A flexible connector centralizer for downhole tools and a method of using the same

Abstract

The present invention discloses a flexible connector straightener for downhole tools and a method for using the same. The flexible connector straightener includes a straightener body and a downhole tool through hole. The downhole tool through hole is offset in the straightener body, and the straightener body can be connected to the oil pipe string through a short section. The inner cavities at both ends of the straightener body are provided with threads and can be connected to the short section, and the downhole tool through hole is arranged in the middle body of the straightener body. The present invention connects a plurality of straighteners with eccentric channel structures in the oil pipe string to prevent flexible connectors, such as cables, wire ropes and other connectors of downhole tools or instruments from causing wear and damage to the inner cavity of the downhole tool when passing through the downhole tool in the oil pipe string. Therefore, the present invention can greatly shorten the purpose of oil testing or operation cycle, and has significant economic and social benefits.

Description

Technical Field

[0001] The invention relates to a centralizing device for a downhole tool or instrument for oilfield exploration and development, in particular to a centralizer for a flexible connector of a downhole tool and a use method thereof. Background Art

[0002] In order to save construction costs, shorten construction cycles, and save oil testing and development costs during oil and gas exploration and development, it is often necessary to connect perforation and pumping and drainage tools and equipment to a string and lower them into the well. Among them, the screw pump in downhole oil production equipment is highly favored for its easy installation and low cost. However, for wells with deep production layers, when a string is lowered to complete perforation and drainage at the same time, due to the limitations of the screw pump's depth and lift capacity, the installation distance between the perforating gun and the screw pump is far apart. Therefore, it is necessary to use a cable to carry a depth calibration instrument through the screw pump stator to calibrate the length of the oil pipe under the pump to ensure that the perforating gun is aligned with the production layer.

[0003] However, the structure of the screw pump itself does not have the function of straightening and anti-wear for the cable passing through it. Especially for long-distance cables, it is easy to cause wear in the inner cavity of the stator, resulting in failure of the seal with the rotor and loss of drainage and lifting capacity. At present, the "A downhole screw pump and a construction method for crossing a downhole screw pump" with application number 201910658238.6 adopts a full-bore tool structure with a diameter smaller than the stator diameter of the screw pump, which can solve the problem of depth calibration of 177.8mm casing through the screw pump, and thus can achieve perforation and screw pump drainage in one trip. However, if a string that can complete perforation and screw pump drainage is to be lowered into a small-diameter casing, since the diameter size of the screw pump connected therein becomes smaller accordingly, it is difficult to pull a sufficient size distance between the diameter size of the straightening and anti-wear tool and the stator diameter of the screw pump, and the straightening and anti-wear effect becomes worse. Especially for high-lift screw pumps, the stator is long, and the diameter of the anti-wear tool is close to the inner diameter of the screw pump, which makes it difficult to ensure that the inner cavity of the upper part of the stator is not worn. Especially when there is a certain bend in the wellbore trajectory, even if the upper part adopts cable sliding straightening measures, it is still difficult to ensure that the inner cavity of the stator is not worn by the cable, affecting the quality of the subsequent drainage.

[0004] In order to solve the problem of downhole tool and cable straightening, there are also the following devices:

[0005] "A tubing and cable centralizer for oil drilling", application number: 201821638916.X, the utility model discloses a tubing and cable centralizer for oil drilling, including a base, a linear motor, a connecting block, a threaded groove, a top plate, a fixed plate, a drive motor, a fixed frame, a side plate, a turntable, a casing, a spring, a support column, an arc plate, a cable pipe, an oil pipe, a threaded rod, a threaded hole and a limit pipe. The utility model has a reasonable structure, simple operation and convenient installation. The top plate is driven to rise or fall by a linear motor, one end of the cable tube is sleeved with the inner ring of the turntable, and the position of the side plate in the inner ring of the turntable is adjusted by threaded holes and bolts, so that one end of the side plate is close to the side wall of the cable tube, thereby fixing the cable tube to the inside of the turntable, and then turning on the drive motor through an external control switch, and the electric work drives the fixed frame and the turntable to rotate, so that the limit tube drives the cable tube to be threadedly connected with the threaded groove inside the oil pipe through the connecting block, and then adjusts the position of the cable tube in the oil pipe, while keeping the cable upright, preventing the cable from rubbing against the oil pipe or the cable from being tangled together. Although the device can prevent the friction between the cable and the oil pipe, it cannot achieve the crossing of the instrument.

