Conversion tool string for coiled tubing through optical fiber logging

Abstract

The present invention relates to the technical field of supporting equipment for oil and gas well logging technology, and is a conversion tool string for continuous oil pipe through optical fiber logging, which includes an upper joint with an axial channel, and an inner ring platform is provided on the inner side of the lower end of the upper joint. The present invention has a reasonable and compact structure and is easy to use. It can fix the outer side of the lower end of the optical fiber through the first sealing component to prevent the tension of pulling the optical fiber upward after the continuous oil pipe enters the well. It can also reliably seal the outer side of the optical fiber to prevent the dirty liquid in the continuous oil pipe from entering the sealing tube from the gap between the upper joint and the optical fiber to affect the logging effect; the second sealing component is used as a piston to protect the optical fiber core from tension to prevent it from pulling out or breaking, and at the same time, the surface of the optical fiber core can be reliably sealed to prevent the dirty liquid from entering the sealing tube cavity located at the lower side of the second sealing component to soak the optical fiber core fracture and affect the logging effect; the inner side of the lower end of the sealing tube is provided with a thread, which is convenient for connecting and assembling other logging tools at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas well logging technology supporting equipment, and is a conversion tool string for continuous oil pipe through optical fiber logging. Background Art

[0002] Fiber optic logging technology mainly includes distributed temperature sensors (DTS) and distributed acoustic sensors (DAS). Distributed temperature sensors and distributed acoustic sensors fiber optic logging technology because the optical fiber itself is the probe, the well measurement is not affected by factors such as the uncleanness of the horizontal wellbore, the production wells with oil pipes, and the passability of the tool string in the well with large-diameter bridge plug completion, and each meter of optical fiber itself can be used as a probe. After the optical fiber is transmitted to the bottom of the well through the continuous oil pipe, data can be collected simultaneously throughout the wellbore, solving the problem that conventional production logging can only measure data at a single point and easily miss accidental events downhole.

[0003] However, the technology of continuous tubing through optical fiber has just started, and there are many difficulties in construction. In particular, after the optical fiber body is soaked in water, the signal transmission ability is seriously attenuated, which reduces the service life of the optical fiber and even causes the optical fiber to be directly scrapped. The existing downhole tools are mature for cable sealing, but the function of optical fiber sealing is too simple and has great limitations. In particular, the optical fiber in the continuous tubing has insufficient margin. After the continuous tubing enters the well, there will be a pulling force on the optical fiber, which will cause problems such as core pulling and optical fiber breakage, thus causing sealing failure. In addition, the existing downhole optical fiber sealing tools for continuous tubing cannot be connected, assembled and applied at the same time as other logging tools. Summary of the invention

[0004] The present invention provides a conversion tool string for continuous tubing through optical fiber logging, which overcomes the shortcomings of the above-mentioned prior art and can effectively solve the problem that the sealing of the existing continuous tubing through optical fiber technology is too simple. When the margin of the optical fiber in the continuous tubing is insufficient, a pulling force will appear on the optical fiber after the continuous tubing enters the well, which is prone to core pulling and optical fiber breakage, thereby causing sealing failure; and further solves the problem that the existing continuous tubing downhole optical fiber sealing tool and other logging tools cannot be connected, assembled and applied at the same time.

[0005] The technical solution of the present invention is achieved through the following measures: a conversion tool string for continuous oil pipe through optical fiber logging, including an upper joint with an axial channel, an inner ring platform is provided on the inner side of the lower end of the upper joint, a first sealing component capable of fixing the optical fiber is installed on the inner side of the inner ring platform, and the first sealing component can form a seal with the outer side of the optical fiber; the outer side of the lower part of the upper joint is fixedly installed together with the inner side of the upper part of the sealing tube, a second sealing component capable of forming a seal with the surface of the optical fiber core is installed on the inner side of the middle part of the sealing tube, the second sealing component can slide up and down along the inner side of the sealing tube, and a plug is provided on the inner side of the lower end of the sealing tube.

[0006] The following are further optimizations and / or improvements to the above technical solutions:

[0007] The above-mentioned first sealing assembly may include a first sealing ring, a cava, a second sealing ring and a first push cylinder. A limiting ring is provided on the inner side of the upper end of the inner ring platform. The first sealing ring, a cava, a second sealing ring and a first push cylinder which are mounted on the lower end of the outer side of the optical fiber are installed from top to bottom on the inner side of the inner ring platform corresponding to the lower side of the limiting ring platform. A number of teeth which can clamp the optical fiber are provided on the inner side of the cava. The lower end of the first push cylinder is located below the upper joint.

