SYSTEM AND METHOD FOR FACILITATING USE OF AN ELECTRIC SUBMERSIBLE PUMPING SYSTEM

DOCKET NO. : IS15.0360-WO-PCT

INVENTORS: Dinesh Patel

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present document is based on and claims priority to U.S. Provisional

Application Serial No.: 62/140,106, filed March 30, 2015, which is incorporated herein by reference in its entirety.

BACKGROUND

[0002] In many hydrocarbon well applications, electric submersible pumping

(ESP) systems are used for pumping of fluids, e.g. hydrocarbon-based fluids. For example, the ESP system may be used to pump oil from a downhole wellbore location to a surface collection location. Some ESP systems are deployed downhole into the wellbore by cable. In some applications, however, the cables may be susceptible to damage due to tension and/or compression forces once the ESP system is deployed. The cable also may be susceptible to torque forces during, for example, ESP system startup. Sometimes testing of sealing engagement with a polished bore receptacle and/or pressure testing of seal assemblies also can be more difficult when using cable deployed ESP systems.

SUMMARY

[0003] In general, a system and methodology facilitate deployment, land out, testing, and/or operation of electric submersible pumping systems in a variety of applications and environments. For example, features may be combined with various types of deployed electric submersible pumping systems to resist potentially detrimental forces and/or to facilitate testing of seals. The features may comprise an anchor, a torque feature, a temporary flow blocking mechanism, and/or other features which facilitate use of a cable deployed electric submersible pumping system or otherwise deployed electric submersible pumping system.

[0004] However, many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Certain embodiments of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein, and:

[0006] Figure 1 is a schematic illustration of a well system comprising an example of a cable deployed electric submersible pumping system positioned in a borehole, e.g. a wellbore, according to an embodiment of the disclosure; [0007] Figure 2 is a schematic illustration of an example of a cable deployed electric submersible pumping system deployed in a borehole, according to an

embodiment of the disclosure;

[0008] Figure 3 is a schematic illustration of an example of an anchor system which may be used to anchor the electric submersible pumping system, according to an embodiment of the disclosure;

[0009] Figure 4 is a schematic illustration of the anchor system illustrated in

Figure 3 but in a different operational position, according to an embodiment of the disclosure;

[0010] Figure 5 is a schematic illustration showing a top view of an example of an anchor system with a plurality of anchors, according to an embodiment of the disclosure;

[0011] Figure 6 is a schematic illustration of an example of a pressure actuated flow control valve which may be used with the electric submersible pumping system, according to an embodiment of the disclosure;

[0012] Figure 7 is a schematic illustration similar to that of Figure 6 but showing the flow control valve in a different operational position, according to an embodiment of the disclosure;

[0013] Figure 8 is an illustration of an example of a ball valve which may be used with the electric submersible pumping system to selectively control flow, according to an embodiment of the disclosure;

[0014] Figure 9 is a schematic illustration similar to that of Figure 8 but showing the ball valve in a different operational position, according to an embodiment of the disclosure; [0015] Figure 10 is a schematic illustration of an example of a torque feature which may be used in combination with the electric submersible pumping system, according to an embodiment of the disclosure; and

[0016] Figure 1 1 is a schematic illustration showing another view of the torque feature illustrated in Figure 10, according to an embodiment of the disclosure.

DETAILED DESCRIPTION

[0017] In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.

[0018] The present disclosure generally relates to a system and methodology which facilitate the deployment, land out, testing, and/or operation of electric submersible pumping systems in a variety of applications and environments. In various embodiments, the electric submersible pumping system is a cable deployed electric submersible pumping system in which a structurally capable power cable is used to deploy the electric submersible pumping system downhole into a borehole, e.g. a wellbore. By way of example, a feature or features may be combined with the electric submersible pumping system to protect the cable during deployment, land out, testing, and/or startup of the electric submersible pumping system.

[0019] It should be noted that the various features described herein may be used with other types of electric submersible pumping systems that are deployed with structures other than a cable. However, many of the features are useful in protecting the cable and/or other components associated with the electric submersible pumping system by, for example, resisting potentially detrimental forces. For example, the feature or features may comprise an anchor system which acts to resist/absorb tension and/or compression forces. According to an embodiment, the anchor system may comprise at least one hydraulic anchor which is actuated by differential pressure between an intake side and a discharge side of the electric submersible pumping system.