[0006] "Cable straightening and protection device", application number: 200620153693.9, the utility model provides a cable straightening and protection device used in the field of oil development technology. There is a notch on the side of the middle of the main body, and the protective block is installed at the notch on the side of the middle of the main body. The protective block is concave, and the cable can pass through the concave groove. The fixing sleeve is connected to the main body, and the fixing sleeve is under the protective block. Pins and screws are installed on the main body, and the pin head is inserted into the protective block. The coupling is connected to the upper part of the main body. Since the cable is in the concave groove, the cable is straightened and will not be squeezed, which effectively plays a role in protecting the cable, and there will be no accidents of squeezing the cable, avoiding economic losses. It can only be used to protect the cable from being squeezed, and has no function of preventing the cable from wearing the tool cavity on the pipe column.

[0007] "Downhole Cable Straightener", application number: 201420502329.3, the utility model relates to the technical field of anti-eccentric wear of downhole cables, and particularly to a downhole cable straightener. The lower end of the circular tubular straightener body of the device is designed with a connecting thread, and one side of the upper end of the circular tubular straightener body is connected to a straightening wheel bracket, and the upper end of the straightening wheel bracket is designed with a core shaft fixing groove, and both ends of the straightening wheel core shaft are fixed in the core shaft fixing groove by fixing screws, and a straightening wheel is installed on the straightening wheel core shaft. The utility model ensures that the cable is always in the center position when it is lifted and lowered during the test construction, and does not hang on the wellhead equipment, prevents the cable from being worn eccentrically due to deviation from the center position, extends the service life of the cable, and reduces the wear on the wellhead equipment. It overcomes the shortcomings of the existing test construction that the cable is severely worn and easy to hang on and wear the wellhead equipment. This patent is only for the straightening and anti-wear of the cable and the wellhead, and is not suitable for the anti-wear protection of downhole tools passing through the cable.

[0008] "Well Logging Hard Electrode Centralizer", application number: 200920249400.0, : A well logging hard electrode centralizer for open hole logging, composed of an electrode body, a centralizer locking hoop, a centralizer locking sheet, a centralizer anti-wear rubber block, a centralizer rigid body, and fixing screws; the centralizer locking hoop is sleeved outside the electrode body, and the centralizer locking sheet is a tenon steel sheet; the centralizer locking sheet and the electrode body are locked with the centralizer locking hoop, the centralizer anti-wear rubber block and the centralizer rigid body are fixed with the inner card slot, the centralizer rigid body and the electrode body are locked and fixed with the centralizer locking sheet and the centralizer locking hoop, and the centralizer locking sheet and the centralizer rigid body are fixed with fixing screws. The centralizer solves the problem of serious well logging wear of well logging hard electrodes in the prior art, which easily leads to the scrapping of well logging hard electrodes. The centralizer is only suitable for protecting electrodes for logging operations in open hole wells, and is a tool installed on instruments carried by cables to protect instruments carried by cables. It cannot protect the inner cavity of the tools on the pipe string.

[0009] 《A kind of centralizer》, application number: 201820512855.6, the utility model discloses a centralizer, comprising a middle centralizer and a left centralizer or a left anti-detachment sucker rod and a right centralizer or a right anti-detachment sucker rod correspondingly connected to two ends of the middle centralizer, the left centralizer or the left anti-detachment sucker rod having a cavity inside one end, the cavity being a cylindrical cavity, the inner surface of the cavity being provided with a first thread, the inner surface of the cavity being provided with a moving block, the moving block being a cylindrical moving block, the outer surface of the moving block being provided with a second thread matching the first thread, the inner surface of the left centralizer or the left anti-detachment sucker rod being provided with an air outlet channel, one end of the air outlet channel being connected with the cavity, the other end of the air outlet channel being connected with the outside, an overflow valve being fixed inside the air outlet channel, and a clamping block being provided at the left end of the middle centralizer. The utility model can effectively avoid the disengagement of the connection of the centralizer, and has a good anti-detachment effect. The centralizer is suitable for preventing the sucker rod from falling off, but is not suitable for protecting the inner cavity of the tool installed on the pipe string from being damaged by wear and tear of cables, etc.

