Dynamic load expansion test bench and method of expanding a tubular

A method and apparatus for a testing facility for simulating downhole conditions is provided. The testing facility may include a test bench for expanding tubular members having one or more threaded connections. The test bench may also be operable to simulate the expansion of a tubular connection downhole and to produce expanded tubular connection test samples.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the invention relate to a testing facility for simulating downhole conditions. More particularly, embodiments relate to a test bench for expanding tubular members having one or more threaded connections. Embodiments of the invention further relate to a test bench for simulating the expansion of a tubular connection downhole and for producing expanded tubular connection test samples.

2. Description of the Related Art

Hydrocarbon and other wells are completed by forming a borehole in the earth and then lining the borehole with pipe or casing to form a wellbore. After a section of the wellbore is formed by drilling, a section of casing is lowered into the wellbore and temporarily hung therein from the surface of the well. Using apparatus and methods known in the art, the casing is cemented into the wellbore by circulating cement into the annular area defined between the outer wall of the casing and the borehole. The combination of cement and casing strengthens the wellbore and facilitates the isolation of certain areas of the formation behind the casing for the production of hydrocarbons.

Recent developments in the oil and gas exploration and extraction industries have included tubulars that are expandable downhole through the use of a cone or a swedge. Some expansion apparatus include expander tools with radially extendable members which, through fluid pressure from a run-in string, are urged outward radially from the body of the expander tool and into contact with a tubular wall. By rotating the expander tool in the wellbore and/or moving the expander tool axially in the wellbore with the extendable members actuated, a tubular can be expanded along a predetermined length.

The most challenging aspect of expanding strings of tubulars in a wellbore relates to the threaded connection between each joint of pipe. The threaded sections of the pin member and the box member are tapered and are typically formed directly into the ends of the tubular. The pin member includes helical threads extending along its length and terminates in a relatively thin “pin nose” portion. The box member includes helical threads that are shaped and sized to mate with the helical threads of the pin member during the make-up of the threaded connection. The threaded section of the pin member and the box member form a connection of a predetermined integrity intended to provide not only a mechanical connection but rigidity and fluid sealing. For example, at each end of the connection, a non-threaded portion of each piece often forms a metal-to-metal seal.

Threaded connections between expandable tubulars are difficult to successfully expand because of the axial bending (forces brought about as a tubular or connection wall is bent outwards) that takes place as an expansion member moves through the connection. For example, when a pin portion of a connector with outwardly facing threads is connected to a corresponding box portion of the connection having inwardly facing threads, the threads experience opposing forces during expansion. Typically, the outwardly facing threads will be in compression while the inwardly facing threads will be in tension. Thereafter, as the largest diameter portion of a conical expander tool moves through the connection, the forces are reversed, with the outwardly facing threads placed into tension and the inwardly facing threads in compression. The result is often a threaded connection that is loosened due to different forces acting upon the parts during expansion. Another problem relates to “spring back” that can cause a return movement of the relatively thin pin nose. Typically, threaded connections on expandable strings are placed in a wellbore in a “pin up” orientation and then expanded from the bottom upwards towards the surface. In this manner, the pin nose is the last part of the connection to be expanded. While threaded connections might have a single set of threads between the two tubulars, many expandable connections include a “two-step” thread body with threads of different diameters and little or no taper. These types of connections suffer from the same problems as those with single threads when expanded by a conical shaped expander tool.

There are a number of ways to test expandable connections but most take place above ground with the connections held in a fixture and expansion tools forced through them. The problem with this type of test is that the stress load conditions present in a wellbore are not recreated. An expandable tubular string and the connections that make up the string experience different tension and compression loads along the length of the string when expanded in a vertical wellbore. The loading in the string varies because the weight of the string above and below the connections is different along the string length. For example, the connections at the top of the tubular string are loaded with a lesser amount of compression (weight thereabove) than the connections at the bottom of the tubular string, which are loaded with a greater amount of string weight from above. Because the expander typically supports the weight of the entire string, as the expander passes through a connection, the loading changes from compression to tension. The connections at the top of the tubular string are then loaded with a greater amount of tension than the connections at the bottom of the tubular string, which are loaded with a lesser amount of string weight hanging below. If the expander is being propelled with fluid pressure, the tension load is further increased due to an end thrust at the bottom of the tubular string from the applied pressure.

In one example, the expandable tubular string may be free hanging in a vertical wellbore via a work string. The tubular string may be supported near its lower end by an expander that is connected to the work string. In the unexpanded position, the portion of the tubular string above the expander is placed in compression under the weight of the string above the expander, and the portion of the tubular string below the expander is placed in tension from the weight of the string below the expander. Fluid communication through the lower end of the tubular string may be closed, and fluid pressure may be supplied through the work string to the lower end of the tubular string. The fluid pressure may pump the expander through the tubular string, as well as aid in expansion of the string. The thrust force of the fluid pressure necessary to move the expander through the tubular string will also place the portion of the tubular string below the expander in tension. Therefore, as the expander moves from the lower end of the tubular string to the upper end, the connections along the length of the string will experience a change in load from compression to tension. In addition, the overall length of the tubular string may shrink as it is expanded. The shortening of the tubular string at one end while the opposite end is fixed, a “fixed-free” configuration, may further vary the loads. In certain situations, however, the tubular string may be prevented from shortening in length, such that the string is fixed at its ends during expansion. This “fixed-fixed” configuration may even further vary the loads provided on the tubular string by an additional tension load. In some configurations, the tubular string may be set on the bottom of the wellbore and/or anchored to the wellbore at one or more locations, which further vary the loads experienced by the tubular string during expansion.

Therefore, there exists a need for a method and apparatus for simulating the downhole expansion a threaded tubular connection in a controlled laboratory environment. There also exists a need for a method and apparatus for testing the expansion of threaded tubular connection designs under various wellbore conditions. There further exists a need for a method and apparatus for producing threaded tubular connection test samples that accurately represent expansion under wellbore conditions.

SUMMARY OF THE INVENTION

Embodiments of the invention include a method of expanding a tubular. The method may include applying a pre-determined compression load to the tubular and applying a pre-determined tension load to the tubular. The method may further include maintaining the pre-determined compression and tension loads while expanding a portion of the tubular.

Embodiments of the invention include a method of expanding a tubular. The method may include securing the tubular to a first actuation assembly and a second actuation assembly. The method may also include applying a compression load to the tubular using the first actuation assembly and applying a tension load to the tubular using the second actuation assembly. The method may further include maintaining the application of the compression and tension loads while expanding the tubular.

Embodiments of the invention include an apparatus for expanding a tubular having one or more connections. The apparatus may include a frame for supporting a first, second, and third crosshead. The apparatus may also include a first actuation assembly that is operable to move the first crosshead relative to at least one of the second and third crossheads. The first actuation assembly may also be operable to apply a first load to the tubular. The apparatus may further include a second actuation assembly that is operable to apply a second load to the tubular. The first load may be a compression load, and the second load may be a tension load. The compression and tension loads may be maintained using the first and second actuation assemblies while the tubular is being expanded.

Embodiments of the invention include a method of expanding a tubular. The method may include applying a compression load to the tubular and applying a tension load to the tubular. The method may also include moving the tubular relative to an expander to expand a portion of the tubular. The method may also include maintaining the compression and tension loads while the tubular is expanded.

Embodiments of the invention include a method of expanding a tubular comprising the steps of expanding one or more test samples of a tubular connection above ground; testing the test samples to define an operating envelope within which the tubular connection will operate without failure when expanded downhole; installing the tubular connection in a wellbore; and expanding the tubular connection in the wellbore while operating the tubular connection within the operating envelope defined by the testing of the test samples.

Embodiments of the invention include a method of expanding a tubular comprising the steps of applying a compression load to a first portion of the tubular, wherein the compression load is greater than a weight of the first portion of the tubular; applying a tension load to a second portion of the tubular; and expanding the first and second portions of the tubular while applying the compression and tension loads.

DETAILED DESCRIPTION

Embodiments of invention discussed herein include a method and apparatus for expanding a tubular connection above ground, while simulating virtually all downhole load conditions described above.

FIGS. 1,2,3, and8illustrate embodiments of a testing configuration for expanding a tubular connection under a “fixed-free” expansion. A fixed-free expansion is when a tubular string is fixed at a first end but free at a second end, thereby permitting the tubular material to accommodate a change in axial length, such as shorten or shrink, as its diameter is enlarged.FIG. 1illustrates a first test configuration100,FIG. 2illustrates a second test configuration200,FIG. 3illustrates a third test configuration300, andFIG. 8illustrates a fourth test configuration800.

