Geologic Framework for the Tengiz and Korolev Fields, Kazakhstan – Tangiz_Carboniferous Isolated Carbonate Platforms

Geologic Framework for the Tengiz and Korolev Fields, Kazakhstan – Carboniferous Isolated Carbonate Platforms*

By Paul M. (Mitch) Harris1

Search and Discovery Article #20060 (2008)

Posted June 26, 2008 *Adapted from 2000-2001 AAPG International Distinguished Lecture 1Chevron Petroleum Technology Company, Houston, TX; currently ETC, Chevron, San Ramon, CA, USA. ([email protected])

Abstract The supergiant Tengiz field exhibits depositional features typically observed in isolated carbonate platforms but rare for the Carboniferous: extensive inner and outer platform deposits, a raised rim feature, steep platform margins, and thick flank deposits. Many of the same platform and slope features observed in Tengiz are inferred from much less well data for Korolev. Platform Growth and Stratigraphic Framework The Tengiz and Korolev platforms formed during the Carboniferous on the Primorskian Arch, one of several structural highs in the southeast portion of the PriCaspian Basin in western Kazakhstan. The platform edges are abrupt, showing a relatively rapid change from the platform top (platform, shoal, or platform margin) to slope environment. Platform deposition includes cycles shoaling upward from open marine packstones to shoal grainstones. A reef (microbial boundstone with scattered megafossils) is localized to a very narrow belt along the platform margin. Boundstones give way downslope to breccias and finally argillaceous lime mudstone beds. A variety of open porosity types are present; karst zones are best developed in the rim, and fractures characterize both the rim and flanks. A hierarchy of cycles, sequences, and composite sequences is developed by integrating core and well logs with newly acquired 3D seismic data. The stratigraphic framework, although not finalized, explains many aspects of the reservoir quality. The buildup (actual thickening) of the platforms was seemingly initiated in the Devonian and accentuated greatly during Visean time. The position of the platform margins is controlled, in part, by deep-seated faults. The areal extent of both platforms generally diminished during the Carboniferous as evidenced by backstepping of the younger margins. Key Platform Well Tengiz well T-220, because of the great amount of continuous core taken in the well, is invaluable from the perspective of understanding the nature of deposition, stratigraphy, diagenesis, reservoir quality, and log response for the interior portion of the platform.

The upper contact of the Bashkirian is significant as it represents the demise of the shallow water platform. Three sequences of similar grainstone-dominated deposits form a composite sequence that comprises most of the Bashkirian. Four sequences recognized within the Serpukhovian form another composite sequence. The boundary between the Bashkirian and Serpukhovian is significant as it represents a major change in the style of deposition on the top of the Tengiz platform and equates with a time gap. Serpukhovian facies reflect slightly deeper water and more skeletal-rich environments. Three composite sequences are tentatively identified within the Visean (Oksky) interval; each contains three sequences consisting of grainstone-packstone cycles that are similar to those of the Serpukhovian. A portion of one sequence recognized within the upper part of the Visean (Tula) contains packstone-grainstone cycles. The difference in the character of the cycles between the Visean (Oksky)-Serpukhovian and the Bashkirian reflects changes in the nature of sea-level variations that occurred between Early and Late Carboniferous. Porosity loss in T-220, and other Tengiz platform wells, is by calcite cementation and minor compaction. The variety of open primary and secondary pore types is a principal reason for the permeability variation that is observed within the well. Core samples are dominantly limestone with local partial dolomitization and silicification associated with tuffs or subaerial exposure. T-220 displays more-or-less constant 15% porosity with 1-10 md permeability, separated by thin tighter intervals at sequence and cycle boundaries. Where bitumen occurs, it displays an inverse correlation with porosity (that is, bitumen is more abundant in rocks with low porosity). Samples with bitumen occur in short intervals, almost always at sequence or cycle boundaries, with long intervals in between with zero bitumen. The downhole porosity logs show an excellent match to core porosities; gamma-ray response increases where tuffs and shales are present. Key Flank Well Tengiz well T-47 is a flank well located off the southeast edge of the platform; it is an important well from the perspective of understanding the nature of deposition, diagenesis, reservoir quality, and log response in the flanks of the platform. The Bashkirian through Visean (Oksky) consists of two general rock types: (1) coarse-grained (rudstones and grainstones rich in boundstone intraclasts), and (2) finer-grained (grainstones, packstones, and wackestones). Both rock types represent debris that was shed down the slope from the platform margin. The Visean (Tula) is predominantly fine-grained slope packstones. The Devonian (Famennian) consists of shallow platform grainstones and packstones. T-47 penetrated a generally limestone stratigraphy, with three important exceptions: (1) dolomite-rich intervals with 50% to 70% dolomite in the basal Serpukhovian, and lower Visean (Tula) through top Devonian; (2) a silica-rich interval in the Visean (Tula); and (3) a barite-rich interval with 0% to 26 wt.% (17 vol.%) barite near the top Devonian. Bitumen fills 10% to 15% of the potential porosity (defined as core measured porosity plus bitumen) in most samples. The Bashkirian through Visean (Oksky) slope deposits have open porosity of three types: isolated vugs, pores between clasts, and microfractures. The Visean (Tula) packstones are varyingly silicified, and a few small, open vugs are the only visible porosity.

