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Title:
METHOD AND SYSTEM FOR INSTALLING AN ELECTRICAL SUBMERSIBLE PUMP
Document Type and Number:
WIPO Patent Application WO/2019/083352
Kind Code:
A1
Abstract:
Method and System for Installing an Electrical Submersible Pump A method and a system for installing an electrical submersible pump, and an assembly for lifting a production fluid in a live well are provided. The method includes installing a retrievable packer at a downhole end of the live well and installing a cable termination block between a tubing-head spool and a production tree of the live well. The retrievable packer is configured to receive the electrical submersible pump, and the cable termination block mechanically and fluidly connects the tubing-head spool and the production tree. The method also includes connecting a pressure control assembly to the production tree, and lowering a first safety valve and the electrical submersible pump through the pressure control assembly and along a tubing string using a cable having a first end attached to the electrical submersible pump. The method further includes installing the first safety valve such that the first safety valve engages with a second safety valve disposed along the tubing string, and installing the electrical submersible pump on the retrievable packer at the downhole end of the live well such that the retrievable packer supports the weight of the electrical submersible pump.

Inventors:
M AYAD, Kamal Mohamad (Petronas Twin TowersKuala Lumpur City Centre, Kuala Lumpur ., 50088, MY)
ALEXANDER, Euan (Petronas Twin TowersKuala Lumpur City Centre, Kuala Lumpur ., 50088, MY)
HASSAN, Hani Sufia (Petronas Twin TowersKuala Lumpur City Centre, Kuala Lumpur ., 50088, MY)
-, Kuswanto (Petronas Twin TowersKuala Lumpur City Centre, Kuala Lumpur ., 50088, MY)
Application Number:
MY2018/050071
Publication Date:
May 02, 2019
Filing Date:
October 23, 2018
Export Citation:
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Assignee:
PETROLIAM NASIONAL BERHAD (PETRONAS) (Tower 1, Petronas Twin Towers,Kuala Lumpur City Centre, Kuala Lumpur ., 50088, MY)
International Classes:
E21B43/12; H02G15/02
Domestic Patent References:
WO2016011326A12016-01-21
Foreign References:
GB2071766A1981-09-23
US6328111B12001-12-11
US3638732A1972-02-01
Attorney, Agent or Firm:
SPRUSON & FERGUSON (M) SDN BHD (A-33-02, Level 33,Menara UOA Bangsar,,No. 5, Jalan Bangsar Utama 1, Kuala Lumpur ., 59000, MY)
Download PDF:
Claims:
Claims

A method for installing an electrical submersible pump in a live well, the method comprising:

installing a retrievable packer at a downhole end of the live well, the retrievable packer configured to receive the electrical submersible pump;

installing a cable termination block between a tubing-head spool and a production tree of the live well, the cable termination block mechanically and fluidly connecting the tubing-head spool and the production tree;

connecting a pressure control assembly to the production tree;

lowering a first safety valve and the electrical submersible pump through the pressure control assembly and along a tubing string using a cable having a first end attached to the electrical submersible pump;

installing the first safety valve such that the first safety valve engages with a second safety valve disposed along the tubing string; and

installing the electrical submersible pump on the retrievable packer at the downhole end of the live well such that the retrievable packer supports the weight of the electrical submersible pump.

The method of claim 1 , further comprising

mechanically coupling a second end of the cable to a cable hanger such that the cable hanger supports the weight of the cable; and

securing the cable hanger within the cable termination block.

The method of claims 1 or 2, wherein installing the retrievable packer at the downhole end of the live well comprises:

providing the retrievable packer comprising an anti-rotation portion and an anti-recirculation portion,

wherein the anti-rotation portion is configured to maintain an angular position of the electrical submersible pump within the tubing string and wherein the anti-recirculation portion is configured to prevent recirculation of fluids in the downhole end of the live well.

The method of any one of claims 1 to 3, wherein installing the cable termination block between the tubing-head spool and the production tree of the live well comprises:

connecting a first end of the cable termination block to a receiving end of the tubing-head spool, the first end of the cable termination block configured to match the receiving end of the tubing-head spool; and

connecting a second end of the cable termination block to an input end of the production tree, the second end of the cable termination block configured to match the input end of the production tree.

5. The method of any one of claims 2 to 4, further comprising routing the

mechanically coupled cable through the cable hanger and the cable termination block, to a cable exit disposed on a side of the cable termination block.

6. The method of any one of claims 1 to 5, wherein connecting the pressure control assembly to the production tree comprises providing a blowout preventer on the production tree, the blowout preventer connected to a pressure test subassembly, a lubricator and a sealing element.

7. The method of any one of claims 1 to 6, wherein the cable is configured to

support at least the weight of the electrical submersible pump and to provide electrical connection to the electrical submersible pump.

