Drill Pipe Steel Research Articles

Aluminum Pipes: A Viable Solution To Boost Drilling and Completion Technology

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper IPTC 13758, ’Aluminium Pipes - A Viable Solution To Boost Drilling and Completion Technology,’ by M.Y. Gelfgat, SPE, A.V. Vakhrushev, D.V. Basovich, SPE, and V.S. Tikhonov, Aquatic Company, and A.C. Odell, SPE, and D.J. Brunnert, SPE, Weatherford, originally prepared for the 2009 International Petroleum Technology Conference, Doha, Qatar, 7-9 December. Modern extended-reach drilling (ERD) projects become more and more challenging. Some of the recently drilled ERD wells probably came close to the limits of available drilling technology. Future targets promise to be even more distant and challenging, which is why there is a need for advanced technology that can either reduce friction in a borehole or reduce the gravity force component acting between contact surfaces. Introduction Aluminum drillpipe (ADP) has a long application history in the USSR and Russia. It has been used for drilling since the end of the 1950s. By the beginning of the 1990s, ADP was involved in drilling 70 to 80% of all oil and gas wells in the Soviet Union. At the present time, approximately 1 000 000 m of ADP is in operation in Russia. Aluminum-Alloy-Drillpipe Performance The most important feature of aluminum alloys used as materials for tubular manufacturing is that, because they are three times lighter than conventional steel alloys, they provide considerable strength properties. This gives them an exceptional strength/weight ratio (i.e., the ratio of tension yield strength of the pipe to its weight in mud). Physically, this ratio can be represented as a length of drillpipe suspended under its own weight in a vertical borehole filled with mud when the stress at the top cross section reaches yield stress of the material. Properties of four aluminum alloys are given in Table 1 in the full-length paper. Despite the fact that aluminum-alloy drillpipe has two steel tool-joint parts threaded onto the aluminum-alloy-drillpipe body, the influence of their weight on the total weight of the assembled pipe is less than 30% and the equivalent density of ADP (which is a calculated density of multimaterial product) has little difference from the density of the aluminum alloy itself. Depending on the size and length of the pipe, the equivalent density of ADP varies from 3200 to 3600 kg/m3, because the initial density of aluminum alloys equals 2800 kg/m3. Most steels are 7800 kg/m3. This means that the weight in air of the ADP is approximately half that for steel pipe. When placed in drilling mud, ADP loses a greater percent of its weight because of a better buoyancy factor. For example 5 7/8-in. steel drillpipe becomes 15% lighter when placed in 1200-kg/m3 drilling mud, whereas 5 7/8-in. ADP loses 35% of its initial weight. ADP in horizontal sections of a borehole produces drag and torque nearly half that of its steel equivalents. This feature provides the ability to extend the limits of drilling from available rigs of limited-load and -torque capacity, decrease the wear of rig equipment (e.g., topdrive, wireline, and block-and-tackle system), and decrease the overall energy consumption of the drilling process. In the extreme applications of ultraextended-reach drilling, use of ADP could extend the displacement significantly.

Determination of the resistance of drill-pipe steels to deformation

Cylindrical specimens of steels 32G2A and 25KhGMA were upset on a cam-operated plastometer within a broad range of strain, strain rate, and temperature to determine the deformation resistance of steels used to make drill pipe. The empirical relations that were obtained made it possible to qualitatively and quantitatively describe the effect of the main parameters of the hot-working operation on the strength of these steels and thus refine the mechanical and thermal regimes for upsetting the ends of drill pipes. The study results will also be used to develop processes for rolling pipes of steels 32G2A and 25KhGMA in rolling-and-heat-treatment shop No. 2 at the TAGMET plant.

