DEEP SEA DRILLING PROJECTTECHNICAL REPORT No. 4
DRILL STRINGDrill PipeBumper SubsDrill CollarsCoring Equipment
CONTRACT NSF C-482
THE REGENTS,UNIVERSITY OF CALIFORNIA
SCRIPPS INSTITUTION OF OCEANOGRAPHYUniversity of California at San Diego
DRILL S T R I N G
Drill PipeBumper SubsDrill Collars
National Science FoundationUnder Provisions of Contract NSF C-482
Deep Sea Drilling ProjectScripps Institution of Oceanography
University of California at San Diego
W.A. Nierenberg, Director M.N.A . PetersonScripps Institution of Oceanography Scripps Institution of OceanographyCo-Principal Investigator Co-Principal Investigator
Many new and complicated technical systems had to coalesce on D/V Glomar Challengerto enable the Deep Sea Drilling Project to enjoy the continuous success it has recordedtodate.
Dynamic positioning worked beyond fondest expectations and the problem of re-entry wasovercome with little difficulty, but without a good, tough drill string - some of which isstill in service after more than three years of drilling and coring in a hostile environmentthere would be no Deep Sea Drilling Project.
Included in this Technical Report are extensive discussions on drill pipe, bumper subs,drill collars and coring equipment.
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Glomar Challenger drilling crewrigs hydraulically operated powersub, center, preparatory tocommencing drilling operationsat a deep water drilling site inthe Gulf of Mexico during thefirst leg of the Deep Sea DrillingProject. At right is the drawworksand, on opposite side of derrickfloor is the specially designedcore line reel used in the retrievingof the core barrel. Beyond derrickfloor is Global Marine designedautomatic drill pipe racker whichholds 24,000 feet of 5-inch drillpipe. View, looking forward, wastaken from wheel house of vessel.
While on station, the drill string is suspended from D/V Glomar Challenger with nolateral support between the keel and the ocean floor. Drilling and coring are accom-plished by turning the string at the top with a power sub. The heave, roll and pitchof the drilling vessel add additional stresses.
Since drilling and coring are done without using a riser system for drilling mud returns,raw sea water is normally used, further increasing the stress on the pipe.
Corrosion inhibitors are used, but the automatic pipe racks are above deck, exposing thepipe to a moist marine environment while in storage.
Sites have been cored with surface observed currents of four knots. Subsurface currentsare not measured. Even with these hazards, drill string losses todate have been causedprimarily by operational problems.
Global Marine Inc. designed the drill string to be part of their answer to the ProjectsRequest for Proposal. This design, with minor modifications, was the one taken tosea. As operational problems arose, the Deep Sea Drilling Project and Global MarineInc. mutually agreed on modifications.
The initial Program Plan attempted to schedule D/V Glomar Challenger to drilling sitesduring the most favorable weather conditions and to stay within the 30 degree parallels.As drilling crews gained confidence, sites were successfully worked in the North Atlanticand the North Pacific. A further three-year extension would take the Challenger intothe Arctic and Antarctic Oceans.
With this increased confidence in the drill string and an upgraded program for the dynamicpositioning system, it would be possible to drill in water depths less than 3,000 feet. Thiscapability would open vast new areas of scientific interest.
Scripps Institution of Oceanography, of the University of California at San Diego, ismanaging institution for the Deep Sea Drilling Project. The Project is funded by theNational Science Foundation, an agency of the United States Federal Government andis a part of the Foundation^ National Ocean Sediment Coring Program.
Actual drilling is being done by Global Marine Inc. , of Los Angeles, California, undercontract to Scripps Institution of Oceanography.
Advice regarding scientific planning for the Deep Sea Drilling Project is being providedby panels whose members are broadly representative of the nation's scientific communitydrawn from many Universities, Government Agencies, and industrial organizations.
The Joint Oceanographic Institutions for Deep Earth Sampling (JOIDES), consisting ofLamont-Doherty Geological Observatory of Columbia University, Woods Hole Oceano-graphic Institution, The Rosenstiel School of Marine and Atmospheric Sciences, of theUniversity of Miami (Florida), The University of Washington (Seattle), and ScrippsInstitution of Oceanography, assisted in the formulation of plans for the Project. JOIDESpanels still give scientific advice and guidance to the Deep Sea Drilling Project.
