Universal high-pressure sealer and method for shaft cable of electric submersible pump

Abstract

According to the technical scheme, one end of a fixed joint is movably connected with a valve body, a high-density core wire penetrates into an inner hole of the fixed joint, and the other end of the fixed joint is connected with a middle sealing screw thread; the sealing bush is arranged in a hole of the middle seal, the semi-ring cone is buckled on the high-density core wire, the outer nut is sleeved outside the semi-ring cone, and the outer nut is connected with the end part of the middle seal through a screw thread; a locking nut is mounted on the valve body, a high-density core wire penetrates through three inner holes, and one end of the high-density core wire is sleeved on a coupling nut and is fixed by a connecting nut; the fixed joint is mounted at the other end; the right end of the coupling nut is connected to the valve flange through an oil pipe short joint; the power cable is connected to the high-density core wire through a copper sleeve; the high-pressure sealer has the beneficial effects that the damage probability when a cable penetrates out of the sleeve four-way joint and the side wing valve is reduced, the sealing piece is installed at the outer end of the high-pressure sealer, and construction and overhauling are convenient; the well completion speed is increased; the sealing performance is more reliable; on-site pressure testing can be achieved, and the oil well production time rate and yield are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of completion construction technology for the lift process of electrical submersible pumps used in the dilution or water injection of heavy oil wells, and particularly relates to a general-purpose high-pressure seal for wellbore cables of electrical submersible pumps and a method thereof. Background Art

[0002] At present, in the completion construction of the lift process of electrical submersible pumps used in the dilution or water injection of heavy oil, the wellhead high-pressure sealing devices used are divided into two types: 45MPa high-pressure flange type and 25MPa slip joint type. According to the different pressure ratings of the wellhead Christmas tree, the high-pressure flanges are further divided into specifications such as 35MPa - BX153, BX154 and 70MPa - BX153, BX154 and 105MPa - BX154. The pitch circle diameters of the stud connections of various flanges are different. Often, due to unclear knowledge of the flange specifications on site, the high-density flanges carried do not match the wellhead flanges on site, affecting the construction progress and the well opening rate. When connecting the high-pressure seal, after the wellbore cable passes through the side valve, the upper body needs to lower the pipe string 4 times, resulting in the power cable rubbing against the edge intersection line formed by the axial and radial holes of the casing cross joint 4 times. In addition, after the installation of the high-pressure seal is completed, the on-site pressure test function cannot be realized and it is difficult to ensure the sealing effect.

[0003] For the completion construction of the electrical submersible pump lifting process for heavy oil dilution or water injection, usually on the ground, the wellbore cable needs to be passed through the casing cross and the wing valve, and connected to the high-voltage sealed core wire. The high-voltage core wire seal body integrates the cable core wire and the seal through potting, penetrates into high-voltage flanges of different specifications, and is connected, fixed, and sealed with the flange of the wing valve of the wellhead casing cross. The high-density core wire is installed on the pressure-bearing inner side of the high-density flange and the wellbore, contacting the well fluid. If the core wire seal fails, breakdown faults are likely to occur. Currently, when the in-use type leaks, during maintenance, it is necessary to organize an operation construction team, lift a tubing string, cut the wellbore cable, and reconnect the high-voltage seal. The operation steps are as follows: 1) According to the pump setting depth in the construction design, lower the electric pump unit to the predetermined position, add one more tubing string, reserve a certain length of the cable, cut off the excess cable, and lower the tubing string to pass the wellbore cable through the casing cross and the wing valve at the wellhead (the first abrasion); 2) Remove the added tubing string, connect and tighten the tubing hanger and the tubing string entering the well with a double-male nipple, lower the tubing hanger and the tubing string, and push the cable inward at the same speed as the tubing string descends (the second abrasion); 3) After the tubing hanger is set in place, install a sealing steel ring in the flange ring groove of the wing valve; 4) Make a mark at the end face of the steel ring where the wellbore cable passes through the wing valve of the casing cross; 5) Lift the tubing string, saw off the cable at a certain distance on the wellbore side of the cable mark, strip the protective armor to expose the cable core wire (the third abrasion); 6) Pass the high-density core wire through the inner hole of the high-voltage flange, and fix the high-voltage sealed core wire and the high-voltage flange together with a fixing nut; 7) Connect the wellbore cable core wire and the high-voltage sealed core wire with a copper sleeve and wrap and seal them; 8) Slowly lower the tubing string to prevent the inner wall edge of the casing cross from scratching the cable, and push the wellbore cable inward at the same speed as the tubing string descends until the tubing hanger is lowered in place (the fourth abrasion). At the same time, the high-voltage sealing flange approaches the flange of the wing valve of the casing cross, and use bolts to connect, fix, and compress the flanges to ensure reliable sealing without leakage. Thus, the workover construction is completed.