[0010] "Quick-mounted screw pump centralizer", application number: 02274266.2, quick-mounted screw pump centralizer, it relates to a centralizer for a screw pump. It is a cylinder with a through hole on the central axis, and a groove connected to the through hole on the circumferential wall of the centralizer, and the two ends of the groove are respectively located at the upper left end and the lower right end of the centralizer. The centralizer has a coating layer of polyurethane material on the outside, and the main lining body of fiber high-strength nylon 66 injection molding inside the centralizer is tightly connected to the coating layer. The width K of the centralizer groove is less than the diameter of the screw pump rod matched with it. The length H of the centralizer is 185-250mm, and there are multiple ridges on the axial direction of the outer wall of the centralizer, and there are arc-shaped concave channels between the ridges. It solves the problems of easy breakage, low strength, poor stability, poor centralization effect, and increased oil pumping resistance existing in the existing centralizer. It is used for the rotational wear protection between the screw pump rod string and the oil pipe. It is not suitable for the wear protection of the inner cavity of the tool due to the up and down movement of the cable on the tool string.

[0011] "Passive Centralizer", application number: 200810083861.5, the present invention discloses a passive centralizer for stable centering in a well. The centralizer has a retracted profile for advancement in the well and is deployable when reaching the operating position for centering. The deployment can be achieved in an automated manner without operator interaction. In addition, because the energy used for deployment is completely stored in the passive centralizer before the passive centralizer is inserted into the well, the centralizer is truly passive. The passive centralizer can also be retracted after centering due to any number of downhole restrictions. In this way, the passive centralizer can also be easily withdrawn from the well. It is a contraction change that occurs as the transported pipe / rod / cable moves to the working position. To adapt to the problem of running in and out of the pipe string under different diameter change conditions. It cannot ensure the purpose of wear protection of the tool lumen when flexible cables, etc. pass through tools on a certain pipe string.

[0012] "A Variable Diameter Roller Non-rotating Straightener", application number: 201710560566.3, the present invention discloses a variable diameter roller non-rotating straightener, including: a straightener shaft male end, a straightening sleeve, a straightener shaft female end, a roller seat, a reducer assembly and a roller. The straightener provided by the present invention allows the variable diameter roller non-rotating straightener to change its outer diameter through a reducer assembly, thereby reducing its size before entering the casing, passing smoothly through the narrowest part of the wellhead, increasing its size after entering the casing, and supporting on the inner wall of the casing, so as to solve the problem that the straightener cannot be directly supported on the inner wall of the casing, causing the cutting knife to shake during cutting and affecting the cutting speed. At the same time, when the variable diameter roller non-rotating straightener is lowered from the wellhead to the casing, the roller is at the outermost side of the straightener, that is, the roller is always in contact with the inner wall of the wellhead and the inner wall of the casing, reducing the resistance encountered by the straightener when it is lowered. It is only a centralizer installed on the pipe string used for casing cutting, which can pass through the small inner diameter and then keep the bottom pipe string centered in the wellbore position with a large inner diameter. It is not suitable for tools on the pipe string to prevent wear of the cable.

[0013] "A downhole tool device with a new type of centralizer", application number: 201821630939.6, the utility model discloses a downhole tool device with a new type of centralizer, including a hollow centralizer, a guide, and an integral centralizer connected in sequence from one end to the other end; the hollow centralizer includes a first centralizer body with a through hole, a first centralizer block, a first fixing bolt, and a first centralizer spring; the integral centralizer includes a second centralizer body, a second centralizer block, a second fixing bolt, and a second centralizer spring; the top of the guide is connected to the bottom of the first centralizer body of the hollow centralizer by a connecting thread connection, and the bottom of the guide is connected to the top of the second centralizer body of the integral centralizer by a connecting thread. The downhole tool device with a new type of centralizer provided by the utility model reduces the number of repeated window opening and universal joint breaking, and the injection tool enters and exits the window smoothly, which improves the construction success rate. The device is a tool that integrates the centralizer and the tool, which is suitable for window opening construction operations and cannot be used to protect the cable passing through the inner cavity of the pipe string tool. Summary of the invention

[0014] The purpose of the present invention is to provide a flexible connector centralizer for downhole tools and a method for using the same, which can center the flexible connector connected to the downhole tool in the tubing string, and prevent the flexible connector from damaging the inner cavity of the downhole tool and affecting the subsequent use of the downhole tool when the flexible connector passes through the downhole tool connected to the tubing string over a long distance. The invention can protect downhole production equipment and ensure the normal operation of production.