[0008] The outer side of the upper end of the above-mentioned slip can be in the shape of a cone with a small top and a large bottom. The inner side of the inner ring platform corresponding to the slip position can be provided with an inner ring groove whose shape matches the shape of the slip. The inner side of the lower end of the inner ring groove and the outer side of the upper end of the first push cylinder can be connected together by threads.

[0009] The above-mentioned second sealing assembly may include a floating cylinder, an upper sealing body and a lower sealing body. The floating cylinder is slidably installed on the inner side of the middle part of the sealing cylinder. A stepped hole with large ends and a small middle is provided in the floating cylinder. An upper sealing body capable of sealing the outer side of the optical fiber core is provided on the inner side of the upper end of the stepped hole. A lower sealing body capable of sealing the outer side of the optical fiber core is provided on the inner side of the lower end of the stepped hole. The lower sealing body and the upper sealing body have the same structure and are symmetrically distributed up and down.

[0010] The upper sealing body may include a second push cylinder and a third sealing ring. The second push cylinder and the third sealing ring are sequentially installed on the inner side of the upper end of the stepped hole from top to bottom and are sleeved on the outer side of the optical fiber core. The lower end of the second push cylinder abuts against the upper side of the third sealing ring.

[0011] The above may also include a fourth sealing ring and a fifth sealing ring. At least one fourth sealing ring is arranged between the outer side of the second sealing component and the inner side of the sealing tube at an interval of up and down. A fifth sealing ring is arranged between the inner side of the lower end of the sealing tube and the outer side of the upper end of the plug.

[0012] The above may also include a logging tool string, and a logging tool string is arranged between the sealing tube and the plug.

[0013] The present invention has a reasonable and compact structure and is easy to use. Through the arrangement of the first sealing component, the outer side of the lower end of the optical fiber can be fixed to prevent the tension that pulls the optical fiber upward after the continuous oil pipe enters the well, and the first sealing component can also reliably seal the outer side of the optical fiber to prevent the dirty liquid in the continuous oil pipe from entering the sealing tube from the gap between the upper joint and the optical fiber to affect the logging effect; through the arrangement of the second sealing component, the second sealing component is used as a piston to protect the optical fiber core from tension to prevent it from pulling out or breaking, and the second sealing component can also reliably seal the surface of the optical fiber core to prevent liquid from entering the sealing tube cavity located at the lower side of the second sealing component to soak the optical fiber core fracture and affect the logging effect; the inner side of the lower end of the sealing tube is provided with a thread, which is convenient for simultaneous connection and assembly of other logging tools. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Attached Figure 1 It is a schematic diagram of the main cross-sectional structure of the best embodiment of the present invention.

[0015] Attached Figure 2 For attachment Figure 1 Schematic diagram of the enlarged structure at position Ⅰ in FIG.

[0016] The codes in the accompanying drawings are: 1 is the upper joint, 2 is the inner ring platform, 3 is the optical fiber, 4 is the sealing cylinder, 5 is the optical fiber core, 6 is the plug, 7 is the first sealing ring, 8 is the slip, 9 is the second sealing ring, 10 is the first push cylinder, 11 is the limiting ring platform, 12 is the floating cylinder, 13 is the second push cylinder, 14 is the third sealing ring, 15 is the fourth sealing ring, 16 is the fifth sealing ring, 17 is the logging tool string, and 18 is the optical fiber armor. DETAILED DESCRIPTION

[0017] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0018] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached Figure 1 The positional relationships such as front, back, top, bottom, left, and right are described according to the layout directions of the drawings in the specification.

