Double-ring isolator short section structure of array lateral logger

Abstract

The invention relates to the technical field of petroleum and natural gas exploration and development, and discloses an array lateral logger double-ring isolator short section which is characterized in that a protective cap is arranged at one end of a double-ring isolator, and a plug is arranged at the other end of the double-ring isolator; a first insulating sleeve, an N ring, a second insulating sleeve, an SP ring and a third insulating sleeve are sequentially sleeved on the double-ring isolator from one end to the other end, and a first socket is arranged at the end part of the double-ring isolator in the protective cap; a second socket is arranged on the end part of the double-ring isolator in the plug, the double-ring isolator comprises a double-ring isolator shell and a double-ring isolator framework, and the double-ring isolator shell and the double-ring isolator framework are in detachable modular design, so that the effect of replacing two traditional hard electrodes is realized, the length is effectively shortened, and the weight is effectively reduced; on the premise that the manufacturing cost is reduced, the feasibility of combination logging of array lateral series instruments and other instruments is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas exploration and development, and particularly to a double-ring isolation short joint of an array laterolog tool. Background Art

[0002] The laterolog operation is an essential and important link in oil exploration and development. During on-site construction, a 26-meter soft electrode or a 3.9-meter extended hard electrode is generally used to ensure that the reference electrode is "infinitely far" to achieve the purpose of passing the acceptance of the logging curve.

[0003] When the array laterolog tool is used for logging, two hard electrodes need to be connected under the pony head. One is a straight-through hard electrode, and the other is a hard electrode with spontaneous potential. The two hard electrodes theoretically play the role of ensuring the length of the upper A6 and determining the N reference point.

[0004] Currently, this method has the following deficiencies: ① The length of the two hard electrodes is 7.8 meters, and the combination logging efficiency is low; ② The weight of the hard electrode is about 85 kg, and the construction risk at the wellhead is high; ③ The general material of the hard electrode is fiberglass, and its temperature and pressure resistance ability is poor; ④ The hard electrode has poor maintainability and high use cost. Summary of the Invention

[0005] In order to overcome the defects of the above-mentioned existing technologies, the purpose of the present invention is to provide a double-ring isolation short joint structure of an array laterolog tool to solve the technical problem of the overall excessive length of the tool string during logging of the array laterolog tool.

[0006] The present invention is realized through the following technical solutions:

[0007] A double-ring isolation short joint structure of an array laterolog tool includes a double-ring isolator, a protective cap, and a plug. The protective cap is arranged at one end of the double-ring isolator, the plug is arranged at the other end of the double-ring isolator, and a first insulating sleeve, an N ring, a second insulating sleeve, an SP ring, and a third insulating sleeve are sequentially sleeved on the double-ring isolator from one end to the other end. A first socket is arranged at the end of the double-ring isolator inside the protective cap, and a second socket is arranged at the end of the double-ring isolator inside the plug.

[0008] Preferably, the double-ring isolator includes a double-ring isolator housing and a double-ring isolator skeleton. The double-ring isolator skeleton penetrates through the double-ring isolator housing. The first socket is arranged at one end of the double-ring isolator skeleton, the second socket is arranged at the other end of the double-ring isolator skeleton. The protective cap is assembled at one end of the double-ring isolator housing, the plug is assembled at the other end of the double-ring isolator housing, and the first insulating sleeve, the N ring, the second insulating sleeve, the SP ring, and the third insulating sleeve are sequentially arranged in the direction from one end to the other end of the double-ring isolator housing.

[0009] Further, an assembly sealing structure is provided at one end of the double-ring isolation body housing close to the first socket, and the protective cap is assembled on the assembly sealing structure.

[0010] Furthermore, the assembly sealing structure includes a multi-sided ring, a snap ring, a retaining ring, and a threaded ring provided on the end of the double-ring isolation body housing. The inner wall of the protective cap is respectively arranged corresponding to the multi-sided ring, the snap ring, the retaining ring, and the threaded ring, and sealing rings are sleeved between the inner wall of the protective cap and the multi-sided ring, the snap ring, the retaining ring, and the threaded ring.