FIG. 1illustrates the first test configuration100for simulating the downhole expansion of a tubular connection. The first test configuration100includes an expandable tubular110, a work string120extending through the tubular110, and an expander130disposed within a lower end of the tubular and connected to the end of the work string120. The tubular110may include one or more tubular members connected together by one or more connections. The tubular110is fixed at a first end by a fixed constraint140. A first load150may be applied to the work string120. In one embodiment, the first load150may be applied to the work string120by one or more ways known by one of ordinary skill in the art. In one embodiment, the first load150may be applied to the work string120using one or more piston cylinders. The first load150is transferred to the tubular110via the expander130, to thereby compress a length112of the tubular ahead of the expander130against the fixed constraint140. Placing the length112of the tubular in compression simulates a compressive load generated by tubular string weight that places a tubular string connection in compression when supported downhole. The amount of compression applied to the length112may simulate the amount of compression experienced by a tubular string connection, depending on its location along a length of a tubular string when downhole. The amount of compression applied to the length112of the tubular110may therefore be greater than, less than, or equal to the amount of compression that may be generated by the actual weight of the length112of the tubular110located ahead of the expander130. A second load160, opposite the first load150, may then be applied to a second end of the tubular110. In one embodiment, the second load160may be applied to the work string120by one or more ways known by one of ordinary skill in the art. In one embodiment, the second load160may be applied to the work string120using one or more piston cylinders. The second load160places a length114of the tubular behind the expander130in tension. Placing the length114of the tubular in tension simulates a tensile load generated by tubular string weight that places a tubular string connection in tension when supported downhole. The amount of tension applied to the length114may simulate the amount of tension experienced by a tubular string connection, depending on its location along a length of a tubular string when downhole. The amount of tension applied to the length114of the tubular110may therefore be greater than, less than, or equal to the amount of tension that may be generated by the actual weight of the length114of the tubular110located behind the expander130. In one embodiment, the application of the first and second loads150and160may be insufficient to move the expander130through the tubular110. In one embodiment, the first and second loads150and160may be pre-determined and may remain constant during expansion of the tubular110.

Prior to expansion, the first test configuration100may apply calculated first and second loads150and160to the tubular110to simulate the run-in and un-expanded position of a tubular connection when located in a vertical, horizontal, and/or lateral wellbore. After the applicable loads are applied to the tubular110, fluid pressure may then be supplied through the work string120into a sealed chamber116, formed between the expander130and the lower end of the tubular110, to move the expander130through the tubular110. In one embodiment, the fluid pressure may be supplied to the sealed chamber116directly through a port in the tubular110. Supplying fluid pressure into the chamber116may further place the length114of the tubular behind the expander130in tension to simulate the tensile load that would be generated by the thrust force of the fluid pressure. In one embodiment, the loads may be applied to the tubular110upon and/or as a result of expansion of the tubular.

The combination of tension, compression, and fluid pressure are calculated to exceed the requisite expansion force necessary to expand the tubular110. During expansion, the first and second loads150and160and the fluid pressure are continuously maintained according to a predetermined schedule as the expander130moves through and expands the tubular110to simulate the tension and compression loads in the tubular when downhole. In one embodiment, the predetermined schedule may include varying one or more of the tension and/or compression loads during expansion of the tubular. In one embodiment, the predetermined schedule may include maintaining one or more of the tension and/or compression loads constant during expansion of the tubular. In one embodiment, as the expander130moves through the tubular110, the compressive load applied to the length112of the tubular remains constant and the tensile load applied to the length114of the tubular remains constant. To ensure a constant load, the mechanism used to provide the first load150is continuously adjusted to account for the application of the second load160and the fluid pressure, and vice versa. The mechanisms used to provide the first load150, second load160, and the fluid pressure are also adjusted to account for changes in the lengths112and114of the tubular110located ahead of and behind the expander130as it moves from one end to the other end. Adjustments may also be made to account for the shrinkage of the tubular110during expansion. In one embodiment, one or more controllers may be used to automatically adjust the mechanisms used to provide the first and second loads150and160and the fluid pressure during expansion.

FIG. 2illustrates the second test configuration200for simulating the downhole expansion of a tubular connection. The second test configuration200includes an expandable tubular210, a work string220extending through the tubular210, and an expander230disposed within a lower end of the tubular and connected to the end of the work string220. The tubular210may include one or more tubular members connected together by one or more connections. The work string220is fixed at an end by a fixed constraint240. A first load250may be applied to a first end of the tubular210. In one embodiment, the first load250may be applied to the tubular210by one or more ways known by one of ordinary skill in the art. In one embodiment, the first load250may be applied to the tubular210using one or more piston cylinders. The first load250is applied to the tubular210to thereby compress a length212of the tubular against the expander230, which is secured to the fixed constraint240via the work string220. Placing the length212of the tubular in compression simulates a compressive load generated by tubular string weight that places a tubular string connection in compression when supported downhole. The amount of compression applied to the length212may simulate the amount of compression experienced by a tubular string connection, depending on its location along a length of a tubular string when downhole. The amount of compression applied to the length212of the tubular210may therefore be greater than, less than, or equal to the amount of compression that may be generated by the actual weight of the length212of the tubular210located ahead of the expander230. A second load260may then be applied to the lower end of the tubular210in a similar manner as the second load160described above. The second load260places a length214of the tubular behind the expander230in tension, as the expander230is secured to the fixed constraint240via the work string220. Placing the length214of the tubular in tension simulates a tensile load generated by tubular string weight that places a tubular string connection in tension when supported downhole. The amount of tension applied to the length214may simulate the amount of tension experienced by a tubular string connection, depending on its location along a length of a tubular string when downhole. The amount of tension applied to the length214of the tubular210may therefore be greater than, less than, or equal to the amount of tension that may be generated by the actual weight of the length214of the tubular210located behind the expander230. In one embodiment, the application of the first and second loads250and260may be insufficient to move the expander230through the tubular210(or move the tubular210over the expander230). In one embodiment, the first and second loads250and260may be pre-determined and may remain constant during expansion of the tubular210.

Prior to expansion, the second test configuration200may apply calculated first and second loads250and260to the tubular210to simulate the run-in and un-expanded position of a tubular connection when located in a vertical, horizontal, and/or lateral wellbore. After the applicable loads are applied to the tubular210, fluid pressure may then be supplied through the work string210into a sealed chamber216, formed between the expander230and the lower end of the tubular210, to move the expander230through the tubular210(or move the tubular210over the expander230). In one embodiment, the fluid pressure may be supplied to the sealed chamber216directly through a port in the tubular210. Supplying fluid pressure into the chamber216may further place the length214of the tubular behind the expander230in tension to simulate the tensile load that would be generated by the thrust force of the fluid pressure. In one embodiment, the loads may be applied to the tubular210upon and/or as a result of expansion of the tubular.

The combination of tension, compression, and fluid pressure are calculated to exceed the requisite expansion force necessary to expand the tubular210. During expansion, the first and second loads250and260and the fluid pressure are continuously maintained according to a predetermined schedule as the expander230moves through and expands the tubular210(or the tubular210moves over the expander230and is expanded) to simulate the tension and compression loads in the tubular when downhole. In one embodiment, the predetermined schedule may include varying one or more of the tension and/or compression loads during expansion of the tubular. In one embodiment, the predetermined schedule may include maintaining one or more of the tension and/or compression loads constant during expansion of the tubular. In one embodiment, as the expander230moves through the tubular210(or the tubular210moves over the expander230), the compressive load applied to the length212of the tubular remains constant and the tensile load applied to the length214of the tubular remains constant. To ensure a constant load, the mechanism used to provide the first load250is continuously adjusted to account for the application of the second load260and the fluid pressure, and vice versa. The mechanisms used to provide the first load250, the second load260, and the fluid pressure are adjusted to account for the changes in the length212and214of the tubular210located ahead of and behind the expander230as it moves from one end to the other end. Adjustments may also be made to account for the shrinkage of the tubular210during expansion. In one embodiment, one or more controllers may be used to automatically adjust the mechanisms used to provide the first and second loads250and260and the fluid pressure during expansion.

FIG. 3illustrates the third test configuration300for simulating the downhole expansion of a tubular connection. The third test configuration300includes an expandable tubular310, a work string320extending through the tubular310, and an expander330disposed within a lower end of the tubular and connected to the end of the work string320. The tubular310may include one or more tubular members connected together by one or more connections. The tubular310is fixed at an end by a fixed constraint340. A first load350may be applied to a first end of the tubular310in a similar manner as the first load250described above. The first load350is applied to the tubular310to thereby compress a length312of the tubular against the expander330(which is secured to the work string320) and the fixed constraint340. Placing the length312of the tubular in compression simulates a compressive load generated by tubular string weight that places a tubular string connection in compression when supported downhole. The amount of compression applied to the length312may simulate the amount of compression experienced by a tubular string connection, depending on its location along a length of a tubular string when downhole. The amount of compression applied to the length312of the tubular310may therefore be greater than, less than, or equal to the amount of compression that may be generated by the actual weight of the length312of the tubular310located ahead of the expander330. A second load360, opposite the first load350, may then be applied to the work string320in a similar manner as the first load150described above. The second load360is transferred to the tubular310via the expander330, to thereby compress the length312of the tubular ahead of the expander330against the first load350as recited above. The second load360also places a length314of the tubular behind the expander330in tension, as the end of the tubular310is secured to the fixed constraint340. Placing the length314of the tubular in tension simulates a tensile load generated by tubular string weight that places a tubular string connection in tension when supported downhole. The amount of tension applied to the length314may simulate the amount of tension experienced by a tubular string connection, depending on its location along a length of a tubular string when downhole. The amount of tension applied to the length314of the tubular310may therefore be greater than, less than, or equal to the amount of tension that may be generated by the actual weight of the length314of the tubular310located behind the expander330. In one embodiment, the application of the first and second loads350and360may be insufficient to move the expander330through the tubular310. In one embodiment, the first and second loads350and360may be pre-determined and may remain constant during expansion of the tubular310.

