This invention relates generally to testing a junction of plural bores in a well, such as a junction between a main wellbore and a lateral bore of a multilateral well.
To produce hydrocarbons from a reservoir in an earth sub-surface, one or more wellbores are drilled into the earth sub-surface to intersect the reservoir. The wellbores are completed by installing casings or liners, packers, tubings or pipes, valves, and other components. Perforations are also formed at one or more zones in the wellbores, with hydrocarbons flowing through the perforations into the wellbores.
To enhance the productivity of a reservoir, multiple lateral bores are drilled from a main wellbore to increase the interface area between the reservoir and the well. Following the drilling of lateral bores from a main wellbore, the junction of the main wellbore and each lateral bore is completed with a junction assembly.
Typically, the junction assembly defines a sealed path from a lateral bore into the main wellbore to enable the flow of hydrocarbons from the reservoir into the lateral bore, through the junction assembly into the main wellbore, and up to the surface of the well.
One of the concerns associated with junction assemblies is that leaks may occur at the junction due to defective components. Usually, such leaks are not detected until after completion of the junctions of a well. For example, a well operator may detect leaks in the junction assemblies during well operation that prevent proper operation of the well. If that occurs, then the well operator will have to perform an expensive intervention operation to fix the faulty junction assembly. Intervention operations are typically time consuming and expensive. In addition to hauling heavy equipment to a well site, the well operator usually has to shut down the well. Well interventions are especially expensive in subsea applications, where it is difficult to move intervention equipment to a well site and to lower the intervention equipment into the subsea well.
In general, methods and apparatus are provided to test a junction assembly during installation of the junction assembly. For example, a method of completing a well includes installing a junction assembly at a junction of first and second bores in a well, and during an installation procedure of the junction assembly, testing a sealed connection in the junction assembly. The method further includes determining, during the installation procedure, whether the sealed connection in the junction assembly is leaking based on the testing.
Other or alternative features will be apparent from the following description, from the drawings, and from the claims.
In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments are possible.
As used here, the terms “up” and “down”; “upper” and “lower”; “upwardly” and downwardly”; “upstream” and “downstream”; “above” and “below”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the invention. However, when applied to equipment and methods for use in environments that are deviated or horizontal, such terms may refer to a left to right, right to left, or other relationship as appropriate.
Referring to
The junction assemblies 22, 24, and 26 can be installed in one trip, or in multiple trips. The process of installing junction assemblies is referred to as an “installation procedure” of the junction assembly. The installation procedure involves running in of the junction assembly equipment on a work string or running string into the well. Each junction assembly may be installed in multiple runs, such as by first installing a template followed by the installation of a connector through the template into a lateral bore. In other embodiments, the installation of each junction assembly may involve only one run instead of multiple runs.
A desired characteristic of each junction assembly is that it has one or more sealed connections to enable fluid to flow from the lateral bore into the main wellbore without leaking into other parts of the well. A “sealed connection” of the junction assembly refers to any connection or interaction between components of the junction assembly or between the junction assembly and another component. It is desired to identify any problems at each junction assembly as early in the well completion process as possible. Waiting until after the well completion has been installed to determine whether a junction assembly is leaking may cause the subsequent repair or replacement of the faulty junction assembly to be time consuming and thus expensive. Therefore, in accordance with some embodiments of the invention, each junction assembly is tested during the installation procedure of the junction assembly. By testing each junction assembly during its installation, faulty junction assemblies can be detected early (that is, during installation). If the junction assembly is detected to be faulty, it can then be removed and replaced with another junction assembly. This avoids the necessity of an intervention run into the wellbore to fix a faulty junction assembly.
As illustrated, a lower portion of the template 102 includes a landing tool 110 that has a profile 112 to mate with a corresponding profile 114 in the casing 14. Although not shown, the landing tool 110 and the landing profiles 112 and 114 are associated with an orienting mechanism to provide a desired azimuthal orientation of the template 102 with respect to the window 104 in the casing 14. The orienting mechanism orients the template 102 such that the window 108 of the template 102 is azimuthally aligned with the window 104 in the casing 14.
A pipe 116 extends from the lower end of the template 102. A plug 118 is provided in the pipe 116 to block fluid flow through the pipe 116. Effectively, the plug 118 blocks fluid flow between the inner bore of the template 102 and the region of the well below the template 102. The plug 118 is a retrievable plug that can be removed from inside the pipe 116 during well operation to enable fluid flow between the inside of the template 102 and the region of the wellbore below the junction assembly 100.
In alternative embodiments, instead of a plug 118, a valve can be used that can be actuated between open and closed positions. For example, the valve can be a formation isolation valve or other type of valve.
A seal 120 is arranged outside the pipe 116 to enable the pipe 116 to be sealably stabbed into a seal bore 122. Another pipe 124 extends below the seal bore 122. A packer 126 is provided around a portion of the pipe 124 to isolate the regions above and below the packer 126. The seal bore 122, packer 126, and pipe 124 are installed in the wellbore before the installation of the template 102.