[0004] In this process, the cable passes through the casing cross, and its inner side has sharp edges, which can easily scratch the cable. Therefore, the number of times the cable passes through the cross should be minimized as much as possible. The existing high-pressure seal is very important for intercepting the reserved length of the wellbore cable passing through the casing cross and the side wing valve: 1) If the length is short, the copper sleeve connection between the wellbore cable and the high-pressure seal core wire is in a tensile state, resulting in a small contact area, increased current, easy burning of the connection, and in severe cases, the cable may break, causing the downhole motor to malfunction; 2) If the length is too long, the gap between the high-pressure flange and the flange surface of the side wing valve of the casing cross is too large, resulting in extrusion deformation and bending of the cable core wire, cracking of the lead sheath, and difficult flange connection sealing. It has high requirements for the operation ability and on-site experience of construction personnel, increasing the construction difficulty and risk. The Chinese patent application number of the patent applied by our company on October 15, 2024 is 2024114384621, and the patent name is "Electric Submersible Pump Wellbore Cable On-site Pressure Testing Type High-pressure Sealing Device and Method". The reserved length of the cable is longer than that of the present invention. When installing the pressure testing type high-pressure sealing device, there is no need to cut the cable, and its sealing performance is reliable and the pressure resistance level is high.

[0005] In addition, during the connection process between the high-pressure seal and the wellbore cable, the wellhead is in an open state, posing a well control risk; secondly, since the high-pressure seal and the wellbore cable are connected by a copper sleeve, the pressing and fixing effect of the copper sleeve directly affects the insulation resistance value of the wellbore cable and the motor operation life of the downhole electric pump unit; thirdly, the connection time between the wellbore cable and the high-pressure seal is long, with high requirements for the proficiency, construction experience and technology of on-site construction personnel, large construction difficulty and high failure rate. Summary of the Invention

[0006] The purpose of the present invention is to address the above-mentioned defects existing in the prior art, and provide a general-purpose high-pressure seal for electric submersible pump wellbore cables and a method, so as to reduce the damage probability of the wellbore cable passing through the casing cross and the side wing valve; reduce the construction difficulty and improve the completion speed; make the operation of connecting the high-pressure seal and the wellbore cable more convenient; have more reliable sealing performance and higher pressure resistance level; ensure that the connection of the wellbore cable is in a balanced state without being stretched or squeezed; the seal of the high-density core wire is at the outer end of the high-pressure seal body and the wellbore. If leakage occurs, it is convenient to observe and handle; the core wire seal of the high-pressure seal is at the outer end, which is convenient for on-site construction personnel to operate; if leakage occurs in the high-pressure seal, there is no need to mobilize the operation construction team to the derrick. The pressure in the wellbore can be relieved for repair, reducing the construction cost, reducing the non-production time of the oil well, and improving the production time rate and output of the oil well; after on-site installation and maintenance, the sealing effect of the high-pressure seal can be detected.

[0007] A general-purpose high-pressure seal for the wellbore cable of an electric submersible pump mentioned in the present invention has the following technical solution: It includes a high-density core wire (1), an outer nut (7), a half-ring cone (8), an intermediate seal (9), a sealing bushing (11), a locking nut (18), a fixed joint (19), a valve body (20), a connecting nut (21), a coupling nut (23), and a tubing nipple (24); one end of the fixed joint (19) is movably connected to the valve body (20), the high-density core wire (1) passes through the inner hole of the fixed joint (19), and the other end of the fixed joint (19) is threadedly connected to the intermediate seal (9); the sealing bushing (11) is installed into the hole of the intermediate seal (9), the half-ring cone (8) is buckled on the high-density core wire (1), and the outer nut (7) is sleeved outside the half-ring cone (8), and the outer nut (7) is connected to the end of the intermediate seal (9) by threads; the locking nut (18) is installed on the valve body (20), three inner holes pass through the high-density core wire (1), one end is sleeved onto the coupling nut (23) and fixed with the connecting nut (21); the other end installs the fixed joint (19); the right end of the coupling nut (23) is connected to the valve flange (27) through the tubing nipple (24), and the power cable (26) is connected to the high-density core wire (1) through the copper sleeve (25).

[0008] Preferably, a sealing bushing (11) is installed in the hole on the right side of the above-mentioned intermediate seal (9), and a sealing sleeve (12) is installed on the right side of the sealing bushing (11). The left end of the fixed joint (19) is threadedly connected to the right end of the intermediate seal (9), and the right end of the fixed joint (19) is threadedly connected to the valve body (20).

[0009] Preferably, the above-mentioned high-density core wire (1) uses a whole cable, and its wire diameter is thicker than that of the wellbore cable (26), and the over-current resistance value is low. The outer layer of the high-density core wire (1) is a fluoroplastic insulation layer.

[0010] Preferably, when the above-mentioned tubing nipple (24) selects the short tubing nipple (24.1), measure the distance L between the lower end of the setting position of the tubing hanger (30) and the setting position of the wellhead four-way hanger, and then measure the protruding section of the wellbore cable (26). The reserved length of the wellbore cable from the outer end of the end face of the coupling nut (23) is: L + X - 30. Cut off the wellbore cable (26), strip the armor, process the connection end, connect and fix it with the high-density core wire (1) through the copper sleeve (25), wrap it. After completion, lower the pipe string, set the tubing hanger (30), pass the three high-density core wires (1) through the inner holes of the valve body (20), connect the valve body (20) and the coupling nut (23) by threads with the connecting nut (21), and tighten with the locking nut (18).