Drillstring Technology for World-Class Extended-Reach Drilling

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper OTC 18512, "Drillstring Technology Vanguard for World-Class Extended-Reach Drilling," by M.J. Jellison, SPE, and R.B. Chandler, SPE, Grant Prideco; M.L. Payne, SPE, BP; and J.S. Shepard, SPE, GlobalSantaFe, prepared for the 2007 Offshore Technology Conference, Houston, 30 April-3 May. Projects that will expand the extended-reach-drilling (ERD) envelope are in the planning stage in various parts of the world. Drilling engineers no longer are wondering if 50,000-ft ERD wells can be drilled but how this can be accomplished safely and efficiently. It has been estimated that the last 10% of the drilled interval can account for 50% of the total drilling cost. The full-length paper discusses the latest drillstring technologies that are essential to achieve the ERD targets planned for the future. Advanced Material Technologies Industry publications have presented the idea of using nonsteel drillstrings for reduction of torque and drag loads in extended-reach (ER) wells. Other torque- and drag-reduction and management tools and techniques that have proved successful are lower in cost, thus being the preferred methods for meeting current ER torque and drag challenges. The competition of these alternative technologies has inhibited the development of commercially available nonsteel drillpipe. The direction toward longer-departure ER wells has led to increased consideration recently for commercially available nonsteel drillpipe. Generally, three advanced materials should be included in this consideration—carbon-fiber-based composites, titanium, and aluminum. Each has been used in drillstrings with varying degrees of success. Each material has strengths and weaknesses relating to its use for drillpipe to drill ER wells and other critical applications such as ultradeep drilling and deep water. Carbon-Fiber-Based Composites. Composite drillpipe (CDP) is manufactured by winding carbon fibers over a mandrel while applying an epoxy matrix to encase the fibers and seal the assembly. CDP manufactured to date has had steel pin-and-box tool joints similar in design to conventional steel-drillpipe connections. The steel tool joints are attached to the composite tube during the winding process in which the carbon fibers are placed over specially designed ends of the tool-joint members to bond with the composite tube and resist fatigue in service. Currently produced CDP is approximately three times the cost of conventional steel drillpipe. As the technology improves and the capabilities of carbon-fiber manufacturers advance, this price differential may decrease. CDP offers several potential advantages over conventional steel drillpipe that could make CDP particularly well suited to ERD and other critical drilling applications.

Helical Collapse of a Whirling Elastic Rod Forced to Lie on a Cylinder

Helical Collapse of a Whirling Elastic Rod Forced to Lie on a Cylinder

Extended-Reach Composite-Materials Drillpipe

Summary This paper presents a new composite drillpipe design that allows for an increase in the drilling reach of high-angle, directional wells. Horizontal reach is greatly limited by resisting friction forces that are created by the interaction between the drillstring and the lower side of the borehole. As the drillstring is advanced further into a highly directional borehole, the resisting friction forces give rise to ever-increasing applied-torque and axial (push)-force requirements. The gravitational forces (i.e., drillstring weight) dominate the buoyancy forces in nearly all modern drillstring designs that are currently used in highly directional drilling operations. These dominating gravitational forces create reaction forces between the drillpipe and the borehole wall. The reaction forces, when multiplied by the coefficient of friction between the drillstring and the borehole, yield tangential surface forces on the drillstring (normal to, and parallel with, the pipe axis). These forces resist the applied torque that rotates the drillstring and the applied axial (push) force that advances the drillstring. The new composite drillpipe design discussed in this paper reduces the specific weight of the drillpipe so that it will have nearly neutral buoyancy in 15.4-lbm/gal drilling muds. With this reduction in drillpipe specific weight, a drillstring with this new design will have greatly reduced gravitational forces and, in turn, greatly reduced resisting friction forces. This design feature allows the applied torque and axial force to be more effective, thus allowing greater extended-reach capabilities. It is estimated that the current extended horizontal-reach approximate limit of 10 km could be increased to 15 km or more with the application of this new composite drillpipe design. Such an increase in reach would have an important impact on the development of oil and gas fields that are economically dependent on advanced directional drilling technologies. This new composite drillpipe technology has been extensively bench and field tested and has been successfully used in short-radius drilling operations. The design features of the proposed light-weight composite drillpipe are discussed and compared to current horizontal drilling operational requirements (using a steel drillpipe). The new light-weight designs can be used with either steel or titanium tool joints (with a filament-wound composite-tube body structure between the tool joints). The drillpipe may be fabricated in either 30- or 42-ft lengths. Engineering feasibility studies have shown that this new light-weight composite drillpipe will be economical to fabricate and should provide significant economic advantages in the development of oil and gas fields requiring extensive directional drilling operations.

