Optical fiber tripping-in device in oil and gas well casing deformation monitoring

Abstract

The utility model discloses an optical fiber tripping-in device in oil and gas well casing deformation monitoring, which comprises a plurality of connecting casings, a tail end casing, a traction cable winch and an optical cable winch, the outer wall of each connecting casing and the outer wall of each tail end casing are respectively provided with a tunnel structure, and each tunnel structure comprises a going tunnel and a returning tunnel; the going tunnel and the returning tunnel are arranged side by side, a pulley is arranged at the end of the tunnel structure of the tail end sleeve, and the pulley is arranged in the center of the tunnel structure. The two adjacent connecting sleeves or the tail end sleeve and the adjacent connecting sleeve are detachably connected; the going tunnel is used for putting down an optical cable and a traction cable, and the returning tunnel is used for providing a returning channel for the traction cable when the optical cable is put down. The tunnel structure is adopted to fix the optical fibers, permanent deployment of the distributed optical fibers on the outer surface of the oil and gas well casing is achieved, and a foundation is laid for optical fiber monitoring in the production operation process.

Description

Technical Field

[0001] The utility model relates to the field of oil and gas well detection devices, in particular to an optical fiber running device in oil and gas well casing deformation monitoring. Background Art

[0002] Oil casing is a steel pipe used to support the well wall of oil and gas wells to ensure the smooth progress of the drilling process and the normal operation of the oil and gas wells during production after completion. However, due to the combined effects of multiple factors such as cementing and perforating operations during completion, fracturing operations during the implementation of production stimulation measures, and ground stress, the casing often deforms.

[0003] Under the existing monitoring conditions, we cannot perceive deformation on the ground in time when it occurs. It is not until a tool is stringed into the well and encounters an engineering accident such as obstruction or jamming that we can suspect the occurrence of deformation and confirm it through multi-arm wellbore logging and other operations. In order to solve the problem of real-time monitoring of casing deformation, the oil and gas industry is considering the promotion and application of distributed fiber optic logging. That is, during the completion process, the distributed optical fiber is deployed on the outer or inner surface of the casing, making it a part of the completion production string, to achieve real-time monitoring of the casing status.

[0004] As a result, the deployment of optical fiber has become one of the difficulties in the application of this technology. The key issues that need to be solved are as follows:

[0005] (1) The casing is connected one by one and is lowered into the well through the threaded connection on the casing coupling. The optical fiber is a whole unit that is several thousand meters long, without bends or joints. How are the two deployed together in the well?

[0006] (2) How to fix the optical fiber to the sleeve.

[0007] (3) How to ensure that the wellhead and bottom parts do not rotate or twist relative to each other after the casing is lowered.

[0008] In order to solve the above problems, the present invention proposes an optical fiber running device for oil and gas well casing deformation monitoring. Utility Model Content

[0009] Therefore, the purpose of the utility model is to provide an optical fiber running device for oil and gas well casing deformation monitoring, which adopts a tunnel structure to fix the optical fiber, realize the permanent deployment of distributed optical fiber on the outer surface of the oil and gas well casing, and lay the foundation for optical fiber monitoring during production operations.

[0010] In order to achieve the above-mentioned purpose, the utility model provides an optical fiber lowering device for casing deformation monitoring in oil and gas wells, comprising: a plurality of connecting sleeves, an end sleeve, a traction rope winch and an optical cable winch, each connecting sleeve and the end sleeve having a tunnel structure on its outer wall, the tunnel structure comprising a forward tunnel and a return tunnel; the forward tunnel and the return tunnel are arranged side by side, a pulley is provided at the end of the tunnel structure of the end sleeve, and the pulley is arranged in the center of the tunnel structure; two adjacent connecting sleeves or the end sleeve and the adjacent connecting sleeves are all detachably connected; the forward tunnel is used for lowering the optical cable and the traction rope, and the return tunnel is used for providing a return channel for the traction rope when lowering the optical cable.

[0011] Further preferably, the cross-sections of the outgoing tunnel and the return tunnel are circular rings with gaps.

[0012] Further preferably, a tunnel entrance clamp is provided on the notched ring.

[0013] Further preferably, the tunnel entrance clamp is a spring clamp, which includes a spring, a sleeve and a telescopic arm; both ends of the spring are respectively connected to the telescopic arms, the spring is fixed inside the sleeve, and a rectangular notch is provided on the sleeve.

[0014] Further preferably, the pulley includes a base and an axle; the base is fixedly mounted on the terminal sleeve, and the center of the axle falls on the midpoint line of the gap between the two tunnels.