8. The method of any one of claims 1 to 7, wherein lowering the first safety valve and the electrical submersible pump is controlled by a lifting system comprising: lifting hooks configured to carry at least one of: a load profile of the cable and the electrical submersible pump, the pressure test subassembly, the lubricator and the sealing element; and

at least one sheave configured to redirect the cable passing through the pressure control assembly towards a cable winch and a wireline unit.

9. A system for installing an electrical submersible pump, the system comprising:

a retrievable packer configured to be disposed at a downhole end of the live well and to receive the electrical submersible pump;

a cable termination block configured to be disposed between a tubing-head spool and an production tree of the live well, thereby mechanically and fluidly connecting the tubing-head spool and the production tree;

a pressure control assembly configured to be connected to the production tree;

a lifting system configured to lower the electrical submersible pump and a first safety valve through the pressure control assembly and along a tubing string using a cable having a first end attached to the electrical submersible pump; wherein the first safety valve is configured to engage with a second valve disposed along the tubing string; and

wherein the retrievable packer is configured to support the weight of the electrical submersible pump. 10. The system of claim 9, further comprising a cable hanger configured to be

secured within the cable termination blockand mechanically coupled to a second end of the cable.

1 1 . The system of claims 9 or 10, wherein the retrievable packer comprises:

an anti-rotation portion and an anti-recirculation portion, wherein the anti- rotation portion is configured to maintain an angular position of the electrical submersible pump within the tubing string and wherein the anti-recirculation portion is configured to prevent recirculation of fluids in the downhole end of the live well.

12. The system of any one of claims 9 to 1 1 , wherein the cable termination block comprises:

a first end configured to match a receiving end of the tubing-head spool; and

a second end configured to match an input end of the production tree.

13. The system of any one of claims 9 to 12, further comprising a cable exit disposed on a side of the cable termination block, the cable exit configured to receive the mechanically coupled cable routed through the cable hanger and the cable termination block.

14. The system of any one of claims 9 to 13, wherein the pressure control assembly comprises a blowout preventer configured to be provided on the production tree and connected to a pressure test subassembly, a lubricator and a sealing element.

15. The system of any one of claims 9 to 14, wherein the cable is configured to

support at least the weight of the electrical submersible pump and to provide electrical connection to the electrical submersible pump.

16. The system of any one of claims 9 to 15, the lifting system comprises:

lifting hooks configured to carry at least one of: a load profile of the cable and the electrical submersible pump, the pressure test subassembly, the lubricator and the sealing element; and

at least one sheave configured to redirect the cable passing through the pressure control assembly towards a cable winch and a wireline unit.

An assembly for lifting a production fluid in a live well, the assembly comprising: an electrical submersible pump;

a retrievable packer installed at a downhole end of the live well, the retrievable packer receiving the electrical submersible pump;

a cable termination block installed between a tubing-head spool and an production tree of the live well, the cable termination block mechanically and fluidly connecting the tubing-head spool and the production tree;

a cable having a first end attached to the electrical submersible pump and a second end terminating at the cable termination block;

wherein the electrical submersible pump is installed on the retrievable packer at the downhole end of the live well such that the weight of the electrical submersible pump is supported by the retrievable packer.

The assembly of claim 17, further comprising a cable hanger secured within the cable termination block, wherein the cable hanger is mechanically coupled to the second end of the cable.

The assembly of claims 17 or 18, wherein the retrievable packer comprises: an anti-rotation portion and an anti-recirculation portion, the anti-rotation portion maintaining an angular position of the electrical submersible pump within a tubing string and the anti-recirculation portion preventing recirculation of fluids in the downhole end of the live well.

The assembly of any one of claims 17 to 19, wherein the cable termination block comprises:

a first end matching a receiving end of the tubing-head spool; and a second end matching an input end of the production tree.

The assembly of any one of claims 18 to 20, further comprising a cable exit disposed on a side of the cable termination block, the cable exit receiving the mechanically coupled cable routed through the cable hanger and the cable termination block. The assembly of any one of claims 17 to 22, wherein the cable is configured to support at least the weight of the electrical submersible pump and to provide electrical connection to the electrical submersible pump.

Description:
Method and System for Installing an Electrical

Submersible Pump

Technical Field

[0001 ] The present invention generally relates to a method and system for installing an electrical submersible pump, and to an assembly for lifting production fluid in a live well.

Background Art

[0002] An electrical submersible pump, typically called an ESP, is a device used in an artificial lift method for lifting production fluids from a wellbore to generate flow from a mature well where low flow is occurring, or to increase flow from a producing well. The electrical submersible pump is typically positioned in a downhole end of the wellbore, and submerged in the production fluid to be pumped.