The Resonant Sonic Drilling Method: An Innovative Technology for Environmental Restoration Programs

AbstractThe resonant sonic drilling method offers unique capabilities to the environmental restoration market. By using a drill head that imparts high‐frequency, high‐force vibrations into a steel drill pipe, continuous, relatively undisturbed cores can be taken through virtually any formation. The resonant sonic method requires no mud, air, water, or other circulating medium for penetration: drills very fast; easily drills at any angle through formations such as rock, clay, sand, boulders, permafrost, or glacial till; and yields no cuttings in the drilling process. Case histories of projects using the method demonstrate excellent results but also indicate several problem areas with the method in its present state. Expanding research efforts to further develop the resonant sonic drilling method should help solve current drawbacks, and could produce a drilling technology for environmental work that significantly changes the way monitoring wells are drilled and constructed.

Degradation of Titanium Drillpipe From Corrosion and Wear

Summary Drilling deeper than 35, 000 ft is limited by the extreme hook loads of steel drillpipe and temperature constraints of aluminum drillpipe. Titanium Alloys Ti-6A1-4V and Beta C have been proposed for use in drillpipe for wells deeper than 35, 000 ft because of their high strength/weight ratios, superior high-temperature corrosion resistance, and thermal stability. Their suitability in drilling environments, however, has not been evaluated. To determine the corrosion and wear characteristics of two types of titanium-alloy drillpipe under dogleg conditions, a test cell was constructed to test titanium drillpipe joints in contact with API Spec. 5CT Grade P-110 casing in different drilling muds. Titanium-alloy pipe and Grade P-110 casing wear rates were measured, and tests showed that both titanium-alloy pipes exhibited much greater wear than did steel drillpipe in water-based mud under the same conditions. Test data showed that the total wear rate of Alloys Ti-6A1-4V and Beta C in a drilling environment is a combination of mechanical wear and corrosion.

Development of Lightweight Steel Drillpipe With a 165-ksi Yield Strength

Summary This paper describes the development of a lightweight steel drillpipe with a 165-ksi [1137-MPa] yield strength. The drill-pipe was developed according to three design objectives and verified by full-size and material-evaluation tests. The lightweight steel drillpipe has two advantages over standard API G-105 pipe with the same pipe-body OD—it weighs 25% less and has a 20% lower hydraulic loss (loss of fluid pressure)—but maintains a performance level comparable with that of G-105 pipe.

North Sea Experience With Aluminum Drillpipe

Summary Aluminum drillpipe was used to drill the first five directional wells from a North Sea platform. A comparison with steel drillpipe showed that the operational problems of using the aluminum drillpipe outweighed the benefits in the directional wells drilled. Therefore, steel drillpipe was specified for subsequent, similar platform wells.