Many individuals from the petroleum industry have also furnished technical advice andassistance to the Project.
The Deep Sea Drilling Project gratefully acknowledges the contributions of manycompanies and individuals to the successful adaptation to drilling in the deep oceansof the various drill string components - drill pipe, bumper subs, drill collars andcoring equipment - which have so far been responsible for recovering more than 10miles of priceless sedimentary core material from beneath the deep ocean floor after21 expeditions of the Project.
Our thanks go to:
Mr. Jack Reed and Dr. Thad Vreeland, of Global Marine Inc. , for design and analysisof the drill string configuration;
Mr. Alex Maradudin (deceased), formerly with Standard Oil Company of California,for review and supervision of manufacture of the drill pipe;
Dr. Arthur Lubinski, of Pan-American Petroleum Corporation^ Research Division,for review of the proposed drill string configuration;
The Petroleum Industry Technical Assistance Panel for its valuable advice;
DRILCO for review of proposed drill collar tool joint change;
Hycalog, Inc. for the design and expediting of basic coring equipment and the trainingof Project personnel;
Christian Diamond Products Company for design of alternate coring methods and counselfor appropriate Project personnel;
Project Engineer Darrell L. Sims for engineering management.
We acknowledge the continuing help of Mr. A. R. McLerran, National ScienceFoundation Field Project Officer with the Deep Sea Drilling Project and the supportof the National Science Foundation.
The support and guidance of the Joint Oceanographic Institutions for Deep EarthSampling (JOIDES) in fostering the Deep Sea Drilling Project is fully acknowledged.
M. N. A. PetersonCo-Principl InvestigatorDeep Sea Drilling Project
Appendix Number 1
Bumper Sub Recommended Inspection and Service
Appendix Number 2
Charpy Impact Curves
Dril l ing, Coring and Core Recovery Through Leg 18
Drill String Loss Through Leg 18
Drilling Status Through Leg 21
Metal Corrosion in Saline Waters
Evaluation of Methods to Alleviate Corrosion Fatigue in Type135 Drill-Pipe Steel for Offshore-Drilling Applications
Mechanics of Long Drill Strings 80
Hydrogen Movement in Steel-Entry, Diffusion, and Elimination 156
Sample Examination, Hillman-Kelley, Global Marine, Inc. 2485" O . D . x 19.50# Special BR-135 Drill Pipe
Study of Hydrogen-Stress Cracking of Deep Sea Drilling Project 253S-135 Drill Pipe if Exposed to Black Sea Water
Stress-Corrosion Cracking and Hydrogen-Stress Cracking of 263High-Strength Steel
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The statement of work in the Request For Proposal for Deep Sea Drilling Project drill pipewas quite short - "Two 23,000-foot drill strings, one working and one spare should beaboard, with all necessary collars, bits, core barrels and accessory items. " Steel, non-ferrous or combination strings were considered. A 2 l/2-inch core encased in a plasticliner was requested. The proposal was to give the type, grade, diameter, weight perfoot and length of stands, and to include an analysis of this design based on relevantoperating conditions.
Global Marine Inc. , selected to be the subcontractor, proposed 5-inch outside diameter,19.6 Ib. per foot grad S-135 external upset steel pipe fitted with modified 5 1/2-inchfull hole flash-weld, 18-degree taper tool joints. A detailed analysis of this string con-ducted by Dr. Thad Vreeland, of Pasadena, California, for Global Marine Inc. concludedthis string would give excellent life up to and including the design depth of 22,500 feettotal drill string length.
The Deep Sea Drilling Project enlisted the assistance of major oil companies to review theproposal. The then Technical Assistance Panel, composed of representatives from majoroil companies, agreed that the proposal was acceptable. Dr. Arthur Lubinski and hisgroup at Pan-American Petroleum Corporation Research Division in Tulsa, Oklahoma,reviewed Dr. Vreeland's mathematical model and advised they were in agreement.
Global Marine Inc. was so advised and placed their order. The pipe was rolled byJones and Laughlan Steel Company, of Pittsburgh, Pennsylvania, and the tool jointsmade and installed by Hughes Tool Company, of Houston, Texas.
The services of Mr. Alex Maradudin (now deceased) were obtained by the Project toreview the Purchase Order for mill and test procedures. Mr. Maradudin, a retiredmetallurgist from Standard Oi l Company of California's Research Laboratory, La Habra,California, and an expert in oil field tubular goods, advised that the Purchase Orderwas technically acceptable.
