revealed that the upper part of the Pumpkin Bay Forma-tion, and to a lesser extent, part of the Lehigh Acres Formation have thebest source potential in the lower beds. The richest of these rocksstudied to date are in the Humble-Lehigh Acres well (P-407) in LeeCounty and the Gulf FSL No. 373 well (P-22) on Big Pine Key (Figure 5).This is a favorable factor for the establishment of commercial oil pro-duction in the Brown Dolomite zone.

55

Another factor favoring possible oil generation in the Brown Dolomiteis its depth. It lies approximately 1,000 feet below the Sunniland Forma-tion. The Sunniland is considered to be near the top of the "oil window,"as it has a low gas-oil ratio (approximately 100 cubic feet of gas per stocktank barrel of oil) and a relatively low API gravityt250. This additionaldepth should ensure that, if oil is found in the Brown Dolomite, it wil behigher gravity oil with a higher gas-to-oil ratio than the oil presentlybeing produced from the Sunniland Formation.

STRUCTURE

The South Florida Basin has experienced at least three majorchanges in size and shape since its formation following the separationof North America from Africa and South America. This division isthought to have occurred during the Triassic and Early Jurassic, peri-ods noted for red beds and volcanic activity in both north and southFlorida (Barnett, 1975; Smith, 1982; Chowns and Wiliams, 1983; andKlitgord, et al., 1984).

According to Winston (personal communication, 1983) the geogra-phic extent of the South Florida Basin in early Comanchean time andduring the deposition of Brown Dolomite was limited to atriangular arearoughly 200 miles on each side. To the east, the basin was limited by theCay Sal Arch, (Figure 6) which came into existence in early Coman-chean time. This feature extended north from Cuba through Cay Saland east to Key Largo and up the present Florida Straits. The basinbends gently around the north side of Lake Okeechobee to the southside of the offshore Sarasota Arch. The Sarasota Arch extends in asouthwest direction from Sarasota County across the west Floridashelfto the reef-capped Comanchean continental edge along the west Flor-ida escarpment. Along the arch, basement is encountered offshore atdepths ranging from about 10,000 to 12,000 feet. This arch separates theSouth Florida Basin from the Tampa Basin, which lies to the north of thearch. After reaching the continental edge, the basin follows the escarp-ment to the southeast.

Although later offshore drilling in the eastern Gulf of Mexico haschanged the shape of the northern part of the South Florida Basin, asoriginally proposed by Oglesby (1965), many of his concepts appear tobe valid. The Cretaceous section shown in his various South FloridaBasin maps (based on seismic interpretation) thins significantly as itapproaches the western edge of the Continental Shelf. If this generalconfiguration of the basin is correct, it is probable that the Brown dolo-mite is present at the western edge of the basin and will provide atempting target for exploratory drilling. This assumption is further bol-stered by the presence of a thick dolomite section in the Marquesaswells and the lack of dolomite in the Gulf-FSL 373 well (P-22) to the easton Big Pine Key. This area was structurally low during the EarlyCretaceous.

56

S/

0• SOUTH EAST.o " GEORGIA EMBAYMENT

%o 0^ 1 BLAKE.3, PLATEAUBASIN

as LAKE OKEECHOBEE

-" SUAT SO UTH F ORIDA I BAHAMASBASTUART I t BASIN B ASIN

CITY REEF . M SA CAY SAL ARCH. / MARQUESAS

CAY SAL

•0 L\ CAYO COCO

S,€ X ^~CUBA

I

A" STRUCTURAL FEATURESYUCATAN PEN. IN FLORIDA

AND OFFSHORE

SCALE100 0 100 200 300 400 500 miles

IFigure 6. Structural features I I da Iand offshore.

Figure 6. Structural features in Florida and offshore.

57SUMMARY

Interest in the Brown Dolomite zone of the Lehigh Acres Formationand other dolomites in the geologic column is certain to increase asattention focuses on the petroleum potential in the offshore portion ofthe South Florida Basin.

Because of porosity and permeability enhancement accompanyingthe chemical processes that transform limestone into dolomite,sucrosic dolomites are by far the most important of the carbonatereservoir rocks.

