Pressure gauge supporting device, pressure gauge lowering method and well washing method

Abstract

The present invention provides a pressure gauge support device and a pressure gauge lowering method, which belongs to the technical field of oil and gas field development engineering. The device includes: an outer tube, an inner tube and a pressure gauge installation tube. The outer tube includes a first cylinder, a second cylinder and a connecting arm. The first cylinder is connected to the oil pipe, the second cylinder is coaxially located in the first cylinder, and the two ends of the connecting arm are respectively connected to the first cylinder and the second cylinder. The outer tube has a first channel that passes through the first cylinder, the connecting arm and the second cylinder. The inner tube is connected to the center tube, and the inner tube is coaxially inserted in the second cylinder. The pressure gauge installation tube is connected to the inner wall of the inner tube, and a fluid channel is provided between the pressure gauge installation tube and the inner wall of the inner tube. The connection between the pressure gauge installation tube and the inner tube has a second channel that passes through the side wall of the pressure gauge installation tube and the inner tube, and the second channel is connected to the first channel. The device can realize the lifting and lowering of the pressure gauge without moving the oil pipe string.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development engineering, and in particular to a pressure gauge supporting device, a pressure gauge lowering method and a well washing method. Background Art

[0002] During the oil and gas development process, it is necessary to install a pressure gauge downhole to monitor the downhole pressure.

[0003] In the related art, the pressure gauge is lowered into the well together with the oil pipe string. A pressure gauge support tube is installed on the outer wall of the oil pipe string, and the pressure gauge is installed in the pressure gauge support tube. The pressure gauge is connected to the equipment on the ground through a cable tied to the outer wall of the oil pipe string.

[0004] During the process of going down into the well, there is a high probability that the cable will be damaged by scratches. Once the cable or pressure gauge is damaged, the oil pipe string needs to be pulled out and the damaged part needs to be replaced. During this process, normal mining cannot be carried out, which affects mining efficiency. Summary of the invention

[0005] The disclosed embodiment provides a pressure gauge support device, a pressure gauge downhole method and a well cleaning method, which can lower the pressure gauge into the well and clean the well without moving the oil pipe string. The technical solution is as follows:

[0006] An embodiment of the present disclosure provides a pressure gauge supporting device, which includes an outer cylinder, an inner cylinder and a pressure gauge mounting cylinder.

[0007] The outer cylinder includes a first cylinder body, a second cylinder body and at least one connecting arm. The first cylinder body is used to connect with the oil pipe. The second cylinder body is coaxially located in the first cylinder body. An annular space is formed between the second cylinder body and the first cylinder body. The two ends of any connecting arm of the at least one connecting arm are respectively connected to the first cylinder body and the second cylinder body. The outer cylinder has a first channel, and the first channel runs through the first cylinder body, the connecting arm and the second cylinder.

[0008] The inner cylinder is used to connect with the central tube, and the inner cylinder is coaxially inserted in the second cylinder. One end of the pressure gauge installation cylinder is open and the other end is closed, the pressure gauge installation cylinder is connected to the inner wall of the inner cylinder, a fluid channel is provided between the pressure gauge installation cylinder and the inner wall of the inner cylinder, and a second channel is provided at the connection between the pressure gauge installation cylinder and the inner cylinder, the second channel passes through the side wall of the pressure gauge installation cylinder and the inner cylinder, and the second channel is communicated with the first channel.

[0009] Optionally, the second cylinder includes an upper cylinder, a joint and a lower cylinder that are coaxially connected in sequence, and the connecting arm is connected between the first cylinder and the joint.

[0010] Optionally, the pressure gauge supporting device further includes a first seal and a second seal, wherein the first seal and the second seal are respectively located on both sides of the first channel in the axial direction, and the first seal and the second seal are embedded in the outer peripheral wall of the inner tube.

[0011] Optionally, an axial distance between the first sealing member and the first channel is 100 mm to 150 mm, and an axial distance between the second sealing member and the first channel is 100 mm to 150 mm.

[0012] Optionally, the pressure gauge supporting device also includes a reducer and a pump rod-free plug coaxially connected to one end of the inner tube in sequence.

[0013] Optionally, the pressure gauge supporting device also includes a stabilizer coaxially sleeved on the other end of the inner tube.

[0014] Optionally, the number of the first channels and the number of the second channels are both 2.