[0019] The present invention will be further described below in conjunction with embodiments and drawings:

[0020] As attached Figure 1 , 2 As shown, the conversion tool string for continuous oil pipe through optical fiber logging includes an upper joint 1 with an axial channel, an inner ring platform 2 is provided on the inner side of the lower end of the upper joint 1, and a first sealing component capable of fixing the optical fiber 3 is installed on the inner side of the inner ring platform 2, and the first sealing component can form a seal with the outer side of the optical fiber 3; the outer side of the lower part of the upper joint 1 is fixedly installed with the inner side of the upper part of the sealing cylinder 4, and a second sealing component capable of forming a seal with the surface of the optical fiber core 5 is installed on the inner side of the middle part of the sealing cylinder 4, and the second sealing component can slide up and down along the inner side of the sealing cylinder 4, and a plug 6 is provided on the inner side of the lower end of the sealing cylinder 4. According to the needs, in order to facilitate the disassembly and replacement of various parts, the upper joint 1 and the sealing cylinder 4, and the sealing cylinder 4 and the plug 6 can be connected by threads, and the shape of the inner side of the upper end of the upper joint 1 matches the shape of the butt joint at the end of the oil pipe; the optical fiber 3 can be a common optical fiber and an armored optical fiber. Since the optical fiber 3 is very easy to be pulled during the use of the present invention, the armored optical fiber is used in this embodiment, which is mainly because the optical fiber armor 18 is set between the outer side of the optical fiber core 5 and the optical fiber jacket, and the tensile effect is better.

[0021] During use, firstly, the protective cover at the end of the optical fiber 3 is peeled off to expose a section of the optical fiber core 5, then the upper connector 1 is put on the outside of the end of the optical fiber 3, and then the upper end of the upper connector 1 is connected to the end of the continuous oil pipe, and then the first sealing component is put on the outside of the end of the optical fiber 3 (the part with the optical fiber jacket), and finally the first sealing component is inserted into the inner side of the inner ring 2, so that the end of the optical fiber 3 is fixedly sealed inside the inner ring 2 to prevent the end of the optical fiber 3 from moving, which can effectively prevent the dirty liquid in the continuous oil pipe from entering the inside of the sealing tube 4 through the gap between the upper connector 1 and the optical fiber 3, thereby preventing the optical fiber 3 from being soaked in water. The signal transmission capability is seriously attenuated, which reduces the service life of the optical fiber 3; then the second sealing component is sleeved on the outside of the optical fiber core 5, and the outside of the optical fiber core 5 is sealed by the second sealing component. Finally, the second sealing component is inserted into the sealing tube 4 so that the sealing tube 4 and the upper joint 1 are fixed together. The second sealing component is used as a piston. When the head end of the optical fiber 3 is pulled at the upper end of the continuous oil pipe, the optical fiber core 5 can drive the second sealing component to slide along the inner side of the sealing tube 4 synchronously, so as to avoid the optical fiber core 5 from being subjected to tension and prevent the optical fiber 3 from being pulled out or broken; finally, the lower end of the sealing tube 4 is sealed with a plug 6.

[0022] According to actual needs, the above conversion tool string for coiled tubing through optical fiber logging can be further optimized and / or improved:

[0023] As attached Figure 1 , 2 As shown, the first sealing assembly includes a first sealing ring 7, a slip 8, a second sealing ring 9 and a first push tube 10. A limiting ring 11 is provided on the inner side of the upper end of the inner ring 2. The first sealing ring 7, slip 8, second sealing ring 9 and first push tube 10 are installed from top to bottom on the inner side of the inner ring 2 corresponding to the lower side of the limiting ring 11. The slip 8 is provided with a plurality of teeth that can clamp the optical fiber 3. The lower end of the first push tube 10 is located below the upper connector 1. According to the needs, the optical fiber jacket at the position where the slip 8 is installed on the armored optical fiber can be peeled off to expose the optical fiber armor 18. The shape of the teeth provided on the inner side of the slip 8 matches the surface shape of the optical fiber armor 18, so that the gap of the optical fiber armor 18 can be better clamped by the teeth in the slip 8 to prevent the end of the optical fiber 3 from moving.

[0024] During use, the first sealing ring 7 can seal the gap between the upper connector 1 and the optical fiber 3 to prevent dirty liquid in the continuous oil pipe from entering the sealing tube 4; the slip 8 can clamp the lower end of the optical fiber 3 through the optical fiber armor 18 to prevent the lower end of the optical fiber 3 from moving, so that the optical fiber 3 can be laid vertically in the continuous oil pipe to achieve better logging effect of the optical fiber 3, and when the optical fiber 3 is pulled from the head end of the optical fiber 3, the slip 8 can further compress the first sealing ring 7, which not only has a better sealing effect but also leaves space for the movement of the end of the optical fiber 3; the second sealing ring 9 can enhance the sealing between the first push cylinder 10, the slip 8 and the optical fiber jacket; the first push cylinder 10 can adjust the tightness of the slip 8 to press the first sealing ring 7 and the second sealing ring 9, and can also block the slip 8 to prevent it from falling off the surface of the optical fiber 3.

