Abstract: Expandable tubing and methods seal a connection between expandable tubulars, and in particular, seal a connection between expandable tubulars post-expansion. In one embodiment, a method includes sealing a connection between expandable tubulars in the form of sections of an expandable liner. The method comprises the steps of connecting a first expandable tubular in the form of a first section of the liner and a second expandable tubular in the form of a second section of the liner. A seal is located between radially overlapping portions of the liner sections, and the seal is configured to maintain sealing between the liner sections both pre and post expansion.

Abstract: An electrical isolation connector subassembly for interconnecting adjacent tubular drill rods of a drilling system used in drilling bore holes in earth formations, the connector comprising an electrically insulative sleeve being sandwiched between two electrically isolated subassembly components, the sleeve providing an exterior gap between the edges of the spaced apart electrically isolated components, the exterior gap having a width of less than 50 cm.

Abstract: The liner assembly (10) is for use in a joint between two pipe segments. The assembly (10) includes a first ring member (50), a second ring member (60) and a corrosion barrier ring (70). The first ring member (50) is configured to cooperate with a first liner (30) inserted in a first pipe segment (12). The second ring member (60) is configured to cooperate with a second liner (34) inserted in a second pipe segment (14) to be joined to the first pipe segment (12). The corrosion barrier ring (70 is disposed between and cooperates with the first ring member (50) and second ring member (60). The corrosion barrier ring (70) includes opposing indented ends (72) cooperating with the second ends (54, 64) of the first and second ring members (50, 60). The second ends (54, 64) of the first and second ring members (50, 60) define corresponding registering shapes to cooperate with the opposing indented ends (72) of the corrosion barrier ring (70).

Abstract: A threaded joint for steel pipes comprising a pin 1 and a box 2 each having a contact surface comprising a threaded portion 3 or 4 and an unthreaded metal contact portion 8 is provided with improved anti-galling propertied by forming a lubricating coating on the contact surface of at least one of the pin and the box, the lubricating coating exhibiting a self-repairing function by liquid lubrication and having a decreased greasiness. The lubricating coating is (1) a coating which comprises a lower lubricant layer which is in liquid form in the temperature range of above 0° C. and below 40° C. and an upper lubricant layer which is in solid form at 40° C., or (2) a coating which is semi-solid or solid at 40° C. and is formed of a mixture comprising a lubricating oil which is in liquid form in the temperature range of above 0° C. and below 40° C. and a wax which is in solid form at 40° C., the mixture preferably having been heated so as to liquefy the wax and dissolve in each other the wax and lubricant oil.

Abstract: An electrical isolation connector subassembly for interconnecting adjacent tubular drill rods of a drilling system used in drilling bore holes in earth formations, the connector comprising an electrically insulative sleeve being sandwiched between two electrically isolated subassembly components, the sleeve providing an exterior gap between the edges of the spaced apart electrically isolated components, the exterior gap having a width of less than 50 cm.

Abstract: A tubular coupling system and method; the system and method in at least certain aspects, using a coupling member with an interior protective ring that has at least one inner energizing member which, upon compression, forces the body of the coupling member against an interior wall of the coupling thereby inhibiting corrosive material from contacting the coupling's interior wall or, in the event some corrosive material does enter this area, holding the interior protective ring against the coupling's interior wall so that the corrosive material remains in and does not exit this area, thus inhibiting or preventing a continuous flow of corrosive material.

Abstract: A modified API Buttress threaded casing connection is disclosed for use in drilling oil and gas wells in lieu of using conventional drill pipe. The coupling threads only are multiple tapered yet can be mated with standard API Buttress pin threads having a single taper. The coupling is also shortened to permit abutment of the mating pins at the center of the coupling and can be further enhanced with an integral, sacrificial wear sleeve on one end of the coupling.

Abstract: The invention is directed to a connection structure that can minimize the formation of cracks of a connector or leakage of liquid. In the structure, a female thread (34) formed on the inner peripheral surface of lock ring (28) in a male connector (22) engages a male thread (25) on the outer peripheral surface of a female connector (21) when the male connector and the female connector are screwed to each other. Further, protrusion strips (26a), (26b) are formed on the rear side portion of the male thread on the outer peripheral surface of female connector, and notches (35a), (35b) that can engage with said protrusion strips are set on the tip portion of lock ring (28). As a result, when the male thread and the female thread are screwed to each other, the screwed state is appropriate when protrusion strips and notches are engaged with each other.