In the northern part of the South Florida Basin, centering aroundCharlotte County, no reserves or good shows have been found, eventhough the geochemistry appears to be favorable. One explanation isthat, since these beds have a gentle southwest dip with no knownfaulting, any oil in the Brown Dolomite could have migrated updip to thenortheast and out of the dolomite into basal clastics. Another possibilityis that no structure has been drilled. It is doubtful that further drilling inthe northern area will be forthcoming until better seismic tools aredeveloped or new discoveries are made in other areas of the SouthFlorida Basin.

The best possibility at present for new discoveries appears to beoffshore Florida where thick porous dolomites are believed to exist.Such dolomites in a stratigraphic or structural trap could have led to theformation of giant fields.

Any exploration program would have at least two attractive targetsbefore reaching the Brown Dolomite zone. The Dollar Bay Formation,lying about 2,000 feet above the Sunniland Formation, has had verygood heavy oil shows in the Lake Okeechobee area. However, the oil,because of low formation temperature, is not sufficiently maturated atthis updip location.

In the offshore, where the same Dollar Bay Formation could be pres-ent, formation temperatures and resulting API gravity could be consid-erably higher. The same reasoning applies to the Sunniland Formation.This formation produces oil of 25-26 degrees API gravity, with a gas-to-oil ratio of approximately 100 onshore. In the offshore, if the formation ispresent, it could be deeper and have a higher gas-to-oil ratio and ahigher API gravity.

This relatively unexplored offshore part of the South Florida Basin,with its thick Cretaceous and Jurassic (?) dolomites, coupled withnumerous anhydrite seals, offers a tempting target. Ready markets foroil and gas, together with benign weather in the offshore, all point to theneed for a sustained driling program to thoroughly test this area.

58

REFERENCES

Applegate, A. V., Winston, G. 0., and Palacas, J. G. 1981, Subdivisionand Regional Stratigraphy of the Pre-Punta Gorda Rocks (LowermostCretaceous-Jurassic ?) in South Florida: Supplement to Gulf CoastAssoc. Geol. Soc. Trans., v. 31, p. 447-453.

Applin, P. L. and Applin, E. R., 1965, The Comanche Series and Asso-ciated Rocks in the Subsurface in Central and South Florida: U.S.Geological Survey Prof. Paper 447.

Banks, J. E., 1964a, Oil and Gas Prospects of the Englewood Area ofLee, Charlotte and Sarasota Counties, Florida: unpublished report forCoastal Pet. Corp. placed in Bureau of Geology Library in Tallahassee,Florida.

Banks, J. E., 1964b, Geologic Investigation for Petroleum in the Area ofState of Florida Drilling Lease 224-B: unpublished report for CoastalPet. Corp. placed in Bureau of Geology Library in Tallahassee, Florida.

Barnett, R. S., 1975, Basement Structure of Florida and its TectonicImplications: Gulf Coast Assoc. of Geol. Socs. Trans., v. 25, p. 122-142.

Chowns, T. M., and Williams, C. T., 1983, Pre-Cretaceous RocksBeneath the Georgia Coastal Plain-Regional Implications: in StudiesRelated to the Charleston, South Carolina Earthquake of 1886 - Tec-tonics and Seismicity: U.S. Geological Survey Prof. Paper 1313, p. 42.

Klitgord, K.D., Popenoe, P., and Schouten, H., 1984, Florida: a JurassicTransform Plate Boundary: Journal of Geophysical Research, vol. 89,no. B-9, p. 7753-7772.

Maync, W., 1950, The Foraminiferal Genus Choffatella schlumberger inthe Lower Cretaceous (Urgonean) of the Caribbean Region (Venezuela,Cuba, Mexico, and Florida): Eclogae Geol. Helv., Lausanne, 1950, v. 42(1949), No. 2, p. 539.

Oglesby, W. R., 1965, Folio of South Florida Basin, a Preliminary Study:Map Series 19, Florida Geological Survey (out of print).