[0020] The feature or features also may comprise a torque feature positioned to resist/absorb torque forces during, for example, startup of the electric submersible pumping system. According to an embodiment, the torque feature may comprise at least one torque key engaged with at least one corresponding slot positioned in a housing associated with a polished bore receptacle. The feature or features also may comprise a temporary flow blocking mechanism used to plug tubing on a downhole side of the electric submersible pumping system. The ability to temporarily block flow facilitates testing as to whether a seal system is properly engaged with a polished bore receptacle and/or to provide additional pressure testing of a given seal assembly or assemblies. By way of example, the flow blocking mechanism may be in the form of a pressure actuated ball valve, a pressure actuated shrouded flow control valve, a rupture disc (e.g. a glass or ceramic rupture disc), a degradable material plug, a salt plug, and/or other feature able to temporarily block fluid flow through the system.

[0021] Referring generally to Figure 1, an example of a well system 20 is illustrated as deployed in a borehole 22, e.g. a wellbore. In this example, the well system 20 may comprise a completion 24 which may be in the form of completion tubing disposed within a casing 26 or within an open hole section of borehole 22. The well system 20 further comprises an electric submersible pumping system 28 deployed into borehole 22 via a cable 30, e.g. a structural power cable. The electric submersible pumping system 28 may comprise a variety of components selected according to the parameters of a given application. In the illustrated embodiment, however, the electric submersible pumping system comprises a submersible motor 32, a motor protector 34, an intake 36, and a submersible pump 38 powered by the submersible motor 32. [0022] During operation of electric submersible pumping system 28, fluid is drawn in through intake 36 and discharged into an isolated annulus 40, e.g. an isolated annulus above a packer 42, for delivery to the surface. However, many other types of tubing structures may be used to deliver the pumped fluid to a desired collection location. In some applications, the packer 42 may be replaced by other mechanisms for sealing the completion tubing 24 with the electric submersible pumping system 28. As illustrated, the electric submersible pumping system 28 may be coupled with cable 30 via a suitable connector 44.

[0023] Referring again to Figure 1, the illustrated embodiment utilizes a shroud or other type of tubing 46 sealably coupled with the electric submersible pumping system 28 and extending in a downhole direction. The tubing 46 may be oriented for engagement with a polished bore receptacle 48. For example, the tubing 46 may be inserted into polished bore receptacle 48 and sealed therein via a seal assembly 50. As discussed above, the well system 20 may comprise various features which work in cooperation with the electric submersible pumping system 28 to facilitate deployment, land out, testing, and/or operation of the electric submersible pumping system 28.

[0024] An example of such a feature is an anchor system 52 which may be used to secure the electric submersible pumping system 28 at a desired location within the borehole 22. In this example, the anchor system 52 comprises anchors 54 which may be actuated between tubing 46 and a surrounding surface 56, e.g. an interior surface of completion tubing 24. The anchor system 52 may be selectively actuated hydraulically via a pressure differential established by operation of the electric submersible pumping system 28. When actuated, anchor system 52 protects the power cable 30 and/or other components of well system 20 from tension forces and/or compression forces while the electric submersible pumping system 28 is deployed. In some applications, the well system 20 also may comprise a torque feature 58 used to counter torque forces during, for example, startup of the electric submersible pumping system 28. Depending on the embodiment, additional and/or other features may be used to facilitate use of the electric submersible pumping system 28 as explained in greater detail below. [0025] Referring generally to Figure 2, another example of a well system 20 is illustrated. In this example, the electric submersible pumping system 28 is illustrated schematically but the system may comprise components such as those described with reference to Figure 1. In the embodiment illustrated in Figure 2, elements similar to those illustrated in the embodiment of Figure 1 have been labeled with the same reference numerals.

[0026] As illustrated, the electric submersible pumping system 28 is similarly located within completion tubing 24. However, completion tubing 24 has radially expanded sections 60 and contracted sections 62, including a lower contracted section 62 which may engage polished bore receptacle 48 externally and extend into cooperation with a production tubing 64. In this embodiment, anchor system 52 comprises a plurality of the anchors 54 which may be selectively actuated into engagement with the surrounding surface 56 at the illustrated contracted section 62.