Wireline logs indicate a porosity distribution that is generally consistent with the limited core data. Small, isolated, bitumen-stained vugs, fenestral pores, and microfractures remain open in a few Devonian grainstone and packstone samples. Wireline logs indicate a porosity distribution that is generally consistent with the limited core data. Porosity from 0% and 9% typifies the section above the Devonian; porosity generally <4% is representative for the Devonian. The Visean (Oksky) slope deposits appear on an FMI log as irregular layers dipping up to 30° that are rarely continuous across the image, and thin continuous layers gently dipping way from the platform characterize the Visean (Tula) slope deposits. Irregular continuous layers with dips <5° typify the Devonian platform deposits.

Acknowledgements I am grateful to the following coworkers for their collaboration: Michael E. Clark, Tengizchevroil, Tengiz, Kazakhstan; Raymond A. Garber, Chevron Petroleum Technology Company, Houston, TX; and Jeff. L. Warner, LA Petrophysical, La Habra Heights, CA.

GEOLOGIC FRAMEWORK FOR TENGIZ AND GEOLOGIC FRAMEWORK FOR TENGIZ AND KOROLEV FIELDS, KAZAKHSTANKOROLEV FIELDS, KAZAKHSTAN

CARBONIFEROUS ISOLATEDCARBONIFEROUS ISOLATEDCARBONATE PLATFORMSCARBONATE PLATFORMS

AAPG International Distinguished Lecture TourAAPG International Distinguished Lecture Tour

Paul M. (Mitch) HarrisPaul M. (Mitch) HarrisChevron Petroleum Technology Company Chevron Petroleum Technology Company

Houston, Texas U.S.A.Houston, Texas U.S.A.

OUTLINE OF TALKOUTLINE OF TALK

Geological SettingGeological Setting

Key Platform WellKey Platform Well

Key Flank WellKey Flank Well

SummarySummary

JV BLOCK4000 km 2

TENGIZCHEVROILJOINT VENTURE

Atyrau

KorolevField

Tengiz Field

K A Z A K H S T A N

C a s p i a nS e a

30 Mi

30 Km

LOCATION MAPLOCATION MAP

PLATFORM BUILDPLATFORM BUILD--UPUP

NONNON--DEPOSITIONDEPOSITION

SALT DEPOSITIONSALT DEPOSITION

drowning drowning

unconformityunconformity

As s elian

Noginsky

PrikamskyCheremchanskiy

MelekesskyVereiskiyKashirskyPodol'skiy

MyachkovskyKrevyaninskyKhamovnicheskyDorogomilovskyKlaz'minskiy

Severokel'tenskiy

Krasnopolyansky

Vosnesensky

CherepetskyKizelovskyKos'vinskiy

Pester'kovskiyIlychskiyTul'skiy

AleksinskyMikhailovskiy

VenevskyTarussky

SteshevskyProtvinsky

Zapaltyubinsky

UpperKalinovskyMalevskyUpinsky

Wolfcampian

Missourian

Wabaunsee

BloydWinslow

CherokeeMarmaton

P le a sa nto nKansas CityLansing

D ou gla sSha w nee

St. GenevieveGasperian

Hombergian

Elvirian

Hale

Glen ParkHannibalChouteau

M e ppe nF e rn G le n

B urlin gton

KeokukWarsawSalem

St. Louis

Leonardian

CapitanWord G u a d a lu p ia n

Kungurian

Artins kian

Sakmarian

KazanianUfimian

Khamovnichesky

Severokel'tenskiy

Krasnopolyansky

Radayevsky

Mikhailovskiy

Zapaltyubinsky

Givetian

Eifelian

LowerUpper

MiddleLower

Harland et al.

280

290

300

310

320

330

340

350

360

260

270

370

380

Kun

Art

Sac

A s s

Vir

Mss

DesAto/Der

Mor

Chs

Mer

Osa

Kin

Fam

Frs

Giv

Eif

Noginsky

PrikamskyCheremchanskiyMelekesskyVereiskiyKashirskyPodol'skiy

MyachkovskyKrevyaninskyDorogomilovskyPa vlovo -P osa dsky

Voznesensky

CherepetskyKizelovsky

Kos'vinskiy

BobrikovskyTul'skiy

Aleksinsky

VenevskyTarussky

SteshevskyProtvinsky

ZavolzhskyGumerovskyMalevskyUpinsky

D o brya tinsky

DankovskyLebedyanskyZandonsky-Eletsky

LivenskyEvlanskyVoronezhskyMendymskyBuregsky

SemilukskySargayevskyKynovskyPashiysky

MullinskyArdatovskyVorob'yevskyBiysky

KoivenskyAfoninsky

IrenskyPhilipovsky

S a ra ninskyS a rginskyIrch inskyBu rtse vsky

Sterlitamaksky

Tastubsky

ShihahskyHolodnolozsky

CC

C

C

C

D

TIMING OF IMPORTANT EVENTSTIMING OF IMPORTANT EVENTS

Ma (BASE) HORIZONS RUSSIAN STAGES RUSSIAN SERIES311.5 (top)-

312.0312.5

Asatausky (Asa)Tashastinsky (Tas)

LATE

312.8313.2313.6314.0

Askynbashsky (Ask)Akavassky (Ak)Syuransky (Syu)

Bogdanovsky (Bog)

EARLY

BASHKIRIAN EARLY MIDDLECARBONIFEROUS

316.75319.5

Zapaltyubinsky (Zap)Protvinsky (Pr)

LATE

322.25325.0

Steshevsky (St)Tarussky (Tar)

EARLYSERPUKHOVIAN

328.5 Venevsky(Ven)

330.5 Mikhailovsky(Mik)

332.75 Aleksinsky(Al)

OkskySuper-horiz.