Palacas, J. G., Daws, T. A., and Applegate, A. V., 1981, PreliminaryPetroleum Source-Rock Assessment of Pre-Punta Gorda rocks (low-ermost Cretaceous-Jurassic?) in South Florida: Gulf Coast Assoc.Geol. Socs. Trans., v. 31, p. 369-376.

APPENDIX ISUMMARY OF WELL DATA

Company Punta Lehigh Twelve Brown Net West Bone Wood& Gorda Acres Mile Dolo Dolo Felda Pumpkin Island River T.D.Fee Name Fm. Fm. Mbr. Zone (ft.) Mbr. Bay Fm. Fm. Fm. ft. Elev. Brown Dolomite Porosity, etc.

CHARLOTTE COUNTYB-5 This well has best dolomiteHORC 12456- seen in any onshore well withTreadwell 11684 12160 12365 12581 100 12720 12800 NR 13300 20 much vugular porosity noted,

especially in upper part ofsection. Twenty feet porosityfrom core and resistivity log.

Samples worthless. All topsare questionable. No Gamma

P-178 or Sonic log in this well. NoGulf 12290- drilling breaks. High re-Vanderbilt 11442 11940 12370 80 12495 12615 NR- 12725 22 sistivity in zone.

Porosity 7 percent from soniclog. Some vugular porositynoted in study of core, Notrace of oil staining noted.

P-310 Dolomite probably wopld pro-Gulf duce because of vugs. WellStevens 12290- produced salt water on drillEstate 11528 11985 12215 12370 55 NR 12395 25 stem test.

P-373 Some spotty fair porosity in

Mobile upper part of Brown Dolomite

Babcock 11930- Zone. Generally poor porosity, 6

Ranch 11290 11675 11825 12010 70 12164 12230 NR 12500 55 percent or less. Sonic log use-less because of washout.

P-375 Samples worthless. EstimateMobil from Gamma Ray, Sonic, andOffshore 11920- comparison nearest wells. NoFSL-224 B.11150 11640 11882 12000 70? 12170 12220 NR 12931 21 porous dolomite.

Porosity estimated from sonic .1P-459 approx, 8 percent. Finely cry- (oExchange 11760- stalline, dense. Best porosityPayson 11151 11512 11652 830 60 11900 12050 12760 NR 13432 81 at base of Interval.

APPENDIX I (Con't.)SUMMARY OF WELL DATA

Company Punts Lehigh Twelve Brown Net West Bone Wood

& Gorda Acres Mile Dolo Dolo Felda Pumpkin Island River T.D.

Fee Name Fm. Fm. Mbr. Zone (ft.) Mbr. Bay Fm. Fm. Fm. ft. Elev. Brown Dolomite Porosity, etc.

P.-472 Dolomite very fine-grained

Exchange throughout this Interval, No

Oil & Gas commercial porosity, Sonic

Babcock 12050- log shows approx. 4 percent

Florida Co. 11366 11780 11940 12158 70 12360 12440 NR 13000 47 porosity.

P-475 Dolomite is fine-grained, Por-

Exchange osity approx. 8-10 percent

Oil & Gas from density log. Porosity

State Lease 11930- from sonic log approx.

2448 11175 11585 11852 12000 80 12034 12120 12786 NR 13232 38 10-12 percent

COLLIER COUNTY

P-346 Much lost circulation notedHORC in 12810-12830 Interval. No

Gulf Coast dolomite noted.

Realties 12803-#24-1 11840 12462 12742 12816 0? 13036 13072 14070 NR 14500 38

P-727 Gamma log misleading. ThisTribal well Is below Punta GordaExxon (-11800') structure contour

Gulf Coast and on southeast edge of

Realtles 12803- "Brown Dolomite" zone. See

#12-4 11870 12490 12780 12872 7 13070 13110 14150 15480 17254 40 text

DESOTO COUNTY

P-609Shell 28' of 8 percent porosity and

Punts 11260- balance 5 percent or less.