Prior to expansion, the third test configuration300may apply calculated first and second loads350and360to the tubular310to simulate the run-in and un-expanded position of a tubular connection when located in a vertical, horizontal, and/or lateral wellbore. After the applicable loads are applied to the tubular310, fluid pressure may then be supplied through the work string320into a sealed chamber316, formed between the expander330and the lower end of the tubular310, to move the expander330through the tubular310. In one embodiment, the fluid pressure may be supplied to the sealed chamber316directly through a port in the tubular310. Supplying fluid pressure into the chamber316may further place the length314of the tubular behind the expander330in tension to simulate the tensile load that would be generated by the thrust force of the fluid pressure. In one embodiment, the loads may be applied to the tubular310upon and/or as a result of expansion of the tubular.

The combination of tension, compression, and fluid pressure are calculated to exceed the requisite expansion force necessary to expand the tubular310. During expansion, the first and second loads350and360and the fluid pressure are continuously maintained according to a predetermined schedule as the expander330moves through and expands the tubular310to simulate the tension and compression loads in the tubular when downhole. In one embodiment, the predetermined schedule may include varying one or more of the tension and/or compression loads during expansion of the tubular. In one embodiment, the predetermined schedule may include maintaining one or more of the tension and/or compression loads constant during expansion of the tubular. In one embodiment, as the expander330moves through the tubular310, the compressive load applied to the length312of the tubular remains constant and the tensile load applied to the length314of the tubular remains constant. To ensure a constant load, the mechanism used to provide the first load350is continuously adjusted to account for the application of the second load360and the fluid pressure, and vice versa. The mechanisms used to provide the first load350, the second load360, and the fluid pressure are also continuously adjusted to account for the changes in the lengths312and314of the tubular310located ahead of and behind the expander330as it moves from one end to the other end. Adjustments may also be made to account for the shrinkage of the tubular310during expansion. In one embodiment, one or more controllers may be used to automatically adjust the mechanisms used to provide the first and second loads350and360and the fluid pressure during expansion.

In one embodiment, the first, second, third, and fourth test configurations100,200,300, and800may also be operable to accurately simulate a “fixed-fixed” expansion. The expandable tubular string can be secured or locked at both ends to prevent the tubular string from shrinking during expansion, which will produce an additional tension load in the tubular string. The tension and compression loads can thus be adjusted as necessary to simulate the loads in a tubular when expanded downhole in a fixed-fixed expansion, such as the expansion of a tubular which has become stuck within a wellbore, or the expansion of a tubular in a horizontal wellbore.

Using the first, second, third, and fourth test configurations, the tension and compression loads can be applied before the expander moves and can then be maintained once the expander starts moving. In one embodiment, the expandable tubular string can be expanded using only a mechanical expansion of the tubular without the addition of fluid pressure. In one embodiment, the expandable tubular string can be loaded by the first load, the second load, and the fluid pressure in any order. In one embodiment, the predetermined schedule of loads applied to the expandable tubular may include provision for changing one or more of the applied loads during and/or after a section of the expandable tubular has been expanded. In one embodiment, the tension and compression loads applied to the expandable tubular may be permitted to change as a result of the expansion process while the expansion is being executed. The first, second, and third test configurations can thus be used to simulate the expansion of test samples from any position in an expandable tubular string.

FIG. 4illustrates a test assembly400for expanding a tubular string having one or more connections, according to the first test configuration100described above. The test assembly400is operable to apply and optionally maintain tension and compression loads on a first length of a tubular string located in front of an expander and a second length of the tubular string located behind the expander, while the expander moves through and expands the tubular. The test assembly400is thus operable to accurately simulate the expansion of tubular string connections under downhole conditions.

The test assembly400includes a frame402, such as a pair or rails, for supporting a first crosshead410, a second crosshead420, and a third crosshead430. The term “frame” as defined herein may be any support structure or surface, including the ground, which is operable to support one or more components of the test assemblies described herein. The term “crosshead” as defined herein may similarly include any type of support structure or surface that is operable to support one or more components of the test assemblies described herein. The first crosshead410is movable relative to the frame402, and the second and third crossheads420and430are stationary and fixed to the frame402. The test assembly400also includes one or more first actuation assemblies440configured to apply a first load to a test sample480, and one or more second actuation assemblies450configured to apply a second load to the test sample480. The test assembly400further includes an expander460, such as a cone, that is connected to the first crosshead410via a work string470. The work string470may be a tubular member or connecting rod having a flow bore therethrough. The work string470may be connected to the first crosshead410, such as by a welded or threaded connection, and may extend through an opening in the second crosshead420and into the test sample480. Fluid communication to the test sample480may be established through an opening412of the first crosshead410which is in fluid communication with the flow bore of the work string470. The expander460may be connected to the lower end of the work string470and positioned within the test sample480. The expander460may be provided with one or more seals462, such as seal cups, to form a sealed chamber486within the test sample480. The test sample480may include an expandable tubular string having one or more expandable tubular members that are connected together by one or more threaded connections. A first end of the test sample480may be supported by the second crosshead420, and a second end of the test sample480may be closed and/or sealingly connected to the second actuation assembly450, such as by a welded or threaded connection.

In one embodiment, the first actuation assembly440may include a pair of piston cylinders442and piston rods444that are operable to move the first cross head410. The piston cylinders442may be connected to the second and third crossheads420and430using one or more flanged connections, and the piston rods444may be connected to the first crosshead410in a manner that the rods444extend through openings in the second crosshead420. The piston cylinders442and rods444may have a stroke within a range of about 5 feet to about 25 feet. In one embodiment, the stroke may be about 15 feet. The first actuation assembly440is configured to apply a compressive force to the test sample480. Placing the test sample480in compression simulates a compressive load generated by tubular string weight that places a tubular string connection in compression when supported downhole. The amount of compression applied to the test sample480may simulate the amount of compression experienced by the tubular string connection, depending on its location along a length of the tubular string when downhole. The compression load is generated by pulling on the expander460, via the work string470and the first crosshead410, by actuation of the piston cylinders442and rods444. The portion of the test sample480ahead of the expander460may thus be compressed between the expander460and the second crosshead420. The compression load is maintained by adjusting the pressure supplied to the first actuation assembly440as the expander460moves through the test sample480and as the test sample480shrinks in length.

In one embodiment, the second actuation assembly450may include a piston cylinder452and a piston rod454that are operable to apply a force to the test sample480. The piston cylinder452may be connected to the third crosshead430using a flanged connection, and the piston rod454may be connected to the test sample480in a manner that the rod454extends through an opening in the third crosshead430. The rod454may be connected to the test sample480using an end cap482that is secured to the end of the rod454. The piston cylinder452and rod454may have a stroke within a range of about 5 feet to about 25 feet. In one embodiment, the stroke may be about 15 feet. The second actuation assembly450is configured to apply a tensile force to the test sample480. Placing the test sample480in tension simulates a tensile load generated by tubular string weight that places a tubular string connection in tension when supported downhole. The amount of tension applied to the test sample480may simulate the amount of tension experienced by the tubular string connection, depending on its location along a length of the tubular string when downhole. The tension load is generated by pulling on the test sample480by actuation of the piston cylinder452and rod454. The portion of the test sample480behind the expander460is thus tensioned by the opposing forces provided by the second actuation assembly450and the expander460via the first actuation assembly440. The tension load is maintained by adjusting the pressure supplied to the second actuation assembly450as the expander460moves through the test sample480and as the test sample480shrinks in length.

The application of the compression and tension loads by the first and second actuation assemblies440and450may be insufficient to move the expander460through the test sample480. The test assembly400may apply calculated compression and tension loads to the test sample to simulate the run-in and un-expanded position of a tubular connection when located in a vertical, horizontal, and/or lateral wellbore. After the pre-loads are applied to the test sample480, fluid pressure may be continuously supplied through the work string470into the sealed chamber486until the expansion force is reached to move the expander460through the test sample480. In one embodiment, the fluid pressure may be supplied to the sealed chamber486directly through a port in the test sample480. Supplying fluid pressure into the chamber486may further place the length of the test sample480behind the expander460in tension to simulate the tensile load that would be generated by the thrust force of the fluid pressure. In one embodiment, a hydraulic fluid such as water may be supplied into the chamber486by a pump to generate the thrust force necessary to move the expander460.