[0003] However, installation of electrical submersible pump systems within a tubing string has proven difficult to execute due to cost considerations, technology and resource constraints. For example, economic considerations can restrict use of electrical submersible pump systems because a well workover, which requires significant time and cost, is conventionally required prior to the installation of the ESP. The components required for successful deployment of these ESP systems inside the tubing string of a live well are also currently unavailable from a single component provider, further complicating technological considerations. While it would be advantageous to avoid a well workover, to date, none of the previous attempts to deploy ESPs by cable have addressed the problems with deployment over a live well, particularly with regard to well barrier control, pressure containment, safety measures and compatibility with existing equipment of the live well. More particularly, stringent requirements for pressure control assembly and strict well barrier policies have made it especially difficult for installation of cable-deployed electrical submersible pump systems within a tubing string in an offshore environment. Furthermore, many companies which operate oil producing wells use production trees in a vertical configuration. This presents a technical challenge for installation of a cable- deployed ESP since the cable attached to the ESP cannot be hung above the vertical production tree, as the cable would prevent the valves from closing. Thus, a new horizontal production tree is typically required to be installed after the ESP is deployed downhole. [0004] Accordingly, what is needed is method and system for installing an electrical submersible pump in a live well, that seeks to address some of the above problems. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the disclosure.

Summary of Invention

[0005] A first aspect of the present invention provides a method for installing an electrical submersible pump in a live well. The method comprises installing a retrievable packer at a downhole end of the live well, the retrievable packer configured to receive the electrical submersible pump, installing a cable termination block between a tubing-head spool and a production tree of the live well, the cable termination block mechanically and fluidly connecting the tubing-head spool and the production tree, and connecting a pressure control assembly to the production tree. The method also comprises lowering a first safety valve and the electrical submersible pump through the pressure control assembly and along a tubing string using a cable having a first end attached to the electrical submersible pump, installing the first safety valve such that the first safety valve engages with a second safety valve disposed along the tubing string and installing the electrical submersible pump on the retrievable packer at the downhole end of the live well such that the retrievable packer supports the weight of the electrical submersible pump. [0006] The method may further comprise mechanically coupling a second end of the cable to a cable hanger such that the cable hanger supports the weight of the cable, and securing the cable hanger within the cable termination block.

[0007] The step of installing the retrievable packer at the downhole end of the live well may comprise providing the retrievable packer comprising an anti-rotation portion and an anti-recirculation portion, wherein the anti-rotation portion is configured to maintain an angular position of the electrical submersible pump within the tubing string and wherein the anti-recirculation portion is configured to prevent recirculation of fluids in the downhole end of the live well.

[0008] The step of installing the cable termination block between the tubing-head spool and the production tree of the live well may comprise connecting a first end of the cable termination block to a receiving end of the tubing-head spool, the first end of the cable termination block configured to match the receiving end of the tubing-head spool, and connecting a second end of the cable termination block to an input end of the production tree, the second end of the cable termination block configured to match the input end of the production tree.

[0009] The method may further comprise routing the mechanically coupled cable through the cable hanger and the cable termination block, to a cable exit disposed on a side of the cable termination block.

[0010] The step of connecting the pressure control assembly to the production tree may comprise providing a blowout preventer on the production tree, the blowout preventer connected to a pressure test subassembly, a lubricator and a sealing element.

[001 1 ] The cable may be configured to support at least the weight of the electrical submersible pump and to provide electrical connection to the electrical submersible pump.

[0012] The step of lowering the first safety valve and the electrical submersible pump is controlled by a lifting system. The lifting system may comprise lifting hooks configured to carry at least one of: a load profile of the cable and the electrical submersible pump, the pressure test subassembly, the lubricator and the sealing element, and at least one sheave configured to redirect the cable passing through the pressure control assembly towards a cable winch and a wireline unit.

[0013] A second aspect of the present invention provides a system for installing an electrical submersible pump. The system comprises a retrievable packer configured to be disposed at a downhole end of the live well and to receive the electrical submersible pump, a cable termination block configured to be disposed between a tubing-head spool and an production tree of the live well, thereby mechanically and fluidly connecting the tubing-head spool and the production tree, a pressure control assembly configured to be connected to the production tree, a lifting system configured to lower the electrical submersible pump and a first safety valve through the pressure control assembly and along a tubing string using a cable having a first end attached to the electrical submersible pump, wherein the first safety valve is configured to engage with a second valve disposed along the tubing string and wherein the retrievable packer is configured to support the weight of the electrical submersible pump.

[0014] The system may further comprise a cable hanger configured to be secured withi the cable termination block and mechanically coupled to a second end of the cable. [0015] The retrievable packer may comprise an anti-rotation portion and an anti- recirculation portion, wherein the anti-rotation portion is configured to maintain an angular position of the electrical submersible pump within the tubing string and wherein the anti- recirculation portion is configured to prevent recirculation of fluids in the downhole end of the live well.

[0016] The cable termination block may comprise a first end configured to match a receiving end of the tubing-head spool and a second end configured to match an input end of the production tree.