[0011] Further, the double-ring isolation body framework includes an upper framework joint and a lower framework joint. The upper framework joint and the lower framework joint are coaxially connected, and the first socket is fixed to the end of the upper framework joint through a coiled pin, and the second socket is fixed to the end of the lower framework joint.

[0012] Furthermore, an annular groove is provided at one end of the upper framework joint close to the first socket, and a spring is sleeved in the annular groove.

[0013] Furthermore, an intermediate insulating sleeve is provided between the upper framework joint and the lower framework joint, and the intermediate insulating sleeve is fixed to the upper framework joint and the lower framework joint through fastening screws.

[0014] Furthermore, grooves are provided on both the upper framework joint and the lower framework joint, and reed assemblies are provided on the grooves. The reed assemblies are fixed in the grooves through screw assemblies, and the N-ring and the SP-ring are located corresponding to the positions of the reed assemblies on the upper framework joint and the lower framework joint.

[0015] Further, a roller assembly is provided at the end of the lower framework joint close to the second socket.

[0016] Further, the first socket is fixed to the double-ring isolation body housing through a positioning pin.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] The present invention provides a double-ring isolator short joint structure for an array laterolog tool. By setting a protective cap at one end of the double-ring isolator and a plug at the other end, and successively sleeving a first insulating sleeve, an N-ring, a second insulating sleeve, an SP-ring, and a third insulating sleeve on the double-ring isolator from one end to the other end. A first socket is provided at the end of the double-ring isolator within the protective cap; a second socket is provided at the end of the double-ring isolator within the plug. Wherein the double-ring isolator includes a double-ring isolator housing and a double-ring isolator skeleton, and the double-ring isolator housing and the double-ring isolator skeleton are designed as detachable modular units, realizing the function of replacing two traditional hard electrodes, effectively shortening the length and reducing the weight; on the premise of reducing the manufacturing cost, the feasibility of combining the array laterolog series tools with other tools for logging is improved. The reduction in the overall weight can not only reduce the work intensity of the on-site team members, but also reduce the occurrence of construction accidents, solving the problem of the overall excessive length of the tool string during the logging of the array laterolog tool.

[0019] Further, one end of the double-ring isolator housing close to the first socket is provided with an assembly sealing structure, and the protective cap is assembled on the assembly sealing structure. The assembly sealing structure includes a multi-sided ring, a snap ring, a retaining ring, and a threaded ring provided at the end of the double-ring isolator housing. The inner wall of the protective cap is correspondingly arranged with the multi-sided ring, the snap ring, the retaining ring, and the threaded ring, and sealing rings are sleeved between the inner wall of the protective cap and the multi-sided ring, the snap ring, the retaining ring, and the threaded ring, improving the tightness of the assembly of the protective cap and the double-ring isolator housing.

[0020] Further, the double-ring isolator skeleton includes an upper skeleton joint and a lower skeleton joint. The upper skeleton joint and the lower skeleton joint are coaxially connected, and the first socket is fixed to the end of the upper skeleton joint by a roll pin, and the second socket is fixed to the end of the lower skeleton joint. An intermediate insulating sleeve is provided between the upper skeleton joint and the lower skeleton joint, and the intermediate insulating sleeve is fixed to the upper skeleton joint and the lower skeleton joint by fastening screws. Grooves are provided on both the upper skeleton joint and the lower skeleton joint, and reed assemblies are provided on the grooves. The reed assemblies are fixed in the grooves by screw assemblies. The N-ring and the SP-ring are located corresponding to the reed assemblies of the upper skeleton joint and the lower skeleton joint. While ensuring the quality of the measured curve and reducing the length of the entire tool string, the workload of on-site personnel can be effectively reduced. During the logging operation, the double-ring isolator can be directly connected under the pony head. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the double-ring isolator short joint structure of the array laterolog tool in the present invention

[0022] Figure 2 Schematic diagram of the double-ring isolator structure in the present invention;