The combination of tension, compression, and fluid pressure are calculated to exceed the requisite expansion force necessary to expand the tubular test sample. During expansion, the tension and compression loads provided by the first and second actuation assemblies440and450are continuously maintained according to a predetermined schedule as the expander460moves through and expands the test sample480to simulate the loads on a tubular connection when downhole. In one embodiment, the predetermined schedule may include varying one or more of the tension and/or compression loads during expansion of the test sample480. In one embodiment, the predetermined schedule may include maintaining one or more of the tension and/or compression loads constant during expansion of the test sample480. In one embodiment, as the expander460moves through the test sample480, the compressive load applied to the length of the test sample480ahead of the expander460remains the same and the tensile load applied to the length of the test sample480behind the expander460remains the same. To ensure a constant load, the fluid pressure and the pressures supplied to the piston cylinders442and452and rods444and454are continuously adjusted to account for the application of different loads and the changes in the lengths of the test sample480ahead of and behind the expander460, as the expander460moves from one end to the other end. In one embodiment, the piston rod454of the second actuation assembly450may extend during expansion of the test sample480to accommodate for the shrinkage of the test sample480, while maintaining the requisite tensile load on the test sample480. In one embodiment, the test assembly400may be operable to accommodate for up to about a 10 percent shortening of the length of the test sample480during expansion. In one embodiment, one or more controllers may be used to automatically adjust the actuation pressure of the piston cylinders442and452and the fluid pressure during expansion. In one embodiment, the predetermined schedule of loads applied to the expandable tubular may include provision for changing one or more of the applied loads during and/or after a section of the expandable tubular has been expanded. In one embodiment, the tension and compression loads applied to the expandable tubular may be permitted to change as a result of the expansion process while the expansion is being executed.

In one embodiment, all of the components of the test assembly400are controlled by a controller, such as a computer that continually monitors the loads that are to be maintained. As the expander460, the piston rods444and454, and the first crosshead410move, the controller maintains the pressures inside the piston cylinders442and452by pumping or removing hydraulic fluid. In one embodiment, the controller may include one or more pump controls that are configured to regulate the flow and pressure of hydraulic fluids to the piston cylinders442and452. In one embodiment, the controller may include one or more sensors, such as load cells, that are configured to communicate to the controller what the loads are in the test sample480during expansion. In one embodiment, the controller may be configured to continuously monitor and maintain the supply of fluid pressure to the test sample480to provide the thrust force necessary to move the expander460.

The test assembly400is operable to accurately simulate numerous variations of a “fixed-free” or a “fixed-fixed” expansion. In one embodiment, the test sample480can be expanded using one or more combinations of the first and second actuation assemblies and fluid pressure. In one embodiment, the test sample480can be constrained at both ends to prevent the test sample480from length shrinkage during expansion.

In one embodiment, the piston cylinders442and452may be operable to supply a force within a range of about a 100,000 pound-force to about a 200,000 pound-force to the test sample. In one embodiment, the piston cylinders442and452may be operable to supply a force within a range of about a 200,000 pound-force to about a 325,000 pound-force to the test sample. In one embodiment, the piston cylinders442and452may be operable to supply a force within a range of about a 325,000 pound-force to about a 500,000 pound-force to the test sample. In one embodiment, the piston cylinders442and452may be operable to supply a force within a range of about a 500,000 pound-force to about a 650,000 pound-force to the test sample.

In one embodiment, the test assembly400may be configured so that the distance between the longitudinal axis of the piston cylinders and rods442and444may be within a range of about 47 inches to about 62 inches. In one embodiment, the test assembly400may be configured so that the distance between the outer diameters of the piston cylinders442may be within a range of about 33 inches to about 48 inches. In one embodiment, the test assembly400may be configured so that the distance between the outer diameter of the test sample after expansion and the outer diameter of the piston cylinders442may be within a range of about 8 inches to about 16 inches.

In one embodiment, the test assembly400may be operable to expand test samples within a range of about 3½ inches in diameter to about 13⅜ inches or about 16 inches in diameter. In one embodiment, the test assembly400may include a pump system operable to supply up to about 10,000 PSI into the test sample. In one embodiment, the test assembly400is operable to move the expander460through the test sample480at a speed up to about 10 feet per minute.

FIGS. 4A-4Dillustrate an operational sequence of the test assembly400according to one embodiment.FIG. 4Aillustrates the start position of the test assembly400. As shown, the expander460is located an end of the test sample480. The first and second actuation assemblies440and450are actuated to apply the preloads to the test sample480. The piston cylinders and rods442and444push on the movable first crosshead410, which pulls on the expander460via the work string470, to apply a compression load to the test sample480between the expander460and the second crosshead420. The amount of compression depends on the downhole conditions being simulated. The amount of compression provided by the test assembly400may accurately simulate string weight compression in one or more threaded connections positioned at various locations along a length of a tubular string when downhole. The piston cylinder and rod452and454pulls on the test sample480to apply a tension load to the test sample480behind the expander460. Similarly, the amount of tension depends on the downhole conditions being simulated. The amount of tension provided by the test assembly400may accurately simulate string weight tension in one or more threaded connections positioned at various locations along a length of a tubular string when downhole. Fluid pressure is then continuously supplied to the chamber486via the work string470(and/or directly into the chamber486via a port in the test sample480) until the expander460begins to move. The fluid pressure in the chamber486generates an additional tension load to the test sample480behind the expander from the end thrust. The compression, tension, and fluid pressure combine to generate the expansion force required to move the expander460and expand the test sample480.

FIG. 4Billustrates the expansion of the test sample480at mid-stroke of the first actuation assemblies440. As shown, the first crosshead410has been pushed to about half of its maximum travel distance by the piston cylinders and rods442and444. The expander460has expanded about half of the test sample480. The applied compression and tension loads are being maintained even though all of the piston cylinders and rods are in motion. The loads may be maintained with the use of one or more controllers that are in communication with the piston cylinders. The test sample480may shrink in length up to about 10 percent, and the length change of the test sample480is compensated by the second actuation assembly450. As show, the piston rod454has extended to accommodate for the shrinkage of the test sample480, while maintaining the tension load. The piston cylinders and rods442and444will also dampen or resist any expander “jump” or quick acceleration.

FIG. 4Cillustrates the expansion of the test sample480at or near full-stroke of the first actuation assemblies440. As shown, the expander460has reached the end of the test sample480and the fluid pressure is released, which stops the expansion motion. At this point, all applied loads by the piston cylinders are also released.FIG. 4Dillustrates the removal of the expander460from the test sample480. In one embodiment, piston cylinders and rods442and444of the first actuation assemblies440are locked in place, and the second actuation assembly450is actuated to retract the piston rod454to pull the test sample480off of the expander460. In one embodiment, piston cylinder and rod452and454of the second actuation assembly450are locked in place, and the first actuation assembly440is actuated to extend the piston rods444to pull the expander460from the test sample480. In one embodiment, a combination of the first and second actuation assemblies440and450are used to remove the expander460and the test sample480. The test sample480can be removed from the test assembly400and used to conduct further analysis of the expanded connections.

In one embodiment, the test assembly400is operable to expand the test sample480under a “fixed-fixed” expansion, to simulate when an expandable tubular is stuck in a wellbore or when the ends of the tubular are constrained. In a fixed-fixed expansion, the tubular will experience an additional tension load since it is prevented from shrinking. The test assembly400may simulate this additional tension load by locking the second actuation assembly450in place before and/or after the loads are applied to the test sample480, and not permitting the piston rod454to extend to compensate for the shortening of the test sample480. In one embodiment, the upper end of the test sample480may be secured to the second crosshead420during expansion to prevent shortening. In one embodiment, the test sample480may be expanded immediately upon actuation of the first actuation assembly440, the second actuation assembly450, and/or the fluid pressure. The pre-determined tension and/or compression loads are may be applied to the test sample480upon and/or as a result of expansion of the test sample480.

In one embodiment, the test assembly400can be used to produce expanded tubular connection samples simulated from any location in a tubular string, whether the string is vertical and unconstrained or horizontal and constrained at both ends. The test assembly400can also be used to expand test samples using only a mechanical force without the addition of fluid pressure, which would simulate cone expansions using a downhole jack or a rig apparatus applying the requisite expansion force. In one embodiment, the different tension and compression forces can be applied to the test sample480in any order. In one embodiment, the first and second loads from the test assembly400may be pre-determined and may remain constant during expansion of the test sample480.

FIG. 5illustrates a test assembly500for expanding a tubular string having one or more connections, according to one or more of the test configurations100,200,300, and800described herein. The embodiments, described above with respect to the test assembly400may also be provided using the test assembly500. The test assembly500is operable to apply and maintain tension and compression loads on a first length of a tubular string located in front of an expander and a second length of the tubular string located behind the expander, while the expander moves through and expands the tubular. The test assembly500is thus operable to accurately simulate the expansion of tubular string connections under downhole conditions.