335.0 Tulsky (Tul)

LATE

341.5343.0

Bobrikovsky (Bob)Radaevsky (Rad)

EARLY

VISEAN

345.5348.0

Kosvinsky (Kos)Kizelovsky (Kiz)

LATE

349.5351.0352.5354.0

Cherepetsky (Ch)Upinsky (Up)

Malevsky (Mal)Gumerovsky (Gum)

EARLYTOURNAISIAN

LOWERCARBONIFEROUS

364.5 FAMENNIAN369.0 FRASNIAN

LATE DEVONIAN

PLATFORM EVOLUTIONPLATFORM EVOLUTION

UNCONFORMITYUNCONFORMITY



DROWNINGDROWNING

TENGIZTENGIZWELLWELL

LOCATIONSLOCATIONSPLATFORMPLATFORM

FLANKFLANK

TENGIZ 3TENGIZ 3--D SEISMICD SEISMIC


KOROLEVKOROLEVFIELDFIELDMAPMAP PLATFORMPLATFORM

FLANKFLANK

KOROLEV 3KOROLEV 3--D SEISMICD SEISMIC

KOROLEV 3KOROLEV 3--D SEISMICD SEISMIC


PLATFORMPLATFORMFLANKFLANK FLANKFLANK

DEVONIANDEVONIAN

EARLY VISEANEARLY VISEAN

BASHKIRIANBASHKIRIAN

TENGIZ STRATIGRAPHIC MODELTENGIZ STRATIGRAPHIC MODEL

DEVONIANDEVONIAN

TOURNAISIANTOURNAISIAN


LATE VISEANLATE VISEAN

SERPHUKHOVIANSERPHUKHOVIAN

BASHKIRIANBASHKIRIANDROWNINGDROWNING

RETROGRADINGRETROGRADING

MAJOR SBMAJOR SBFLANK DEPOSITIONFLANK DEPOSITION

PROGRADINGPROGRADINGAGGRADINGAGGRADING

AGGRADINGAGGRADINGFILLFILL--IN RELIEFIN RELIEF

RELIEF ON MAJOR SBRELIEF ON MAJOR SBAGGRADINGAGGRADINGBACKSTEPBACKSTEP

AGGRADINGAGGRADING

MAJOR SBMAJOR SBAGGRADINGAGGRADING

PLATFORM STYLEPLATFORM STYLE

TENGIZ STRATIGRAPHIC MODELTENGIZ STRATIGRAPHIC MODEL

4000

4100

4200

4300

4400

4500

4600

4700

4800

4900

5000

5100

5200

5300

5400

5500

5600

5700

3900

4000

4100

4200

4300

4400

4500

4600

4700

4800

4900

5000

5100

5200

5300

5400

5500

4300

4400

4500

4600

4700

4800

4900

4000

4100

4200

4300

4400

45004500

4600

4700

4800

4900

5000

5100

5200

5300

5400

5500

LATE VISEANLATE VISEAN

BASHKIRIANBASHKIRIANSERPUKHOVIANSERPUKHOVIAN

DEVONIANDEVONIAN


TOURNAISIANTOURNAISIAN

TT--463463

TT--220220 TT--50505050TT--50565056

TT--4141

SWSW NENE

(~ 5X vertical(~ 5X vertical exaggeration)exaggeration)

DROWNINGDROWNING

RETROGRADINGRETROGRADINGMAJOR SBMAJOR SB

FLANK DEPOSITIONFLANK DEPOSITION

PROGRADINGPROGRADING

AGGRADINGAGGRADING

AGGRADINGAGGRADING

FILLFILL--IN RELIEFIN RELIEF

RELIEF ON SBRELIEF ON SB

AGGRADINGAGGRADINGBACKSTEPBACKSTEP

AGGRADINGAGGRADING

MAJOR SBMAJOR SB

AGGRADINGAGGRADING

AGGRADINGAGGRADING

TT--463 T463 T--220 T220 T--5050 T5050 T--50565056

T/BASHT/BASHT/SERPT/SERP

T/L.VIST/L.VIS

T/E. VISEANT/E. VISEAN

T/TOURNT/TOURN

T/DEVT/DEV

T/BASHT/BASH•• MINOR FLANKMINOR FLANK•• GENERALLY RETROGRADATIONALGENERALLY RETROGRADATIONAL

T/SERPT/SERP•• SERP DOMINATES FLANKSERP DOMINATES FLANK•• AGGRADING THEN PROGRADING MARGINAGGRADING THEN PROGRADING MARGIN•• MAJOR BACKSTEPMAJOR BACKSTEP