[0011] Preferably, when the above tubing nipple (24) is selected as the long tubing nipple (24.2), there is no need to measure the length of the power cable (26) of the casing side valve (33) passing through the Christmas tree. Directly set the tubing hanger (30) in place and fasten it, and install the Christmas tree; reserve an appropriate length from the outer end of the casing side valve (33), cut the wellbore cable (26), strip the armor, process the connection end, connect and fix it with the high-density core wire (1) through the copper sleeve (25), wrap it. After completion, fit the connection nut (21) on the overall outer circle where the long tubing nipple (24.2) is tightened with the collar nut (23). Pass the three high-density core wires (1) through the inner hole of the long tubing nipple (24.2). After threading the raw tape around the threads at the other end of the long tubing nipple (24.2), connect and fasten it to the casing side valve (33) of the Christmas tree. Then pass the high-density core wire (1) through the inner hole of the valve body (20), and connect and tighten the valve body (20) and the collar nut (23) with the connection nut (21) through the threads, and back-tighten with the lock nut (18).

[0012] Preferably, the left end of the above valve body (20) is connected to a pressure test tooling. The pressure test tooling includes a sealing screw pipe (2), a pressure test valve body (4), a pressure test nut (15), and a pressure test joint (28). The right end face of the pressure test valve body (4) is closely attached to the end face of the valve body (20) and is fixed by the pressure test nut (15). The high-density core wire (1) passes through three holes in the right end face. The left end of the pressure test valve body (4) passes through the three high-density core wires (1) through the sealing screw pipe (2); a pressure test hole is provided on the outer wall of the pressure test valve body (4), and a pressure test joint (28) is installed on the pressure test hole.

[0013] Preferably, a first sealing ring (3) is installed on the outer wall of the above sealing screw pipe (2), and the right end of the sealing screw pipe (2) is connected to the left end internal thread of the pressure test valve body (4) through a second sealing ring (5) and a sealing gasket ring (6).

[0014] Preferably, a third sealing ring (10) is installed on the outer wall of the above sealing bushing (11), and a fourth sealing ring (13) is provided on the outer wall of the fixed joint (19); the right end of the pressure test valve body (4) is connected to the left end face of the valve body (20) through a pressure test valve body flange (14), and a fifth sealing ring (16) and a gasket ring (17) are provided between the pressure test valve body flange (14) and the left end face of the valve body (20); a sixth sealing ring (22) is provided between the right end face of the valve body (20) and the collar nut (23).