The test assembly500may include a frame, such as a pair or rails, for supporting a first crosshead510, a second crosshead520, and a third crosshead530. The first and second crossheads510and520may be movable relative to the frame, and the third crosshead530may be stationary and fixed to the frame. The test assembly500also includes one or more first actuation assemblies540configured to apply a first load to a test sample580, one or more second actuation assemblies550configured to apply a second load to the test sample580, and one or more third actuation assemblies570configured to apply a third load to the test sample580. The test assembly500further includes an expander560, such as a cone, that is connected to the third actuation assembly570via a piston rod574. The piston rod574may be a tubular member or connecting rod having a flow bore therethrough. The piston rod574may extend through an opening in the third crosshead530and into the test sample580. Fluid communication to the test sample580may be established through the flow bore of the piston rod574. The expander560may be connected to the lower end of the piston rod574and positioned within the test sample580. The expander560may be provided with one or more seals562, such as seal cups, to form a sealed chamber586within the test sample580. The test sample580may include an expandable tubular string having one or more expandable tubular members that are connected together by one or more threaded connections. The upper end of the test sample580may be connected to an end cap584that is supported by the first crosshead510, and the lower end of the test sample580may be closed and/or sealingly connected to an end cap582that is supported by the second crosshead520.

In one embodiment, the first actuation assembly540may include a pair of piston cylinders542and piston rods544that are operable to move the first crosshead510. The piston cylinders542may be connected to the third crosshead530using one or more flanged connections, and the piston rods544may be connected to the first crosshead510in a similar manner. The piston cylinders542and rods544may be the same piston cylinders and rods442and444described above. The first actuation assembly540is configured to apply a compressive force to the test sample580. Placing the test sample580in compression simulates a compressive load generated by tubular string weight that places a tubular string connection in compression when supported downhole. The amount of compression applied to the test sample580may simulate the amount of compression experienced by the tubular string connection, depending on its location along a length of the tubular string when downhole. The compression load is generated by pushing the first crosshead510by actuation of the piston cylinders542and rods544. The portion of the test sample580ahead of the expander560may thus be compressed between the end cap584of the first crosshead510and the expander560, which is secured by the third crosshead530and the third actuation assembly570. The compression load is maintained by adjusting the pressure supplied to the first actuation assembly540as the expander560moves through the test sample580and as the test sample580shrinks in length.

In one embodiment, the second actuation assembly550may include a pair of piston cylinders552and piston rods554that are operable to move the second crosshead520. The piston cylinders552may be connected to the third crosshead530using one or more flanged connections, and the piston rods554may be connected to the second crosshead520in a similar manner. The piston cylinders552and rods554may be the same piston cylinders and rods452and454described above. The second actuation assembly550is configured to apply a tensile force to the test sample580. Placing the test sample580in tension simulates a tensile load generated by tubular string weight that places a tubular string connection in tension when supported downhole. The amount of tension applied to the test sample580may simulate the amount of tension experienced by the tubular string connection, depending on its location along a length of the tubular string when downhole. The tension load is generated by pushing on the second crosshead520by actuation of the piston cylinders552and rods554, which in effect applies a pull force to the lower end of the test sample580via the end cap582. The portion of the test sample580behind the expander560is thus tensioned by the opposing forces provided by the second actuation assembly550and the expander560via third actuation assembly570. The tension load is maintained by adjusting the pressure supplied to the second actuation assembly550as the expander560moves through the test sample580and as the test sample580shrinks in length.

In one embodiment, the third actuation assembly570may include a piston cylinder572and a piston rod574that are operable to secure and/or move the expander560through the test sample580. The piston cylinder572may be connected to the third crosshead530using a flanged connection, and the piston rod574may extend through openings in the third and first crossheads530and510and into the test sample580. The piston cylinder572and rod574may be the same piston cylinder and rod442and444described above. The third actuation assembly570may be configured to constrain the expander560against the forces applied by the first and second actuation assemblies540and550to produce the loads in the test sample580. The third actuation assembly570may also apply a pull force to move the expander560through the test sample580. The pull force may be maintained by adjusting the pressure supplied to the third actuation assembly570as the expander560moves through the test sample580and as the test sample580shrinks in length. The piston rod574may be retracted into the piston cylinder572as the expander560moves through the test sample580.

The application of the compression and tension loads by the first and second actuation assemblies540and550may be insufficient to move the expander560through the test sample580. The test assembly500may apply calculated compression and tension loads to the test sample to simulate the run-in and un-expanded position of a tubular connection when located in a vertical, horizontal, or lateral wellbore. After the pre-loads are applied to the test sample580, the third actuation assembly570may be actuated until the expansion force is reached to move the expander560through the test sample580.

In one embodiment, the test assembly500may also be operable to supply fluid pressure into the chamber586to further place the length of the test sample580behind the expander560in tension to simulate the tensile load that would be generated by the thrust force of the fluid pressure. In one embodiment, a hydraulic fluid such as water may be supplied into the chamber586by a pump to generate the thrust force necessary to move the expander560. The fluid pressure may be supplied through the flow bore of the piston rod574. In one embodiment, the fluid pressure may be supplied to the sealed chamber586directly through a port in the test sample580.

The combination of tension, compression, and fluid pressure are calculated to exceed the requisite expansion force necessary to expand the tubular test sample. During expansion, the loads provided by the actuation assemblies and the fluid pressure are continuously maintained according to a predetermined schedule as the expander560moves through and expands the test sample580to simulate the loads when downhole. In one embodiment, the predetermined schedule may include varying one or more of the tension and/or compression loads during expansion of the test sample580. In one embodiment, the predetermined schedule may include maintaining one or more of the tension and/or compression loads constant during expansion of the test sample580. In one embodiment, as the expander560moves through the test sample580, the compressive load applied to the length of the test sample580ahead of the expander560remains the same and the tensile load applied to the length of the test sample580behind the expander560remains the same. To ensure a constant load, the fluid pressure and the pressures supplied to the piston cylinders542,552, and572and rods544,554, and574are adjusted to account for the application of the different loads and the changes in the lengths of the test sample580ahead of and behind the expander560, as the expander560moves from one end to the other end. In one embodiment, the piston rod554of the second actuation assembly550may retract during expansion of the test sample580to accommodate for the shrinkage of the test sample580, while maintaining the requisite tensile load on the test sample580. In one embodiment, the test assembly500may be operable to accommodate for up to about a 10 percent shortening of the length of the test sample580during expansion. In one embodiment, one or more controllers may be used to automatically adjust the actuation pressure of the piston cylinders542,552, and572and the fluid pressure during expansion. In one embodiment, the predetermined schedule of loads applied to the expandable tubular may include provision for changing one or more of the applied loads during and/or after a section of the expandable tubular has been expanded. In one embodiment, the tension and compression loads applied to the expandable tubular may be permitted to change as a result of the expansion process while the expansion is being executed.

In one embodiment, all of the components of the test assembly500are controlled by a controller, such as a computer that continually monitors the loads that are to be maintained. As the expander560, the piston rods544,554, and574and the first and second crossheads510and520move, the controller maintains the pressures inside the piston cylinders542,552, and572by pumping or removing hydraulic fluid. In one embodiment, the controller may include one or more pump controls that are configured to regulate the flow and pressure of hydraulic fluids to the piston cylinders542,552, and572. In one embodiment, the controller may include one or more sensors, such as load cells, that are configured to communicate to the controller what the loads are in the test sample580during expansion. In one embodiment, the controller may be configured to continuously monitor and maintain the supply of fluid pressure to the test sample580to provide the thrust force necessary to move the expander560.

The test assembly500is operable to accurately simulate numerous variations of a “fixed-free” or a “fixed-fixed” expansion. In one embodiment, the test sample580can be expanded using one or more combinations of the first, second, and third actuation assemblies and fluid pressure. In one embodiment, the test sample580can be constrained at both ends to prevent the test sample580from length shrinkage during expansion. In one embodiment, the different tension and compression forces can be applied to the test sample580in any order.

In one embodiment, the test assembly500may be operable to expand test samples within a range of about 3½ inches in diameter to about 13⅜ inches or about 16 inches in diameter. In one embodiment, the test assembly500may include a pump system operable to supply up to about 10,000 PSI into the test sample. In one embodiment, the test assembly500is operable to move the expander560through the test sample580at a speed up to about 10 feet per minute.

FIGS. 6A and 6Billustrate a test assembly600for expanding a tubular string having one or more connections, according to one or more of the test configurations100,200,300, and800described herein. The embodiments, described above with respect to the test assemblies400and500may also be provided using the test assembly600.FIG. 6Aillustrates the test assembly600in a load or test configuration, andFIG. 6Billustrates the test assembly600in a combination expansion configuration.

The test assembly600may include a rectangular frame602, having one or more rails604, for supporting a first crosshead610, a second crosshead620, a third crosshead630, and a fourth crosshead635. The first crosshead610may be movable relative to the frame602along the rails604. The second, third, and fourth crossheads620,630, and635may be stationary and fixed to the frame602. The second and fourth crossheads620and635may integral with the frame602, such as the ends of the frame602. The third crosshead630may be fixed to the frame602at different locations depending on whether the test assembly600is used in the load or test configuration as shown inFIG. 6Aor in the combination expansion configuration shown inFIG. 6B. The test assembly600also includes one or more first actuation assemblies640configured to apply a first load to a test sample680, one or more second actuation assemblies650configured to apply a second load to the test sample680, and one or more third actuation assemblies670configured to apply a third load to the test sample680.