[0015] Optionally, the two first channels are arranged symmetrically about the center line of the outer tube, and the two second channels are arranged symmetrically about the center line of the inner tube.

[0016] The embodiment of the present disclosure also provides a method for lowering a pressure gauge into a well, which is implemented by using any of the aforementioned pressure gauge supporting devices, and the method for lowering a pressure gauge into a well includes:

[0017] Lower the pressure gauge support device into the well along with the tubing string and the central pipe string;

[0018] The pressure gauge is lowered into the central pipe column and is sent into the pressure gauge installation cylinder by water pressure.

[0019] The disclosed embodiment also provides a well washing method, which is implemented by using any of the aforementioned pressure gauge supporting devices. The pressure gauge supporting device is located in the well, and the outer cylinder of the pressure gauge supporting device is connected to the oil pipe string, the oil pipe string includes an oil pipe, an outer cylinder and a rodless pump group, the oil pipe and the second cylinder of the outer cylinder are coaxially connected, and the rodless pump group is connected to the lower end of the second cylinder; the inner cylinder of the pressure gauge supporting device is connected to the central pipe string, the central pipe string includes a central pipe, an inner cylinder, a pressure gauge mounting cylinder and a rodless pump plug, the central pipe, the inner cylinder and the rodless pump plug are coaxially connected in sequence, and the pressure gauge mounting cylinder is connected to the inner wall of the inner cylinder.

[0020] The well washing method comprises:

[0021] Sequentially lifting out the pressure gauge and the central pipe string;

[0022] Fluid is pumped into the oil pipe, and the well is washed using the well-washing channel formed by the first channel.

[0023] The beneficial effects brought by the technical solution provided by the embodiments of the present disclosure include at least:

[0024] The outer tube of the pressure gauge supporting device is connected to the oil pipe, and the inner tube is connected to the central tube, so that the pressure gauge supporting tube device can be lowered into the well along with the oil pipe string and the central tube string, and then the pressure gauge is dropped from the central tube into the pressure gauge installation tube to achieve the central tube inside fishing of the pressure gauge. During the fishing process of the pressure gauge, the cable of the pressure gauge is located in the inner tube, and there is no need to place the pressure gauge and the cable outside the oil pipe and lower them together with the oil pipe, which can protect the pressure gauge and the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 It is a structural schematic diagram of a pressure gauge support device provided by an embodiment of the present disclosure;

[0027] Figure 2 is a schematic structural diagram of an outer cylinder provided in an embodiment of the present disclosure;

[0028] Figure 3 It is a schematic diagram of the structure after the inner cylinder and the pressure gauge supporting cylinder provided by the embodiment of the present disclosure are assembled;

[0029] Figure 4 yes Figure 2 Schematic diagram of the cross section along line AA;

[0030] Figure 5 yes Figure 3 Schematic diagram of the cross section along line BB;

[0031] Figure 6 is a schematic diagram of the structure of a pressure gauge provided by an embodiment of the present disclosure;

[0032] Figure 7 It is a flow chart of the method for lowering a pressure gauge into a well provided by an embodiment of the present disclosure.

[0033] The descriptions of the symbols in the figure are as follows:

[0034] 10. outer cylinder; 10a. first channel;

[0035] 11. The first cylinder;

[0036] 12. second cylinder; 121. upper cylinder; 122. joint; 123. lower cylinder;

[0037] 13. Connecting arm;

[0038] 20, inner cylinder; 20a, first sealing groove; 20b, second sealing groove;

[0039] 21. a first sealing member; 22. a second sealing member;

[0040] 30. Pressure gauge installation tube; 30a. Second channel;

[0041] 31. Install the cylinder; 32. Boss;

[0042] 50. Pressure gauge; 51. Cable; 52. Electronic compartment; 53. Bottom hole plug;

[0043] 60. lower joint; 61. sealing member;

[0044] 70. Center tube; 71. Centralizer;

[0045] 81. Reducer; 82. Plug without pump rod;

[0046] S1, annular space; S2, fluid channel. DETAILED DESCRIPTION

[0047] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0048] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons with ordinary skills in the field to which the present disclosure belongs. The words "first", "second", "third" and similar words used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate a quantity limitation, but indicate the existence of at least one. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", "top", "bottom" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0049] Figure 1Schematic diagram of a pressure gauge support device provided by an embodiment of the present disclosure. Figure 1 As shown, the pressure gauge supporting device includes: an outer cylinder 10, an inner cylinder 20 and a pressure gauge mounting cylinder 30.