[0015] Further preferably, the alignment thread includes an alignment pin, a detachable thread ring and a sealing ring.

[0016] The optical fiber running device for oil and gas well casing deformation monitoring disclosed in the present application has at least the following advantages compared with the prior art:

[0017] 1. The tunnel structure is adopted. After the optical fiber is inserted by traction, it is fixed, which conveniently and quickly realizes the permanent deployment of distributed optical fiber on the outer surface of oil and gas well casing, laying the foundation for optical fiber monitoring during production operations.

[0018] 2. The present application adopts alignment threads to achieve detachable connection between the various casings, and uses the alignment threads to tighten the casing to ensure that the wellhead part and the bottom part of the well do not rotate or twist relative to each other after the casing is lowered. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of an optical fiber lowering device for oil and gas well casing deformation monitoring provided by the utility model;

[0020] Figure 2 This is a schematic diagram of the tunnel structure provided by the utility model.

[0021] Figure 3 This is a schematic diagram of the tunnel cross section provided by the utility model.

[0022] Figure 4 A schematic diagram of the structure of the tunnel entrance clamp provided by the utility model

[0023] Figure 5 The utility model is a schematic structural diagram of the counter-threaded buckle provided by the utility model.

[0024] In the figure: 1. connecting sleeve; 2. end sleeve; 3. traction rope winch; 4. optical cable winch; 5. outgoing tunnel; 6. return tunnel; 7. pulley; 8. ring; 9. tunnel entrance clamp; 901. spring; 902. sleeve; 903. telescopic arm; 10. alignment pin; 11. detachable threaded ring; 12. sealing ring. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below through the accompanying drawings and specific implementation methods.

[0026] like Figure 1-5 As shown, an optical fiber lowering device for casing deformation monitoring in oil and gas wells provided by an embodiment of the utility model on one hand comprises: a plurality of connecting sleeves 1, an end sleeve 2, a traction rope winch 3 and an optical cable winch 4, a tunnel structure is provided on the outer wall of each connecting sleeve 1 and the end sleeve 2, the tunnel structure comprises an outgoing tunnel 5 and a return tunnel 6; the outgoing tunnel 5 and the return tunnel 6 are arranged side by side, a pulley 7 is provided at the end of the tunnel structure of the end sleeve 2 (between the outgoing tunnel 5 and the return tunnel 6), and the pulley 7 is arranged in the center of the tunnel structure; two adjacent connecting sleeves 1 or the end sleeve 2 and the adjacent connecting sleeves 1 are all detachably connected; the outgoing tunnel 5 is used for lowering the optical cable and the traction rope, and the return tunnel 6 is used for providing a return channel for the traction rope when lowering the optical cable.

[0027] like Figure 2 As shown, the cross-section of the outgoing tunnel 5 and the return tunnel 6 is a circular ring 8 with a notch. It should be noted that the tunnel structure is used to lower the traction rope in advance, and the optical cable is lowered and retained in the later stage; the function of the return tunnel is to provide a return channel for the traction rope when the optical cable is lowered. The traction rope is made of steel wire or chemical fiber, with a diameter of 5 mm and a breaking tensile force greater than its own total weight of more than 1 ton. The end of the traction rope is treated with a metal head to protect the rope itself and facilitate on-site operation.

[0028] Before going down the well, the traction rope is coiled on the lowering drum of the traction rope winch. During the process of going down the well, the traction rope is released from the lowering drum, goes into the well, enters the outbound tunnel, then turns through the pulley, enters the return tunnel, exits the wellhead, and winds back on the lifting drum.

[0029] When the optical cable enters the well, its lower end is connected to the upper end of the traction rope in the tunnel. Then, with the downward traction of the traction rope, the optical cable can run smoothly in the tunnel until the lower end reaches the upper end of the pulley. The traction rope and the optical cable are connected together through a set of connector components and a special tool (crimping pliers).

[0030] like Figure 3-4 As shown, a tunnel entrance clamp 9 is provided on the notched ring 8. Furthermore, the tunnel entrance clamp 9 is a spring clamp, and the tunnel entrance clamp 9 includes a spring 901, a sleeve 902 and a telescopic arm 903; the two ends of the spring 901 are respectively connected to the telescopic arm 903, and the spring 901 is fixed inside the sleeve 902. After pressing the spring 901, the telescopic arm 903 retracts into the sleeve 902. When the spring 901 recovers, the telescopic arm 903 is stuck on the tunnel. A tool such as a special circlip pliers is used to extend into the rectangular notch 904 of the sleeve (the notch is an operating window) to press the spring. After completion, the tunnel entrance clamp is clamped at both ends of the tunnel entrance. The tunnel entrance clamp can be set one every 1 meter or so according to the length of the casing.