[0017] The system may further comprise a cable exit disposed on a side of the cable termination block, the cable exit configured to receive the mechanically coupled cable routed through the cable hanger and the cable termination block.

[0018] The pressure control assembly may comprise a blowout preventer configured to be provided on the production tree and connected to a pressure test subassembly, a lubricator and a sealing element. [0019] The cable may be configured to support at least the weight of the electrical submersible pump and to provide electrical connection to the electrical submersible pump.

[0020] The lifting system may comprise lifting hooks configured to carry at least one of: a load profile of the cable and the electrical submersible pump, the pressure test subassembly, the lubricator and the sealing element, and at least one sheave configured to redirect the cable passing through the pressure control assembly towards a cable winch and a wireline unit.

[0021 ] A third aspect of the present invention provides an assembly for lifting a production fluid in a live well. The assembly comprises an electrical submersible pump, a retrievable packer installed at a downhole end of the live well, the retrievable packer receiving the electrical submersible pump, a cable termination block installed between a tubing-head spool and an production tree of the live well, the cable termination block mechanically and fluidly connecting the tubing-head spool and the production tree, and a cable having a first end attached to the electrical submersible pump and a second end terminating at the cable termination block, wherein the electrical submersible pump is installed on the retrievable packer at the downhole end of the live well such that the weight of the electrical submersible pump is supported by the retrievable packer. [0022] The assembly may further comprise a cable hanger secured within the cable termination block, wherein the cable hanger is mechanically coupled to the second end of the cable.

[0023] The retrievable packer may comprise an anti-rotation portion and an anti- recirculation portion, the anti-rotation portion maintaining an angular position of the electrical submersible pump within a tubing string and the anti-recirculation portion preventing recirculation of fluids in the downhole end of the live well.

[0024] The cable termination block may comprise a first end matching a receiving end of the tubing-head spool, and a second end matching an input end of the production tree. [0025] The assembly may further comprise a cable exit disposed on a side of the cable termination block, the cable exit receiving the mechanically coupled cable routed through the cable hanger and the cable termination block.

[0026] The cable may be configured to support at least the weight of the electrical submersible pump and to provide electrical connection to the electrical submersible pump.

Brief Description of Drawings

[0027] Embodiments of the invention will be better understood and readily apparent to one of ordinary skill in the art from the following written description, by way of example only, and in conjunction with the drawings, in which: Fig.1

[0028] Fig. 1 shows a flowchart illustrating a method for installing an electrical submersible pump, in accordance with embodiments of the invention.

Fig.2

[0029] Fig. 2 shows a schematic diagram of a system configured for installation of an electrical submersible pump, in accordance with embodiments of the invention.

Fig.3

[0030] Fig. 3 shows a schematic diagram of a cable termination block in accordance with embodiments of the invention. Fig.4

[0031 ] Fig. 4 shows a front perspective view of a blowout preventer used in the method and system for installing an electrical submersible pump.

Fig.5 [0032] Fig. 5 shows a front perspective view of a sealing element used in the method and system for installing an electrical submersible pump.

Fig.6

[0033] Fig. 6 shows a schematic diagram of an assembly for lifting a production fluid from a live well, in accordance with embodiments of the invention. [0034] Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been depicted to scale. For example, the dimensions of some of the elements in the illustrations, block diagrams or flowcharts may be exaggerated in respect to other elements to help to improve understanding of the present embodiments. Description of Embodiments

[0035] The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description. Herein, a method and system for installing an electrical submersible pump (ESP) are presented. Embodiments of the present invention can advantageously allow the installation and/or retrieval of the electrical submersible pump through an existing tubing string inside a wellbore without requiring a well workover. More particularly, the method and system can advantageously allow cable deployment of an electrical submersible pump within a live well, comply with industrial well barrier control policies, and meet pressure containment and safety standards. In various embodiments of the present invention, the method and system can be compatible with existing equipment of the live well i.e. with an existing vertical production tree of the live well, thereby advantageously eliminating the need for replacement equipment after the electrical submersible pump is installed. [0036] Fig. 1 shows a flowchart illustrating a method 100 for installing an electrical submersible pump 202 (Fig. 2) in a live well, in accordance with embodiments of the invention. The method 100 is described in conjunction with Fig. 2, which shows a schematic diagram of a system 200 configured for installation of the electrical submersible pump 202.