[0015] The usage method of the general-purpose high-pressure seal for the electric submersible pump wellbore cable mentioned in the present invention includes the following steps: I. Workover construction 1). According to the pump setting depth in the construction design, lower the electric pump unit to the predetermined position, and pass the wellbore cable (26) through the casing side valve (33) of the Christmas tree; 2), Connect the tubing (29) lowered into the wellbore to the tubing hanger (30) using a tubing double male pup joint (31); 3), Select different lengths of tubing pup joints (24) to reserve a certain length for the wellbore cable (26), cut off the excess wellbore cable (26) in the wellbore, and connect the high-density core wire (1); 4), Slowly lower the tubing hanger (30) through the tubing (29) until it is set in place, and at the same time push the wellbore cable (26) to prevent the inner wall edge of the wellhead casing cross-over (34) from scratching the wellbore cable (26); II. Installation of on-site general-purpose high-pressure sealers: 5), Peel the protective armor of the cable passing through the casing side valve (33) to the end face of the valve flange (27) to form three cable core wires (26); 6), Process the connection end, connect and fix it to the high-density core wire (1) through a copper sleeve (25) and wrap it. After completion, fit a connection nut (21) on the outer circumference of the whole tightened by the tubing pup joint (24) and the coupling nut (23). Pass the three high-density core wires (1) through the inner hole of the tubing pup joint (24). After winding the thread of the other end of the tubing pup joint (24) with PTFE tape, connect and tighten it to the valve flange (27) on the wellhead side. Then pass the high-density core wire (1) through the inner hole of the valve body (20), connect and tighten the valve body (20) and the coupling nut (23) through threads with the connection nut (21), and tighten it with a lock nut (18); 7), Install the fourth sealing ring (13) on the fixed joint (19), and pass the high-density core wire (1) through the inner hole and tighten it to the valve body (20); 8), Fit the sealing sleeve (12) and the sealing bushing (11) with the third sealing ring (10) onto the high-density core wire (1), and push it to the right end of the intermediate seal (9) for connection; 9), Fit the second sealing ring (5) onto the high-density core wire (1) and push it to the sealing bushing (11); 10), Fit the intermediate joint (9) onto the high-density core wire (1) and tighten it to the fixed joint (19) through threads; 11), Fasten the half-ring cone (8) onto the high-density core wire (1), install the outer nut (7), and tighten it to the intermediate nut to lock the high-density core wire (1); 12), Complete the sealing and fixing of the remaining two high-density core wires (1) according to the above steps; 13), Install the pressure test tooling according to requirements and conduct on-site pressure testing. The steps are as follows: 13.1, On the right end face of the pressure test valve body (4), install a gasket ring (17) and the fifth sealing ring (16), make it close to the end face of the valve body (20), and fix it with a pressure test nut (15); 13.2. The high-density core wire (1) passes through the three holes on the right end face; 13.3. Install the sealing gasket (6) and the second sealing ring (5), install the first sealing ring (3) on the sealing spiral tube (2), tighten it by threading, and compress the second sealing ring (5) to achieve the purpose of sealing the high-density core wire (1); 13.4. Pour the motor oil of the submersible motor into the inner cavity of the pressure test valve body (4) through the pressure test hole. After the inner cavity is filled, install the pressure test joint (28) into the pressure test hole of the pressure test valve body (4) and tighten it. 13.5. Connect the manual pressure test pump, pressurize to the appropriate pressure value, stabilize the pressure for a certain period of time as required, release the pressure after reaching the requirement, and remove the pressure test tooling in the reverse order.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) The invention facilitates the on-site operation of the construction team; 2) After the wellbore cable passes through the casing spool, the tubing hanger is connected to the wellbore tubing with a double male short-circuit and tightened, and then the pipe string is directly lowered, the wellbore cable is pushed down at the same speed, the tubing hanger is sealed, and the top screw is tightened to complete the wellbore sealing in one go, reducing the operation and construction risks; 3) The construction team saves time for well completion, and the wellhead Christmas tree can be installed and tightened after the hanger is sealed in place; 4) The oil well construction time is shortened, the completion efficiency is improved, and the wellbore sealing is completed in one go. The production time of oil wells should be improved; 5) The present invention reduces the number of scrapes of the wellbore cable after passing through the wellhead casing four-way and the casing side valve, reducing the probability of cable damage; according to the short-circuit length of the oil pipe, the length of the reserved wellbore cable to the side valve flange is cut, and there is no need to accurately measure the length of the reserved wellbore cable, which is convenient for construction personnel to operate; 6) When the wellbore cable and a single high-density core wire are connected and fixed with a copper sleeve one by one, the construction space is open, which is convenient for the insulation layer wrapping construction; 7) In the past, 25MPa and 45MPa, the two types of high-pressure sealers are universal; 8) The pressure resistance level of the present invention is much higher than the actual requirement of the high-pressure sealer; 9) The seal of the high-density core wire is installed piece by piece on the outside of the valve body that is sealed with the wellbore liquid, fixed and sealed, which is convenient for construction; 10) The copper sleeve connection between the high-pressure core wire and the wellbore cable is not subject to tension and compression, avoiding failure due to pulling, the difficulty of closing the flange connection due to pressure, and the bending of the connection end; ensuring that the wellbore cable is in a free state without tension and compression; 11) After the on-site installation is completed, the on-site pressure test can be carried out to test its sealing performance and reduce the operation risk; 12) After the pressure test is completed, the pressure test tooling can be removed; 13) If a high-pressure seal leak occurs, there is no need to mobilize the construction team, as long as the wellbore pressure is relieved to zero, it can be disassembled and repaired, which greatly reduces the maintenance cost; 14) When inspecting and replacing, the seal only needs to be replaced: high-density core wire, sealing ring and sealing sleeve, high versatility, cost saving and other characteristics.

[0017] In summary, the present invention reduces construction costs, decreases the non - production time of oil wells, and increases the production time rate and output of oil wells; after on - site installation and maintenance, the sealing effect of the high - pressure seal can be detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of on - site installation of the present invention; Figure 2 It is a schematic structural diagram of on - site pressure testing of the present invention; Figure 3 It is a schematic assembly diagram of a single high - density core wire and a seal; Figure 4 It is a schematic structural diagram of on - site actual application; Figure 5 It is a schematic diagram of wellhead cable crossing; Figure 6 Schematic diagram of the tubing hanger set in place and the wellbore cable cut after reserving a certain length; Figure 7 Schematic diagram of processing the connection section of the wellbore cable; Figure 8 Schematic diagram of installing the Christmas tree and connecting the production process; Figure 9 Schematic diagram of installing the tubing nipple, coupling nut and connecting nut; Figure 10 Schematic diagram of installing and fastening the high - pressure seal body; Figure 11 Schematic diagram of completing the installation of the high - pressure seal seal; In the above figures: high - density core wire 1, sealing screw tube 2, first sealing ring 3, pressure - testing valve body 4, second sealing ring 5, sealing gasket ring 6, outer nut 7, half - ring cone 8, intermediate seal 9, third sealing ring 10, sealing bushing 11, sealing sleeve 12, fourth sealing ring 13, pressure - testing valve body flange 14, pressure - testing nut 15, fifth sealing ring 16, gasket ring 17, locking nut 18, fixed joint 19, valve body 20, connecting nut 21, sixth sealing ring 22, coupling nut 23, tubing nipple 24, copper sleeve 25, power cable 26, valve flange 27, pressure - testing joint 28, tubing 29, tubing hanger 30, tubing double - male nipple 31, elevator 32, casing side - wing valve 33, wellhead casing cross 34. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The following is a description of the preferred embodiments of the present invention with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only for the purpose of illustrating and explaining the present invention and are not intended to limit the present invention.