[0027] In the embodiment of Figure 2, the torque feature 58 comprises at least one anti -rotation key 66, e.g. a plurality of keys 66, slidably received in at least one corresponding slot 68, e.g. a plurality of corresponding slots 68. By way of example, slots 68 may be formed in an upper housing portion of polished bore receptacle 48 and keys 66 may be mounted to tubing 46. The well system 20 also may comprise a temporary flow blocking mechanism 70 positioned along the tubing 46 to enable selective blocking of fluid flow to electric submersible pumping system 28. In some applications, the flow blocking mechanism 70 is in the form of a ball valve 72 but other types of flow blocking mechanisms 70 may be employed.

[0028] Depending on the application, the well system 20 may comprise various other components. For example, the system may comprise a flow diverter valve 74 and a pressure gauge 76 to monitor, for example, annular pressure and tubing pressure proximate anchor system 52. The flow diverter valve 74 and pressure gauge 76 may be coupled via control lines 78 to corresponding control lines within cable 30. The well system also may comprise features such as a surface controlled circulating valve 80, a pressure/temperature gauge 82, and a surface controlled barrier valve 84 mounted, for example, along production tubing 64. The valve 80, gauge 82, and barrier valve 84 may be controlled from and/or provide data to the surface via control lines 86. In this example, a production tubing packer 88 is disposed between production tubing 64 and casing 26. It should be noted that tubing 24 may be joined with polished bore receptacle 48 to create a debris sump 90 and to enable pumping of production fluids up through annulus 40. However, other techniques may be used to isolate annulus 40 so that production fluids may be pumped to the surface (see, for example, packer 42 illustrated in Figure 1).

[0029] When the electric submersible pumping system 28 is deployed downhole into borehole 22, seal assembly 50 and keys 66 are received at polished bore receptacle 48. To verify receipt in polished bore receptacle 48 and to test seal assembly 50, flow blocking mechanism 70 may be closed while pressure is applied down through annulus 40. Subsequently, the electric submersible pumping system 28 may be operated. The torque feature 58, e.g keys 66 received in slots 68, prevent rotation of the electric submersible pumping system 28 during startup and thus protect cable 30 against unwanted torque forces.

[0030] As the electric submersible pumping system 28 is started, well fluid is drawn up through production tubing 64 and through intake 36, as represented by arrows 91. The operation of electric submersible pumping system 28 creates an intake pressure within tubing 46 which is the pressure along the region of inflowing fluid 91. The electric submersible pumping system 28 discharges the fluid into annulus 40 through an outlet 94 for production up through annulus 40, as represented by arrows 96. This downstream flow creates a discharge pressure in annulus 40 which is greater than the intake pressure within tubing 46. As described in greater detail below, the pressure differential between the discharge pressure and the intake pressure may be used to actuate anchors 54 of anchor system 52. [0031] Referring generally to Figure 3, an embodiment of anchor system 52 is illustrated. In this example, anchor system 52 comprises a plurality of the actuatable anchors 54 which are oriented to act between tubing 46 and surrounding surface 56, e.g. the interior surface of tubing 24. According to the illustrated embodiment, each actuator 54 comprises a housing 92 having an interior 94 extending therethrough and a piston 96 slidably received within the interior 94. The piston 96 may include a radially expanded section 98, and the longitudinal travel of piston 96 may be limited by a housing abutment 100 on one longitudinal end and by an abutment ring 102 on the opposite longitudinal end. A plurality of seals, e.g. seals 104, 106 and 108 may be disposed between piston 96/abutment ring 102 and housing 92 of each actuator 54. A spring 110, e.g. a coil spring, may be positioned within an interior 94 to bias piston 96 in a desired direction, e.g. toward a disengaged position as illustrated in Figure 3.

[0032] Each piston 96 further comprises an engagement end 112 oriented for engagement with the surrounding wall surface 56. By way of example, each engagement end 112 may comprise a carbide button 114, however other engagement features may be utilized to securely grip the surrounding surface 56. Each piston 96 further comprises a pressure communication passageway 1 16 providing pressure communication between the interior of tubing 46 and a region surrounding piston 96 between seals 104 and 106. Passageway 1 16 allows an intake pressure 118 to be communicated to one side of piston 96 in the region between seals 104 and 106, as represented by arrows 120.