[0023] Figure 3 Wiring diagram of the double-ring isolator skeleton in the present invention;

[0024] In the figure: 1 - double-ring isolator; 2 - protective cap; 3 - plug; 4 - first socket; 5 - first insulating sleeve; 6 - N-ring; 7 - second insulating sleeve; 8 - SP-ring; 9 - third insulating sleeve; 10 - second socket; 11 - positioning pin; 12 - multi-sided ring; 13 - sealing ring; 14 - snap ring; 15 - retaining ring; 16 - threaded ring; 17 - double-ring isolator housing; 18 - coiled pin; 19 - spring; 20 - upper joint of the skeleton; 21 - reed assembly; 22 - screw assembly; 23 - fastening screw; 24 - middle insulating connection sleeve; 25 - lower joint of the skeleton; 26 - roller assembly; 27 - double-ring isolator skeleton. Specific embodiments

[0025] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] The present invention will be further described in detail below with reference to the accompanying drawings:

[0027] The purpose of the present invention is to provide a short section structure of a double-ring isolator for an array laterolog tool, so as to solve the technical problem that the overall length of the tool string is too long during logging with an array laterolog tool.

[0028] See Figure 1 , in an embodiment of the present invention, a short section structure of a double-ring isolator for an array laterolog tool is provided, including a double-ring isolator 1, a protective cap 2 and a plug 3; the protective cap 2 is arranged at one end of the double-ring isolator 1, the plug 3 is arranged at the other end of the double-ring isolator 1, and a first insulating sleeve 5, an N-ring 6, a second insulating sleeve 7, an SP-ring 8 and a third insulating sleeve 9 are sequentially sleeved on the double-ring isolator 1 from one end to the other end; a first socket 4 is arranged at the end of the double-ring isolator 1 inside the protective cap 2; a second socket 10 is arranged at the end of the double-ring isolator 1 inside the plug 3.

[0029] Specifically, the double-ring isolator 1 includes a double-ring isolator housing 17 and a double-ring isolator skeleton 27; the double-ring isolator skeleton 27 is disposed through the double-ring isolator housing 17, the first socket 4 is disposed at one end of the double-ring isolator skeleton 27, the second socket 10 is disposed at the other end of the double-ring isolator skeleton 27, the protective cap 2 is assembled at one end of the double-ring isolator housing 17, the plug 3 is assembled at the other end of the double-ring isolator housing 17, and the first insulating sleeve 5, N-ring 6, second insulating sleeve 7, SP-ring 8, and third insulating sleeve 9 are sequentially arranged in the direction from one end to the other end of the double-ring isolator housing 17.

[0030] Wherein, one end of the double-ring isolator housing 17 close to the first socket 4 is provided with an assembly sealing structure, and the protective cap 2 is assembled on the assembly sealing structure.

[0031] Specifically, the assembly sealing structure includes a multi-sided ring 12, a snap ring 14, a retaining ring 15, and a threaded ring 16 provided on the end of the double-ring isolator housing 17. The inner wall of the protective cap 2 is respectively arranged corresponding to the multi-sided ring 12, the snap ring 14, the retaining ring 15, and the threaded ring 16, and sealing rings 13 are sleeved between the inner wall of the protective cap 2 and the multi-sided ring 12, the snap ring 14, the retaining ring 15, and the threaded ring 16.

[0032] Specifically, the double-ring isolator skeleton 27 includes a skeleton upper joint 20 and a skeleton lower joint 25. The skeleton upper joint 20 and the skeleton lower joint 25 are coaxially connected, and the first socket 4 is fixed to the end of the skeleton upper joint 20 through a cotter pin 18, and the second socket 4 is fixed to the end of the skeleton lower joint 25.

[0033] Wherein, an annular groove is provided on one end of the skeleton upper joint 20 close to the first socket 4, and a spring 19 is sleeved in the annular groove.

[0034] Wherein, an intermediate insulating sleeve 24 is provided between the skeleton upper joint 20 and the skeleton lower joint 25, and the intermediate insulating sleeve 24 is fixed to the skeleton upper joint 20 and the skeleton lower joint 25 through fastening screws 23.