Gorda 10745 • 11060 11210 11340 70 11400 11550 12190 NR 13000 77

APPENDIX I (Con't.)SUMMARY OF WELL DATA

Company Punta Lehigh Twelve Brown Net West Bone Wood& Gorda Acres Mile Dolo Dolo Felda Pumpkin Island River T.D.Fee Name Fm. Fm. Mbr. Zone (ft.) Mbr. Bay Fm. Fm. Fm. ft. Elev. Brown Dolomite Porosity, etc.

P-679A Brown Dolomite Zone veryAMOCO sandy. Dolomite fine-arained,Knight non-porous with interbedded

10280- light gray limestone. Sand9916 10130 10264 10340 35? Not present 11655 121 below 10,340 ft.

GLADES COUNTY

P-152 Information from lithology logCoastal of Banks. Very low porosityTledke in Interval. Trace dead oil. No

11605- samples through this Interval11048 11340 11540 11705 30 11815 11860 12760 NR 13424 30 in sample library.

HARDEE COUNTY

P-62 Redbeds 11382'. Lack of por-HORC 10570- osity, a 20' sampling Interval,Keen 10134 ? ? 10640? 30 10770 10835 Not Pre. 11934 63 and quartz sand in the Brown

Dolomite Zone make all es-timates very questionable in

HENDRY COUNTY this well.

P-314 * Extremely poor samples. DrillSun Oil 12440- stem test shows porosity andRed Cattle 11648 12160 12378 12520 50? 12618 NR 12680 54 permeability in interval. PoorP-424 suite of logs. Much of interval

probably chalk.

Exchange Approximately 6' in upper partOil & Gas of zone with 8 percent por-Fla. Land 12350- 1 33 osty. Very rapid decrease In& Timber 11552 12052 12246 12364 10 NR 1244 dolomite in this well. May be oi

close to eastern edge of zone. -*

APPENDIX I (Con't.)SUMMARY OF WELL DATA

Company Punta Lehigh Twelve Brown Net West Bone WoodA Gorda Acres Mile Dolo Dolo Felda Pumpkin Island River T D.Fee Name Fm.r Fm, Mbr. Zone (Ift) Mbr Bay Fm. Fm. Fm. ft. Elev. Brown Dolomite Porosity, etc.

P-•858. Dolomite fine-grained withMobil no visible porosity. DensityPhillips 12446- log shows washout, MuchSeminole C11600 12190 12400 12500 15 12690 12720 13750 15100 17025 35 chalk In Interval.

P-758 25' of fair porosity in upperShell 12272- part of Interval (7-11 percent)Alico 11560 11990 12240 12328 45 12515 12552 13490 14840 16000 45 with some well cuttings misl-

Ing. Porosity 6 percent or lessIn lower part of interval.

P-789 Variable porosity. Approx.Shell Oil one-half of Brown Dolo-Consol. mite has porosity up to 24Tomoka 12132- percent. Samples Indicate thisCo. 11484 11870 12090 92 22? 12374 12416 NR 12423 44 Interval is a porous chalk.

P-951 22' coarselv crystalline dolo-Ashland Oil mite. Balance of dolomiteA. Duda & 12400- has low porosity of 5 percent.Sons 11578 12078 12292 486 58 NR 12603 44 Much lost circulation material

but excellent samples.

HIGHLANDS COUNTY

Dolo 10796-10808, silty andB-1 lacks porosity. Some vugularHORC 10796- porosity to 20 percent. Por-

Carlton 10380 10622 10758 10880 75 10990 11052 11722 12985 114 osity 10832-10880, variablewith some good vugular. Nosonic log. Est. 25' porous.

APPENDIX I (Con't.)SUMMARY OF WELL DATA

Company Punts Lehigh Twelve Brown Net West Bone Wood& Gorda Acres Mile Dolo Dolo Felds Pumpkin Island River T.D.Fee Name Fm. Fm. Mbr. Zone (ft.) Mbr. Bay Fm. Fm. Fm. ft. Elev. Brown Dolomite Porosity, etc.P-225 No ditch or core samples. Es-Continental 10818- timated only from electric logCarlton 10640 10740 10895 75? 11025 11100 NR 12630 88 and mud log In comparison.

with HORC Carlton well.Micro-log shows no porosity.No drilling break.