Abstract: A threaded connection between adjacent tubular members includes a pin member providing an external wedge thread and a box member providing an internal wedge thread, wherein the internal wedge thread corresponds with the external wedge thread. Further, the threaded connection includes at least one interruption along a helical thread length of one of the external wedge thread and the internal wedge thread and at least two regions along an axial length of the threaded connection where the external wedge thread and the internal wedge thread form a thread seal.

Abstract: A bore seal for connecting and sealing oil and gas tubular members is disclosed which has a metal core manufactured from a high yield strength ferrous material and a protective overlay of corrosion and abrasion resistant stainless steel and/or nickel based alloy. The protective overlay is applied to the entire outer surface of the bore seal by a metal thermal spray process, such as plasma thermal spraying. In a preferred embodiment of the invention, the bore seal has a fishtail profile which facilitates the use of resilient seals to provide resistance to external pressures in addition to the traditional metal-to-metal seal between the bore seal and the tubular members. In an alternative embodiment, a pressure relief valve is disposed within the bore seal to verify the integrity of the metal-to-metal seal with respect to internal bore pressure.

Abstract: A premium threaded tubular connection including, on at least one threaded element, a distal abutment surface at the free end of a threaded element, and a lip sealing surface at a given distance from the threading. The lip includes an appendix that extends the lip towards its free end beyond the lip sealing surface so that the lip has both high radial stiffness and low axial stiffness. This results in enhanced performance as regards the seal of the threaded connection under pressure and/or under tension, and other advantages of precision of real makeup torque, mechanical strength in axial compression, a shock barrier effect, and tolerance in engaging the threaded elements.

Abstract: The present invention is generally directed to shoulder refacing indicator. In one illustrative embodiment, the shoulder refacing indicator includes a body having a first side and a second side, the first and second sides being formed at an included angle of 135 degrees relative to one another, the first side adapted to engage an engaging surface of a make-up shoulder of a pipe connector and the second side adapted to engage a tapered surface of the pipe connector. The shoulder refacing indicator further includes at least one scribe line formed on the body.

Abstract: A pipeline (20) that lies primarily in the sea and that consists of multiple steel pipe sections connected in tandem at pipe joints, includes a protective coating around the pipe sections and around the pipe joints. Each pipe section is first covered, at an onshore facility, by an initial coating (30, 32) that extends along at least 80% of the pipe section length while leaving its ends uncovered, to leave gripping areas (40, 42) where the steel of the pipe is uncovered so the pipe can be clamped by tools such as those with steel jaws to position and slide it axially, or turn it, or prevent it from turning. After a pair of pipe sections are connected, a completion coating (50) is applied around the pipe joint to leave the pipeline with a coating around all of it.

Abstract: A submersible pump drop pipe and casing assembly and method of manufacture is disclosed. The drop pipe/casing has a seated connector and base. The seated connector has a first and second cylinder section, the first cylinder section being used to align and direct the base into the seated connector and to provide lateral strength to the pipe.

Abstract: A threaded tube joint for oil extraction industry has a trapezoidal thread and a toroidal sealing surface (11) placed at its end near the thread and engages, for sealing, a corresponding frusto-conical sealing surface (12) wherein the toroidal sealing surface (11) has a radius Rs value comprised within the range given by the formula E 2 ? Vo ? ( b 2.15 ) 2 ? Rs ? ? · E 2 ? tn n 3 ? OD 2 240 ? ? ? · ? ad 2 ? wt 2 ? ( 1 - ? 2 ) ? [ 3 ? ( 1 - ? 2 ) R n 2 ? tn 2 ] 3 / 4 .

Abstract: A threaded connection includes a continuous pin thread including at least a first step, a mid-step, and a second step formed sequentially thereon. A continuous box thread includes at least a first step, a mid-step, and a second step formed sequentially thereon, wherein the steps on the box thread correspond generally in axial position with the steps on the pin thread. The first step has a first wedge ratio, the mid-step has a transition wedge ratio, and the second step has a second wedge ratio, wherein thread leads are substantially constant within each of the steps. The connection is designed such that at make-up of a pin member with a box member, a clearance exists between at least one of corresponding load flanks and corresponding stab flanks on at least one of the first step, the mid-step, and the second step.