[0037] The method 100 broadly includes:

- step 102: installing an retrievable packer 204 at a downhole end of the live well, the retrievable packer 204 configured to receive the electrical submersible pump 202; - step 104: installing a cable termination block 206 between a tubing-head spool

208 and a production tree 210 of the live well, the cable termination block 206 mechanically and fluidly connecting the tubing-head spool 208 and the production tree 210;

- step 106: connecting a pressure control assembly 212 to the production tree 210; - step 108: lowering a first safety valve 214 and the electrical submersible pump

202 through the pressure control assembly 212 and along a tubing string 216 using a cable 218 having a first end attached to the electrical submersible pump 202;

- step 1 10: installing the first safety valve 214 such that the first safety valve 214 engages with a second safety valve 220 disposed along the tubing string 216; and

- step 1 12: installing the electrical submersible pump 202 on the retrievable packer 204 at the downhole end of the live well such that the retrievable packer 204 supports the weight of the electrical submersible pump 202 [0038] In various embodiments of the present invention, the electrical submersible pump 202 comprises a motor, a pressure equalizing chamber, a pump and a packer stinger. The packer stinger of the electrical submersible pump 202 is configured to engage with an anti-rotation portion of the retrievable packer 204. In various embodiments of the present invention, the method 100 can further include mechanically coupling a second end of the cable 218 attached to the electrical submersible pump 202 to a cable hanger 302 (Fig. 3) such that the cable hanger 302 supports the weight of the cable 218, and securing the cable hanger 302 within the cable termination block 206. The cable 218 is configured to support at least the weight of the electrical submersible pump 202 and to provide electrical connection to the electrical submersible pump 202. In embodiments of the present invention, the cable can include a plurality of electrical connectors configured to provide power to the electrical submersible pump 202, and strength members for mechanical robustness such that the cable 218 can safely carry all loading profiles of the electrical submersible pump 202 and weight of a length of cable 218 deployed downhole. The cable can also be wound around a winch drum with a diameter of no less than about 812.8 mm (32 inches).

[0039] At step 102, the retrievable packer 204 is installed at the downhole end of the live well. The retrievable packer 204 is configured to receive the electrical submersible pump 202. In embodiments of the invention, the step of installing the retrievable packer 204 at the downhole end of the live well can include first, performing a clearance check to verify the inner diameter of the tubing string 216, and then pressure testing the tubing string 216 to verify the well integrity. The step of performing the clearance check can include running a cylindrical tool with a known outer diameter along the tubing string 216. Pressure testing of the tubing string 216 can include (i) running a sliding sleeve shifting tool along the tubing string 216 to close a sliding sleeve that is configured to control flow of production fluid between the tubing string 216 and a casing void, (ii) removing a standing valve that configured to hold pressure from above the tubing string 216 while allowing production fluids to flow from below and (iii) installing a first blanking plug configured to establish a fluid seal within the tubing string 216 at a depth above a no-go landing nipple disposed at the downhole end of the well. The portion of tubing string 216 above the first blanking plug is then pressurized to predetermined limit for a predefined period of time, to check and verify the pressure parameters within the tubing string 216. The first blanking plug is then retrieved and the sliding sleeve shifting tool is run along the tubing string 216 again to open the sliding sleeve.

[0040] The retrievable packer 204 is then installed at the downhole end of the live well. The retrievable packer 204 comprises an anti-rotation portion and an anti-recirculation portion. The anti-rotation portion of the retrievable packer 204 is configured to maintain an angular position of the installed electrical submersible pump 202 within the tubing string 216 and the anti-recirculation portion is configured to prevent recirculation of fluids in the downhole end of the live well. The step of installing the retrievable packer 204 generally comprises providing the retrievable packer 204 at a predetermined position at the downhole end of the live well. In various embodiments of the present invention, the retrievable packer 204 is installed using a setting tool, the setting tool can be a non- explosive setting tool that enable downhole tools to be set without the use of explosives.

[0041 ] It can be appreciated that in embodiments of the present invention, the anti- rotation portion and the anti-recirculation portion can be two separate devices that together form the retrievable packer 204. In other words, a packer having the anti- recirculation portion can be first set in the downhole end of the live well, followed by installation of the anti-rotation portion. The anti-rotation portion is also known as a polished bore receptacle, and is configured to engage with a stinger portion of the electrical submersible pump 202. Thus, the installation of the retrievable packer 204 can include first disposing a packer having the anti-recirculation portion, and then coupling the lowered anti-rotation portion with the packer having the anti-recirculation portion such that the anti-rotation portion and anti-recirculation portion forms part of the retrievable packer 204. The step of installing the retrievable packer 204 can further include verifying the integrity of the retrievable packer 204 by installing a dummy ESP assembly comprising a stinger within the retrievable packer 204, pulling the dummy assembly that is coupled with the retrievable packer 204 with a predetermined force and pressure testing the retrievable packer 204 with a predetermined pressure.