[0035] Specifically, grooves are provided on both the skeleton upper joint 20 and the skeleton lower joint 25, and reed assemblies 21 are provided on the grooves. The reed assemblies 21 are fixed in the grooves through screw assemblies 22, and the N-ring 6 and the SP-ring 8 are corresponding to the positions of the reed assemblies 21 on the skeleton upper joint 20 and the skeleton lower joint 25.

[0036] In the present invention, a roller assembly 26 is provided at the end of the skeleton lower joint 25 close to the second socket 10, and the first socket 4 is fixed to the double-ring isolator housing 17 through a positioning pin 11.

[0037] The present invention provides a double-ring isolator short section for an array laterolog tool, which has the following remarkable advantages on the premise of ensuring well logging effect: ① The length of the new double-ring isolator is 1.119 meters, which is nearly 85% shorter than the length of two traditional hard electrodes. When combined with acoustic, radioactive and other instruments for well logging, it can reduce the length of the downhole tool string, reduce the wellhead installation workload, improve the well logging efficiency and reduce the construction risk; ② Compared with the fiberglass hard electrode with poor temperature and pressure resistance, the temperature and pressure resistance index of the new double-ring isolator can reach 210°C / 170MPa, which broadens the application of the array laterolog in ultra-deep wells; ③ Due to its mechanical design, the traditional hard electrode cannot install a skeleton inside, which restricts its further on-site application. Different from this, the double-ring isolator belongs to a mechanical design with a skeleton that can be installed from a structural point of view, and the core can be directly removed for inspection and maintenance. It has the characteristics of convenient disassembly and easy maintenance compared with the traditional hard electrode; ④ The weight of the new double-ring isolator is about 22.5 kg, and the weight of two hard electrodes is about 170 kg, which is about 87% lighter in weight and reduces the workload of wellhead construction personnel; ⑤ The cost of the new double-ring isolator is about 112,000 yuan, and the cost of two hard electrodes is about 290,000 yuan, which is about 61% lower in cost.

[0038] In the present invention, the double-ring isolator short section adopts a detachable modular design. The overall structure of the double-ring isolator is formed by the combination of the outer shell and the skeleton. When installing, use a φ90 universal extractor to fix the skeleton first, and then install the skeleton into the outer shell. The head of the double-ring isolator is a universal 31-core socket, the tail is a universal 31-core plug, a protective cap is installed at the head of the double-ring isolator, and a plug is installed at the tail of the double-ring isolator to protect the internal skeleton during normal transportation. Figure 3 As can be seen, both the upper and lower connectors are 31-core standard plugs. The 1st and 4th cores are AC 220V, the 8th core is SP, the 9th core is N, the 10th core is B, the 16th core is CANGND, the 21st is CANH, and the 22nd is CANL. Among them, the 16th, 21st, and 22nd cores use twisted pair shielded wires, the 8th and 9th cores use thick single-core shielded wires, and the rest use 0.16 connecting wires. The 8th core SP and the 9th core N are both connected to the SP and N engraved on the outer shell of the double-ring isolator through the reeds on the skeleton. When disassembling and extracting the core, the skeleton can be extracted for inspection using a φ90 universal extractor, which is convenient for maintenance.

[0039] Relying on this double-ring isolator, the problem of the overall excessive length of the tool string during well logging of the array laterolog tool is solved. Before use, use a multimeter to measure the continuity of each core of the upper and lower plugs. Among them, focus on checking the continuity between the 8th core and the SP ring of the double-ring isolator outer shell, and the continuity between the 9th core and the N of the double-ring isolator outer shell. At the same time, use a megohmmeter to detect its insulation performance, and the insulation value is required to be ≥200MΩ.

[0040] In practice, two hard electrodes must be used in the array laterolog instrument series. Compared with the traditional hard electrodes, the novel double-ring insulator used in this patent can ensure the quality of the measurement curve while reducing the length of the entire instrument string, and can effectively reduce the workload of on-site personnel. During logging operations, the double-ring insulator can be directly connected under the tool joint.