As illustrated inFIG. 6A, a test sample680may be secured at one end to the third crosshead630and at the other end to the fourth crosshead635via the third actuation assembly670. In one embodiment, the third actuation assembly670may be a 1.5M lb-load cylinder. The test sample680may be an unexpanded tubular string having one or more connections or an expanded tubular string having one or more expanded connections. In this configuration, a tension or a compression load may be applied to the test sample680by actuation of the third actuation assembly670. The test assembly600may therefore be used to test and analyze the structural integrity of the test sample680before and/or after expansion.

As illustrated inFIG. 6B, the test assembly600may further include an expander660, such as a cone, that is connected to the third and/or fourth crossheads630and635via a piston rod674. The piston rod674may be a tubular member or connecting rod having a flow bore therethrough. The piston rod674may extend through an opening in the first crosshead610and into the test sample680. Fluid communication to the test sample680may be established through the flow bore of the piston rod674. The expander660may be connected to the lower end of the piston rod674and positioned within the test sample680. The expander660may be provided with one or more seals662, such as seal cups, to form a sealed chamber686within the test sample680. The test sample680may include an expandable tubular string having one or more expandable tubular members that are connected together by one or more threaded connections. The upper end of the test sample680may be connected to an end cap684that is supported by the first crosshead610, and the lower end of the test sample680may be closed and/or sealingly connected to an end cap682that is supported by the second actuation assembly650.

In one embodiment, the first actuation assembly640may include a pair of piston cylinders642and piston rods644that are operable to move the first crosshead610. The piston cylinders642may be connected to the second crosshead620using one or more flanged connections, and the piston rods644may be connected to the first crosshead610in a similar manner. The piston cylinders642and rods644may be the same piston cylinders and rods442and444described above. The first actuation assembly640is configured to apply a compressive force to the test sample680. Placing the test sample680in compression simulates a compressive load generated by tubular string weight that places a tubular string connection in compression when supported downhole. The amount of compression applied to the test sample680may simulate the amount of compression experienced by the tubular string connection, depending on its location along a length of the tubular string when downhole. The compression load is generated by pulling the first crosshead610by actuation of the piston cylinders642and rods644. The portion of the test sample680ahead of the expander660may thus be compressed between the end cap of the first crosshead610and the expander660, which is secured by the third and/or fourth crossheads via the third actuation assembly670. The compression load is maintained by adjusting the pressure supplied to the first actuation assembly640as the expander660moves through the test sample680and as the test sample680shrinks in length.

In one embodiment, the second actuation assembly650may include a piston cylinder652and a piston rod654that are operable to apply a load to the test sample680. The piston cylinder652may be connected to the second crosshead620using one or more flanged connections, and the piston rod654may be connected to test sample680via the end cap682. The piston cylinder652and rod654may be the same piston cylinder and rod452and454described above. The second actuation assembly650is configured to apply a tensile force to the test sample680. Placing the test sample680in tension simulates a tensile load generated by tubular string weight that places a tubular string connection in tension when supported downhole. The amount of tension applied to the test sample680may simulate the amount of tension experienced by the tubular string connection, depending on its location along a length of the tubular string when downhole. The tension load is generated by pulling on the test sample680by actuation of the piston cylinder652and rod654. The portion of the test sample680behind the expander660may thus be tensioned by the opposing forces provided by the second actuation assembly650and the expander660via the third actuation assembly670. The tension load is maintained by adjusting the pressure supplied to the second actuation assembly650as the expander660moves through the test sample680and as the test sample680shrinks in length.

In one embodiment, the third actuation assembly670may include a piston cylinder672and a piston rod674that are operable to secure and/or move the expander660through the test sample680. The piston cylinder672may be connected to the fourth crosshead635using a flanged connection, and the piston rod674may extend through openings in the third and first crossheads630and610and into the test sample680. The piston cylinder672and rod674may be the same piston cylinder and rod442and444described above. The third actuation assembly670may be configured to constrain the expander660against the forces applied by the first and second actuation assemblies640and650to produce the loads in the test sample680. The third actuation assembly670may also apply a pull force to move the expander660through the test sample680. The pull force may be maintained by adjusting the pressure supplied to the third actuation assembly670as the expander660moves through the test sample680and as the test sample680shrinks in length. The piston rod674may be retracted into the piston cylinder672as the expander660moves through the test sample680.

The application of the compression and tension loads by the first and second actuation assemblies640and650may be insufficient to move the expander660through the test sample680. The test assembly600may apply calculated compression and tension loads to the test sample680to simulate the run-in and un-expanded position of a tubular connection when located in a vertical, horizontal, or lateral wellbore. After the pre-loads are applied to the test sample680, the third actuation assembly670may be actuated until the expansion force is reached to move the expander660through the test sample680.

In one embodiment, the test assembly600may also be operable to supply fluid pressure into the chamber686via a pump690to further place the length of the test sample680behind the expander660in tension to simulate the tensile load that would be generated by the thrust force of the fluid pressure. In one embodiment, a hydraulic fluid such as water may be supplied into the chamber686by the pump690to generate the thrust force necessary to move the expander660. The fluid pressure may be supplied through the flow bore of the piston rod674. In one embodiment, the fluid pressure may be supplied to the chamber686directly through a port in the test sample680.

The combination of tension, compression, and fluid pressure are calculated to exceed the requisite expansion force necessary to expand the tubular test sample. During expansion, the loads provided by the actuation assemblies and the fluid pressure are continuously maintained according to a predetermined schedule as the expander660moves through and expands the test sample680to simulate the loads when downhole. In one embodiment, the predetermined schedule may include varying one or more of the tension and/or compression loads during expansion of the test sample680. In one embodiment, the predetermined schedule may include maintaining one or more of the tension and/or compression loads constant during expansion of the test sample680. In one embodiment, as the expander660moves through the test sample680, the compressive load applied to the length of the test sample680ahead of the expander660remains the same and the tensile load applied to the length of the test sample680behind the expander660remains the same. To ensure a constant load, the fluid pressure and the pressures supplied to the piston cylinders642,652, and672and rods644,654, and674are adjusted to account for the application of the different loads and the changes in the lengths of the test sample680ahead of and behind the expander660, as the expander660moves from one end to the other end. In one embodiment, the piston rod654of the second actuation assembly650may extend during expansion of the test sample680to accommodate for the shrinkage of the test sample680, while maintaining the requisite tensile load on the test sample680. In one embodiment, the test assembly600may be operable to accommodate for up to about a 10 percent shortening of the length of the test sample680during expansion. In one embodiment, one or more controllers may be used to automatically adjust the actuation pressure of the piston cylinders642,652, and672and the fluid pressure during expansion. In one embodiment, the predetermined schedule of loads applied to the expandable tubular may include provision for changing one or more of the applied loads during and/or after a section of the expandable tubular has been expanded. In one embodiment, the tension and compression loads applied to the expandable tubular may be permitted to change as a result of the expansion process while the expansion is being executed.

In one embodiment, all of the components of the test assembly600are controlled by a controller, such as a computer that continually monitors the loads that are to be maintained. As the expander660, the piston rods644,654, and674and the first crosshead610move, the controller maintains the pressures inside the piston cylinders642,652, and672by pumping or removing hydraulic fluid. In one embodiment, the controller may include one or more pump controls that are configured to regulate the flow and pressure of hydraulic fluids to the piston cylinders642,652, and672. In one embodiment, the controller may include one or more sensors, such as load cells, that are configured to communicate to the controller what the loads are in the test sample680during expansion. In one embodiment, the controller may be configured to continuously monitor and maintain the supply of fluid pressure to the test sample680to provide the thrust force necessary to move the expander660.

The test assembly600is operable to accurately simulate numerous variations of a “fixed-free” or a “fixed-fixed” expansion. In one embodiment, the test sample680can be expanded using one or more combinations of the first, second, and third actuation assemblies and fluid pressure. In one embodiment, the test sample680can be constrained at both ends to prevent the test sample680from length shrinkage during expansion. In one embodiment, the different tension and compression forces can be applied to the test sample680in any order.

In one embodiment, the test assembly600may be operable to expand test samples within a range of about 3½ inches in diameter to about 13⅜inches or about 16 inches in diameter. In one embodiment, the test assembly600may include a pump system operable to supply up to about 10,000 PSI into the test sample. In one embodiment, the test assembly600is operable to move the expander660through the test sample680at a speed up to about 10 feet per minute.

FIGS. 7A and 7Billustrate a test assembly700for expanding a tubular string having one or more connections, according to one or more of the test configurations100,200,300, and800described herein. The embodiments, described above with respect to the test assemblies400,500, and600may also be provided using the test assembly700. The test assembly700is operable to apply and maintain tension and compression loads on a first length of a tubular string located in front of an expander and a second length of the tubular string located behind the expander, while the expander expands the tubular. The test assembly700is thus operable to accurately simulate the expansion of tubular string connections under downhole conditions.