P-862 Approx. 8' of porosity fromAMOCO 10856- neutron-density log with bal-Jackson 10450 10686 10792 10898 30 11036 11106 11750 12625 25 ance of dolomite low porosity.

Samples confirm this.

LEE COUNTY

P-161 Porosity to 15 percent. SomeHumble 12830- Vugular porosity. Some slightKirchoff 11855 12450 12734 54 24 NR 12877 22 oil staining in upper 10' of

dolomite,

P-289 Dolomite microcrystalline toCalifornia finely crystalline. Some testCoastal 12485- circulation material. Drill stemFSL 224B. 11564 12152 12410 12598 103 12748 12800 13772 NR 13975 39 that produced water. Neutron

log and drilling time logindicate porosity. Samplescomminuted.

P-297 Dolomite comminuted. MuchCalifornia lost circulation material.Coastal 12445- Microcrystalline to finelyFSL 224B. 11524 12104 12380 12560 110 NR 12600 40 crystalline. Estimated 40'

porous._O

APPENDIX I (Con't.)SUMMARY OF WELL DATA 2

Company Punts Lehigh Twelve Brown Net Wesl Bone Wood& Gorda Acres Mile Dolo Dolo Felda Pumpkin Island River T.D.Fee Name Fm. Fm. Mbr. Zone (ft.) Mbr. Bay Fm. Fm. Fm. ft. Elev Brown Dolomite Pority, ste

P-407 Eleven feet of poroeity fromHORC sonic log. Reet of Interval 4-6Lehigh percent porosity. SamplesAcres 12588- show very fine-grainedWell No. 1 11700 12250 12460 12684 70 12760 12800 13660 14672 15710 58 dolomite.

P-758 No porosity found In cuttlngs.Exxon Porosielty 4-5 percent fromCity of logkna•yse.Ft. Myers 12528-#16-2 11578 12112 12506 78 50 NR 12599 43

MANATEE COUNTY

P-236 Dolomite 11020-1105 calc.,MagnolIa 10966- Not fine-grained. Very littleSchroeder 10371 10710 10905 11038 10 11115 Present 11228 70 porosity in dolomite.

MARQUESAS KEYS

P-275 Oil stain 14670-14680, tar OilGulf 14620- 14754-14760. Much lost circ.FSL-826Y 12860 14270 14550? 15036 400 14955 NR 15475 58 material This zone of dolomite

has much good porosity highlyvugular.

P-264 Oil stain 14563,1457614578.Gulf-Cal- Variable poroelty in the Brown

Ifomrnl Co. 14420- Dolomite, but approx. 14 per-

BIk 28 OCS12740 14105 14310 14640 240 14790 14806 NR 15294 72 cent average.

APPENDIX I (Con't.)SUMMARY OF WELL DATA

Company Punts Lehigh Twelve Brown Net West Bone Wood& Gorda Acres Mile Dolo Dolo Felda Pumpkin Island River T.D.Fee Name Fm. Fm. Mbr. Zone (ft.) Mbr. Bay Fm. Fm. Fm. ft. Elev. Brown Dolomite Porosity, etc.

MONROE COUNTY

P-22 Dolomite very fine-grained,Gulf calcftic. No porosity.FSL 373Big Pine 14590-Key 12710 14220 14500 14740 30 14865 14910 NR 15455 23

P-148 Dolomite, very fine-grained,Sinclair 11090- anhydritic, calcitic, Inter-Williams 10162 10805 11045 11124 20 11280 11318 NR 11968 20 bedded S, light brown,

forams, No trace of oill ortar sand. No porosity.

PALM BEACH COUNTY

P-47 All tops tentative, Brown dol-HORC Not omite not present. This zoneTUCSON 10757 10770 10770 Present 11040 11075 11790 13110 13375 34 possibly 10900-1000 inter- of

buff colitc., mlloliticlimestone. Punta Gorda andAble member believed to be10757-10770 anhydrite bed.