[0042] At step 104, the cable termination block 206 is installed between the tubing-head spool 208 and the production tree 210 of the live well. The cable termination block 206 is configured to mechanically and fluidly connect the tubing-head spool 208 and the production tree 210. An exemplary cable termination block 206 is shown in Fig. 3. The cable termination block 206 comprises a first end 304 configured to match a receiving end of the tubing-head spool 208; and a second end 306 configured to match an input end of the production tree 210. The cable termination block 206 also comprises a hollow portion along an axial length of the cable termination block 206, the hollow portion configured to receive the cable hanger 302. The cable hanger 302 can be mechanically coupled to the cable 218 after the electrical submersible pump 202 is installed in the live well. The cable termination block 206 can also include a cable exit 310 disposed on a side of the cable termination block. The cable exit 310 is configured to receive the mechanically coupled cable 218 that is routed through the cable hanger 302 and the cable termination block. In embodiments of the present invention, the cable exit 310 can also be known as an electrical penetrator system.

[0043] The step 104 can include, (i) installing a second blanking plug at a depth above the sliding sleeve, and (ii) installing a third blanking plug at a position above the second blanking plug. The second and the third blanking plugs are configured to seal the tubing string 216. In embodiments of the present invention, the third blanking plug can be installed at a landing nipple proximate to the second safety valve 220. Pressure testing of the sealed tubing string 216 is then carried out. After the pressure testing procedures are completed, the production tree 210 is safely separated from the tubing-head spool 208. It can be appreciated that various fluid, electrical and/or gas connections between the production tree 210 can be isolated and/or disconnected during the separation procedure, as the second and the third blanking caps advantageously seals the tubing string 216 and prevents further flow of production fluids into the production tree 210. The cable termination block 206 is then installed. Installing the cable termination block 206 between the tubing-head spool 208 and the production tree 210 can include first, (i) connecting the first end 304 of the cable termination block 206 to a receiving end of the tubing-head spool 208, and then (ii) connecting the second end 306 of the cable termination block 206 to an input end of the production tree 201 . After the installation of the cable termination block 206 is completed, the various fluid, electrical and/or gas connections on the production tree 210 can be reconnected. Pressure testing of the seals between the cable termination block 206, the tubing-head spool 208 and the production tree 210 is then performed against the third blanking plug. In embodiments of the present invention, pressure testing of the seals can include testing the seals at about 6.9 MPa (1000 psi) for about 15 minutes. After testing is completed, the third blanking plug is retrieved, followed by the second blanking plug. Operability of the second safety valve 220 is tested, and the second safety valve 220 is locked open for subsequent installation of the first safety valve 214 and the electrical submersible pump 202.

[0044] At step 106, the pressure control assembly 212 is provided on the production tree 210. The arrangement of the various elements of the pressure control assembly 212 is shown in Fig. 2. The pressure control assembly 212 includes a blowout preventer (BOP) 222 provided on the production tree 210, the BOP 222 connected to a pressure test subassembly 224, a lubricator 226 and a sealing element 228. In an exemplary embodiment of the present invention, the BOP 222 is "quad BOP" having four sets of rams as shown in Fig. 4, the first set of rams 402 being shear and blind rams configured to either close on or cut through a tubular member present within the BOP 222, the second set of rams 404 being slip rams configured to close on and hold onto the tubular member, preferably without damaging the surface of the tubular member, and the third and fourth set of rams 406, 408 being cable seal rams configured to seal around the cable 218. The lubricator 226 includes a high-pressure grease-injection section and a series of valves, and is configured to allow well tools to be placed into the tubing string 216 under pressure. The sealing element 228, also known as a wireline pack-off is shown in detail in Fig. 5. The sealing element 228 comprises a housing 502, at least one conduit 504 and an elastomeric sealing element (not shown) disposed within the housing 502. The sealing element 228 is configured to create a seal around members having irregular surfaces (e.g. wirelines), by compressing the elastomeric sealing element with the hydraulic pressure supplied through the conduit 504 around the members. It can also be appreciated that in various embodiments of the present invention, the pressure control assembly can optionally include an alignment system 230 configured to connect a pumping tee 232 to the production tree 210, and a pumping tee 232 connected to an inlet end of the blowout preventer 222 at one end, and configured to divert fluids exiting the production tree 210 to a piping system (not shown). The pumping tee 232 is also configured to allow for injection of fluids into the tubing string 216 for pressure testing purposes, which can be performed during the intermittent steps in the method 100. [0045] At step 108, the method 100 includes lowering the first safety valve 214 and the electrical submersible pump 202 through the pressure control assembly 212 and along a tubing string 216 using a cable 218 having a first end attached to the electrical submersible pump 202. The first safety valve is provided on the cable 218 above the electrical submersible pump 202. Particularly, in embodiments of the present invention, the lowering of the first safety valve 214 and the electrical submersible pump 202 is advantageously controlled by a lifting system 234. The lifting system 234 can include (i) lifting hooks 236 configured to carry at least one of a load profile of the cable 218 and the electrical submersible pump 202, the pressure test subassembly 224, the lubricator 226 and the sealing element 228, and (ii) at least one sheave 238a, 238b configured to redirect the cable 218 passing through the pressure control assembly 212 towards a cable winch 240 and wireline unit 242. The lifting hooks 236 can be suspended using a telescopic mast 244.