T/E. VISEANT/E. VISEAN•• RELIEF ON SEQUENCE BOUNDARYRELIEF ON SEQUENCE BOUNDARY•• AGGRADING PLATFORMAGGRADING PLATFORM•• MINOR MARGIN/SLOPEMINOR MARGIN/SLOPE

T/DEVONIANT/DEVONIAN•• FAMENNIAN PLATFORM SMALLERFAMENNIAN PLATFORM SMALLER•• PLATFORM MARGIN/SLOPE POSSIBLEPLATFORM MARGIN/SLOPE POSSIBLE

~312 MA~312 MA

~314 MA~314 MA

~337 MA~337 MA

~354 MA~354 MASBSB

SBSB

SBSB

SBSB

TENGIZ GEOLOGIC MODELTENGIZ GEOLOGIC MODEL

Improved ReservoirQuality

August 2000 August 2000 -- Structural DatumStructural Datum

Kilometers

0 1 2

T-4 1

T-38T-39

T-1 08

T -11 3

T-8

T-122

T-110 0

T-1K

T -1

T-17T-10

T-1 4

T-9

T-1 02

T-3 20

T-4

T-107

T-3 K

T -11 8

T-72

T-42

T-1 06

T-11

T-4 19T-16T-1 101

T -40

T -7

T-10 3

T-1 05T-70

T-43

T-1 11 T-117

T-1 12T-1 5

T-5 K T -19T-3 18T-2 4

T-1 10 T-317

T-115T-1 16

T-2 1T-1 14

T -44

T-104

T-10 9

T-20

T-6

T-11 9

T-120

T-1 21

T-25

T -22

T-505 0T-5

T -10 0

T -37

T-12T-2 3

T-123

T -12 4T-2 9

T-3 0

T-27 T-26

T-28

T-4 7

T-3 1

T-3 4

T-45Tengiz ReservoirTop Bashkirian (m)

North

5,8005,800

5,600

5,2005,000

4,8004,600

4,400

4,2004,4004,6004,8005,000

5,2005,400

5,600

5,400

T-220

KEY KEY PLATFORMPLATFORM

WELLWELLTT--220220

Highstand Facies

Transgressive Facies

Toe-of-Slope(Mud and Grainstone Debris)

Slope(Breccias)

Depositionon Slope

Minor Depositionon Slope

CalcreteKarst

Non-Deposition

Shallow Platform(Cyclic Packstone and Grainstonewith Crinoids, Algae and Locally Reefs)

Packstone with Crinoids,Brachiopods, and Locally Reef Mounds

Lowstand Facies

Shoal(Grainstone)

Platform Margin(Reef and Grainstone)

Fully Developed CarbonatePlatform Top, Margin and Flanks

Deep Platform

Subaerial Exposure

DEPOSITIONALDEPOSITIONALMODELMODEL

PLATFORMPLATFORMFLANKFLANK

PLATFORM SHOAL COMPLEXPLATFORM SHOAL COMPLEX OUTER PLATFORMOUTER PLATFORMPLATFORM MARGINPLATFORM MARGIN TOE OFTOE OF

SLOPESLOPEANDAND

BASINBASINUPPERUPPERSLOPESLOPE

LOWERLOWERSLOPESLOPE

3030-- 5

0 m

50 m

OOID, PELOID,OOID, PELOID,SKELETAL GRAINSTONESKELETAL GRAINSTONE

SKELETAL PELOIDSKELETAL PELOIDGRAINSTONE/PACKSTONEGRAINSTONE/PACKSTONE

SKELETAL PELOIDSKELETAL PELOIDPACKSTONE/GRAINSTONEPACKSTONE/GRAINSTONE

+ MICROBIAL BOUNDSTONE+ MICROBIAL BOUNDSTONE

MICROBIAL

MICROBIAL

BOUNSTONE

BOUNSTONE

ANDANDSLOPESLOPE

DEBRISDEBRIS

PLATFORM ANDPLATFORM ANDSLOPE DEBRISSLOPE DEBRIS

AND MUDSTONEAND MUDSTONEPLATFORM CYCLES THIN, POTENTIALLY DISCONTINUOUSPLATFORM CYCLES THIN, POTENTIALLY DISCONTINUOUS

GOOD INTERPARTICLE POROSITY IN PLATFORMGOOD INTERPARTICLE POROSITY IN PLATFORM

MINOR EQUANT CALCITE FILLING INTERPARTICLE POROSITYMINOR EQUANT CALCITE FILLING INTERPARTICLE POROSITY

mBmBmBmB mBmB

BASHKIRIAN MODELBASHKIRIAN MODEL

SERPUKHOVIAN SERPUKHOVIAN -- LATE VISEAN MODELLATE VISEAN MODEL

PLATFORM SHOAL COMPLEXPLATFORM SHOAL COMPLEX OUTER PLATFORMOUTER PLATFORM PLATFORMPLATFORMMARGIN AND SLOPEMARGIN AND SLOPE

TOE OFTOE OFSLOPESLOPE

ANDANDBASINBASIN

20 m

20 m

SKELETAL PELOIDSKELETAL PELOIDPACKSTONE/GRAINSTONEPACKSTONE/GRAINSTONE

+ MICROBIAL BOUNDSTONE+ MICROBIAL BOUNDSTONE

ACCRETIONARYACCRETIONARYBOUNDSTONE (CPM)BOUNDSTONE (CPM)

BOUNDSTONEBOUNDSTONEBRECCIABRECCIA

LIME MUDSTONELIME MUDSTONEAND PLATFORM CARB.AND PLATFORM CARB.