[0015] The technical solution of the present invention is:

[0016] A centralizer for a downhole tool flexible connector comprises a centralizer body and a downhole tool through hole. The downhole tool through hole is offset in the centralizer body. The centralizer body can be connected to an oil pipe string through a short joint.

[0017] The inner cavities at both ends of the centralizer body are provided with threads and can be connected with the short joints, and the downhole tool penetration hole is arranged in the middle body of the centralizer body.

[0018] The minimum distance between the downhole tool passing hole and the center line of the centralizer body is greater than the radius of the flexible connector; the aperture of the downhole tool passing hole is greater than the outer diameter of the downhole tool or instrument.

[0019] Conical inner cavities are arranged in the centralizer bodies at both ends of the downhole tool through-hole, and the conical inner cavities are communicated with the downhole tool through-hole.

[0020] The middle outer wall of the centralizer body is provided with a wrench square or is not provided with a wrench square, and at least two flexible connector centralizers are connected in the oil pipe string.

[0021] The spacing between the flexible connector centralizers connected in the oil pipe string is greater than the length of the downhole tool or instrument carried by the flexible connector.

[0022] A method for using a flexible connector centralizer for a downhole tool is:

[0023] A. Choose a short section that is longer than the downhole tool or instrument;

[0024] B. Connect the short joints at both ends of the downhole tool that is passed through the oil pipe string;

[0025] C. Connect the flexible connector centralizer to the tubing string through a short section.

[0026] The flexible connector centralizer is connected above the downhole tool to be penetrated through a short section and is connected to more than two.

[0027] The flexible connector centralizer is connected below the downhole tool to be penetrated through a short section and is connected to more than two.

[0028] The flexible connector centralizer is connected above and below the downhole tool to be traversed through a short section and is respectively connected to more than two.

[0029] The beneficial effects of the present invention are as follows: the flexible connector straightener of the downhole tool in the present invention is an eccentric straightener, wherein the downhole tool through hole is offset on one side of the straightener body. Since the minimum distance between the downhole tool through hole and the center line of the straightener body in the present invention is greater than the radius of the flexible connector, the aperture of the downhole tool through hole is greater than the outer diameter of the downhole tool or instrument. When multiple straighteners are connected in the tubing string, the center hole formed by the vertical common overlap area of ​​the downhole tool through holes of multiple straighteners is concentric with the center hole of the tubing string, and the aperture of the downhole tool through hole is greater than the outer diameter of the downhole tool or instrument, so that the tool or instrument lowered into the well can pass smoothly and the flexible connector above the downhole tool or instrument can be straightened, so that the flexible connector can always be located in the center of the downhole tool connected in the tubing string. The problem of eccentric wear of the inner cavity of the downhole tool is effectively solved. For example, the problem of the wear of the logging cable connected to the inner cavity of the screw pump stator in the tubing string eliminates the trouble for the later use of the screw pump. Another example is the downhole tools such as the landing joint of the wireline fishing tool and the rod-type oil pump support which are connected to the oil pipe string and need to be protected.

[0030] The present invention connects multiple centralizers with eccentric channel structures in the oil pipe string to prevent flexible connectors, such as cables, wire ropes and other downhole tools or instrument connectors from wearing and damaging the inner cavity of the downhole tool when passing through the downhole tool in the oil pipe string. It is particularly suitable for completing perforation and screw pump drainage or incidental testing in one trip of the pipe string, and has a significant protective effect on the inner cavity of the screw pump stator and can produce significant subsequent use effects.

[0031] The present invention can solve the wear problem existing in the screw pump carried by the logging cable in the small-sized casing well, so that the construction pipe string can pass through the screw pump and calibrate the depth of the pipe string under the pump, thereby ensuring the accuracy of the perforated layer and preventing the inner cavity of the screw pump stator from being worn, realizing the rapid rotation of the pump to pump out liquid after perforation, and significantly improving the construction efficiency.

[0032] The present invention can combine the downhole tools or instruments that require two trips of tubing to be lowered into the well into one trip of tubing, thereby reducing thread loss during tubing trips, improving construction efficiency, reducing operating costs, and facilitating reservoir protection.

[0033] The invention is simple and convenient to connect and install in the oil pipe string, can significantly shorten the construction time and the oil testing cycle, improve the safety of production, and has significant economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0035] Figure 1 It is a connection and use principle diagram of the present invention.

[0036] Figure 2 It is the front view of the schematic diagram of the flexible connector centralizer structure.