The template 102 is configured to receive a connector 130 having a portion 130A that extends through the window 108 of the template 102. The connector portion 130A protrudes into the lateral bore 106. Another portion of the connector 130 is portion 130B that is in the main wellbore 12. The connector 130 is sealably connected to the template 102 such that fluids and solids are blocked from being communicated between the inside fluid path of the junction assembly 100 and the outside of the junction assembly 100.
A pipe section 132 extends from a distal end of the connector 130 inside the lateral bore 106. The pipe section 132 is sealably engaged inside a seal bore 134, with another pipe 136 extending below the seal bore 134.
For purposes of testing the seal integrity of the junction assembly, a test tool 138 is run into and through the connector 130. The test tool 138 has a conduit 140 that extends through the connector 130 and into the pipe section 132. The lower end of the test tool 138 includes a ball seat 142 to receive a ball 144 that is dropped into the test tool 138 from the well surface for testing the junction assembly 100. A running string 143 is attached to the upper end of the test tool 138. The running string 143 lowers the test tool 138 into the junction assembly 100.
The upper portion of the connector 130 sealably receives the test tool 138 by providing a seal 147 at the inner surface of the connector 130 to engage an outer surface of the test tool 138. The lower end of the test tool 138 is sealably engaged inside the pipe 132 by providing a seal 146 between an outer surface of the connector test tool 138 and an inner surface of the pipe 132.
Instead of the arrangement that includes the ball 144 and ball seat 142 for shutting in the distal portion of the test tool 138, other types of mechanisms are used in other embodiments for shutting in the distal portion of the test tool 138.
Radial circulation ports 148 are also provided somewhere along the length of the test tool 138. Flow through the circulation ports are controlled by a sleeve valve 150, which can be actuated to move so that the radial ports 148 are exposed to enable communication of fluid between the inner bore of the test tool conduit 140 and an annular region 152 between the test tool 138 and the connector 130.
In one embodiment, the sleeve valve 150 is responsive to an elevated pressure. For example, the sleeve valve is attached by a shear mechanism (not shown) to the test tool 138. Once the pressure inside the test tool 138 is raised to a sufficient pressure level, the shear mechanism is broken to enable the elevated pressure to act on the sleeve valve 150 to open the sleeve valve 150 so that flow can occur between the inner bore of the test tool conduit 140 and the annular region 152 through the circulation ports 148. In other embodiments, other mechanisms are used for opening the sleeve valve 150. Such other mechanisms include mechanisms that are electrically operated, actuated by mechanical force, and so forth.
Instead of a sleeve valve 150, other types of valves are used in other embodiments. For example, such other types of valves include flapper valves, ball valves, or other types of valves.
Next, the ball 144 is dropped (at 210) into the test tool 38. Once the ball 144 is seated on the ball seat 142, flow through the test tool conduit 140 is blocked, which causes the pressure within the test tool conduit 140 to increase (at 212). Upon the pressure increasing to a predetermined level, the sleeve valve 150 is actuated to the open position so that the circulation ports 148 are exposed to enable fluid inside the test tool conduit 140 to flow into the annulus region 152 between the test tool 138 and the connector 130. Pumping of the test fluid is continued (at 214) so that fluid is flowed through the circulation ports 148. At this point, the well operator monitors (at 216) the pressure level, referred to as P2. Because of the blockage of the test tool conduit 140 by the ball 144 at the distal portion of the test tool 138, the pressure within the test tool conduit 140 increases to a level (referred to as P2) that is higher than the pressure P1 without the blockage provided by the ball 144. The seal integrity of the junction assembly is determined (at 218) by the monitoring system 50. An indication of the seal integrity may also be provided.
The extent of the pressure increase depends upon whether there is seal integrity in the junction assembly 100. If the seal integrity of the junction assembly 100 is “good” (that is, there is no substantial leakage at the one or more sealed connections of the junction assembly 100), then the pressure P2 increases to a relatively high level that is greater than a predetermined threshold 200, as shown in FIG. 4A. However, if the seal integrity of the junction assembly 100 is not good (that is, there is substantial leakage at the sealed connections of the junction assembly), then the pressure P2 increases to a level that is below the predetermined threshold, as shown in FIG. 4B.
Initially, after a test flow has been generated in the test tool 138 and before the ball 144 has been dropped, the pressure inside the test tool conduit 140 is at P1. Once the ball 144 is seated in the ball seat 142, the pressure inside the test tool increases. If the seal connections of the junction assembly 100 are working properly, then the pressure increases to a P2 level that is greater than the predetermined threshold 200. However, if the junction assembly is leaky, then the pressure P2 increases to a level that is below the predetermined threshold 200 (FIG. 4B).
A benefit of the procedure discussed in connection with
The following
As shown in
In
As further shown in
Each continuous groove 312 has an upper end 312A (the “proximal end”) and a lower end 312B (the “distal end”). In the embodiment shown, the width of the groove 312 near the upper end 312A is larger than the width of the groove 312 near the lower end 312B. The width of the groove 312 gradually decreases along its length, starting at the upper end 312A, so that the groove has a maximum width at the upper end 312A and a minimum width at the lower end 312B. In other embodiments, other arrangements of the continuous grooves 312 are possible. For example, each continuous groove can have a generally constant width along its length. Alternatively, instead of a gradual variation of the groove width, step changes of the groove can be provided.