The test assembly700may include a frame702having four symmetrically positioned rails704for supporting a first crosshead710, a second crosshead720, a third crosshead730, and a fourth crosshead735. The first and second crossheads710and720may be movable along different sets of the rails704, and the third and fourth crossheads730and735may be stationary and fixed to all four of the rails704. The test assembly700also includes one or more first actuation assemblies740configured to apply a first load to a test sample780, and one or more second actuation assemblies750configured to apply a second load to the test sample780. The test assembly700further includes an expander760, such as a cone, that is connected a work string770. The work string770may be a tubular member or connecting rod having a flow bore therethrough. The work string770is connected to the third crosshead730and may extend through an opening in the first crosshead710into the test sample780. Fluid communication to the test sample780may be established through the flow bore of the work string770. The expander760may be connected to the lower end of the work string770and positioned within the test sample780. The expander760may be provided with one or more seals762, such as seal cups, to form a sealed chamber786within the test sample780. The test sample780may include an expandable tubular string having one or more expandable tubular members that are connected together by one or more threaded connections. The upper end of the test sample780may be connected to an end cap784that is supported by the first crosshead710, and the lower end of the test sample780may be closed and/or sealingly connected to an end cap782that is supported by the second crosshead720.

In one embodiment, the first actuation assembly740may include a pair of piston cylinders742and piston rods744that are operable to move the first crosshead710along a first set of the rails704. The piston cylinders742may be connected to the third crosshead730using one or more flanged connections, and the piston rods744may be extend through openings in the third crosshead730and connect to the first crosshead710. The piston cylinders742and rods744may be the same piston cylinders and rods442and444described above. The first actuation assembly740is configured to apply a compressive force to the test sample780. Placing the test sample780in compression simulates a compressive load generated by tubular string weight that places a tubular string connection in compression when supported downhole. The amount of compression applied to the test sample780may simulate the amount of compression experienced by the tubular string connection, depending on its location along a length of the tubular string when downhole. The compression load is generated by pushing the first crosshead710by actuation of the piston cylinders742and rods744. The portion of the test sample780ahead of the expander760may thus be compressed between the end cap784of the first crosshead710and the expander760, which is secured by the third crosshead730via the work string770. The compression load is maintained by adjusting the pressure supplied to the first actuation assembly740as the test sample780is moved over the expander760and as the test sample780shrinks in length.

In one embodiment, the second actuation assembly750may include a pair of piston cylinders752and piston rods754that are operable to move the second crosshead720along a second set of the rails704. The piston cylinders752may be connected to the third crosshead730using one or more flanged connections, and the piston rods754may extend through openings in the third crosshead730and connect to the second crosshead720. The piston cylinders752and rods754may be the same piston cylinders and rods452and454described above. The second actuation assembly750is configured to apply a tensile force to the test sample780. Placing the test sample780in tension simulates a tensile load generated by tubular string weight that places a tubular string connection in tension when supported downhole. The amount of tension applied to the test sample780may simulate the amount of tension experienced by the tubular string connection, depending on its location along a length of the tubular string when downhole. The tension load is generated by pushing on the second crosshead720by actuation of the piston cylinders752and rods754, which in effect applies a pull force to the lower end of the test sample780via the end cap782. The portion of the test sample780behind the expander760may thus be tensioned by the opposing forces provided by the second actuation assembly750and the secured connection of the expander760to the third crosshead730via the work string770. The tension load is maintained by adjusting the pressure supplied to the second actuation assembly750as the test sample780is moved over the expander760and as the test sample780shrinks in length.

The application of the compression and tension loads by the first and second actuation assemblies740and750may be insufficient to move the test sample780over the expander760. The test assembly700may apply calculated compression and tension loads to the test sample to simulate the run-in and un-expanded position of a tubular connection when located in a vertical, horizontal, or lateral wellbore. After the pre-loads are applied to the test sample780, fluid pressure may be continuously supplied through the flow bore of the work string770into the sealed chamber786until the expansion force is reached to move the test sample780over the expander760. In one embodiment, the fluid pressure may be supplied to the chamber786directly through a port in the test sample780. Supplying fluid pressure into the chamber786may further place the length of the test sample780behind the expander760in tension to simulate the tensile load that would be generated by the thrust force of the fluid pressure. In one embodiment, a hydraulic fluid such as water may be supplied into the chamber786by a pump to generate the thrust force.

The combination of tension, compression, and fluid pressure are calculated to exceed the requisite expansion force necessary to expand the tubular test sample. During expansion, the loads provided by the actuation assemblies and the fluid pressure are continuously maintained according to a predetermined schedule as the test sample780is moved over the expander760and is expanded to simulate the loads when downhole. In one embodiment, the predetermined schedule may include varying one or more of the tension and/or compression loads during expansion of the test sample780. In one embodiment, the predetermined schedule may include maintaining one or more of the tension and/or compression loads constant during expansion of the test sample780. In one embodiment, as the expander760passes through the test sample780, the compressive load applied to the length of the test sample780ahead of the expander760remains the same and the tensile load applied to the length of the test sample780behind the expander760remains the same. To ensure a constant load, the fluid pressure and the pressures supplied to the piston cylinders742and752and piston rods744and754are adjusted to account for the application of the different loads and the changes in the lengths of the test sample780ahead of and behind the expander760, as the expander760passes from one end to the other end. In one embodiment, at least one of the piston rods744and754of the actuation assemblies may be operable to adjust the spacing between the first and second crossheads710and720during expansion of the test sample780to accommodate for the shrinkage of the test sample780, while maintaining the requisite loads on the test sample780. In one embodiment, the test assembly700may be operable to accommodate for up to about a 10 percent shortening of the length of the test sample780during expansion. In one embodiment, one or more controllers may be used to automatically adjust the actuation pressure of the piston cylinders742and752and the fluid pressure during expansion. In one embodiment, the predetermined schedule of loads applied to the expandable tubular may include provision for changing one or more of the applied loads during and/or after a section of the expandable tubular has been expanded. In one embodiment, the tension and compression loads applied to the expandable tubular may be permitted to change as a result of the expansion process while the expansion is being executed.

In one embodiment, all of the components of the test assembly700are controlled by a controller, such as a computer that continually monitors the loads that are to be maintained. As the test sample780, the piston rods744and754, and the first and second crossheads710and720move, the controller maintains the pressures inside the piston cylinders742and752by pumping or removing hydraulic fluid. In one embodiment, the controller may include one or more pump controls that are configured to regulate the flow and pressure of hydraulic fluids to the piston cylinders742and752. In one embodiment, the controller may include one or more sensors, such as load cells, that are configured to communicate to the controller what the loads are in the test sample780during expansion. In one embodiment, the controller may be configured to continuously monitor and maintain the supply of fluid pressure to the test sample780to provide force necessary to move the test sample780over the expander760.

The test assembly700is operable to accurately simulate numerous variations of a “fixed-free” or a “fixed-fixed” expansion. In one embodiment, the test sample780can be expanded using one or more combinations of the first and second actuation assemblies and the fluid pressure. In one embodiment, the test sample780can be constrained at both ends by locking the spacing between the first and second crossheads710and720to prevent the test sample780from length shrinkage during expansion. In one embodiment, the different tension and compression forces can be applied to the test sample780in any order.

In one embodiment, the test assembly700may be operable to expand test samples within a range of about 3½ inches in diameter to about 13⅜ inches or about 16 inches in diameter. In one embodiment, the test assembly700may include a pump system operable to supply up to about 10,000 PSI into the test sample. In one embodiment, the test assembly700is operable to move the test sample780over the expander760at a speed up to about 10 feet per minute.

FIG. 7Billustrates the test sample780in an expanded state. As illustrated, the first and second actuation assemblies740and750and the fluid pressure supplied to the chamber786have moved the test sample over the expander760. The expander760remains in a stationary position and the first and second crossheads710and720, which are secured to the test sample780, are moved along the rails704to move the test sample780over the expander760. The test assembly700is operable to move the entire length of the test sample780over the expander760. The spacing between the first and second crossheads710and720may be adjusted to accommodate for a variety of lengths of test samples780.

In one embodiment, each of the actuation assemblies of the test assemblies400,500,600, and700may be operable to apply both a tensile load and a compressive load to the test samples. Each of the test assemblies400,500,600, and700may thus have the flexibility to expand a test sample in one or more different configurations by controlling, adjusting, and/or changing the operation of the actuation assemblies. Each of the test assemblies400,500,600, and700may therefore be arranged according to at least the test configurations100,200,300, and800shown inFIGS. 1-3and8.