[0046] In an embodiment of the present invention, with reference to Fig. 2, the cable 218 that is attached to the electrical submersible pump 202 is run from the cable winch 240 which is mechanically and electrically connected to the wireline unit 242. The cable 218 is routed from the winch 240 to the sheave 238b which is secured to a wellhead of the live well, and then onto the sheave 238a which is secured to the lifting hook 236. As mentioned above, the first safety valve 214 and the electrical submersible pump 202 is lowered into the tubing string 216 using the cable 218. The cable 218 is attached to the top of the electrical submersible pump 202. In embodiments of the present invention, the cable 218 can include a calibrated weak point provided directly above the electrical submersible pump 202 such that should the electrical submersible pump 202 becomes stuck in the tubing string 216, the cable 218 can be disconnected at the calibrated weak point and recovered safely. In that case, the electrical submersible pump 202 is then retrieved using methods that would be understood by persons skilled in the art. Provision of the calibrated weak point directly above the electrical submersible pump 202 can advantageously reduce the chance of cable-snap at any other points along the length of the cable, and thus reduce the need for cable recovery operations.

[0047] At step 1 10, the method 100 includes installing the first safety valve 214 such that the first safety valve 214 engages with the second safety valve 220 disposed along the tubing string 216. In embodiments of the present invention, the first safety valve 214 is known as an insert safety valve and the second safety valve 220 is known as a tubing retrievable surface controlled sub-surface safety valve. The installation of the first safety valve 214 can include (i) lowering the first safety valve 214 and the electrical submersible pump 202 through the pressure control assembly 212 to a depth of the second safety valve 220, (ii) landing the first safety valve 214 within the second safety valve 220, (iii) applying an over-pressure within the tubing string to activate the first safety valve 214 and (iv) applying a first overpull having a first predetermined tension to engage the first safety valve 214 with the second safety valve 220. The landing of the first safety valve 214 within the second safety valve 220 includes setting the first safety valve 214 inside a landing nipple of the second safety valve 220, the landing nipple straddling upper and lower seal bores of the second safety valve 220. The step can further include (v) applying a test overpull having a second predetermined tension higher than the first predetermined tension to ensure that the first safety valve 214 is fully engaged with the second safety valve 220, (vi) relaxing the tension within the cable 218 and then applying a second overpull having the first predetermined tension to disengage the electrical submersible pump 202 from the first safety valve 214, so that the electrical submersible pump 202 can be freed and lowered further down the tubing string 216.

[0048] At step 1 12, the electrical submersible pump 202 is installed on the retrievable packer 204 at the downhole end of the live well such that the retrievable packer 204 supports the weight of the electrical submersible pump 202. Generally, the installation of the electrical submersible pump 202 on the retrievable packer 204 is preceded by a procedure for marking the cable 218 such that the cable can be severed and mechanically coupled to the cable hanger 302. The procedure can ensure that when the installation is complete, the length of the cable 218 is sufficient long for the weight of the electrical submersible pump 202 to be supported by the retrievable packer 204 and for the weight of the cable 218 to be supported by the cable hanger 302 secured within the cable termination block 206. The cable-marking procedure in the step 1 12 includes (i) lowering and positioning the electrical submersible pump 202 into the retrievable packer 204 such that the packer stinger of the electrical submersible pump 202 is engaged with the anti- rotation portion of the retrievable packer 204, (ii) spooling out an additional predetermined distance of cable 216, and (iii) recording a tension on the cable 218. As a non-limiting example, the predetermined distance can be about 6 meters (20 feet). It can be appreciated that the predetermined distance may vary from one implementation to another. The procedure also includes subsequently (iv) marking the cable 218 with a first paint stick mark at a cable marking point. In embodiments of the present invention, the cable marking point is a specific location directly above the BOP 222 and between the lubricator 226. The pressure test subassembly 224 and/or the lubricator 226 can be removed to expose the cable marking point. The distance between the cable marking point and the lower flange of the cable termination block 206 is also noted. The procedure further includes retrieving (iv) a length of the cable 218 such that a predetermined tension, e.g. approximately 890N (200 Ibf), above the previously recorded tension is registered, and marking the cable 218 with a second paint stick mark at the cable marking point. As will be appreciated by a person skilled in the art, the predetermined tension may differ from one implementation to another. An overpull is then applied to the cable 218 to disengage the electrical submersible pump 202 from the retrievable packer 204, and a further length of the cable 218 is retrieved. The length of cable 218 can be between about 9 meters to 12 meters (30 to 40 feet).