The enlarged upper portion of each groove 312 provides an orientation mechanism for guiding a corresponding rail 326 of the connector 130 into the groove 312. The upper portion of the groove 312 has at least one angulated surface 319 for guiding the connector rail 326.
The lower end 312B of each groove 312 in the template 102 defines a lower connector stop 316, which is engageable by the lower end of the connector rail 326 to prevent further downward movement of the connector 130 once the connector rails 326 are fully engaged in the grooves 312.
Referring to
Each continuous rail 326 has an upper end 326A (the “proximal end”) and a lower end 326B (the “distal end”). The width of the upper end 326A is larger than the width of the lower end 326B. The rail 326 gradually decreases in width along its length starting from the upper end 326A. In other embodiments, other arrangements of the rails 326 are possible. The variation of the width of the rails 326 is selected to correspond generally to the variation of the width of the grooves 312 in the template 102.
As further shown in
Also, as the connector 130 is forced to follow the inclined path provided by the inclined grooves 312 and rails 326, the connector 130 is elastically and/or plastically deformed to follow the inclined path. Thus, as bending force is applied to the connector housing 321 by the ramping action of the rail and groove interlocks, the connector housing 321 is deformed or flexed to permit its lower end to move through the casing window and into the lateral branch bore.
The continuous rail and groove interlocking mechanism shown in
In an alternative embodiment, instead of a continuous rail 326 as shown in
Another desired feature of some embodiments of the invention is that a continuous fluid seal path is defined around the periphery of the lateral window 108 of the template 102. As schematically illustrated in
To provide the closed seal path, the sealing element in one embodiment is routed along the rails 326 (
At the lower end of the continuous seal path 350, the sealing element wraps around, or makes a “U-turn” around the lower end 326B of the rails 326. Thus, when the lower end 326B, and the sealing element wrapped around the lower end, engages the stop 316 (
Referring to
In the illustrated example, the sealing element 360 undulates along the rail 326 to form a generally wavy sealing element. The generally wavy form of the sealing element 360 enables a more secure engagement in a groove formed in the rail 326. Other shapes of the sealing element 360 may be used in other embodiments.
In the template 102 shown in
Referring to
The body member 402 defines a diverter surface 418 for directing lateral branch equipment, including the packer 414 and a portion of the tubing 406 into the lateral bore.
One or more radial circulation ports 420 are defined near the upper end of the tubing 406. Flow through the circulation ports 420 is controlled by a sleeve valve 422 (or by some other type of valve). Also, plugs 426 and 428 are provided at the distal ends of tubings 404 and 406, respectively. Alternatively, the plug 426 can be a retrievable plug and is similar to the plug 118 shown in FIG. 2. The plug 428 can be a ball-type plug (where a ball is dropped from the surface to a ball seat at the lower end of the tubing 406). In yet other embodiments, other types of plugs can be used, including valves, and so forth.
In operation, the packers 412 and 414 are first set in the main wellbore and lateral bore respectively. Next, an assembly including the dual packer 416, body member 402, and tubings 404 and 406 are lowered into the main wellbore and run to the junction between the main wellbore and lateral bore. Initially, the tubings 404 and 406 are attached to the body member 402 such that the lower ends of the tubings 404 and 406 are above the diverter surface 418. As the assembly is being installed at the junction, an orienting member 430 is used to orient the body member 402 with respect to a casing 403 set in the main wellbore. The body member 402 is oriented such that the tubing 406 is aligned with respect to the lateral window 401. Once installed, a downward force is applied on the work string that is connected to the assembly to push the tubings 404 and 406 downwardly. The tubing 406 is diverted by the diverter surface 418 into the lateral bore. The ends of the tubings 404 and 406 are engaged into the packers 412 and 414, respectively, and thereby sealably engaged in respective seal bores of the packers 412 and 414
As part of the installation procedure, leaks in the junction assembly 400 can be tested for according to some embodiments. As with the embodiment of
The plug 428 is then closed, which causes the pressure in the tubing 406 to increase. Once the pressure reaches a predetermined level, the valve 422 is actuated to the open position to allow flow between the inside of the tubing 406 and the region outside the tubing 406. The pressure increase to some level P2 is monitored. If P2 is greater than a predefined threshold, then there is no substantial leakage at the junction assembly 400.
According to yet another arrangement, another type of junction assembly 500 (
The branching sub 502 can be of any desired configuration. In one embodiment, as shown in
After the branching outlets have been expanded, closure members 514, 516, and 518 (
The branching sub 502 also has radial circulation ports 520 that are defined at the upper end of the branching sub 502. Flow through the circulation ports 520 are controlled by a valve 522, such as a sleeve valve.
To perform the test, all closure members 514, 516, and 518 are closed, which causes pressure to increase. The increasing pressure causes actuation of the valve 522 to open the circulation ports 520. This enables the flow of fluid from inside of the branching sub 502 to outside the branching sub 502. The increase in pressure in the junction is monitored to determine if there are any leaks.
While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover such modifications and variations as fall within the true spirit and scope of the invention.
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