FIG. 8illustrates the fourth test configuration800for simulating the downhole expansion of a tubular connection. The fourth test configuration800includes a tubular810, a work string820extending through the tubular810, and an expander830disposed within a lower end of the tubular and connected to the end of the work string820. The tubular810may include one or more tubular members connected together by one or more connections. A first load850, a second load840, and a third load860may be applied to the tubular810during expansion of the tubular810. The first load850may be applied to a first end of the tubular810. In one embodiment, the first load850may be applied to the tubular810by one or more ways known by one of ordinary skill in the art. In one embodiment, the first load850may be applied to the tubular810using one or more piston cylinders. The first load850is applied to the tubular810to thereby compress a length812of the tubular against the expander830, which is constrained by the second load840that is applied to the work string820. Placing the length812of the tubular in compression simulates a compressive load generated by weight of a tubular string that places a connection of the tubular string in compression when supported downhole. The amount of compression applied to the length812may simulate the amount of compression experienced by a tubular string connection, depending on its location along a length of a tubular string when downhole. The third load860may be applied to the lower end of the tubular810in a similar manner as the second load160described above. The third load860places a length814of the tubular behind the expander830in tension, as the expander830is constrained by the second load840that is applied to the work string820. Placing the length814of the tubular in tension simulates a tensile load generated by weight of a tubular string that places a connection of the tubular string in tension when supported downhole. The amount of tension applied to the length814may simulate the amount of tension experienced by a tubular string connection, depending on its location along a length of a tubular string when downhole. The second load840may be applied to an end of the work string820in a similar manner as the first load150described above, to secure and/or move the expander830through the tubular810. The second load840may be configured to constrain the expander830against the forces applied by the first and third loads850and860to produce the loads in the tubular810. The second load840may also apply a pull force to move the expander830through the tubular810. In one embodiment, the application of the first, second, and/or third loads may be insufficient to move the expander830through the tubular810(or move the tubular810over the expander830). In one embodiment, the first, second, and third loads may be pre-determined and may remain constant during expansion of the tubular810.

Prior to expansion, the fourth test configuration800may apply calculated first, second, and third loads850,840, and860to the tubular810to simulate the run-in and un-expanded position of a tubular connection when located in a vertical, horizontal, and/or lateral wellbore. After the applicable loads are applied to the tubular810, fluid pressure may then be supplied through the work string810into a sealed chamber816, formed between the expander830and the lower end of the tubular810, to move the expander830through the tubular810(or move the tubular810over the expander830). In one embodiment, the fluid pressure may be supplied to the sealed chamber816directly through a port in the tubular810. Supplying fluid pressure into the chamber816may further place the length814of the tubular behind the expander830in tension to simulate the tensile load that would be generated by the thrust force of the fluid pressure. In one embodiment, the loads may be applied to the tubular810upon and/or as a result of expansion of the tubular.

The combination of tension, compression, and fluid pressure are calculated to exceed the requisite expansion force necessary to expand the tubular810. During expansion, the first, second, and third loads850,840, and860and the fluid pressure are continuously maintained according to a predetermined schedule as the expander830moves through and expands the tubular810(or the tubular810moves over the expander830and is expanded) to simulate the tension and compression loads in the tubular when downhole. In one embodiment, as the expander830moves through the tubular810(or the tubular810moves over the expander830), the compressive load applied to the length812of the tubular remains constant and the tensile load applied to the length814of the tubular remains constant. To ensure a constant load, the mechanism used to provide the first load850is continuously adjusted to account for the application of the second and third loads840and860and the fluid pressure, and vice versa. The mechanisms used to provide the first load850, the second load840, the third load860, and the fluid pressure are adjusted to account for the changes in the length812and814of the tubular810located ahead of and behind the expander830as it moves from one end to the other end. Adjustments may also be made to account for the shrinkage of the tubular810during expansion. In one embodiment, one or more controllers may be used to automatically adjust the mechanisms used to provide the first, second, and third loads850,860, and840and the fluid pressure during expansion. In one embodiment, the predetermined schedule of loads applied to the expandable tubular may include provision for changing one or more of the applied loads during and/or after a section of the expandable tubular has been expanded. In one embodiment, the tension and compression loads applied to the expandable tubular may be permitted to change as a result of the expansion process while the expansion is being executed.

FIG. 9Aillustrates one embodiment of a bending assembly900that may be used with one or more of the test assemblies described herein to help simulate the expansion of a tubular connection in a deviated or curved wellbore. The bending assembly900includes a first fixture910, a second fixture920, and a third fixture930, which are used to secure a test sample980onto a curved support surface940of the assembly900to provide a bend in the test sample980. The test sample980may include an expandable tubular having one or more connections, such as threaded connections. The curved support surface940may be in the form of a curve, arc, or other similar shape such that the ends of the surface are tapered at an angle relative to a crest of the surface, which may be located at a middle portion of the surface between the ends. In one embodiment, the curved support surface940may include a plurality of plates having machined surfaces that form the curved support surface940. The plates940may be secured to a support member950, such as an I-beam, and may be replaceable to change the bend radius of the curved support surface940. In one embodiment, the curved support surface940may include a bend angle in a range of about 1 degree to about 30 degrees, including a range of about 5 degrees to about 15 degrees.

The first, second, and third fixtures910,920, and930are used to force the test sample980against the curved support surface940to create a bend in the test sample980. In one embodiment, the bend in the test sample980may have a constant bend radius. Other, varying bend radii are also contemplated. The first and second fixtures910and920may secure the test sample980to the curved plates940and the support member950via a cylindrical sleeve960. The portion of the cylindrical sleeve960that contacts the curved support surface940may include a machined flat section to help ensure a constant bend radius when contacting the support surface. The cylindrical sleeve960supports one end of the test sample980to allow the test sample980to move or shorten in length during expansion. In one embodiment, the first, second, and third fixtures910,920, and930may each include a (hydraulic, pneumatic, and/or electric) piston-cylinder arrangement912disposed between a fixed support member914and a movable support member916, which are supported by guide rails918, for applying a force to the test sample980. Upon actuation, the piston-cylinder arrangement912may react against the fixed support member914and force the movable support member916against the test sample980and the curved support surface940. In one embodiment, the fixtures910,920, and930may be mechanically actuated, such as with a threaded configuration, to force the test sample980against the curved support surface940.

FIG. 9Billustrates a cross-sectional view of an end985of the test sample980.FIG. 9Bshows an expander990installed in the test sample980and an end cap970that is connected to the end985of the test sample980to form a sealed chamber986therebetween. The end cap970may be used to facilitate connection of the bending assembly900and the test sample980to any one of the test assemblies described herein. The expander990could then be pressurized and/or pulled through the test sample980to expand the test sample980. The pressure could be released before the expander990reaches the cylindrical sleeve960.

In one embodiment, the test assemblies400,500,600,700, and800may be configured to simulate downhole expansion in a wellbore deviation using the bending assembly900. Prior to expansion a test sample may be provided with a bend using the bending assembly900. The test sample and bending assembly900may be connected to the test assemblies using threaded connections, tubing adapters, and/or swivel arrangements. The swivel arrangement may allow the application of compression and/or tension loads to the bent test sample while preventing straightening of the test sample. A tensile load may be generated in the test sample on one side of the bend and/or a compression load may be generated in the test sample on the other side of the bend. The test sample may then be expanded as described above, with or without the addition of fluid pressure and in a fixed-free and/or fixed-fixed configuration, while maintaining the constant bend radius in the test sample and the one or more loads applied to the test sample. The test assemblies are thus operable to simulate the downhole expansion of a tubular connection when in a deviated or curved wellbore.

FIGS. 10A and 10Billustrate a top view and a side view, respectively, of a test assembly1000and the bending assembly900secured thereto. The test assembly1000includes a frame1002, a first crosshead1010, a second crosshead1020, and a first actuation assembly1040. The test sample980may be secured to the bending assembly900as described above. The test sample980may also be secured to the first and second crossheads1010and1020using one or more end caps1090, threaded adapters1095, and/or swivels1070to accommodate for the curved ends of the test sample980. One or more buckling assemblies1080may also be provided as part of the test assembly1000to prevent bucking of the test sample980and/or the additional support/connection members used to connect the test sample980to the test assembly1000.

In one embodiment, the first actuation assembly1040may include a pair of piston cylinders1042and piston rods1044, similar to the actuation assemblies described above. The piston cylinders1042may be connected to the first crosshead1010using one or more flanged connections, and the piston rods1044may be connected to the second crosshead1020in a similar manner. The first and second crosshead1010and1020may be movably connected to frame1002via one or more rollers to accommodate various lengths of test samples980. The first actuation assembly1040is configured to apply a compressive force and/or a tension force to the test sample980, similar to the others test assemblies described above. Fluid pressure may be supplied to the test sample980to pump an expander through the test sample980for expansion thereof while a load is applied to the bent test sample980.

In one embodiment, the test assemblies described herein are operable to expand tubular test samples having one or more connections, such as threaded connections. The test assemblies are operable to simulate virtually all different types of downhole expansion loading conditions and scenarios. Numerous expandable tubular connection designs may thus be expanded and tested using the test assemblies. The expanded tubular connection designs may then be further tested and analyzed to define an operating envelope, including structural integrity, sealing capacity, etc., within which the connection designs may perform effectively without failure.

In one embodiment, one or more well designs may be planned according to the operating envelopes of one or more expandable tubular connections designs. In one embodiment, the drilling and completion of a well may be planned according to the operating envelope of one or more expandable tubular connections. During a wellbore operation within the well, such as a drilling operation, a completion operation, a remedial operation, the tubular connections may then be installed and expanded in the well.

In one embodiment, one or more expandable tubular connection designs may be tested using the test assemblies described herein. The tubular connection designs may be subjected to one or more loading conditions during expansion. The loading conditions may simulate the downhole loading conditions expected or anticipated during downhole expansion in one or more current or future well designs. Based on the results of the testing, one or more of the tubular connection designs may be selected for use in the well designs and may then be installed and expanded in the wells.