[0020] Example 1, referring to Figures 1-11, a general-purpose high-pressure seal for wellbore cables of an electric submersible pump mentioned in the present invention, includes a high-density core wire 1, an outer nut 7, a half-ring cone 8, an intermediate seal 9, a sealing bushing 11, a locking nut 18, a fixed joint 19, a valve body 20, a connecting nut 21, a coupling nut 23, and a tubing nipple 24; one end of the fixed joint 19 is movably connected to the valve body 20, the high-density core wire 1 passes through the inner hole of the fixed joint 19, and the other end of the fixed joint 19 is threadedly connected to the intermediate seal 9; the sealing bushing 11 is installed into the hole of the intermediate seal 9, the half-ring cone 8 is buckled on the high-density core wire 1, and the outer nut 7 is sleeved outside the half-ring cone 8, and the outer nut 7 is connected to the end of the intermediate seal 9 by threads; the locking nut 18 is installed on the valve body 20, three inner holes pass through the high-density core wire 1, one end is sleeved on the coupling nut 23 and fixed with the connecting nut 21; the other end installs the fixed joint 19; the right end of the coupling nut 23 is connected to the valve flange 27 through the tubing nipple 24, and the power cable 26 is connected to the high-density core wire 1 through the copper sleeve 25.

[0021] Preferably, a sealing bushing 11 is installed in the hole on the right side of the above-mentioned intermediate seal 9, a sealing sleeve 12 is installed on the right side of the sealing bushing 11, the left end of the fixed joint 19 is threadedly connected to the right end of the intermediate seal 9, and the right end of the fixed joint 19 is threadedly connected to the valve body 20.

[0022] Preferably, the above-mentioned high-density core wire 1 uses a whole cable, and its wire diameter is thicker than that of the wellbore cable 26, with a low over-current resistance value, and the outer layer of the high-density core wire 1 is a fluoroplastic insulation layer.

[0023] Preferably, when the above-mentioned tubing nipple 24 selects the short tubing nipple 24.1, by measuring the distance L between the lower end of the setting position of the tubing hanger 30 and the setting position of the wellhead cross hanger, and then measuring the protruding section of the wellbore cable 26, the reserved length of the wellbore cable from the outer end of the end face of the coupling nut 23 is: L + X - 30 cm, where X represents the length of the tubing nipple 24. For example: when the tubing nipple selects 700 mm, the reserved length of the wellbore cable from the valve flange end face is 400 mm, which is convenient for the connection of the two cable core wires. As long as the tubing nipple is greater than 700 mm, there is no need to consider measuring the L value, and the reserved length of the wellbore cable can be directly calculated with X - 30 cm.

[0024] Cut off the wellbore cable 26, strip the armor, process the connection end, connect and fix it with the high-density core wire 1 through the copper sleeve 25 and wrap it. After completion, lower the pipe string, set the tubing hanger 30, pass the three high-density core wires 1 through the inner holes of the valve body 20, threadedly connect the valve body 20 and the coupling nut 23 with the connecting nut 21, and tighten it with the locking nut 18.

[0025] Preferably, when the tubing nipple 24 is selected as the long tubing nipple 24.2, there is no need to measure the length of the power cable 26 of the casing side valve 33 passing through the Christmas tree. Directly set the tubing hanger 30 in place and fasten it, and install the Christmas tree; reserve an appropriate length from the outer end of the casing side valve 33, cut the wellbore cable 26, strip the armor, process the connection end, and connect and fix it with the high-density core wire 1 through the copper sleeve 25 and wrap it. After completion, on the overall outer circle where the long tubing nipple 24.2 and the coupling nut 23 are tightened, sleeve the connection nut 21. Pass the three high-density core wires 1 through the inner hole of the long tubing nipple 24.2. After threading the raw tape around the threads at the other end of the long tubing nipple 24.2, connect and fasten it to the casing side valve 33 of the Christmas tree. Then pass the high-density core wire 1 through the inner hole of the valve body 20, connect and tighten the valve body 20 and the coupling nut 23 through threads with the connection nut 21, and back-tighten with the lock nut 18.

[0026] Preferably, a pressure test tooling is connected to the left end of the valve body 20. The pressure test tooling includes a sealing screw pipe 2, a pressure test valve body 4, a pressure test nut 15, and a pressure test joint 28. The right end face of the pressure test valve body 4 is closely attached to the end face of the valve body 20 and is fixed by the pressure test nut 15. The high-density core wire 1 passes through three holes in the right end face. The left end of the pressure test valve body 4 passes through the three high-density core wires 1 through the sealing screw pipe 2; a pressure test hole is provided on the outer wall of the pressure test valve body 4, and a pressure test joint 28 is installed on the pressure test hole.

[0027] Preferably, a first sealing ring 3 is installed on the outer wall of the sealing screw pipe 2, and the right end of the sealing screw pipe 2 is connected to the left-end internal thread of the pressure test valve body 4 through a second sealing ring 5 and a sealing gasket ring 6.

[0028] Preferably, a third sealing ring 10 is installed on the outer wall of the sealing bushing 11, and a fourth sealing ring 13 is provided on the outer wall of the fixed joint 19; the right end of the pressure test valve body 4 is connected to the left end face of the valve body 20 through a pressure test valve body flange 14, and a fifth sealing ring 16 and a gasket ring 17 are provided between the pressure test valve body flange 14 and the left end face of the valve body 20; a sixth sealing ring 22 is provided between the right end face of the valve body 20 and the coupling nut 23.