Abstract: A tubing connection arrangement and a method used for coupling expandable tubing sections together. In one embodiment, there is disclosed a tubing connection arrangement comprising a first expandable tubing section defining a male portion; a second expandable tubing section defining a female portion, the first and second expandable tubing sections being engageable with one another; one of the first and second expandable tubing sections including a restraining member for restraining part of the other expandable tubing section; and the first expandable tubing section including a tapered shoulder for co-operating with a corresponding tapered shoulder of the second expandable tubing section.

Abstract: A method of joining two pipe ends, by forming male threads on an end of a first pipe with a steep taper angle, forming matching female threads on an end of a second pipe, and applying adhesive material to the threads before twisting the pipes to fully engage the male and female threads, thereby spreading the adhesive material across adjacent load-bearing surfaces of the threads. The threads have multiple start locations for thread engagement so that the pipe ends may be twisted to achieve full engagement in less than one full relative rotation. The male and female threads are formed with a squeeze angle between matching surfaces of the threads between 0.5 and 5.0 degrees. The finished joint provides immediate leak-tightness, and immediate tensile, compressive and torsional strength and does not protrude outside of the pipe profile.

Abstract: A double shoulder drill stem connection for high torque applications includes a thread taper within a range between about 1.0 and 1.2 inch per foot. The thread form is characterized by a stab angle between about 35 and 42 and a load angle between about 25 and 34 degrees and by a short thread height with elliptical roots and with crests having an angle which slopes in an opposite direction with respect to the joint centerline from the thread taper. A drill string includes a tool joint having different inner diameters for a substantial axial length to provide enhanced strength in the threaded portion of the joint.

Abstract: A tubular assembly 10 is disclosed for passing fluids within a hydrocarbon recovery well. The tubular assembly 10 has an insulated connection 12 between insulated tubing segments 14, 16. Tubing segments 14, 16 are connected via a threaded connection, and the resulting joint 10 is insulated by an external insulating sleeve 18. The insulating sleeve 18 may have unitary construction, such that the sleeve 18 may only be installed or removed by first breaking apart the joint 10. Alternatively, the sleeve 18 may comprise a plurality of arcuate partial-sleeves, which may be assembled about or removed from the completed joint 10 without first breaking apart the joint 10.

Abstract: A drill string comprises a first drill string member having a male end; and a second drill string member having a female end configured to be joined to the male end of the first drill string member, the male end having a threaded portion including generally square threads, the male end having a non-threaded extension portion coaxial with the threaded portion, and the male end further having a bearing surface, the female end having a female threaded portion having corresponding female threads, the female end having a non-threaded extension portion coaxial with the female threaded portion, and the female end having a bearing surface. Installation methods, including methods of installing instrumented probes are also provided.

Abstract: A connector for oilfield applications has high resistance against cyclical bending stress and fatigue failure. In a preferred embodiment, the threaded connector has a pin-box arrangement for joining two components. The pin and box have threads with a pre-determined profile different from that specified by conventional (e.g., API) specification and provide improved strength characteristics. Certain embodiments of the present invention include a pitch-to-root radius ratio that is less than that specified by the API, a thread height-to-root radius ratio that is less than that specified by the API, a flank angle that is less than that specified by the API, and a taper that is less than that specified by the API for said pre-determined outside diameter. Certain other embodiments have less than all of these ratios and dimensions.

Abstract: A method and apparatus for providing an expandable threaded connection between segments of expandable tubulars. Threaded connections are machined into pre-expanded ends of tubulars. Once the threaded connections are machined into the pre-expanded ends, two joints of tubulars are connected using the threads, thus creating a pre-expanded threaded connection. After a tubular string is made up and lowered into a wellbore, the entire length of the string is expanded using known methods for expanding tubulars. During the downhole expansion operation, the pre-expanded threaded connections experience minimal expansion. The minimal downhole expansion of the pre-expanded threaded connections allows the threaded connections to maintain their sealing ability and coupling strength.

Abstract: A composite lined tube is disclosed having end couplings. The tube includes a resin impregnated fiber preform pressed progressively along an inner wall of the tube. The tube may further include an inflatable bladder inserted into the tube. The bladder is adapted to inflate along a length thereof on application of increasing pressure to the interior of the bladder. The bladder has disposed on its exterior surface the fiber preform impregnated with resin, which is adapted to fit within the tube. The bladder is then inflated along its length by applying increasing pressure to the bladder. The preform is clamped to a shoulder of one of the couplings at another end of the tube, and the end of the preform is trimmed to conform to the shoulder. Pressure is maintained in the bladder while curing the resin.