[0050] The outer cylinder 10 includes a first cylinder 11, a second cylinder 12 and at least one connecting arm 13. The first cylinder 11 is used to connect with the oil pipe, and the second cylinder 12 is coaxially located in the first cylinder 11. An annular space S1 is formed between the second cylinder 12 and the first cylinder 11. The two ends of the connecting arm 13 are respectively connected to the first cylinder 11 and the second cylinder 12. The outer cylinder 10 has a first channel 10a, which runs through the first cylinder 11, the connecting arm 13 and the second cylinder 12, so as to connect the inside and the outside of the outer cylinder 10.

[0051] The inner cylinder 20 is used to connect with the central tube 70, and the inner cylinder 20 is coaxially inserted in the second cylinder 12. One end of the pressure gauge installation cylinder 30 is open and the other end is closed. The pressure gauge installation cylinder 30 is connected to the inner wall of the inner cylinder 20, and a fluid channel S2 is provided between the pressure gauge installation cylinder 30 and the inner wall of the inner cylinder 20. The connection between the pressure gauge installation cylinder 30 and the inner cylinder 20 has a second channel 30a, and the second channel 30a passes through the side walls of the pressure gauge installation cylinder 30 and the inner cylinder 20, and the second channel 30a is connected to the corresponding first channel 10a.

[0052] The outer tube of the pressure gauge supporting device is connected to the oil pipe, and the inner tube is connected to the center pipe, so that the pressure gauge supporting tube device can be lowered into the well along with the oil pipe string and the center pipe string, and then the pressure gauge is dropped from the center pipe into the pressure gauge installation tube to achieve the center pipe fishing of the pressure gauge. During the fishing process of the pressure gauge, the cable of the pressure gauge is located in the inner tube, and there is no need to place the pressure gauge and the cable outside the oil pipe and lower them together with the oil pipe, which can protect the pressure gauge and the cable. In addition, the downhole pressure gauge can be lifted out of the ground and replaced without moving the oil pipe string, which increases the replacement speed of the pressure gauge.

[0053] When the pressure gauge is installed in place in the pressure gauge installation tube, the first channel and the second channel are connected to form an external pressure transmission channel. Through the external pressure transmission channel, the pressure gauge installed in the pressure gauge installation tube can perform downhole pressure detection.

[0054] The fluid channel S2 is the central pipe injection channel, which can provide high-pressure power fluid for the downhole pump group. The annular space S1 can be used as a channel for oil pipe injection and production fluid, and the mixed fluid formed by the production fluid and the spent power fluid is transported to the wellhead through this channel.

[0055] Figure 2 Schematic diagram of the structure of the outer cylinder provided by the embodiment of the present disclosure. Figure 2 The first cylinder 11 is a cylinder with two ends open. Exemplarily, the upper end of the first cylinder 11 is provided with an internal thread to be threadedly connected to the oil pipe, and the lower end of the first cylinder 11 is provided with an external thread to be threadedly connected to the lower joint 60. Optionally, a sealing member 61, such as an O-ring, is provided between the lower end of the first cylinder 11 and the lower joint 60.

[0056] For example, Figure 2 As shown, the second cylinder 12 includes an upper cylinder 121, a joint 122 and a lower cylinder 123 which are coaxially connected in sequence. The connecting arm 13 is connected between the first cylinder 11 and the joint 122. That is, one end of the connecting arm 13 is connected to the inner peripheral wall of the first cylinder 11, and the other end of the connecting arm 13 is connected to the outer peripheral wall of the joint 122.

[0057] For example, in order to facilitate the assembly of the pressure gauge supporting device, the connecting arm 12 and the joint 122 are integrally formed, and the connecting arm 13 is welded to the first cylinder 11. The joint 122 is connected to the upper cylinder 121 and the lower cylinder 123 by threaded connection.

[0058] Optionally, the cross section of the first channel 10a on the outer cylinder 10 is in the shape of an elongated strip, and the length direction of the cross section of the first channel 10a is consistent with the length direction of the outer cylinder 10. Exemplarily, the length of the cross section of the first channel 10a is 45 mm to 50 mm, and the width of the cross section of the first channel 10a is 12 mm to 15 mm. Designing the cross section of the first channel 10a to be in the shape of an elongated strip is conducive to increasing the flow area.