[0037] Figure 3 yes Figure 2 Cross-sectional view along the A-A axis.

[0038] In the figure: an oil pipe string 1, a downhole tool 2 to be penetrated, a flexible connector 3, a flexible connector centralizer 4, a short section 5, a downhole tool or instrument 6, a centralizer body 4-1, a downhole tool penetration hole 4-2, and a wrench square 4-3. DETAILED DESCRIPTION

[0039] The accompanying drawings are for reference and illustration only and are not intended to limit the scope of protection of the present invention. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0041] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0042] See also Figures 1 to 3A flexible connector straightener for a downhole tool comprises a straightener body 4-1 and a downhole tool through hole 4-2, wherein the downhole tool through hole 4-2 is offset in the straightener body 4-1, and the straightener body 4-1 can be connected to a tubing string 1 through a short section 5. The short section 5 can be a tubing short section, a drill pipe short section or a casing short section. After a plurality of flexible connector straighteners 4 are connected to the tubing string 1, a center hole formed by the offset downhole tool through hole 4-2 is located at the center of the tubing string 1, and a flexible connector 3 is constrained in a center hole formed by the downhole tool through hole 4-2 in a plurality of flexible connector straighteners 4, so that the inner cavity of the downhole tool 2 being passed through is ensured not to be worn by the flexible connector 3 carrying the downhole tool or instrument 6.

[0043] The inner cavities at both ends of the centralizer body 4-1 are provided with threads and can be connected to the short section 5, and the downhole tool through hole 4-2 is set in the middle body of the centralizer body 4-1.

[0044] The minimum distance between the downhole tool passing hole 4-2 and the center line of the stabilizer body 4-1 is greater than the radius of the flexible connector 3. After multiple flexible connector stabilizers 4 are connected to the oil tubing string 1, the center hole formed by the offset downhole tool passing hole 4-2 in the oil tubing string 1 can make the flexible connector 3 located in the center of the oil tubing string 1; the aperture of the downhole tool passing hole 4-2 is greater than the outer diameter of the downhole tool or instrument 6, so that the downhole tool or instrument 6 can pass smoothly.

[0045] The centralizer body 4-1 at both ends of the downhole tool through hole 4-2 is provided with a conical inner cavity, which is connected to the downhole tool through hole 4-2. The conical inner cavity at both ends of the downhole tool through hole 4-2 can guide the downhole tool or instrument 6 to pass through the downhole tool flexible connector centralizer 4.

[0046] The central outer wall of the centralizer body 4-1 is provided with a wrench square 4-3 or no wrench square, and the flexible connector centralizer 4 is connected to at least two in the oil pipe string 1. The central outer wall of the centralizer body 4-1 is provided with a wrench square 4-3, which can facilitate the connection of the flexible connector centralizer 4, or when no wrench square is provided, a pipe clamp can be used for operation, see Figure 2 .

[0047] The spacing between the flexible connector centralizers 4 and the flexible connector centralizers 4 connected in the oil pipe string 1 is greater than the length of the downhole tool or instrument 6 carried by the flexible connector 3. That is, the length of the short section 5 connected between the flexible connector centralizers 4 is greater than the length of the downhole tool or instrument 6, which can prevent the downhole tool or instrument 6 with a long length from being unable to pass through the flexible connector centralizer 4 smoothly.

[0048] The flexible connector 3 is a flexible component such as a steel wire, a steel rope, an electric cable, a carbon fiber continuous rod, and a carbon fiber continuous tube that can carry a downhole tool or instrument 6 downhole.

[0049] A method for using a flexible connector centralizer for a downhole tool is:

[0050] A. Select a short section 5 that is longer than the downhole tool or instrument 6;

[0051] B. Connecting short joints 5 at both ends of the downhole tool 2 passing through the oil pipe string 1;

[0052] C. Connect the flexible connector centralizer 4 to the oil pipe string 1 through the short section 5.

[0053] The flexible connector centralizer 4 is connected above the downhole tool 2 to be penetrated through a short section 5 and is connected to more than two.

[0054] The flexible connector centralizer 4 is connected below the downhole tool 2 to be penetrated through a short section 5 and is connected to more than two.

[0055] The flexible connector centralizer 4 is connected above and below the downhole tool 2 to be penetrated through a short section 5 and is connected to more than two of them respectively.