Abstract: Improved sucker rod joints for down hole petroleum pumping applications are provided within the form factor of standard API sucker rods, such that existing inventory in suitable condition is fully usable in more demanding applications. The pin ends are selected or processed such as to provide preselected axial distance between a flat pin end and at least one reference surface, such as a threaded region or reference shoulder or both. The coupler is dimensioned such that the pin ends are in abutment either with each other or with opposite sides of an intervening torque washer in the central region, when the connection is made to a selected level of thread engagement. Furthermore, the engagement is such as to put the pin ends in compression and the coextensive length of coupler in tension. This increases frictional restraints and locks the elements together to resist fatigue failure upon cycling and to insure together with an anaerobic adhesive sealant, against back threading.

Abstract: The present invention includes a downhole component adapted for transmitting downhole data. The downhole component includes a threaded end on a downhole component. The threaded end furthermore includes an interior region, and exterior region, and a mating surface wherein a cavity is formed. A data transmission element is disposed in the cavity and displaces a volume of the cavity. At least one passageway is formed in the threaded region between interior and exterior regions. The passageway is in fluid communication with both the interior and exterior regions and thereby relieves pressure build up of thread lubricant upon tool joint make up.

Abstract: Connectors and connections that enhance mechanical and sealing engagement between the ends of tubular bodies that are radially expanded by a forging tool. The connectors are designed to maintain or restore mechanical and sealing engagement following expansion. The connections are made by joining components that exhibit different spring back characteristics following mechanical deformation. Dissimilar material may be used for the connectors or the connected components can be made of the same materials but dimensioned and configured to exert an interfering force between engaged components following expansion. In operation, a material or component with a high spring back characteristic is positioned adjacent a material or component having a lower spring back characteristic. Following passage of a forging tool, the expanded components spring back differently toward their original unexpanded dimensions to produce the enhanced seal or mechanical engagement.

Abstract: In a protector for protecting a trapezoidal female thread of a pipe formed to an end thereof, the protector has a male thread formed thereto so as to be threaded with the female thread as well as the height of the thread of the male thread is made larger than the height of the thread of the female thread. With this arrangement, a surface treatment applied to the surface of the female thread or a male thread formed to the end of the pipe can be prevented from being damaged, and in particular, a surface treatment applied to a guide flank surface, a load flank surface, a corner portion, and the like of the thread can be prevented from being subjected to wear, damage, and the like.

Abstract: A robust transmission element for transmitting information between downhole tools, such as sections of drill pipe, in the presence of hostile environmental conditions, such as heat, dirt, rocks, mud, fluids, lubricants, and the like. The transmission element maintains reliable connectivity between transmission elements, thereby providing an uninterrupted flow of information between drill string components. A transmission element is mounted within a recess proximate a mating surface of a downhole drilling component, such as a section of drill pipe. The transmission element may include an annular housing forming a trough, an electrical conductor disposed within the trough, and an MCEI material disposed between the annular housing and the electrical conductor.

Abstract: At least a first expandable tubular and a second expandable tubular are connected to each other by a connector system. The connector system is expandable and utilizes a plurality of extensions that may be used to create an interlocking engagement. The system design enables both the tubulars and the connector system to be expanded to an increased diameter.

Abstract: An electrical isolation connector subassembly for interconnecting adjacent tubular drill rods of a drilling system used in drilling bore holes in earth formations, the connector comprising an electrically insulative sleeve being sandwiched between two electrically isolated subassembly components, the sleeve providing an exterior gap between the edges of the spaced apart electrically isolated components, the exterior gap having a width of less than 50 cm.

Abstract: A wellbore expandable connection, which includes a tubular pin member having an outwardly facing tapered threaded section and a tubular box member having an inwardly facing tapered threaded section. The threaded sections form a connection of a predetermined integrity when the tubular pin member is mated with the tubular box member. The integrity of the connection is substantially maintained during radial expansion of the connection.

Abstract: A strengthened pipe fitting has an internally threaded surface and a compression band. The compression band is sized to compress the internally threaded surface sufficiently so that the pipe fitting is subjected to a compressive preload. The compression band is covered with a non-corrosive material.

Abstract: An expandable tubular coupling comprises a threaded male portion and a corresponding threaded female portion, wherein the thread portions feature thread profiles configured such that the coupling may be made up to a predetermined extent, and once made up to the predetermined extent be made up no further. In a disclosed embodiment the thread profiles are a combination of a square thread profile and dovetail thread profile.