To insure the minimum of manufacturing defects, Mr. Maradudin was retained by GlobalMarine Inc. to supervise the manufacture and inspection of the S-135 drill pipe.
The drill pipe was cleaned and sandblasted after the tool joints were attached and givenfinal sonoscope and end area inspection. The outside was coated with a zinc-rich organiccoating and the inside coated with corrosion preventative o i l .
The drill pipe was not plactic-coated on the inside. The Project and Technical AssistancePanel felt the coating could become brittle at the low temperatures of the deep oceanand that extensive coring would scar and peel the coating.
The external coating definitely has retarded corrosion. External corrosion was firstnoticed on Leg 12, or two years after the pipe was placed in service.
External corrosion of 5-inchdrill pipe at least two yearsafter being placed in service.
On the first few runs in deep water, the external coating seemed to form blisters. Whenthe pipe was pulled up in shallower water, these blisters would flake off, making enoughacoustical noise to confuse the positioning system.
Blisters in external coating apparentlycaused by water at depth being trapped.
Hydruliclly installed rubber drill pipe protectors were installed at 5-foot intervalsalong the single 30-foot stands of pipe. This was done to reduce resonant motion, toprotect the drill string during automatic pipe-racking operation, and to provide colorcoding of the protector rings as a reference system for identification of individuallengths. Although this color code would have made it possible to establish stress expo-sure of the pipe, it was operationally impossible to establish and follow such a program.As the Deep Sea Drilling Project progressed, stress fatigue did not appear as a problem,so interest in such a program diminished.
Color coded drill pipe protectorsat 5 foot intervals on the drill string.
Mechanical pipe racker used tostore the drill string.
Thread protectors were installed and the pipe transported to Orange, Texas, where itwas loaded aboard D/V Glomar Challenger after builder's trials. When placed in theautomatic pipe racker, each joint of the pipe was made up and broken down severaltimes with a high zinc-content thread lube to prevent galling.
The drill pipe is run into and pulled out of the hole with an IDECO Dual Elevator system.One elevator is used to pull the pipe in the conventional manner. The second set re-places the drill pipe slips and supports the pipe on the rotary table. As the drill pipe islaid down in the pipe racker, the No. 1 elevator has been lowered back to the drill floor.This elevator is set to one side and the links that attach the elevators to the travelingblock are removed and hooked onto the No. 2 elevator. This elevator now becomes theNo. 1 elevator and the string is lifted and set off on the remaining elevator, thus theelevators are leap-frogged while pulling or running the pipe.
This system eliminates marking and necking the pipe with slips. As S-135 is notch sensitive,eliminating slip marks undoubtedly has extended the drill pipe life.
The introduction of re-entry to the Program Plan also introduced several problems involv-ing the dri l l pipe. The actual use factor of re-entry was an unknown, but if re-entry wasto be used frequently, it would be operationally desirable to run the cones and basesthrough the moon pool. This would require either removing or modifying the dril l pipesupporting epotential horn. As re-entry was specifically eliminated from the originalRequest For Proposal, and casing was the only other tubular goods to be run through thehorn, the opening at the top of the fixed horn was 30 inches. In addition, the Projecthad received requests to dri l l sites that required a dril l string longer than 22,500 feet.
A subcontract was entered into with the Southwest Research Institute to determine thefeasibility of these questions. Their report indicated dri l l pipe support, such as given bythe epotential horn, is necessary. The present horn is structurally over designed andcould be a lighter removable structure. The "piccalo" or scabbard-type support couldbe shortened from 80 to 50 feet and given necessary support to the dri l l pipe. The report,in addition to supporting Dr. Vreland's work, extended computed estimates of dri l l pipelife for a 30,000 foot string. The computer program for this report is available if modi-fication or review of the dri l l pipe is required.
The Request For Proposal included pipe inspection at frequent intervals as a requirement,but did not specify the type of inspection. Global Marine Inc. officials stated in theirreply they would furnish magnetic particle and Magna Glo ultra violet inspection fortool joints and heavy sections. A sonic (assumed to be Sonoscope, trade name ofTuboscope's electromagnetic inspection equipment) pipe inspection unit would be usedto inspe...