Remotely Operated Guideposts Reduce Drilling Time and Costs

Summary Remotely operated guideposts were successfully used to establish, release, and re-establish guidelines for a template installation in 1,758 ft [536 m] ofwater in the Gulf of Mexico. The guideposts were used to reduce thedrilling-template weight, to improve accessibility of the remotely operatedvehicle (ROV) around the well slots, and to reposition the blowout preventer(BOP) stack on a new well without tripping the stack to the surface. Beforefield installation, procedures were developed and the guideposts and runningtools were function tested. Wet tests verified the reliability of the ROV andguidepost interface. This testing contributed to the successful use ofguideposts. Drilling-template costs dropped significantly. The approach helpedsave about 36 days of drilling time. The guideposts were also used to tie backthe tendons and production risers for the tension-leg well production risersfor the tension-leg well platform (TLWP). platform (TLWP). Introduction The Jolliet Project has been under development since June 1987 in 1,758 ft[536 m] of water in Green Canyon Block 184 of the Gulf of Mexico. Drillingthrough a template in this depth requires safe, cost-effective subsea-guidelineanchoring techniques. Therefore, guideposts and associated equipment weredesigned to be used with an unmanned ROV. The guideposts were used to install the template well pod and to positionthe BOP stack (Fig. 1). Because of the importance of reliable procedures andequipment, especially in a deepwater environment, contingency planning wasemphasized. This included operational testing before field use. This paper discusses objectives for guidepost use, the remotely installedguidepost, guidepost running tools, and equipment testing. It also presentsfield performance results, conclusions, and performance results, conclusions, and recommendations for future applications. Objective and Results Use of removable guideposts improved drilling-template design and optimizedprocedures. The elimination of permanent procedures. The elimination ofpermanent guideposts reduced the template weight and decreased the materialcosts because only four primary and four backup guideposts were required. Italso provided an uncluttered template work area. This increased the ROV'spossible work scope while reducing the complexity of its operations. Procedures that allowed the BOP stack to be kept on bottom for 90 days bymoving from well to well were simplified by a topaccess guidepost design. Stackrepositioning, including raising and relatching, was completed in about 9hours, which saved 1.8 days/well. With minor modifications, the guideposts were also used to optimize twoother operations (Fig. 2). When the production riser is run, special shearbolts that break with a reduced tensile load on the guidepost are used. Toassist in the installation of the tendons for the TLWP, the guidepost wasfitted with an outer sleeve that has a sheave Fig. 3). Equipment Guideposts. Skeels and Landeis described the design of the remotely operatedguidepost (Fig. 4). The post has an 8.62-in. [219-mm] -diameter outer body witha latching profile on top and a landing ring near the bottom that lands in thefunnel receptacles on the template. Two spring-loaded, outwardly biased latchdogs at the bottom of the post anchor the guidepost to the receptacle. Theguidepost has an inner sleeve and cam mechanism so that a top-access tool canretract the latch dogs and release the post. A backup release mode is providedby four shear bolts. The tensile force to shear the bolts is applied byattaching a strong wire rope to the guidepost or latching onto the guidepostwith a steel drillpipe tool. Tools. Two types of guidepost tools can be used to release a guidepost fromits funnel receptacle. Both types have a collet that slips over the latchingprofile at the top of a post. Hydraulic cylinders in the tool move a ring downover the collet to lock the tool to the post (Fig. 5). Continued movement ofthe post (Fig. 5). Continued movement of the ring depresses the guidepost innersleeve, which causes the cam mechanism in the guidepost to retract the latchdogs for release of the post from its funnel receptacle. The steel version of the tool is run on drillpipe with two hydraulic linesconnecting it to a 3,000-psi [21-MPa] hydraulic pump on the rig. TheROV-compatible version of the tool was made for this project by usinglightweight materials and adding flotation elements. The ROV positions the tooland then supplies the hydraulics to operate it. Ancillary tools, such as guideframes and remote cable anchors, allowflexibility in procedures. To re-establish a guideline, for procedures. Tore-establish a guideline, for example, the remote cable anchor can be latchedto a guidepost with the guidepost tool. Equipment Testing Guideposts and tools of this basic design were developed and tested in 1985and successfully used in 1,400 ft [427 m] of water in the Gulf of Mexico. Additional testing was needed for the Jolliet Project because of the concernfor ROV dependability and use of prototype ROV tool designs. P. 272

Usefulness of Steel or Rubber Drillpipe Protectors

Rubber or steel drillpipe protectors are lateral supports placed on drillpipe between tool joints. Everyone knows that drillpipe protectors prevent drillpipe wear. An important fact not known is that drillpipe protectors will allow permissible hole curvatures (dogleg severity) greater than usual. The additional hole curvature allowed with the protectors is a result of their ability to reduce drillpipe fatigue and wear with no increase in casing wear. Conversely, for the same drilling conditions, drillpipe protectors can significantly increase drillpipe life. Range 3 drillpipe (45 ft (13.7) long) has the advantage of faster handling because less time is spent on connections and possibly also on round trips. Because it has the disadvantage of increased drillpipe wear and fatigue, very little Range 3 drillpipe is used today. With drillpipe protectors, the advantage of Range 3 drillpipe can be retained, without this disadvantage. Greater permissible hole curvature (dogleg severity) when drillpipe protectors are used (on either Range 2 or Range 3 drillpipe) may permit carrying heavier bit weights. The result should be faster drilling and reduced drilling cost.