Abstract: A flush-type integral threaded joint with truncated-cone threads, with two scaling surfaces 11?, 12?, 11?, 12?) set at the end of the threaded portions (7, 8), and with two annular scaling shoulders (5?, 6?, 5?, 6?). The two threaded portions (7, 8) of the male element (1) and female element (2), respectively, have the same value of conicity, and the two sealing surfaces (11?, 12?, 11?, 12?) are, in one case, conical or cylindrical, and in the other spherical. The threaded portion of each male and female element may have an end area with a thread that is not perfect.

Abstract: A threaded pipe connection includes a box member, a pin member and a wear indicator for the connection. The pin member has internal threads and the box member has external threads. The internal threads of the box member each increase in width in one direction, while the external threads of the pin member increase in width in the other direction so that the complementary internal and external threads move into engagement upon make-up of the connection.

Abstract: A threaded pin and box connection having thread geometries and/or dissimilar thread fits that prevent the pin thread of a connection from hanging up in the box thread as the pin is being stabbed into or destabbed from the box. Dissimilar geometries and/or threads include dissimilar thread types, dissimilar leads, overlapping leads, thread tooth widths of one component greater than thread grooves of the other component, multiple start threads, and combinations thereof.

Abstract: A connector arrangement used for connecting a first tubular to a second tubular. The first tubular member has at least one circumferential ring profile, and the second tubular member has a corresponding number of matching circumferential ring profiles. When the ring profiles of the two tubulars are mated and interlocked, they form separate and independent fluid seals as well as a mechanical lock able to hold the tubulars together during future expansion of the entire tubular and joint. Further, selecting properties of the tubulars such as yield strength and modulus of elasticity or constraining a diameter of one of the tubulars during expansion or compression forms a tight connection due to elastic recovery of the tubulars.

Abstract: A pipe fitting has a body with an internally threaded bore and at least one female starter thread. The at least one female starter thread is disposed either within the bore or immediately outside of the bore. The starter thread is axially aligned with the bore threads. The starter thread is made from a material which is stronger than the material from which the bore threads are made. The starter thread most proximate to the threads of the internally threaded bore has a pitch diameter which is at least two percent greater than the pitch diameter of the most proximate thread within the internally threaded bore.

Abstract: An elongated drive string assembly includes a plurality of hollow sucker rods and connecting elements between a drive head located at the surface of an oil well and a rotary pump located deep down in an oil well, with a series of holes at each end to substantially increase the flow of extracted fluid. Each hollow sucker rod has a first end with a torque shoulder, which engages a torque shoulder formed on a connecting element. The threads are frusto-conical, non-symmetrical threads with a differential diametral taper. The torque shoulders have a maximized mean diameter and cross-sectional area to resist storing reactive torque in the drive string.

Abstract: A threaded connection for a conduit is disclosed. The connection includes a male member having threads on it defining a load flank lead, a stab flank lead and a nominal lead. A female member has threads thereon adapted to mate with the threads on the male member. The threads on the female member define a load flank lead, a stab flank lead and a nominal lead. At least one of the load flank lead and the stab flank lead, on at least one of the female member and the male member, is changed at a predetermined rate beginning at a selected distance from an end of the threads. The load lead and the stab lead are different from each other over at least part of the thread length.

Abstract: A threaded metallic pipe for oil extraction industry has a threaded end portion with treated surface in which the metal surface has a roughness (Ra) comprised of 2.0 ?m and 6.0 ?m, which is covered by a uniform layer (7) of a dry corrosion inhibiting coating and a second uniform layer (8) of dry lubricant coating. Alternatively the layers (8, 9) combined into one uniform layer (9) of a dry corrosion inhibiting coating containing a dispersion of particles of solid lubricant.

Abstract: An expandable threaded connection between segments of expandable tubulars that provides multiple sealing points along the pin and box members that can withstand high pressure is disclosed. The present invention utilizes a gap that is created between the pin nose and the back of the box member when the threaded connection is made up and a reverse trapping angle machined into the pin nose end and the back of the box. The radial expansion of the tubulars causes axial movement of the pin nose and the box member until the pin nose is in contact with the back of the box member, thereby closing the gap and forcing the pin nose into sealing engagement with the back of the box member. The reverse trapping angle forces the nose of the pin member outwardly (i.e., toward the outer diameter of the expandable tubular string) as it is forced into contact with the back of the box member during the expansion process.