DEBRISDEBRIS

BEST POROSITY AND MATRIX PERMEABILITY IN PLATFORM FACIESBEST POROSITY AND MATRIX PERMEABILITY IN PLATFORM FACIES

BEST PERMEABILITY IN PLATFORM MARGIN AND SLOPE BOUNDSTONES BEST PERMEABILITY IN PLATFORM MARGIN AND SLOPE BOUNDSTONES --SURFACE SURFACE -- BURIAL KARST AND/OR TECTONIC FRACTURESBURIAL KARST AND/OR TECTONIC FRACTURES

BITUMEN FILLED POROSITY INCR. TOWARD PLATFORM MARGIN AND SLOPEBITUMEN FILLED POROSITY INCR. TOWARD PLATFORM MARGIN AND SLOPE

300

m30

0 m

SKELETAL PELOIDSKELETAL PELOIDGRAINSTONE/PACKSTONEGRAINSTONE/PACKSTONE

DETRITALDETRITALBRECCIABRECCIA

mBmB mBmB

CPM=CLOTTED PELOIDALCPM=CLOTTED PELOIDALMICRITEMICRITE

0% 20% 40% 60% 80% 100%

B4

B3

B2

B1 ClasticP/W'stonePackstoneG/P'stoneGrainstone

Lithology Distribution -- Bashkirian Sequences

0% 20% 40% 60% 80% 100%

S4

S3

S2

S1 ClasticP/W'stonePackstoneG/P'stoneGrainstone

Lithology Distribution -- Serpukhovian Sequences

0% 20% 40% 60% 80% 100%

VO9

VO7

VO5

VO3

VO1

ClasticP/W'stonePackstoneG/P'stoneGrainstone

Lithology Distribution -- Visean (Oksky) Sequences Sequences

STRATIGRAPHYSTRATIGRAPHYAND AND

ROCK TYPEROCK TYPE

PLATFORM CYCLEPLATFORM CYCLEtoptop

Grainstone Grainstone 15.8% 15.8% 3.9 mD3.9 mD

basebase

Packstone Packstone 4.5% 4.5%

0.06 mD0.06 mD

BASHKIRIAN CYCLEBASHKIRIAN CYCLETOPTOP

BOTTOMBOTTOM

4 MM ACROSS FIELD4 MM ACROSS FIELD

SKELETAL SKELETAL -- COATED GRAIN GRAINSTONE COATED GRAIN GRAINSTONE

SERPUKHOVIAN CYCLESERPUKHOVIAN CYCLETOPTOP

BOTTOMBOTTOM


SKELETAL GRAINSTONE AND PACKSTONESKELETAL GRAINSTONE AND PACKSTONE

UPPER VISEAN CYCLEUPPER VISEAN CYCLETOPTOP

BOTTOMBOTTOM


SKELETAL SKELETAL -- PELOID GRAINPELOID GRAIN--PACKSTONEPACKSTONE

SUMMARY OF PLATFORM DIAGENESISSUMMARY OF PLATFORM DIAGENESISEARLY DIAGENESISEARLY DIAGENESIS

RIM AND SYNTAXIAL CEMENTS RIM AND SYNTAXIAL CEMENTS MOLDIC POROSITY AND MICROPOROSITYMOLDIC POROSITY AND MICROPOROSITY

EQUANT CALCITE CEMENTSEQUANT CALCITE CEMENTSKARST KARST -- VUGS, BRECCIA, AND MICROFRACTURESVUGS, BRECCIA, AND MICROFRACTURES

BURIALBURIAL DIAGENESISDIAGENESIS

MICROFRACTURES AND MICROSTYLOLITESMICROFRACTURES AND MICROSTYLOLITESMICROVUGGY POROSITY AND MICROPOROSITYMICROVUGGY POROSITY AND MICROPOROSITY

CALCITE, DOLOMITE, SILICA, OR ANHYDRITE CEMENTSCALCITE, DOLOMITE, SILICA, OR ANHYDRITE CEMENTSBITUMEN EMPLACEMENTBITUMEN EMPLACEMENT

AUTHIGENIC PYRITEAUTHIGENIC PYRITECROSSCROSS--CUTTING FRACTURESCUTTING FRACTURES

COARSE CALCITE IN VUGS, VEINS, AND FRACTURESCOARSE CALCITE IN VUGS, VEINS, AND FRACTURES

MOSCOVIAN (?) SEQUENCEMicroporosity in grains and matrix, minor interparticle porosity, and an openmicrofracture.