[0059] In the embodiment of the present disclosure, the first channel 10 a is formed by connecting the opening on the first cylinder 11 and the through holes on the connecting arm and the joint 122 .

[0060] Figure 3 Schematic diagram of the structure after the inner cylinder and the pressure gauge support cylinder provided by the embodiment of the present disclosure are assembled. Figure 3 As shown, the inner wall of the inner cylinder 20 is fixedly connected to the pressure gauge mounting cylinder 30. Exemplarily, the outer peripheral wall of the inner cylinder 20 is closely connected to the inner peripheral wall of the second cylinder 12.

[0061] In the disclosed embodiment, the inner cylinder 20 is detachably connected to the second cylinder 12. In this way, the outer cylinder 10 can be lowered into the well along with the oil pipe, and the inner cylinder 20 and the pressure gauge installation cylinder 30 can be lowered into the well along with the central pipe, thereby realizing the downhole assembly of the pressure gauge support device.

[0062] Optionally, see again Figure 1The pressure gauge support device further includes a first seal 21 and a second seal 22, which are respectively located on both sides of the first channel 10a in the axial direction, and are embedded in the outer peripheral wall of the inner cylinder 20. In this way, when the inner cylinder 20 and the outer cylinder 10 are assembled together, the first seal 21 and the second seal 22 are sandwiched between the inner cylinder 20 and the second cylinder body 12 to play a sealing role.

[0063] Exemplarily, the first sealing member 21 includes at least one O-ring, and the second sealing member 22 includes at least one O-ring.

[0064] For example, in combination Figure 3 The outer wall of the inner cylinder 20 has a first sealing groove 20a and a second sealing groove 20b. The first sealing member 21 is installed in the first sealing groove 20a, and the second sealing member 22 is installed in the second sealing groove 20b. For example, the outer wall of the inner cylinder 20 has three first sealing grooves 20a and three second sealing grooves 20b arranged at intervals along the axial direction of the inner cylinder 20, and an O-ring is installed in each first sealing groove 20a and each second sealing groove 20b.

[0065] The axial distance between the first sealing member 21 and the first channel 10a is 100 mm to 150 mm, and the axial distance between the second sealing member 22 and the first channel 10a is 100 mm to 150 mm, so as to facilitate the processing of the first sealing groove 20a and the second sealing groove 20b.

[0066] Optionally, the pressure gauge supporting device further includes a center tube 70 coaxially sleeved on the upper end of the inner tube 20 and a centralizer 71 sleeved outside the center tube. Exemplarily, the upper end of the inner tube 20 is threadedly connected to the center tube 70. The centralizer 71 can protect the first seal 21 and the second seal 22 during the process of the inner tube 20 being lowered into the oil pipe, thereby preventing the first seal 21 and the second seal 22 from being worn.

[0067] Optionally, the pressure gauge support device further includes a reducer 81 and a pump rod-free plug 82 coaxially connected to the lower end of the inner tube 20. Exemplarily, the reducer 81 is threadedly connected to the lower end of the inner tube 20, and the reducer 81 is threadedly connected to the pump rod-free plug 82.

[0068] Exemplarily, the pressure gauge mounting cylinder 30 includes a mounting cylinder 31 and a boss 32 connected to the outer wall of the mounting cylinder 31, the boss 32 is connected to the inner wall of the inner cylinder 20, and the second channel 30a passes through the side wall of the mounting cylinder 31 and the boss 32. In the embodiment of the present disclosure, the mounting cylinder 32 and the boss 32 are integrally formed, and the boss 32 is welded to the inner wall of the inner cylinder 20.

[0069] Optionally, the opening of the pressure gauge installation tube 30 is in a trumpet shape that is larger at the top and smaller at the bottom, so that the pressure gauge can be easily inserted into the pressure gauge installation tube 30 .

[0070] In the embodiment of the present disclosure, the electronic pressure gauge 50 is a bottom pressure transmission electronic pressure gauge. Figure 6 As shown, the electronic pressure gauge 50 includes a cable 51, an electronic compartment 52 and a bottom hole plug 53. The electronic compartment 52 and the bottom hole plug 53 are threadedly connected. A sealing member 54 is provided on the outer wall of the bottom hole plug 53, so that after the bottom hole plug 53 is inserted into the pressure gauge installation tube 30, it cooperates with the pressure gauge installation tube 30 to achieve a sealed connection.