[0029] The usage method of the general-purpose high-pressure seal for the electric submersible pump wellbore cable mentioned in the present invention includes the following steps: I. Workover construction 1). According to the pump setting depth in the construction design, lower the electric pump unit to the predetermined position, and pass the wellbore cable 26 through the casing side valve 33 of the Christmas tree; 2). Connect the tubing 29 lowered into the wellbore and the tubing hanger 30 with a tubing double male nipple 31; 3). Select different lengths of the tubing nipple 24, reserve a certain length for the wellbore cable 26, cut off the redundant wellbore cable 26 in the wellbore, and connect the high-density core wire 1; 4), Slowly lower the tubing hanger 30 through the tubing 29 until it is seated in place. At the same time, push the wellbore cable 26 to prevent the inner wall edge of the wellhead casing cross-over 34 from scratching the wellbore cable 26. II. Installation of on-site general-purpose high-pressure sealers: 5), Peel the protective armor of the cable passing through the valve 33 on the side wing of the casing until it reaches the end face of the valve flange 27, forming three cable cores 26. 6), Process the connection end, connect and fix it with the high-density core wire 1 through the copper sleeve 25 and wrap it. After completion, fit the connection nut 21 on the outer circumference of the whole formed by tightening the tubing nipple 24 and the coupling nut 23. Pass the three high-density core wires 1 through the inner hole of the tubing nipple 24. After winding the thread of the other end of the tubing nipple 24 with PTFE tape, connect and tighten it with the valve flange 27 on the side wing of the wellhead. Then pass the high-density core wire 1 through the inner hole of the valve body 20, connect and tighten the valve body 20 and the coupling nut 23 through the thread with the connection nut 21, and back-tighten with the lock nut 18. 7), Install the fourth sealing ring 13 on the fixed joint 19, and pass the high-density core wire 1 through the inner hole and tighten it with the valve body 20. 8), Fit the sealing sleeve 12 and the sealing bushing 11 with the third sealing ring 10 onto the high-density core wire 1 and push it to the right end of the intermediate seal 9 for connection. 9), Fit the second sealing ring 5 onto the high-density core wire 1 and push it to the sealing bushing 11. 10), Fit the intermediate joint 9 onto the high-density core wire 1 and tighten it with the fixed joint 19 through the thread. 11), Fit the half-ring cone 8 onto the high-density core wire 1, put on the outer nut 7, and tighten it with the intermediate nut to lock the high-density core wire 1. 12), Complete the sealing and fixing of the remaining two high-density core wires 1 according to the above steps. 13), Install the pressure test tooling according to requirements and conduct on-site pressure testing. The steps are as follows: 13.1, On the right end face of the pressure test valve body 4, install the gasket ring 17 and the fifth sealing ring 16, make it close to the end face of the valve body 20, and fix it with the pressure test nut 15. 13.2, Pass the high-density core wire 1 through the three holes on the right end face. 13.3, Install the sealing gasket ring 6 and the second sealing ring 5. Install the first sealing ring 3 on the sealing screw tube 2 and tighten it through the thread to compress the second sealing ring 5 to achieve the purpose of sealing the high-density core wire 1. 13.4, Pour the motor oil of the submersible motor into the inner cavity of the pressure test valve body 4 from the pressure test hole. After filling, install the pressure test joint 28 on the pressure test hole of the pressure test valve body 4 and tighten it. 13.5. Connect the manual pressure test pump, pressurize to an appropriate pressure value, stabilize for a certain period according to the regulations, relieve the pressure after meeting the requirements, and remove the pressure test tooling in the reverse order.

[0030] Embodiment 2. A general-purpose high-pressure seal for the electric submersible pump wellbore cable mentioned in the present invention includes a high-density core wire 1, an outer nut 7, a half-ring cone 8, an intermediate seal 9, a sealing bushing 11, a locking nut 18, a fixed joint 19, a valve body 20, a connecting nut 21, a coupling nut 23, and a tubing nipple 24. One end of the fixed joint 19 is movably connected to the valve body 20, the high-density core wire 1 passes through the inner hole of the fixed joint 19, and the other end of the fixed joint 19 is threadedly connected to the intermediate seal 9. The sealing bushing 11 is installed into the hole of the intermediate seal 9. The half-ring cone 8 is buckled on the high-density core wire 1, and the outer nut 7 is sleeved outside the half-ring cone 8. The outer nut 7 is threadedly connected to the end of the intermediate seal 9. The locking nut 18 is installed on the valve body 20. Three inner holes pass through the high-density core wire 1. One end is sleeved on the coupling nut 23 and fixed with the connecting nut 21. The other end installs the fixed joint 19. The right end of the coupling nut 23 is connected to the valve flange 27 through the tubing nipple 24, and the power cable 26 is connected to the high-density core wire 1 through the copper sleeve 25.