UPPER BASHKIRIAN SEQUENCEB1 - Solution-enlarged interparticle and intraskeletal porosity, microfractures,

microporosity in grains and between cement crystals.LOW ER BASHKIRIAN COMPOSITE SEQUENCEB2 - Solution-enhanced interparticle and intraskeletal porosity, moldic porosity,

microporosity in grains, local microvuggy and microfracture porosity.B3 - Cement-reduced interparticle, moldic, microfracture, and microvuggy porosity;

microporosity in grainsB4 - Solution-enlarged interparticle, intraskeletal, vuggy, moldic, and microfracture

porosity; microporosity in grains.SERPUKHOVIAN COMPOSITE SEQUENCES1 - Solution-enhanced interparticle, microvuggy, moldic, and microporosity in grains.S2 - Solution-enhanced interparticle, intraskeletal, moldic, microvuggy and microfracture

porosity; microporosity in grains and matrix.S3 - Interparticle, intraskeletal, moldic, microfracture, and microvuggy porosity;

microporosity in grains and matrix.S4 - Solution enhanced interparticle, intraskeletal, moldic microfracture, and microvuggy

porosity; microporosity in matrix and grains.UPPER VISEAN (OKSKY) COMPOSITE SEQUENCEVO1 - Locally solution-enhanced interparticle and intraskeletal porosity; moldic,

microfracture, and microvuggy porosity. Microporosity in grains and matrix.VO2 - Interparticle and intraskeletal porosity, locally solution enhanced; moldic and

microvuggy porosity; microporosity in matrix and peloids.VO3 - Interparticle, moldic, and intraskeletal porosity; microporosity in grains and

matrix; microvuggy and microfracture porosity.MIDDLE VISEAN (OKSKY) COMPOSITE SEQUENCEVO4 - Solution-enhanced interparticle, intraskeletal, microvuggy, and microfracture

porosity; microporosity in grains.VO5 - Solution-enhanced interparticle, intraskeletal, local microvuggy porosity;

microporosity in grains and matrix.VO6 - Interparticle, intraskeletal, and moldic porosity; microporosity in grains and

matrix.LOW ER VISEAN (OKSKY) COMPOSITE SEQUENCEVO7 - Solution-enhanced interparticle to microvuggy porosity.VO8 - Interparticle, intraskeletal, moldic and microfracture porosity; microporosity in

grains.VO9 - Intraskeletal, moldic, and interparticle porosity.UPPER VISEAN (TULA) COMPOSITE SEQUENCEVT1 – Intraskeletal, moldic, and microfracture porosity; also microporosity in grains.

STRATIGRAPHYSTRATIGRAPHYANDAND

POROSITYPOROSITYTYPETYPE

0.001

0.01

0.1

1

10

100

1000

0.0 5.0 10.0 15.0 20.0 25.0

Porosity (% BV)

Perm

eabi

lity

(md)

Non-FractureedFractured

T -220All DataN=1,305

PLATFORM RESERVOIR QUALITYPLATFORM RESERVOIR QUALITY

0.001

0.01

0.1

1

10

100

1000

0 5 10 15 20 25P o ro sity (% B V)

Per

mea

bilit

y (m

d)

T -2 2 0Uppe r V is e a n (Tula )

N = 4 4

0 .001

0.01

0.1

1

10

100

1000

0 5 10 15 20 25P o ro sity (% B V)

Per

mea

bilit

y (m

d)

N o n -F ra ctu re d

F ra ctu re d

T-2 2 0Low e r V is e a n (O k s k y)

N = 2 4 6

0 .001

0.01

0.1

1

10

100

1000

0 5 10 15 20 25P o ro sity (% B V)

Per

mea

bilit

y (m

d)

T -2 2 0M iddle V is e a n (O k s k y)

N = 1 4 0

0 .001

0.01

0.1

1

10

100

1000

0 5 10 15 20 25P o ro sity (% B V)

Per

mea

bilit

y (m

d)

T -2 2 0Uppe r V is e a n (O k s k y)

N = 2 4 40 .001

0.01

0.1

1

10

100

1000

0 5 10 15 20 25P o ro sity (% B V)

Per

mea

bilit

y (m

d)

N o n -F ra ctu re d

F ra ctu re d

T-2 2 0S e rpuk hovia n

N = 3 5 3

0 .001

0.01

0.1

1

10

100

1000

0 5 10 15 20 25P o ro sity (% B V)

Per

mea

bilit

y (m

d)

T -2 2 0Low e r Ba s hk ir ia n

N = 2 5 6

STRATIGRAPHY ANDSTRATIGRAPHY ANDRESERVOIR QUALITYRESERVOIR QUALITY

0

1

2

3

4

5

6

7

8

9

10

0 5 10 15 20 25

P ote n t ial P o ro s ity (% B V )

Bit

umen

(v

ol.