[0056] One or more flexible connector centralizers 4 are connected above or below the downhole tool 2 to be protected, or above and below. When the flexible connector 3 carries the downhole tool or instrument 6 to the flexible connector centralizer 4, it will be introduced into the downhole tool through hole 4-2 by the tapered inner cavity at both ends of the downhole tool through hole 4-2 in the centralizer body 4-1, and pass through the downhole tool through hole 4-2.

[0057] When the downhole tool or instrument 6 completely passes through the downhole tool crossing hole 4-2 in the upper-level flexible connector centralizer 4 and reaches the downhole tool crossing hole 4-2 in the next-level flexible connector centralizer 4, the above process will be repeated to pass through all the flexible connector centralizers 4 connected to the oil pipe string 1.

[0058] The upper part of the downhole tool or instrument 6 is connected to a flexible connector 3 of the type of flexible rod / tube / cable / wire, which has been fixed to the center of the oil pipe string 1 by the center hole formed by the downhole tool passing hole 4-2 in each flexible connector straightener 4, and will not produce rigid constraints on the curved motion trajectory of the downhole tool or instrument 6, so that it can achieve multi-stage crossing of the downhole tool passing holes 4-2 in different directions in each flexible connector straightener 4. Since each level of the flexible connector straightener 4 straightens the flexible connector 3 to the center position from a certain angle, when the flexible connector 3 is subjected to a tensile force and is in a straightened state, it can be in the center position of the oil pipe string 1. Avoid the flexible connector 3 from contacting the inner cavity of the downhole tool 2 being crossed, thereby avoiding friction and damage to the inner cavity of the downhole tool 2 being crossed when the flexible connector 3 is lifted and lowered for a long distance in the oil pipe string 1.

[0059] The embodiments described above are only typical embodiments, but the present invention is not limited to these embodiments, and those skilled in the art can make modifications without departing from the spirit and enlightenment of the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the creative spirit and creative concept of the present invention should be included in the protection scope of the present invention. Therefore, the protection scope is not limited to the above description.

Claims

1. A flexible connector centralizer for a downhole tool, characterized in that: The centralizer body (4-1) comprises a centralizer body (4-1) and a downhole tool through hole (4-2); the downhole tool through hole (4-2) is offset in the centralizer body (4-1); the centralizer body (4-1) can be connected to the oil pipe string (1) through a short joint (5); the inner cavities at both ends of the centralizer body (4-1) are provided with threads and can be connected to the short joint (5); the downhole tool through hole (4-2) is arranged in the middle body of the centralizer body (4-1); the downhole tool through hole (4-2) and the centralizer body (4-1) are connected to each other. The minimum distance between the center lines is greater than the radius of the flexible connector (3); the diameter of the downhole tool through hole (4-2) is greater than the outer diameter of the downhole tool or instrument (6); a conical inner cavity is provided in the centralizer body (4-1) at both ends of the downhole tool through hole (4-2), and the conical inner cavity is connected to the downhole tool through hole (4-2); the middle outer wall of the centralizer body (4-1) is provided with a wrench square (4-3) or is not provided with a wrench square, and at least two flexible connector centralizers (4) are connected in the oil pipe string (1).

2. A flexible connector centralizer for downhole tools as claimed in claim 1, characterized in that the connector The spacing between the flexible connector centralizers (4) in the oil pipe string (1) is greater than the length of the downhole tool or instrument (6) carried by the flexible connector (3).

3. A method for using a flexible connector centralizer for a downhole tool as claimed in claim 2, comprising: A. selecting a short section (5) that is longer than the downhole tool or instrument (6); B. connecting the short sections (5) at both ends of the downhole tool (2) to be passed through the oil pipe string (1); and C. connecting the flexible connector centralizer (4) to the oil pipe string (1) via the short section (5).

4. A method for using a flexible connector centralizer for a downhole tool as claimed in claim 3, characterized in that: The flexible connector centralizer (4) is connected above the downhole tool (2) to be traversed via a short section (5) and is connected to more than two of them.

5. A method for using a flexible connector centralizer for a downhole tool as claimed in claim 3, characterized in that: The flexible connector centralizer (4) is connected below the downhole tool (2) to be penetrated through a short section (5) and is connected to more than two.

6. A method for using a flexible connector centralizer for a downhole tool as claimed in claim 3, characterized in that: The flexible connector centralizer (4) is connected above and below the downhole tool (2) to be traversed via a short section (5), and is respectively connected to more than two.

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