[0025] As attached Figure 1 , 2 As shown, the outer side of the upper end of the cava 8 is in the shape of a cone with a small top and a large bottom. The inner side of the inner ring platform 2 corresponding to the position of the cava 8 is provided with an inner ring groove whose shape matches the shape of the cava 8. The inner side of the lower end of the inner ring groove is connected to the outer side of the upper end of the first push cylinder 10 through threads.

[0026] Through such an arrangement, when the optical fiber 3 is pulled from the head end of the optical fiber 3, as the cava 8 becomes tighter and tighter, the cava 8 can further clamp the optical fiber armor 18 to prevent the end of the optical fiber 3 from loosening and affecting the sealing effect; for easy disassembly and assembly, the first push cylinder 10 and the upper connector 1 are connected together by threads, and a square or hexagonal wrench platform can also be provided on the outer side of the lower end of the first push cylinder 10.

[0027] As attached Figure 1 As shown, the second sealing assembly includes a floating cylinder 12, an upper sealing body and a lower sealing body. The floating cylinder 12 is slidably installed on the inner side of the middle of the sealing cylinder 4. A stepped hole with large ends and a small middle is provided in the floating cylinder 12. An upper sealing body capable of sealing the outer side of the optical fiber core 5 is provided on the inner side of the upper end of the stepped hole. A lower sealing body capable of sealing the outer side of the optical fiber core 5 is provided on the inner side of the lower end of the stepped hole. The lower sealing body and the upper sealing body have the same structure and are symmetrically distributed up and down.

[0028] With such an arrangement, the floating cylinder 12 is used as a piston, and the floating cylinder 12 and the optical fiber core 5 are fixedly sealed together by the upper sealing body and the lower sealing body. In this way, when the optical fiber 3 is pulled from the head end of the optical fiber 3, the optical fiber core 5 can move up and down with the floating cylinder 12, preventing the optical fiber core 5 from being pulled out or torn off due to the tension. It can also prevent dirty liquid from entering the space below the floating cylinder 12 through the gap between the optical fiber core 5 and the floating cylinder 12, soaking the broken end of the optical fiber core 5, and thus affecting the logging effect of the entire optical fiber 3. In addition, in order to prevent the optical fiber jacket and the optical fiber armor 18 from affecting the sliding of the floating cylinder 12, the lower ends of the optical fiber jacket and the optical fiber armor 18 can be flush with the lower end of the first push cylinder 10.

[0029] As attached Figure 1As shown, the upper sealing body includes a second push cylinder 13 and a third sealing ring 14. The second push cylinder 13 and the third sealing ring 14 are sequentially installed on the inner side of the upper end of the stepped hole from top to bottom, and the lower end of the second push cylinder 13 abuts against the upper side of the third sealing ring 14. According to the needs, in order to facilitate the adjustment of the compression degree of the second sealing ring 9 by the second push cylinder 13, the second push cylinder 13 and the floating cylinder 12 can be connected by threads; in addition, in order to facilitate the rotation of the second push cylinder 13 by a wrench, a square or hexagonal wrench stand can be provided on the outer side of the upper end of the second push cylinder 13.

[0030] As attached Figure 1 As shown, it also includes a fourth sealing ring 15 and a fifth sealing ring 16. At least one fourth sealing ring 15 is arranged between the outer side of the second sealing assembly and the inner side of the sealing cylinder 4, and a fifth sealing ring 16 is arranged between the inner side of the lower end of the sealing cylinder 4 and the outer side of the upper end of the plug 6. By such an arrangement, it is possible to prevent the dirty liquid in the well from entering the cavity at the end of the optical fiber core 5 from the gap between the sealing cylinder 4 and the floating cylinder 12 and the plug 6, soaking the end break of the optical fiber 3, and thus affecting the logging effect of the entire optical fiber 3.