[0031] Due to the production trees with different pressure ratings at the site, the supporting high-pressure flanges 27 are divided into two types: BX153 and BX154. Each type is further divided into specifications such as 34 MPa, 70 MPa, or 103.5 MPa. The pitch circle diameters of the flange stud connection holes of each specification are different, but each specification of the flange is processed with the same 2⅞" flush female thread. The high-pressure seal of the present invention uses the 2⅞" flush female thread to connect with the wellhead flange 27, so it realizes the generalization of medium specifications. By installing the pressure test valve body 14, the pressure test nut 15, the sealing rings 35 and 16, the spacer ring 17, the sealing gasket ring 6, the sealing screw pipe 2 and fastening them, it seals with the high-density core wire 1. Inject the pressure test oil from the inner hole of the pressure test joint 28, connect the pressure test pump, and conduct the pressure test of the on-site high-pressure seal. After the pressure test is qualified, remove the pressure test tooling, and install and seal the ground cable protection pipe at the end of the valve body 20.

[0032] The difference from Embodiment 1 is: The outer ends of the three cable core wires mentioned in this embodiment are connected to the electric control cabinet through the copper sleeve 25 and the ground cable. A protection pipe can be sleeved outside the valve body 20, so as to play a role in protecting the cable core wire outside the device of the present invention.

[0033] The above are only some preferred embodiments of the present invention. Any person skilled in the art may modify the above-described technical solutions or modify them into equivalent technical solutions. Therefore, the corresponding simple modifications or equivalent transformations made according to the technical solutions of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A universal high-pressure sealer for electric submersible pump wellbore cables, characterized by: The invention comprises a high-density core wire (1), an outer nut (7), a semi-ring cone (8), an intermediate seal (9), a sealing bushing (11), a locking nut (18), a fixed joint (19), a valve body (20), a connecting nut (21), a coupling nut (23), and an oil pipe short-circuit (24); one end of the fixed joint (19) is movably connected to the valve body (20), the inner hole of the fixed joint (19) is penetrated by the high-density core wire (1), and the other end of the fixed joint (19) is threadedly connected to the intermediate seal (9); the sealing bushing (11) is installed in the hole of the intermediate seal (9), and the semi-ring cone ( 8) is buckled on the high-density core wire (1), an outer nut (7) is sleeved on the outer surface of the semi-annular cone (8), and the outer nut (7) is connected to the end of the middle seal (9) through a thread; a locking nut (18) is installed on the valve body (20), and the high-density core wire (1) is passed through the three inner holes, one end is sleeved on the coupling nut (23), and fixed with a connecting nut (21); a fixing joint (19) is installed on the other end; the right end of the coupling nut (23) is connected to the valve flange (27) through an oil pipe short circuit (24), and the power cable (26) is connected to the high-density core wire (1) through a copper sleeve (25).

2. The universal high-pressure sealer for electric submersible pump wellbore cables according to claim 1 is characterized by: A sealing bushing (11) is installed in the hole on the right side of the middle seal (9), and a sealing sleeve (12) is installed on the right side of the sealing bushing (11). The left end of the fixed joint (19) is connected to the right end of the middle seal (9) by means of a thread, and the right end of the fixed joint (19) is connected to the valve body (20) by means of a thread.

3. The universal high-pressure sealer for electric submersible pump wellbore cables according to claim 2 is characterized by: The high-density core wire (1) adopts a whole cable, and the wire diameter is thicker than the wire diameter of the wellbore cable (26), and the current resistance value is low. The outer layer of the high-density core wire (1) is a fluoroplastic insulation layer.

4. The universal high-pressure sealer for electric submersible pump wellbore cables according to claim 3 is characterized by: When the tubing short-circuit (24) is a short tubing short-circuit (24.1), the distance L between the lower end of the tubing hanger (30) sealing position and the wellhead spool hanger sealing position is measured, and then the exit section of the wellbore cable (26) is measured. The wellbore cable length reserved from the outer end of the end face of the coupling nut (23) is: L+X-30, the wellbore cable (26) is cut off, the armor is stripped off, the connection end is processed, and it is connected and fixed with the high-density core wire (1) through the copper sleeve (25) and wrapped. After completion, the pipe string is lowered, the tubing hanger (30) is sealed, and the three high-density core wires (1) are passed through the inner hole of the valve body (20). The valve body (20) and the coupling nut (23) are connected by threading using the connecting nut (21), and tightened with the locking nut (18).

5. The universal high-pressure sealer for electric submersible pump wellbore cables according to claim 3 is characterized by: When the tubing short-circuit (24) is a long tubing short-circuit (24.2), it is not necessary to measure the length of the power cable (26) passing through the casing flank valve (33) of the Christmas tree. The tubing hanger (30) can be directly set in place and tightened to install the Christmas tree. A suitable length is reserved from the outer end of the casing flank valve (33), the wellbore cable (26) is cut, the armor is peeled off, the connection end is processed, and it is connected, fixed, and wrapped with the high-density core wire (1) through the copper sleeve (25). After completion, the long tubing short-circuit (24.2) and the The coupling nut (23) is tightened on the overall outer circle, and the connecting nut (21) is installed. The three high-density core wires (1) are passed through the inner hole of the long oil pipe short-circuit (24.2). The other end of the long oil pipe short-circuit (24.2) is threadedly wrapped with a raw tape and connected to and tightened with the casing wing valve (33) of the oil tree. Then, the high-density core wire (1) is passed through the inner hole of the valve body (20), and the valve body (20) and the coupling nut (23) are connected and tightened by threading with the connecting nut (21), and then tightened with the locking nut (18).