% o

f Roc

k)75 %

F ille d

1 00 %F ille d

5%F ille d

T -2 20All D a ta

N = 1 ,4 2 0C or r e c te d D a ta

BITUMEN AND POROSITYBITUMEN AND POROSITY

0 20 40 60 80 100

Calcite

Dolomite

Abund an ce (wt.%)

Perm. (m d)

Permeability (m d)

0 5 10 15 20 25

4070

4090

4110

4130

4150

4170 Porosity (% BV)Bitumen (% BV)

Volum e (% BV)

0 20 40 60 80 100

QuartzFeldsparClay

Ab und ance (wt.% )

Artinskian

Moscovian (?)B1

B2

B3

B4

S1

BASHKRIAN RESERVOIR QUALITYBASHKRIAN RESERVOIR QUALITYAND MINERALOGYAND MINERALOGY

0 5 10 15 20 25

4160

4180

4200

4220

4240

4260


Volum e (% BV)

Perm. (m d)

Permeability (md)

0 20 40 60 80 100

Calcite

Dolomite

Abund an ce (wt.%)

VO1

S2

S4

S3

B4

S1

0 20 40 60 80 100

QuartzFeldsparClay

Ab und ance (wt.% )

SERPUKHOVIAN RESERVOIR QUALITYSERPUKHOVIAN RESERVOIR QUALITYAND MINERALOGYAND MINERALOGY

0 20 40 60 80 100

QuartzFeldsparC lay

Ab undance (wt.% )

0 5 10 15 20 25

4270

4290

4310

4330

4350

4370

Porosity (% BV)Bitumen (% BV)

Volum e (% BV)

0 20 40 60 80 100

Calcite

Dolomite

Ab undance (wt.%)

Perm. (m d)

Perm eabil ity (md)

VO1

VO3

S4

VO4

VO2

UPPER VISEAN RESERVOIR QUALITYUPPER VISEAN RESERVOIR QUALITYAND MINERALOGYAND MINERALOGY

0 20 40 60 80 100

QuartzFeldsparClay

Ab undan ce (wt.% )

0 20 40 60 80 100

Calcite

Dolomite

Ab undan ce (wt.%)

0 5 10 15 20 25

4350

4360

4370

4380

4390

4400

4410

4420

4430

Porosity (% BV)Bitumen (% BV)

Volum e (% BV)

Perm. (m d)

Perm eabil ity (m d)

VO6

VO3

VO7

VO4

VO5


0 20 40 60 80 100

Calcite

Dolomite

Abundance (wt.%)

0 20 40 60 80 100

QuartzFeldsparC lay

Ab und an ce (wt.% )

0 5 10 15 20 25

4410

4430

4450

4470

4490

4510


Volum e (% BV)

Perm. (m d)

Perm eabil ity (m d)

VO6

VT1

VO7

VO9

VO8


LogsLogs CoreCore Wireline PressureWireline Pressure

STRATIGRAPHY ANDSTRATIGRAPHY ANDWIRELINE PRESSURESWIRELINE PRESSURES

Major FlowMajor FlowBarriersBarriers Minor FlowMinor Flow

BarriersBarriers

PLATFORM POROSITY DISTRIBUTIONPLATFORM POROSITY DISTRIBUTION

CYCLESCYCLES

PLATFORM POROSITY DISTRIBUTIONPLATFORM POROSITY DISTRIBUTION

CYCLESCYCLES

WELL TIEWELL TIETO 3D TO 3D

SEISMICSEISMIC

Kilometers

0 1 2

T-4 1

T-38T-39

T-1 08

T -11 3

T-8

T-122

T-110 0

T-1K

T -1

T-17T-10

T-1 4

T-9

T-1 02

T-3 20

T-4

T-107

T-3 K

T -11 8

T-72

T-42

T-1 06

T-11

T-4 19T-16T-1 101

T -40

T -7

T-10 3

T-1 05T-70

T-43

T-1 11 T-117

T-1 12T-1 5

T-5 K T -19T-3 18T-2 4

T-1 10 T-317

T-115T-1 16

T-2 1T-1 14

T -44

T-104

T-10 9

T-20

T-6

T-11 9

T-120

T-1 21

T-25

T -22

T-505 0T-5

T -10 0

T -37

T-12T-2 3

T-123

T -12 4T-2 9

T-3 0

T-27 T-26

T-28

T-4 7

T-3 1

T-3 4

T-45Tengiz ReservoirTop Bashkirian (m)

North

5,8005,800

5,600

5,2005,000

4,8004,600

4,400

4,2004,4004,6004,8005,000

5,2005,400

5,600

5,400

T-220

KEY KEY FLANKFLANKWELLWELL

T-220

TT--4747

KUNGURIAN SALTKUNGURIAN SALT

ANHYDRITEANHYDRITE

ARTINSKIANARTINSKIAN

KEY FLANK WELLKEY FLANK WELL

PLATFORMPLATFORM

FLANKFLANK

FLANK DEVELOPMENTFLANK DEVELOPMENT

PLATFORMPLATFORM FLANKFLANK

TOP DEVTOP DEV

TOP BASHTOP BASH

Flank Wells Interior Wells

Highstand Facies

Transgressive Facies

Toe-of-Slope(Mud and Grainstone Debris)

Slope(Breccias)

Depositionon Slope

Minor Depositionon Slope

CalcreteKarst

Non-Deposition

Shallow Platform(Cyclic Packstone and Grainstonewith Crinoids, Algae and Locally Reefs)