P-265 Limestone cream to brown toHORC gray. Some algal piates,State 12438- millolids, anhydrite. DolomiteLease 1004 11624 12712 12380 12478 8 12700 12730 NR 12810 34 very fine-gralned with no

visible porosity. Trace tar oilin limestone.

NR = Not Reached

APPENDIX II 1DRILL STEM TEST DATA FROM BROWN DOLOMITE ZONE

ChloridesPermit Operator & Interval Duration of Cushion Total IFBHP ISIBHP TotalCounty Fee Name Tested ft. Test (hrs.) Chokes Recovery FFBHP FSIBHP Solids (ppm)

P-310 Gulf Oil 500 ft. 11750 ft. salt '3027 '5489 -Charlotte No. 1 Stevens 12184-12459 1 10/64" & 3/8" water. No show, "532 N"5489 -

P-289 Cal-CoastalLee No. 1

Fla, state 1000 ft. 9372 ft. salt 1081 5315 140,000224B 12463-12494 2 1/4" & 5/8" water. No show. 4730 5803 256,600

P-161 HORC 11700 ft. salt 1273 - -

Lee No. 1 Kirchoff 12824-12877 71 1/4 water. No show. 3499 4732 -

P-275 Gulf Oil Corp. 127 bbls.offshore No. 1 state of 21.3 bbls, salt water. LOST PACKER AND PRESSURE RECORDS IN HOLEMonroe Fla, 826Y 14642-14702 5 1/3 1/4" & 1" No show.

P-314 Sun Oil Co, 2000 ft. salt 1100 ft. mudHRIry No. 1 Red water and 9000 ft. 3782 - 131,000

Cattle 12475-12680 1 1/2 1/4" & 5/8" salt water. 5539 5566 271,000

P-'84 Gulf 9350 ft. blackoffshore California Co. 3600 ft. fresh salt water 5514 6940 -Monroe OCS BIk 28 14409-14508 2 1/2 water and 560 ft. mud. 6460 6940 -

* Initial flowing bottom hole pressure.*' Final flowing bottom hole pressure." Initial shut-In bottom hole pressure,

" Final shut-in bottom hole pressure.

VA1CT5 SCIENCE LIBRARY 3 1262 04707 0882

FLORIDA DEPARTMENT OF NATURAL RESOURCES ABUREAU OF GEOLOGY

FLORIDA GEOLOGICAL SURVEY903 WEST TENNESSEE STREET SCIENCE

TALLAHASSEE, FLORIDA 32304-7795 LBRY

Walter Schmidt, ChiefPeter M. Dobbins, Admin. Asst. Alison Lewis, LibrarianJessie Hawkins, Custodian Sandie Ray, Secretary

GEOLOGICAL INVESTIGATIONS SECTION

Thomas M. Scott, Senior Geologist/AdministratorAlbert V. Applegate, Geologist Ed Lane, GeologistKen Campbell, Geologist Margaret Lehey, Staff Asst.Cindy Collier, Secretary Jacqueline M. Lloyd, GeologistRichard Howard, Laboratory Tech. John Morrill, Core DrillerRichard Johnson, Geologist Albert Phillips, Asst. DrillerJim Jones, Draftsman Frank Rupert, GeologistTed Kiper, Draftsman Wei Wuchang, Research Asst.

OFFICE OF MINERAL RESOURCE INVESTIGATIONSAND

ENVIRONMENTAL GEOLOGY SECTION

J. William Yon, Senior Geologist/AdministratorPaulette Bond, Geologist Ron Hoenstine, GeologistShelton Graves, Research Asst. Steve Spencer, Geologist

OIL AND GAS SECTION

L. David Curry, AdministratorPete Parker, Engineer Scott Hoskins, GeologistBrenda Brackin, Secretary Barbara McKamey, SecretaryRobert Caughey, Geologist David Poe, GeologistJoan Gruber, Secretary Joan Ragland, GeologistDon Hargrove, Staff Asst. Clay Roark, Staff Asst.

Charles Tootle, Engineer

-FLORIDA-GEOLOGICAL-SURVEY

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