6. The universal high-pressure sealer for electric submersible pump wellbore cables according to claim 4 or 5, characterized in that: The left end of the valve body (20) is connected to a pressure test fixture, which comprises a sealing spiral tube (2), a pressure test valve body (4), a pressure test nut (15), and a pressure test joint (28). The right end face of the pressure test valve body (4) is in close contact with the end face of the valve body (20) and is fixed by the pressure test nut (15). The high-density core wire (1) passes through three holes in the right end face. Three high-density core wires (1) pass through the left end of the pressure test valve body (4) through the sealing spiral tube (2). A pressure test hole is provided on the outer wall of the pressure test valve body (4), and a pressure test joint (28) is installed on the pressure test hole.

7. The universal high-pressure sealer for electric submersible pump wellbore cables according to claim 6 is characterized by: A first sealing ring (3) is installed on the outer wall of the sealing spiral tube (2), and the right end of the sealing spiral tube (2) is connected to the left end internal thread of the pressure test valve body (4) through a second sealing ring (5) and a sealing gasket ring (6).

8. The universal high-pressure sealer for electric submersible pump wellbore cables according to claim 7 is characterized by: A third sealing ring (10) is installed on the outer wall of the sealing bushing (11), and a fourth sealing ring (13) is installed on the outer wall of the fixed joint (19); the right end of the pressure test valve body (4) is connected to the left end face of the valve body (20) via the pressure test valve body flange (14), and a fifth sealing ring (16) and a gasket (17) are installed between the pressure test valve body flange (14) and the left end face of the valve body (20); and a sixth sealing ring (22) is installed between the right end face of the valve body (20) and the coupling nut (23).

9. The method for using the universal high-pressure sealer for electric submersible pump wellbore cables according to claim 8, characterized in that: The following steps are involved:

1. Well repair construction 1) According to the designed pump hanging depth, lower the electric pump unit to the predetermined position, and pass the wellbore cable (26) through the casing wing valve (33) of the Christmas tree; 2) Connecting the oil pipe (29) lowered into the wellbore with the oil pipe hanger (30) using an oil pipe double male short circuit (31); 3) Select different lengths of the tubing short-circuit (24), reserve a certain length for the wellbore cable (26), cut off the excess wellbore cable (26), and connect the high-density core wire (1); 4) Slowly lower the tubing hanger (30) through the tubing (29) to set it in place, while pushing the wellbore cable (26) to prevent the inner wall edge of the wellhead casing spool (34) from scratching the wellbore cable (26); 2. On-site universal high-pressure sealer installation: 5) Strip the protective armor of the cable passing through the casing side valve (33) to the end face of the valve flange (27) to form three cable core wires (26); 6) Process the connection end, connect and fix the high-density core wire (1) through the copper sleeve (25), wrap it, and after completion, put the connecting nut (21) on the overall outer circle of the tubing short-circuit (24) and the coupling nut (23) to tighten, pass the three high-density core wires (1) through the inner hole of the tubing short-circuit (24), wrap the thread of the other end of the tubing short-circuit (24) with the raw material tape, connect and tighten it with the valve flange (27) on the side of the wellhead, then pass the high-density core wire (1) through the inner hole of the valve body (20), connect the valve body (20) and the coupling nut (23) through the thread with the connecting nut (21) and tighten it, and tighten it with the locking nut (18); 7) Install the fourth sealing ring (13) on the fixed joint (19), pass the high-density core wire (1) through the inner hole, and tighten it to the valve body (20); 8) Put the sealing sleeve (12) and the sealing bushing (11) equipped with the third sealing ring (10) onto the high-density core wire (1) and push them to the right end of the middle seal (9) for connection; 9) Put the second sealing ring (5) onto the high-density core wire (1) and push it onto the sealing bushing (11); 10) Put the intermediate joint (9) onto the high-density core wire (1) and tighten it with the fixed joint (19) through the threaded buckle; 11) Buckle the semi-ring cone (8) onto the high-density core wire (1), install the outer nut (7), and tighten it with the middle nut to lock the high-density core wire (1); 12) Follow the above steps to complete the sealing and fixing of the remaining two high-density core wires (1); 13) According to the requirements, install the pressure test tooling and conduct on-site pressure test. The steps are as follows: 13.

1. Install the gasket (17) and the fifth sealing ring (16) on the right end face of the pressure test valve body (4), make them close to the end face of the valve body (20), and fix them with the pressure test nut (15); 13.

2. The high-density core wire (1) passes through the three holes on the right end face; 13.

3. Install the sealing gasket (6) and the second sealing ring (5), install the first sealing ring (3) on the sealing spiral tube (2), tighten it by threading, and compress the second sealing ring (5) to achieve the purpose of sealing the high-density core wire (1); 13.

4. Pour the motor oil of the submersible motor into the inner cavity of the pressure test valve body (4) through the pressure test hole. After the inner cavity is filled, install the pressure test joint (28) into the pressure test hole of the pressure test valve body (4) and tighten it. 13.

5. Connect the manual pressure test pump, pressurize to the appropriate pressure value, stabilize the pressure for a certain period of time as required, release the pressure after reaching the requirement, and remove the pressure test tooling in the reverse order.

Images