[0041] In the present invention, the double-ring refers to the N ring and the SP ring. The position of the N ring is relatively forward compared to the position of the SP ring, and an insulating sleeve is used to isolate the two rings from each other.

[0042] Embodiment

[0043] The present invention provides a novel double-ring insulator applied to the array laterolog instrument series, which is used to improve and solve the problem of the excessive length of the entire instrument string during logging operations. The logging effect of the double-ring insulator is further verified through tests in two blocks. The specific data is as follows:

[0044] ① Well X1

[0045] During logging operations, the formation with obvious formation characteristics, stable wellbore and relatively complete curves in the repeated well section of 75.0 - 140.0 m was selected. After two logging operations using the double-ring insulator, the errors of the RAL1 - RAL5 curves were analyzed as shown in Table 1. It can be seen from Table 1 that the relative errors of the five resistivity curves, namely RAL1 - RAL5, obtained by using the double-ring insulator to replace the two hard electrodes in the through-tubing array laterolog are all less than 5%, meeting the industry standards, and the curves are accepted as qualified.

[0046]

[0047] Table 1 Curve repeatability comparison table of Well X1

[0048] ② Well X2

[0049] During logging operations, the logging section of about 1407 - 1780 m was selected. After two logging operations using the double-ring insulator, the errors of the RAL1 - RAL5 curves were analyzed as shown in Table 2. It can be seen from Table 2 that the curve errors are all less than 5% when using the double-ring insulator for logging, and the curves are accepted as qualified.

[0050]

[0051]

[0052] Table 2 Curve repeatability comparison table of Well X2

[0053] Therefore, the logging data collected by using the novel double-ring insulator during logging operations of the array laterolog instrument series are all within the error range, and the curves are all accepted without error, achieving the effect of replacing the two hard electrodes.

[0054] In summary, the present invention provides a double-ring isolator short joint structure for an array laterolog tool. By setting a protective cap at one end of the double-ring isolator, a plug at the other end of the double-ring isolator, and successively sleeving a first insulating sleeve, an N-ring, a second insulating sleeve, an SP-ring, and a third insulating sleeve on the double-ring isolator in the direction from one end to the other end, a first socket is set on the end of the double-ring isolator within the protective cap; a second socket is set on the end of the double-ring isolator within the plug. The double-ring isolator includes a double-ring isolator housing and a double-ring isolator skeleton, and the double-ring isolator housing and the double-ring isolator skeleton are of a detachable modular design, realizing the function of replacing two traditional hard electrodes, effectively shortening the length and reducing the weight. On the premise of reducing the manufacturing cost, the feasibility of combined logging of the array laterolog series tools with other tools is improved. The reduction in the overall weight can not only reduce the work intensity of the on-site team members, but also reduce the occurrence of construction accidents, solving the problem of the overall excessive length of the tool string during array laterolog logging.

[0055] The novel double-ring isolator of the present invention realizes the function of replacing two traditional hard electrodes. The length is reduced from 7.6 meters to 1.119 meters, shortening by nearly 85%, and the weight and manufacturing cost are reduced by nearly 87% and 61% respectively. On the premise of significantly reducing the manufacturing cost, the feasibility of combined logging of the array laterolog series tools with other tools is improved. The reduction in the overall weight can not only reduce the work intensity of the on-site team members, but also reduce the occurrence of construction accidents.

[0056] From the application results, the present invention can ensure the logging curve quality of the array laterolog series tools. The logging curves in Changqing and Tianjin regions are all accepted as qualified, and the error is within the allowable range. The present invention is beneficial to both single logging and combined logging of the array laterolog series tools, and is also beneficial to daily maintenance, improving the applicability and maintainability of the tools.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the specific implementation manners of the present invention can still be modified or equivalently replaced, and any modification or equivalent replacement without departing from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A double-ring isolator short section structure for an array laterolog tool, Characterized in that, It includes a double-ring isolator (1), a protective cap (2) and a plug (3); the protective cap (2) is arranged at one end of the double-ring isolator (1), the plug (3) is arranged at the other end of the double-ring isolator (1), and a first insulating sleeve (5), an N-ring (6), a second insulating sleeve (7), an SP-ring (8) and a third insulating sleeve (9) are sequentially sleeved on the double-ring isolator (1) from one end to the other end; a first socket (4) is arranged at the end of the double-ring isolator (1) inside the protective cap (2); a second socket (10) is arranged at the end of the double-ring isolator (1) inside the plug (3).