Packstone with Crinoids,Brachiopods, and Locally Reef Mounds

Lowstand Facies

Shoal(Grainstone)

Platform Margin(Reef and Grainstone)

Fully Developed CarbonatePlatform Top, Margin and Flanks

Deep Platform

Subaerial Exposure


PLATFORMPLATFORMFLANKFLANK

OUTCROP OF PLATFORM FLANKOUTCROP OF PLATFORM FLANK

ASTURIAS, SPAINASTURIAS, SPAIN

FLANK FACIES DISTRIBUTIONFLANK FACIES DISTRIBUTION

BOUNDSTONEBOUNDSTONEAND GRAINSTONEAND GRAINSTONE

DETRITAL BRECCIADETRITAL BRECCIA


FORFORSLOPESLOPE

0% 20% 40% 60% 80% 100%

Devonian Deep

Devon. Sha llow

Visean (Tula )

Vise an (Oksky)

Serpukhovian

Bashkirian

Artinskian

All Tengiz-47 Mudstone

W ackestone

P/W 'stone

Packstone

G/P'stone

Gra instone

Breccia /Rudstone

STRATIGRAPHY AND ROCK TYPESTRATIGRAPHY AND ROCK TYPE

SLOPE BOUNDSTONE AND CLASTSSLOPE BOUNDSTONE AND CLASTS

BOUNDSTONEBOUNDSTONE

CLASTSCLASTS

LOWER SLOPE PACKSTONESLOWER SLOPE PACKSTONES

SILICASILICAREPLACEMENTREPLACEMENT

FRACTUREFRACTURE

0.001

0.01

0.1

1

10

100

0 3 6 9 12 15

Porosity (%)

Perm

eabi

lity

(m

d)

BashkirianSerpukhovianVisean (Oksky)Visean (Tula)

Fractured

SLOPE RESERVOIR QUALITYSLOPE RESERVOIR QUALITY

0

3

6

9

0 3 6 9 12 15

Potential Porosity (%)

Bitu

men

(v

ol.%

)All Tengiz-47Bashkirian

100% Filled

10% Filled

30% Filled

BITUMEN AND POROSITYBITUMEN AND POROSITY

SLOPESLOPEDIAGENESISDIAGENESIS

BURIALBURIAL(HYDROTHERMAL?)(HYDROTHERMAL?)

DOLOMITEDOLOMITESILICASILICABARITEBARITE

URANIUMURANIUM

0 10 20 30 40 50

QuartzC layBarite

Abund ance (wt.%)

V

Devonian

Visean (Tula)

Visean (Oksky)

Serpukhovian

Bashkirian

Deb

ris S

lope

Slope

Plat

form

SGR0 200

CGR0 200

BARITECALCITE

SIDERDOLOMPYRITE

LOGSLOGS CORECORE

FRACTURES AND VUGSFRACTURES AND VUGS

SOLUTIONSOLUTION--ENLARGEDENLARGEDFRACTURESFRACTURES

VUGS IN FLANK WELLSVUGS IN FLANK WELLS

IMAGE_STATIC.IMVI

4556

4557

DEPTHMETRES

IMAGE_DYNAMIC.IMVIWIRE.HSGR_2

GAPI0 150

WIRE.HCGR_3GAPI0 150

FBSTB_DSSTB_S_1.C1_1MM150 275


WIRE.PHIX_DN_10.3 0

WIRE.CMRP_3MS_20.3 0

WIRE.AT90_22 2000

WIRE.PEFL_19 19

Large Vug

IMAGE_STATIC.IMVI

4516

DEPTHMETRES


GAPI0 150




WIRE.PHIX_DN_10.3 0


WIRE.PEFL_19 19

WIRE.AT90_22 2000

FRACTURES IN FLANK WELLSFRACTURES IN FLANK WELLS

Fractures

FRACTURES IN FLANK WELLSFRACTURES IN FLANK WELLS

IMAGE_STATIC.IMVI

4576

4577

DEPTHMETRES


GAPI0 150




WIRE.PHIX_DN_10.3 0


WIRE.AT90_22 2000

WIRE.PEFL_19 19

Fracture with whole mud invasion

TENGIZ AND KOROLEV

4576

4577

TENGIZ AND KOROLEVTENGIZ AND KOROLEV

STRATIGRAPHIC FRAMEWORKSTRATIGRAPHIC FRAMEWORK

RESERVOIR QUALITYRESERVOIR QUALITY

SUMMARY POINTSSUMMARY POINTS

•• Carboniferous Isolated Carbonate Carboniferous Isolated Carbonate Platforms with Steep FlanksPlatforms with Steep Flanks

•• Platform Growth Viewed in Sequence Platform Growth Viewed in Sequence Stratigraphic ContextStratigraphic Context

•• Reservoir Quality in Platform Controlled Reservoir Quality in Platform Controlled by Stratigraphy and Limited Diagenesisby Stratigraphy and Limited Diagenesis

•• Reservoir in Flanks Related to Fracturing Reservoir in Flanks Related to Fracturing and Diagenesisand Diagenesis

Documents

Geologic Framework for the Tengiz and Korolev Fields, Kazakhstan – Tangiz_Carboniferous Isolated Carbonate Platforms