[0071] It should be noted that Figures 1 to 3 It is not a schematic diagram of the axial section of the pressure gauge support device. Figures 1 to 3 In the figure, the left half is a schematic diagram of half of the axial cross section passing through the first channel 10a or the second channel 30a, and the right half is a schematic diagram of half of the axial cross section not passing through the first channel 10a and the second channel 30a.

[0072] Figure 4 yes Figure 2 Schematic diagram of the cross section along line AA. Figure 4 As shown, in the embodiment of the present disclosure, the number of the first channels 10 a is 2. The two first channels 10 a are symmetrically arranged about the center line of the outer cylinder 10 .

[0073] Figure 5 yes Figure 3 Schematic diagram of the cross section along line BB. Figure 5 As shown, in the embodiment of the present disclosure, the number of the second channels 30 a is 2. Moreover, the two second channels 30 a are symmetrically arranged about the center line of the inner cylinder 20 .

[0074] It should be noted that, in other embodiments, the number of first channels a and second channels 30a can be set according to actual needs.

[0075] In some examples, the dimensions of the components of the pressure gauge resting device are as follows:

[0076] Outer tube: outer diameter 89mm, length 0.7m, used to connect two and a half inch oil pipe.

[0077] First cylinder: the inner diameter of the upper cylinder is 50.8 mm, and the length of the upper cylinder is 0.35 m. The inner diameter of the lower cylinder is 50.8 mm, and the length of the lower cylinder is 0.35 m.

[0078] The second cylinder has an outer diameter of 50.8 mm, an inner diameter of 38 mm and a length of 0.9 m. The opening on the second cylinder is a through hole with a hole diameter of 6 mm. It is suitable for connecting a central tube with an outer diameter of 36 mm. The outer diameter of the centralizer is 58 mm.

[0079] The inner diameter of the pressure gauge mounting barrel matches the outer diameter of the bottom hole plug of the pressure gauge.

[0080] Pressure gauge: The outer diameter of the electronic compartment is 20mm, and the outer diameter of the bottom hole plug is 16mm. The pressure gauge is connected to the armored cable with an outer diameter of 5.6mm, and can withstand a tensile force of more than 3 tons, and the water-tight pressure bearing capacity is more than 30MPa.

[0081] The disclosed embodiment also provides a method for lowering a pressure gauge into a well, which is implemented based on the aforementioned pressure gauge supporting device. Figure 7 A schematic diagram of a process for lowering a pressure gauge into a well provided by an embodiment of the present disclosure. Figure 7 As shown, the method includes:

[0082] In 701, a pressure gauge support device is lowered into the well along with the tubing string and the central pipe string.

[0083] The first step is to lower the tubing string according to the designed pump hanging depth.

[0084] The tubing string includes an oil pipe, an outer tube and a rodless pump group, wherein the upper end of the outer tube is connected to the lower end of the oil pipe (e.g., threaded connection), and the lower end of the outer tube is connected to the rodless pump group. The rodless pump group at least includes a rodless pump, and optionally, the rodless pump group also includes a sand and gas prevention device and a sand settling device.

[0085] In the disclosed embodiment, the rodless pump is a hydraulic pump. Optionally, the hydraulic pump is a hydraulic tube pump or a hydraulic jet pump.

[0086] The second step is to lower the center pipe column until the lower end of the center pipe column is connected to the rodless pump.

[0087] The central pipe column includes a central pipe, an inner tube, a pressure gauge mounting tube and a rodless pump plug, wherein the lower end of the central pipe is connected to the upper end of the inner tube (e.g., threaded connection), the pressure gauge mounting tube is connected to the inner wall of the inner tube, and the rodless pump plug is connected to the lower end of the inner tube. The lower end of the rodless pump plug is connected to the rodless pump (e.g., connected by a thread). In the disclosed embodiment, the lower end of the central pipe column is connected to the rodless pump means that the rodless pump plug is inserted into the rodless pump.

[0088] Optionally, 701 also includes: injecting clean water from the central tube to complete the cleaning of the central tube.

[0089] In 702, a pressure gauge is lowered from the central pipe string and is sent into the pressure gauge installation tube using water pressure.