[0031] Further preferably, the pulley 7 includes a base and an axle; the base is fixedly mounted on the terminal sleeve 2, and the center of the axle falls on the midpoint line of the gap between the two tunnels.

[0032] like Figure 5 Furthermore, the alignment thread includes an alignment pin 10, a detachable thread ring 11 and a sealing ring 12. After the external threads are arranged at the head and tail ends of each sleeve and screwed together with the internal threads of the detachable thread ring, the alignment pin is inserted into the thread ring to fix the sleeve to prevent the sleeve from slipping off. Further, a groove is arranged on the sleeve at a position corresponding to the pin for positioning the pin. A positioning boss is also arranged at the end of the internal thread for placing the sealing ring. After the external thread of the sleeve is screwed together with the internal thread, the end of the sleeve abuts against the sealing ring to improve the airtightness.

[0033] During the implementation of the utility model, while the connecting casing and the end casing are connected one by one, the traction rope is first embedded in the casing using the tunnel structure, and a tunnel entrance clamp is set on the tunnel mechanism at every one-meter distance, and the traction rope winch needs to keep synchronization with the up and down movement of the casing column. After each casing column is connected, a traction rope of the same length is lowered into the destination tunnel, and a traction rope of the same length is lifted up to the return tunnel. When the casing equipped with a pulley reaches the predetermined depth, the casing column connection is completed. At this time, the traction rope in the destination tunnel is cut off and the optical cable is connected. The traction rope winch retracts the traction rope in the return tunnel, so that the optical cable in the destination tunnel is pulled to the predetermined position (pulley). After the optical cable is deployed, the cementing process will bond the optical cable with the cement ring, casing, etc., so that the optical cable in the destination tunnel and the traction rope in the return tunnel become part of the production pipe string. Next, the optical cable can monitor the status of the casing at any time during cementing, perforating, fracturing, and oil and gas production. The process is as follows:

[0034] (1) Before the operation, connect the optical time domain reflectometer (OTDR) to the optical cable at the wellhead to perform optical loss detection and record the detection data.

[0035] (2) During the operation, select key operation nodes, connect the ground monitoring system to the optical cable, and record the monitoring data.

[0036] (3) The above data are collected and analyzed to obtain the changes in the shape and trajectory of the casing before and after the operation.

[0037] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention of the utility model.

Claims

1. An optical fiber lowering device for oil and gas well casing deformation monitoring, characterized in that: include: A plurality of connecting sleeves, end sleeves, traction rope winches and optical cable winches, each connecting sleeve and end sleeve is provided with a tunnel structure on the outer wall, the tunnel structure comprises an outgoing tunnel and a return tunnel; the outgoing tunnel and the return tunnel are arranged side by side, a pulley is provided at the end of the tunnel structure of the end sleeve, and the pulley is arranged in the center of the tunnel structure; two adjacent connecting sleeves or the end sleeve and the adjacent connecting sleeves are all detachably connected; the outgoing tunnel is used for lowering the optical cable and the traction rope, and the return tunnel is used for providing a return channel for the traction rope when lowering the optical cable.

2. The optical fiber running device for oil and gas well casing deformation monitoring according to claim 1 is characterized in that: The cross sections of the outgoing tunnel and the return tunnel are circular rings with gaps.

3. The optical fiber running device for oil and gas well casing deformation monitoring according to claim 2 is characterized in that: A tunnel entrance clamp is arranged on the circular ring with the notch.

4. The optical fiber running device for oil and gas well casing deformation monitoring according to claim 3 is characterized in that: The tunnel entrance clamp is a spring clamp, which includes a spring, a sleeve and a telescopic arm; the two ends of the spring are respectively connected to the telescopic arms, the spring is fixed inside the sleeve, and a rectangular notch is provided on the sleeve.

5. The optical fiber running device for oil and gas well casing deformation monitoring according to claim 1, characterized in that: The pulley comprises a base and an axle; the base is fixedly mounted on the end sleeve, and the center of the axle falls on the midpoint line of the gap between the two tunnels.

6. The optical fiber running device for oil and gas well casing deformation monitoring according to claim 1, characterized in that: The two adjacent connecting sleeves or the end sleeve and the adjacent connecting sleeve are detachably connected by means of counter-threaded fasteners.

7. The optical fiber running device for oil and gas well casing deformation monitoring according to claim 6, characterized in that: The alignment type thread comprises an alignment pin, a detachable thread ring and a sealing ring.

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