[0049] Step 1 12 can also include mechanically coupling the cable 218 attached to the electrical submersible pump 202 to the cable hanger 302. The process of mechanically coupling the cable 218 to cable hanger 302 is described below. After the further length of cable 218 is retrieved, the cable rams on the BOP 222 are engaged on the portion of the retrieved cable 218, and a cable clamp is used to secure the cable 218 above the BOP 222 such that the weight of the cable 218 and the electrical submersible pump 202 is borne by the BOP 222. A length of the cable 218 is then fed out from the cable winch 240 and the wireline unit 242, and the lubricator 226 is lifted by a predetermined distance so that the first and the second paint stick marks are visible. The cable 218 is then cut. A cable hanger 302 is provided and prepared for installation. The preparation for installation of the cable hanger 302 can include installing downhole connectors into ports on a lower face of the cable hanger 302 and mechanically coupling the cable 218 to the cable hanger 302. The cable hanger 302 and the cable 218 is then picked up using a slickline. The cable clamp is disengaged, and the cable hanger 302 and the cable 218 is lowered through the BOP 222 and the production tree 210 into the cable termination block 206. As the cable hanger 302 and the cable 218 is lowered, sufficient length is present in the cable 218 such that the electrical submersible pump 202 is installed on the retrievable packer 204 at the downhole end of the live well before the cable hanger 302 is secured within the cable termination block 206. In embodiments of the present invention, the cable hanger 302 is lowered through the alignment system 230 which can ensure that the cable hanger 302 is in a correct orientation when secured within the cable termination block 206. The cable hanger 302 can be secured within the cable termination block 206 using a downhole device. In an example implementation, the downhole device can be a lock mandrel.

[0050] The cable exit 310 on the cable termination block 206 is prepared after the electrical submersible pump 202 is installed on the retrievable packer 204, and the cable hanger 302 is secured within the cable termination block 206. In some embodiments of the present invention, the cable exit 310 is known as an electrical penetrator system. Preparing the cable exit 310 can include electrically connecting the cable exit 310 to a power supply configured to power the electrical submersible pump 202, pressure testing seals on the cable termination block and testing the electrical submersible pump 202. The pressure control assembly 212 is then removed after testing of the electrical submersible pump 202 is complete. The live well, having the electrical submersible pump 202 as part of an assembly 600 (Fig. 6) can then be commissioned for service.

[0051 ] In use, the electrical submersible pump 202 can provide additional throughput of the production fluid from the downhole end to the surface. Fig. 6 shows a schematic diagram of the assembly 600 for lifting a production fluid from a live well, in accordance with embodiments of the invention. The assembly 600 includes (i) an electrical submersible pump 202, (ii) an retrievable packer 204 installed at a downhole end of the live well, the retrievable packer 204 receiving the electrical submersible pump 202, (iii) a cable termination block 206 installed between a tubing-head spool 208 and an production tree 210 of the live well, the cable termination block 206 mechanically and fluidly connecting the tubing-head spool 2008 and the production tree 210, and (iv) a cable 218 having a first end attached to the electrical submersible pump 202 and a second end terminating at the cable termination block 206, wherein the electrical submersible pump 202 is installed on the retrievable packer 204 at the downhole end of the live well such that the weight of the electrical submersible pump 202 is supported by the retrievable packer 204.

[0052] The assembly 600 can further comprise a cable hanger 302 (Fig. 3) secured within the cable termination block 206, and the second end of the cable 218 is mechanically coupled to the cable hanger. The weight of the cable 218 is supported by the cable hanger 302. A cable exit 310 is disposed on a side of the cable termination block 206, and is configured to receive the mechanically coupled cable 218. The cable exit 310 allows an electrical connection to a power supply located on the surface that powers the electrical submersible pump 202. Advantageously, the cable termination block 206 can allow the existing production tree 210 to be used while allowing power to be transmitted through the cable 218 to the electrical submersible pump 202 downhole. Advantageously, the assembly 600 having the electrical submersible pump 202 disposed at the downhole end of the live well can provide artificial lift of production fluids from the wellbore, and increase production rate. In an exemplary implementation, the production rate can be increased by 27%, from 331 bpd (barrels per day) to 420 bpd.

[0053] Thus it can be seen that the method and system for installing an electrical submersible pump (ESP) in accordance with the present embodiments can advantageously allow the installation of the electrical submersible pump through an existing tubing string inside a wellbore without requiring a well workover. More particularly, the method and system, particularly with use of pressure control assembly, along with an insert type safety valve engaged with the tubing retrievable safety valve can advantageously allow safe cable deployment of an electrical submersible pump within a live well while complying with industrial well barrier control policies and meeting pressure containment and safety standards. In various embodiments of the present invention, the method and system with the cable termination block can be compatible with existing equipment of the live well i.e. with an existing vertical production tree of the live well, thereby advantageously eliminating the need for replacement equipment after the electrical submersible pump is installed. While exemplary embodiments have been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist.

[0054] It should further be appreciated that the exemplary embodiments are only examples, and are not intended to limit the scope, applicability, operation, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements and method of operation described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.