Endurance of welded joints in steel drill pipes

Endurance of welded joints in steel drill pipes

Inhibitive protection of steel drill pipes from corrosion fatigue

Inhibitive protection of steel drill pipes from corrosion fatigue

Cumulative Fatigue Damage of Drill Pipe in Dog-Legs

Abstract Rotating drill pipe passing through dog-legs suffers fatigue damage due to cyclic bending stresses. Curves of the cumulative fatigue damage incurred in either steel or aluminum drill pipe going through such dog-legs are presented. These curves provide means for properly planning the rate of angle build-up in directionally drilled wells and allow discarding of drill pipe which has been fatigue-damaged in dog-legs. Introduction Drill pipe which is subjected to bending as it rotates, experiences a cyclically varying bending stress. If this bending stress is sufficiently large, the drill pipe is fatigue-damaged by each revolution, and ages as fatigue damage accumulates. Drill pipe can be bent intentionally, as in the case of directionally drilled holes, or unintentionally due to undesired changes in hole direction caused by variations in formation properties, weight on bit, etc. These changes in hole direction, whether intentional or unintentional, are called dog-legs. The theoretical limits of dog-legs which are permissible before the drill pipe begins to fatigue can be calculated. However, in wells where the maximum permissible dog-leg is exceeded, the concept of cumulative fatigue damage can be used to estimate damage suffered by the drill pipe. This concept has already been used to estimate the cumulative fatigue damage of drill pipe due to drilling vessel roll. The purpose of this paper is to extend the usage of the cumulative fatigue damage concept to drill pipe in dog-legs, and to draw conclusions which may be beneficial in preventing numerous frustrating and expensive drill pipe failures. FATIGUE OF STEEL DRILL PIPE IN IDEALIZED GRADUAL AND LONG DOG-LEGS It is taken for granted that, if necessary, the reader will become familiar with the definitions and concepts which follow by examining the reference cited in each case. For Ref. 1, it will suffice to read only through the section Abrupt Dog-Legs.Concept of the two extreme kinds of idealized dog-legs: gradual and long dog-legs and abrupt dog-legs,Concept of why the bending moment in drill pipe under tension is the largest in the vicinity of the tool joint,Concept of why dog-leg severity which drill pipe can withstand decreases with an increase in tension, andDefinition of the rate of change of over-all hole angle (dog-leg severity). Figs. 1 and 2 indicate the aging (fraction of life expended) of steel drill pipe passing through a gradual and long dog-leg. Both figures have a left-hand ordinate scale labled Length of Drill Pipe Below Dog-Legs. This scale can be used for cases in which the drill collar weight is applied to the bit and does not contribute to the tension in the drill pipe. It can be used for either 3 1/2-, 4 1/2- or 5-in. drill pipe. This is due to the fact that, if the drill collars do not contribute to the drill pipe tension, then the effect of pipe tension on bending due to a change in pipe size is nearly compensated for by a corresponding change in pipe rigidity. On the other hand, if drill pipe is rotated off bottom, then drill collars contribute to the tension in the drill pipe and this increase in tension is not compensated for. In this case, one of the three right-hand ordinates must be used (the one which corresponds to the correct drill pipe size). In the right-hand ordinates, tension should be understood as the weight in mud of the portion of the drilling string below the dog-leg, minus the weight on bit. JPT P. 359ˆ