[0033] The housing 92 also comprises a pressure communication passageway 122 extending between an exterior region surrounding tubing 46 in annulus 40 and a region surrounding piston 96 between seal 104 and abutment 100. Passageway 122 allows a discharge pressure 124 to be communicated to an opposite side of piston 96 (relative to the intake pressure 118) in the region between seal 104 and abutment 100, as represented by arrows 126. When the electric submersible pumping system 28 is not being operated, the intake pressure 118 is generally equal with the discharge pressure 124 so that each spring 110 biases the corresponding piston 96 and its engagement end 1 12 to a disengaged position as illustrated in Figure 3. [0034] However, once the electric submersible pumping system 28 is started to pump well fluid up along annulus 40 the discharge pressure 124 becomes greater than the intake pressure 118, thus creating a pressure differential. The pressure differential is experienced on opposite sides of piston 96 via pressure communication passageways 116 and 122. At each actuator 54, the pressure differential increases to a level which overcomes the spring force exerted by spring 1 10 and shifts the corresponding piston 96 radially outwardly until its engagement end 112 is securely engaged with the surrounding surface 56, as illustrated in Figure 4. Engagement of anchor system 52 via anchors 54 effectively resists/ab sorbs tension and/or compression forces that would otherwise be transferred to cable 30 from electric submersible pumping system 28.

[0035] Referring generally to Figure 5, an example of an arrangement of actuators

54 is illustrated. In this example, the housing 92 is disposed around the entire

circumference of tubing 46. A plurality of the interiors 94 are formed in housing 92 for receiving corresponding pistons 96 for selective actuation, as described above. In the example illustrated, four actuators 54 are arranged to provide four pistons 96 which are circumferentially spaced equal distances about tubing 46. However, a single actuator 54 or other numbers of actuators 54 can be used in a variety of arrangements to enable the desired anchoring upon establishing a pressure differential via operation of electric submersible pumping system 28.

[0036] Referring generally to Figures 6 and 7, another embodiment of the flow blocking mechanism 70 is illustrated. In this embodiment, the flow blocking mechanism 70 is in the form of a pressure actuated, shrouded flow control valve 128. The flow control valve 128 may be selectively actuated to temporarily close off fluid flow along the internal tubing 46 while, for example, testing proper receipt and sealing of seal assembly 50 in polished bore receptacle 48.

[0037] In this embodiment, the flow control valve 128 comprises a housing 130 having an interior passage 132 in which a mandrel 134 is slidably received. The housing 130 is coupled to tubing 46 via a flow shroud 136, and a plug 138 is used to block flow along internal passage 132 of housing 130. When the flow control valve 128 and electric submersible pumping system 28 are run in hole, the mandrel 134 is positioned in a closed configuration, as illustrated in Figure 6. A plurality of seals 140 maintain a seal between mandrel 134 and the internal housing surface forming interior passage 132.

[0038] After the flow control valve 128 and the electric submersible pumping system 28 are run in hole and seal assembly 50 is engaged with polished bore receptacle 48, the seal assembly 50 may be pressure tested by increasing pressure along annulus 40. When operation of electric submersible pumping system 28 is desired for production of borehole fluids, the pressure may be increased to a level sufficient to open a flow control mechanism 142, e.g. a rupture disc 144. Once flow control mechanism 142 is opened, the pressurized fluid is able to flow through passage 146 so as to act on mandrel 134 and to shift the mandrel 134 to an open flow configuration, as illustrated in Figure 7. Shifting the mandrel 134 to the open flow configuration opens a flow port 148 which allows borehole fluids, e.g. well production fluids, to flow up through tubing 46 and through flow control valve 128, as represented by arrows 150, for entry into electric submersible pumping system 28.