2. The double-ring isolator short section structure for an array laterolog tool according to claim 1, Characterized in that, The double-ring isolator (1) includes a double-ring isolator housing (17) and a double-ring isolator skeleton (27); the double-ring isolator skeleton (27) penetrates through the double-ring isolator housing (17), the first socket (4) is arranged at one end of the double-ring isolator skeleton (27), the second socket (10) is arranged at the other end of the double-ring isolator skeleton (27), the protective cap (2) is assembled at one end of the double-ring isolator housing (17), the plug (3) is assembled at the other end of the double-ring isolator housing (17), and the first insulating sleeve (5), the N-ring (6), the second insulating sleeve (7), the SP-ring (8) and the third insulating sleeve (9) are sequentially arranged in the direction from one end to the other end of the double-ring isolator housing (17).

3. The double-ring isolator short section structure for an array laterolog tool according to claim 2, Characterized in that, One end of the double-ring isolator housing (17) close to the first socket (4) is provided with an assembly sealing structure, and the protective cap (2) is assembled on the assembly sealing structure.

4. The double-ring isolator short section structure for an array laterolog tool according to claim 3, Characterized in that, The assembly sealing structure includes a multi-sided ring (12), a snap ring (14), a retaining ring (15) and a threaded ring (16) arranged at the end of the double-ring isolator housing (17), the inner wall of the protective cap (2) is correspondingly arranged with the multi-sided ring (12), the snap ring (14), the retaining ring (15) and the threaded ring (16), and sealing rings (13) are sleeved between the inner wall of the protective cap (2) and the multi-sided ring (12), the snap ring (14), the retaining ring (15) and the threaded ring (16).

5. The double-ring isolator short section structure for an array laterolog tool according to claim 2, Characterized in that, The double-ring isolator skeleton (27) includes a skeleton upper joint (20) and a skeleton lower joint (25), the skeleton upper joint (20) and the skeleton lower joint (25) are coaxially connected, and the first socket (4) is fixed to the end of the skeleton upper joint (20) through a cotter pin (18), and the second socket (4) is fixed to the end of the skeleton lower joint (25).

6. The double-ring isolator short section structure for an array laterolog tool according to claim 5, Characterized in that, An annular groove is provided at one end of the skeleton upper joint (20) close to the first socket (4), and a spring (19) is sleeved in the annular groove.

7. A double-ring isolation short substructure of an array laterolog tool according to claim 5, characterized in that an intermediate insulating sleeve (24) is provided between the skeleton upper joint (20) and the skeleton lower joint (25), and the intermediate insulating sleeve (24) is fixed to the skeleton upper joint (20) and the skeleton lower joint (25) by fastening screws (23).

8. A double-ring isolation short substructure of an array laterolog tool according to claim 5, characterized in that grooves are provided on both the skeleton upper joint (20) and the skeleton lower joint (25), reed assemblies (21) are provided on the grooves, the reed assemblies (21) are fixed in the grooves by screw assemblies (22), and the N-ring (6) and the SP-ring (8) are located at the positions of the reed assemblies (21) corresponding to the skeleton upper joint (20) and the skeleton lower joint (25).

9. A double-ring isolation short substructure of an array laterolog tool according to claim 2, characterized in that a roller assembly (26) is provided at the end of the skeleton lower joint (25) close to the second socket (10).

10. A double-ring isolation short substructure of an array laterolog tool according to claim 2, characterized in that the first socket (4) is fixed to the double-ring isolation housing (17) by a positioning pin (11).

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