[0090] The 702 includes:

[0091] The first step is to seal the wellhead for the first time after the pressure gauge is lowered, so that there is a gap between the cable of the pressure gauge and the seal;

[0092] Step 2: Pump clean water into the central tube and use the water pressure to push the pressure gauge into the pressure gauge installation cylinder;

[0093] The third step is to seal the wellhead for the second time to ensure a sealed connection between the cable and the seal.

[0094] During the process of lowering the pressure gauge, the wellhead is sealed twice. The first seal can prevent water from leaking, which is conducive to maintaining water pressure to allow the pressure gauge to descend; at the same time, the gap between the cable and the seal can reduce the friction of the cable during the downward movement of the pressure gauge. The second seal ensures that the pressure gauge can withstand a pressure of more than 20MPa and a downward pull of more than 2 tons after being sent into the pressure gauge installation cylinder, ensuring that the cable does not slide downward due to its own weight.

[0095] The sealing members used for wellhead sealing include but are not limited to rubber seals, compression glands, etc., and the present disclosure does not impose any restrictions on this.

[0096] In this second step, after the pressure gauge is lowered into the central pipe, clean water is pumped until the pressure gauge bottom hole plug is inserted into the pressure gauge mounting tube and forms a sealed connection. At this time, the surface pump pressure increases, indicating that the pressure gauge pumping is completed.

[0097] Subsequently, the wellhead pipeline is connected to the relevant interfaces of the ground equipment and can be started and put into operation for drainage and production.

[0098] Optionally, after the drainage system has been running for a period of time, the pressure gauge may fail, and at this time, the pressure gauge needs to be replaced. In this case, the method further includes: pulling out the pressure gauge; and lowering a new pressure gauge.

[0099] Exemplarily, pulling out the pressure gauge includes: rotating a cable drum at the wellhead to pull out the pressure gauge and the cable together.

[0100] If the pressure gauge fails, the pump is stopped, the secondary seal of the wellhead is released, and then the pressure gauge is pulled out, and then a new pressure gauge is lowered again. The replacement of the pressure gauge does not require the pulling out of the pipe string. The method of lowering the new pressure gauge is shown in 702, and the detailed description is omitted here.

[0101] In other examples, after the drainage system has been running for a period of time, the pump or the pipe string may also fail. In this case, a pump inspection operation is required. Accordingly, the method also includes: pulling out the pressure gauge; pulling out the center pipe string; and pulling out the oil pipe string and the rodless pump.

[0102] After the pressure gauge is pulled out, the central pipe, tubing and casing are connected, and the pump is checked. When the central pipe string and tubing string are pulled out, the liquid in the string can all fall back into the well, without polluting the well site and reducing operation pollution. After replacing the appropriate parts, repeat 701 and 702 to resume drainage.

[0103] For the low-lying areas of the down-dip horizontal section of the horizontal well, particulate matter may accumulate and block the casing annulus. In this case, well washing operations are required before pulling out the tubing string and rodless pump.

[0104] In the embodiment of the present disclosure, the downward-dipping horizontal section refers to a horizontal section of a horizontal well that has a small downward tilt angle and has ups and downs, and the small angle is, for example, 0 to 20 degrees.

[0105] To this end, the present disclosure also provides a well washing method, which includes:

[0106] After the pressure gauge and the central pipe string are pulled out, fluid (such as gas or liquid) is pumped into the oil pipe to perform well washing using the well washing channel formed by the first channel.

[0107] After the central pipe string is pulled out, the inner tube is separated from the outer tube, and the oil pipe is connected to the annular space of the casing through the first channel on the outer tube to form a well washing channel. Gas or liquid is pumped into the oil pipe through the well washing channel to wash the well, so that the particles deposited in the annular space of the horizontal section of the well are washed to the wellhead, and the annular space of the casing is dredged, so that the drainage and production string in the downward horizontal section, that is, the oil pipe string, can be smoothly pulled out.

[0108] Optionally, the ratio of the flow area of ​​the well-washing channel to the cross-sectional area of ​​the oil pipe is between one third and one half. This ratio range can ensure the strength of the outer cylinder and the first cylinder body, and can ensure that no serious throttling occurs during large-volume well-washing, thereby improving the well-washing efficiency.

[0109] The above does not limit the present disclosure in any form. Although the present disclosure has been disclosed as above through the embodiments, it is not used to limit the present disclosure. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present disclosure. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present disclosure without departing from the content of the technical solution of the present disclosure still falls within the scope of the technical solution of the present disclosure.