Abstract: An expandable threaded connection includes a first tubular member, a second tubular member and a threaded connection for coupling the tubular members that includes one or more sealing members.

Abstract: A threaded joint which economically imparts effective sealing properties to a metal-to-metal seal portion and which can prevent seizing at the time of make-up comprises a steel pipe 1 having at its tip a male thread 1b and an unthreaded sealing surface 1a, and a coupling 2 having on its inner surface a female thread 2b and an unthreaded sealing surface 2a. With the yield pressure of the inner surface of the pipe being Py, (1) the average pressure Pm of the annular contact portion satisfies Pm/Py?3, and the width in the axial direction of the portion which receives a pressure Ps which satisfies Ps/Py?1 in the annular contact portion is at least 1 mm (or at least 2 mm), and the surface roughness Ry of both unthreaded sealing surfaces is at most 25 ?m (or at most 30 ?m), or (2) the relationship between the average pressure Pm of the annular contact portion and the surface roughness Ry (?m) of the unthreaded sealing surface satisfies Pm/Py?0.0032×Ry2+1.

Abstract: A system for making and breaking connections between the pin ends of sucker rods and coupling sleeves employs a hydraulically powered system of radially driven gripper heads which are interchangeable to accept different sucker rod sizes. A torqueing system adjacent the gripper head system is also hydraulically driven, employing a pivotally coupled free end on a torque wrench which engages the wrench flat on the sucker rod at its opposite end. The coupling is securely retained without marring the coupling surface while the torque necessary to make or break the connection is applied rapidly and controllably. The system can also be used to advantage in preassemble sucker rods into couplings with precise prestress, using an improved connection design. A sucker rod string can then be assembled readily in the field with invariant optimum prestress conditions at each connection.

Abstract: The invention concerns a threaded component for a seizure-resistant tubular threaded joint wherein a lubricating substance is deposited in a thin film on at least the surface of the threads of the threading, said surface being treated to adsorb said lubricating substance. The lubricating substance consists of a homogeneous mixture of a) a thickening agent; b) a set of extreme-pressure additives physically and chemically compatible with the thickening agent and comprising at least an extreme-pressure additive with chemical action called chemical EP additive and capable of being used at Hertz pressures not less than 1000 Mpa's; c) an oil. The proportions of the constituents of the lubricating substance are selected such that said lubricating substance has a consistency capable of ensuring a self-induced and film-forming lubricating process. The invention also concerns a method for producing the thin film.

Abstract: An insulated transition spool apparatus for mounting unheading devices to pressure vessels, such as coker vessels, and enabling repetitive operation thereof is disclosed. The apparatus comprises an outer housing, an inner housing that encloses an insulating space between the inner and outer housing, a side feed entry aperture in each housing and a spool adapter flange to facilitate attachment of the spool to the vessel.

Abstract: Described herein is a threaded joint, in which the threads are coated with a layer of dry lubricant having a thickness of between 5 ?m and 30 ?m and in which the nominal void volume NVV of the space (6, 7) between the thread of the male tube and the thread of the female tube, is sized by means of the following formulae: NVV ? [ cm 3 ] ? 4 × OD ? [ inch ] NVV ? [ cm 3 ] OD ? [ inch ] × Wt ? [ mm ] ? 1 g T ? 0.4 ? ? ? mm 2 ? / ? pitch where OD is the nominal outer diameter and Wt is the thickness of the wall of the pipes.

Abstract: A drill pipe 10 comprises an elongate pipe section 12 having a substantially uniform pipe outer diameter 18 and a substantially uniform pipe inner diameter 20. A pin tool joint 14 is welded at one end to the pipe section, and a box tool joint 16 is welded to the other end of the pipe section. Each of the pin and box tool joints includes a thread for mating engagement and preferably first and second shoulders. The drill pipe has a ratio, R, which takes into consideration the pipe inner diameter, PID, the pipe outer diameter, POD, the tool joint inner diameter, TJID, and the tool joint outer diameter, TJOD. This ratio may be expressed as: R = ( P ID + TJ ID ) ( TJ OD - P OD ) . According to the present invention, this ratio is greater than 8.0, and is preferably from 8.1 to 8.5, thereby providing a drill pipe with desired strength and fluid flow capabilities.