[0039] Another example of flow blocking mechanism 70 is illustrated in Figures

8 and 9. In this embodiment, temporary flow blocking mechanism 70 comprises ball valve 72 rotatably mounted in a housing 152 which may be positioned along tubing 46. Within housing 152 a ball valve operator 154 is coupled between ball valve 72 and a piston 156 to enable selective shifting of the ball valve 72 between a closed position, as illustrated in Figure 8, and an open position as illustrated in Figure 9. The ball valve 72 comprises a flow passage 158, and when the flow passage 158/ball valve 72 are rotated to the closed position, a seal 160 maintains sealing engagement between ball valve 72 and the surrounding housing 152. In some applications, a lock mechanism 162 may be used to at least temporarily secure ball valve operator 154 at a desired position. Some applications also incorporate a drain valve 163. [0040] When the ball valve 72 and electric submersible pumping system 28 are run in hole, the ball valve operator 154 and ball valve 72 are positioned in a closed configuration, as illustrated in Figure 8. After the electric submersible pumping system 28 is run in hole and seal assembly 50 is engaged with polished bore receptacle 48, the seal assembly 50 may be pressure tested by increasing pressure along annulus 40. When operation of electric submersible pumping system 28 is desired for production of borehole fluids, the pressure may be increased to a level sufficient to open a flow control mechanism 164, e.g. rupture disc 144.

[0041] Once flow control mechanism 164 is opened, the pressurized fluid is able to flow through a passage 166 to act against piston 156 in a manner which shifts ball valve operator 154 and ball valve 72 to an open flow configuration, as illustrated in Figure 9. Shifting the ball valve 72 to the open flow configuration allows borehole fluids, e.g. well production fluids, to flow up through tubing 46 and through flow passage 158 for entry into electric submersible pumping system 28.

[0042] Referring generally to Figures 10 and 11, an embodiment of torque feature

58 is illustrated. In this embodiment, the torque feature 58 comprises a plurality of the torque keys 66 which may be mounted to tubing 46. By way of example, the torque keys 66 may be affixed, e.g. welded, attached by fasteners, or otherwise secured, to tubing 46 such that the torque keys 66 extend radially outwardly. The torque keys 66 are sized to extend into and slide along the corresponding key slots 68. In some embodiments, the torque keys 66 may be equally spaced circumferentially about tubing 46 for receipt in correspondingly spaced slots 68. The slots 68 may have wider, tapered entries 168 to help guide keys 66 down into the corresponding key slots 68 to a desired location. In this example, the slots 68 are formed in an upper housing of polished bore receptacle 48, however the slots 68 may be formed in other structures of the overall well system 20. Similarly, the keys 66 may be mounted to other structures.

[0043] After the keys 66 are fully received in corresponding slots 68, the tubing

46 and the electric submersible pumping system 28 are restricted, e.g. prevented, from rotating about their longitudinal axes. By preventing rotation of electric submersible pumping system 28, potentially detrimental torque forces are prevented from acting on cable 30 (or other conveyance).

[0044] The anchor system 52, torque feature 58, and/or temporary flow blocking mechanism 70 may be combined with the electric submersible pumping system 28 to protect the cable 30 (or other conveyance) during deployment, land out, testing, and/or startup of the electric submersible pumping system 28. For example, the anchor system 52 may be used to resist/absorb tension and/or compression forces. The torque feature 58 may be positioned to resist/absorb torque forces during, for example, startup of the electric submersible pumping system 28. The temporary flow blocking mechanism 70 may utilize various mechanisms to temporarily plug tubing 46 on a downhole side of the electric submersible pumping system 28 to enable seal testing and/or other testing.

[0045] Depending on the parameters of a given application and/or environment, the structure of features 52, 58, 70 may be adjusted. In the embodiments described above, the anchor system 52 utilizes at least one hydraulic anchor actuated by differential pressure between an intake side and a discharge side of the electric submersible pumping system 28. However, the anchor system 52 may utilize various other types of actuators, such as other types of electro-mechanical or hydro-mechanical actuators. Similarly, the torque feature 58 may comprise various types of inter-meshing features able to resist torque forces during, for example, startup and operation of the electric submersible pumping system 28.

[0046] The flow blocking mechanism 70 also may have various constructions, such as the pressure actuated ball valve, pressure actuated shrouded flow control valve, a rupture disc (e.g. a glass or ceramic rupture disc), a degradable material plug, a salt plug, and/or other feature able to temporarily block fluid flow through the system. Similarly, the overall well system 20 may have various additional and/or other features selected according to the parameters of a given operation. [0047] Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.