Claims

1. A pressure gauge support device, characterized in that: The pressure gauge supporting device comprises: An outer cylinder (10) comprises a first cylinder (11), a second cylinder (12) and at least one connecting arm (13); the first cylinder (11) is used to connect to an oil pipe; the second cylinder (12) is coaxially located in the first cylinder (11); an annular space (S1) is formed between the second cylinder (12) and the first cylinder (11); two ends of any connecting arm (13) of the at least one connecting arm (13) are respectively connected to the first cylinder (11) and the second cylinder (12); the outer cylinder (10) has a first channel (10a); the first channel (10a) runs through the first cylinder (11), the connecting arm (13) and the second cylinder (12); An inner cylinder (20) is used to be connected to the central tube (70), and the inner cylinder (20) is coaxially inserted into the second cylinder (12); a pressure gauge installation tube (30), one end of the pressure gauge installation tube (30) being open and the other end being closed, the pressure gauge installation tube (30) being connected to the inner wall of the inner tube (20), a fluid channel (S2) being provided between the pressure gauge installation tube (30) and the inner wall of the inner tube (20), and a second channel (30a) being provided at the connection between the pressure gauge installation tube (30) and the inner tube (20), the second channel (30a) passing through the side walls of the pressure gauge installation tube (30) and the inner tube (20), and the second channel (30a) being communicated with the first channel (10a); The second cylinder (12) comprises an upper cylinder (121), a joint (122) and a lower cylinder (123) which are coaxially connected in sequence, and the connecting arm (13) is connected between the first cylinder (11) and the joint (122); The pressure gauge supporting device further comprises a first sealing member (21) and a second sealing member (22), wherein the first sealing member (21) and the second sealing member (22) are respectively located on two sides of the first channel (10a) in the axial direction, and the first sealing member (21) and the second sealing member (22) are embedded in the outer peripheral wall of the inner tube (20); The axial distance between the first sealing member (21) and the first channel (10a) is 100 mm to 150 mm; The axial distance between the second sealing member (22) and the first passage (10a) is 100 mm to 150 mm.

2. The pressure gauge support device according to claim 1, characterized in that: The pressure gauge supporting device further comprises a reducer (81) and a pump rod-free plug (82) which are coaxially connected in sequence to one end of the inner tube (20).

3. The pressure gauge support device according to claim 2, characterized in that: The pressure gauge supporting device further comprises a centralizer (71) coaxially sleeved outside the other end of the inner cylinder (20).

4. The pressure gauge support device according to claim 1, characterized in that: The number of the first channels (10a) and the number of the second channels (30a) are both 2.

5. The pressure gauge support device according to claim 4, characterized in that: The two first channels (10a) are symmetrically arranged about the center line of the outer cylinder (10), and the two second channels (30a) are symmetrically arranged about the center line of the inner cylinder (20).

6. A method for lowering a pressure gauge into a well, characterized in that: The pressure gauge supporting device according to any one of claims 1 to 5 is used to implement the pressure gauge lowering method, which comprises: Lower the pressure gauge support device into the well along with the tubing string and the central pipe string; The pressure gauge is lowered into the central pipe column and is sent into the pressure gauge installation cylinder by water pressure.

7. A well washing method, characterized in that: The pressure gauge supporting device according to any one of claims 1 to 5 is adopted for implementation, wherein the pressure gauge supporting device is located in a well, the outer cylinder of the pressure gauge supporting device is connected to an oil pipe string, the oil pipe string comprises an oil pipe, an outer cylinder and a rodless pump group, the oil pipe and the second cylinder of the outer cylinder are coaxially connected, and the rodless pump group is connected to the lower end of the second cylinder; the inner cylinder of the pressure gauge supporting device is connected to the central pipe string, the central pipe string comprises a central pipe, an inner cylinder, a pressure gauge mounting cylinder and a rodless pump plug, the central pipe, the inner cylinder and the rodless pump plug are coaxially connected in sequence, and the pressure gauge mounting cylinder is connected to the inner wall of the inner cylinder; The well washing method comprises: Sequentially lifting out the pressure gauge and the central pipe string; Fluid is pumped into the oil pipe, and the well is washed using the well-washing channel formed by the first channel.

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