[0031] As attached Figure 1 As shown, a logging tool string 17 is also included, and a logging tool string 17 is provided between the sealing tube 4 and the plug 6. According to the requirements, the logging tool string 17 can be a logging tool or a combination of multiple logging tools, and different logging tools can be combined according to various downhole environments. In this embodiment, the logging tool string 17 is a pressure gauge drag tube, and a pressure gauge is installed in the pressure gauge drag tube, which is used to measure the pressure and temperature in real time during the lifting and lowering of the pipe string during the optical fiber logging of oil, gas and water wells. In order to prevent the dirty liquid in the well from entering the sealing tube 4 through the gap between the sealing tube 4 and the pressure gauge drag tube, the sealing tube 4 and the pressure gauge drag tube can be sealed by a fifth sealing ring 16, and no sealing ring may be provided between the plug 6 and the pressure gauge drag tube.

[0032] The above technical features constitute the best embodiment of the present invention, which has strong adaptability and best implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A conversion tool string for coiled tubing through optical fiber logging, characterized in that The invention comprises an upper joint with an axial channel, an inner ring platform is provided on the inner side of the lower end of the upper joint, a first sealing component capable of fixing the optical fiber is installed on the inner side of the inner ring platform, and the first sealing component can form a seal with the outer side of the optical fiber; the outer side of the lower part of the upper joint is fixedly installed together with the inner side of the upper part of the sealing tube, a second sealing component capable of forming a seal with the surface of the optical fiber core is installed on the inner side of the middle part of the sealing tube, the second sealing component can slide up and down along the inner side of the sealing tube, and a plug is provided on the inner side of the lower end of the sealing tube; the first sealing component comprises a first sealing ring, a slip, a second sealing ring and a first push tube, a limiting ring platform is provided on the inner side of the upper end of the inner ring platform, and a first sealing ring, a slip, a second sealing ring and a first push tube are installed from top to bottom on the inner side of the inner ring platform corresponding to the lower side position of the limiting ring platform, a plurality of teeth capable of clamping the optical fiber are provided on the inner side of the slip, the lower end of the first push tube is located below the upper joint, the outer side of the upper end of the slip is in the shape of a cone with a small top and a large bottom, an inner ring groove matching the shape of the slip is provided on the inner side of the inner ring platform corresponding to the position of the slip, and the inner side of the lower end of the inner ring groove matches the first push tube. The outer side of the upper end of a push cylinder is connected together by threads; the second sealing component includes a floating cylinder, an upper sealing body and a lower sealing body, a floating cylinder is slidably installed on the inner side of the middle part of the sealing cylinder, a stepped hole with large ends and small middle is provided in the floating cylinder, an upper sealing body capable of sealing the outer side of the optical fiber core is provided on the inner side of the upper end of the stepped hole, and a lower sealing body capable of sealing the outer side of the optical fiber core is provided on the inner side of the lower end of the stepped hole, the lower sealing body and the upper sealing body have the same structure and are symmetrically distributed up and down; the floating cylinder is used as a piston, and the floating cylinder and the optical fiber core are fixed and sealed together by the upper sealing body and the lower sealing body, so that when the optical fiber is pulled from the head end of the optical fiber, the optical fiber core can move up and down with the floating cylinder to prevent the optical fiber core from being pulled out or torn off due to tension, and to prevent dirty liquid from entering the space below the floating cylinder from the gap between the optical fiber core and the floating cylinder, soaking the broken end of the optical fiber core, thereby affecting the logging effect of the entire optical fiber, in addition, to prevent the optical fiber jacket and the optical fiber armor from affecting the sliding of the floating cylinder, the lower ends of the optical fiber jacket and the optical fiber armor are flush with the lower end of the first push cylinder.

2. The conversion tool string for coiled tubing through optical fiber logging according to claim 1 is characterized in that The upper sealing body includes a second push cylinder and a third sealing ring. The second push cylinder and the third sealing ring are installed on the inner side of the upper end of the stepped hole from top to bottom, and the lower end of the second push cylinder abuts against the upper side of the third sealing ring.

3. The conversion tool string for coiled tubing through optical fiber logging according to claim 1 or 2, characterized in that It also includes a fourth sealing ring and a fifth sealing ring. At least one fourth sealing ring is arranged between the outer side of the second sealing component and the inner side of the sealing tube at an interval of up and down. A fifth sealing ring is arranged between the inner side of the lower end of the sealing tube and the outer side of the upper end of the plug.

4. The conversion tool string for coiled tubing through optical fiber logging according to claim 1 or 2, characterized in that It also includes a logging tool string, which is arranged between the sealing tube and the plug.

5. The conversion tool string for coiled tubing through optical fiber logging according to claim 3, characterized in that It also includes a logging tool string, which is arranged between the sealing tube and the plug.

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