The Design and Performance Characteristics of Aluminum Drill Pipe

Abstract This paper outlines the approach and solutions to the problems associated with the design and development of aluminum as a drill stem for rotary drilling. A current field history on aluminum as a drilling tool is included to assist the reader in judging the selection of engineering compromises in the light of present field performance and to acquaint the reader with the present status of aluminum drill stem in the drilling art. Following proof of satisfactory operation of the first aluminum drill string, 25 more strings (see Table 1) have gone into worldwide operational use. A study of their performance indicates:no operational disadvantages,compatibility with present drilling muds,mixed-string operations are successful,hand and power slips are operational,no failures in the tool-joint area,no problems in fishing or other special uses,normal wear on pipe body comparable to steel andless than normal wear on tool joints. These facts about the present operational status of aluminum drill pipe demonstrate that successful drilling tools can be designed and constructed of aluminum. Field and laboratory studies are continuing in order to improve and expand the use of aluminum for drill pipe. Introduction To make functional drill pipe from aluminum required more than a casual selection of engineering compromises. The target was a drilling tool that would substantially meet the physical characteristics of Grade E steel drill pipe but, if possible, also incorporate the many desirable characteristics found in low-alloy steel drill pipe (Grade D) such as toughness, concentric wear and low embrittlement rate. It was recognized early in the aluminum drill pipe program that aluminum alloys could not be best utilized in a design that copied the then available steel drill pipe. It was necessary to balance the design, alloy choice, strength, corrosion and wear resistance of aluminum alloys into a workable tool, one capable of sustaining the stresses of rotary drilling. The application of steel tool joints to aluminum pipe posed many problems in order to achieve a satisfactory transfer of stresses and a satisfactory fatigue life. This and other design and performance considerations are dealt with in this report. After the development of a satisfactory aluminum drill pipe it was necessary to demonstrate the economic advantage of this tool. This too has been accomplished and data are available to show the competitive position of aluminum drill pipe. Acceptance of aluminum drill pipe is attested to by demonstrated success and by re-orders by present users. Five users have purchased their second strings of aluminum drill pipe. One user has purchased his fourth string. Statement of Theory If aluminum could be successfully fabricated into dependable drill stem, the advantages of this light material should reduce drilling costs. A few of the readily apparent areas of improved economy are:rig investment,transportation,wireline life,hoisting fuel savings andhoisting time reduction. TABLE 1-REYNOLDS DRILL STRINGS-JULY 1, 1963 Length Footage No. Avg.(ft) Drilled Wells Depth Location 4/2-in. Pipe 1. 10,400 148,361 15 9,890 Central Texas, Calif. 2. 5,250 106,280 23 4,620 Kansas 3. 1,020 101,945 16 6,350 Okla. 4. 7,500 6,563 1 6,563 Chile 5. 11,010 38,254 4 9,550 N.E. Texas 6. 11,010 68,000 8 8,500 N.E. Texas 7. 5,010 36,176 8 4,500 Alberta, Canada 8. 5,010 56,583 12 4,650 Alberta, Canada 9. 14,520 19,600 1 1/2 13,200 N.E. Texas, Calif. 10. 4,000 * * * 11. 11,520 77,000 9 8,550 N.E. Texas 12. 12,000 61,634 5 12,300 La., Miss. 13. 1,050 39,013 10 3,900 Oklahoma 14. 12,510 11,355 1 11,355 Libya 15. 5,010 15,000 6 * Mont. 16. 4.020 9,670 1 * Utah 17. 5,010 e * * Calif. 18. 7,020 4,558 1 * Colo. 19. 4,740 57,351 12 7,790 N. Okla. 20. 8,520 25,190 2 1/2 10,080 N.E. Texas 4.in. Pipe 21. 11,520 113,427 19 5,950 Miss.3 1/2in. Pipe 22. 7,030 201,372 33 6,100 La., Miss.. Tex, 23. 7,500 9,000 * Saudi Arabia 24. 6,000 5,800 * Alaska 25. 10,020 * * * Calif. 26. 2,520 * * * Utah JPT P. 1285^