An over-the-cable distributed optical fiber anti-shooting device and method

Abstract

The application provides a casing-out distributed optical fiber shooting-avoiding device, which comprises a terminal and a light source emitting device and a light source receiving device in communication connection with the terminal; the light source emitting device comprises a first light source emitting device arranged at a non-toe end of the casing and a second light source emitting device arranged at a toe end of the casing; a gyroscope is arranged on the second light source emitting device; the light source receiving device is arranged at a wellhead and the inner wall of the light source receiving device is provided with an angle scale for recording the horizontal rotation angle of the light source emitting device; and the terminal is used for obtaining the relative position of the optical cable outside the casing. The application can obtain the distribution of the optical cable outside the casing through the horizontal angle difference generated by the optical cable during the lowering process, the relative position of the optical cable and the casing at the toe end of the casing during the lowering of the casing and after the lowering of the casing is completed, thereby providing a basis for perforating construction, avoiding damage of the perforation to the optical cable, guaranteeing the observation length of the optical cable, reducing the construction cost and improving the utilization rate of the optical fiber. In addition, the application also provides a casing-out distributed optical fiber shooting-avoiding method.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of acquisition and processing of geophysical exploration seismic data, and particularly relates to a casing-out distributed optical fiber anti-shooting device and method for downhole microseismic monitoring during oil and gas well fracturing. BACKGROUND

[0002] In recent years, with the breakthrough and innovation of oil and gas geology theory and the progress of engineering technology, China's continental shale oil and gas and tight oil and gas exploration and development have made significant breakthroughs. Hydraulic fracturing is an essential technology for unconventional oil and gas reservoir reconstruction and single well production improvement. In order to achieve safe and efficient fracturing, a seismic detector is usually used for microseismic monitoring and fracturing effect evaluation. Generally, the number of downhole detectors is small and the azimuth angle is narrow, making it difficult to obtain accurate microseismic source location, resulting in inaccurate evaluation of reservoir reconstruction.

[0003] Distributed optical fiber monitoring technology has gradually become the mainstream mode of hydraulic fracturing detection due to its unique advantages. Currently, the distributed optical fiber sensors applied to hydraulic fracturing monitoring mainly include distributed temperature sensing (DTS), distributed acoustic sensing (DAS), and distributed strain sensing based on Rayleigh frequency shift (DSS-RFS). The first three types were first applied to hydraulic fracturing monitoring in 2006, 2014, and 2021, respectively. The physical quantities monitored have developed from temperature to acoustic wave (vibration) and strain signals, which can more directly reflect the crack propagation and crack impact phenomena during hydraulic fracturing, and can monitor the transient strain at the perforation hole during the opening and closing of the well to evaluate the degree of crack opening (closure) and confirm the crack monitoring during the fracturing process. Distributed optical fiber acoustic sensing technology, as the latest development of distributed optical fiber sensing technology, has been applied to the hydraulic fracturing monitoring of shale and tight sandstone reservoirs in recent years and has achieved good results.

[0004] The distributed optical fiber acoustic sensing technology mainly realizes the horizontal well optical fiber distributed acoustic sensing by permanently laying the optical fiber outside the casing of the horizontal well of the shale gas reservoir. However, due to the fact that the optical fiber is fixed outside the casing and the casing often rotates during the process of being lowered into the well, the optical cable deforms outside the casing, which causes the specific distribution of the optical cable outside the casing to be unable to be determined, that is, the relative position relationship between the optical cable and the casing cannot be determined, so that the optical fiber cannot be avoided during the perforation construction, and the optical fiber is often broken, which reduces the length of the optical fiber observation section and affects the microseismic acquisition effect. Therefore, before perforation, the optical fiber needs to be positioned, and the perforation angle is selected according to the positioning result to avoid damage to the optical fiber. The commonly used methods at present mainly include: using a logging tool to detect the clamp of the fixed optical fiber to the casing and a beacon positioning device. This method can determine the position of the optical cable, but cannot determine the distribution of the optical cable attached to the outer layer of the casing, and the success rate of perforation avoidance is low.

[0005] CN112068267A relates to a downhole casing optical cable perforation avoidance method and system, which obtains the position information of the optical cable on the casing circumference by using the acquisition information of the optical cable itself combined with a positioning device, mainly the light source reception and temperature information, etc. This technology is greatly affected by factors such as cementing quality, and the positioning is prone to errors. CN111425188A relates to a casing outside armored optical cable directional system and data acquisition method based on a variable frequency sound source. The primary condition for the variable frequency sound source to determine the position of the optical cable is that the angle difference of the optical cable between two adjacent sound source transmitters is not greater than 360°, that is, the winding of the optical cable outside the casing is less than one turn. However, during the process of lowering the casing, the casing often rotates, and it is difficult to ensure that the rotation angle of the casing is less than 360°. Under such conditions, the method based on the variable frequency sound source has a large error and is difficult to realize accurate positioning of the optical cable outside the casing.

[0006] Therefore, it is necessary to develop an accurate positioning device and method to position the optical cable to present the distribution of the optical cable outside the casing, thereby improving the success rate of optical cable perforation avoidance, reducing optical fiber loss, and reducing construction cost. SUMMARY

[0007] The application aims at solving the problems in the prior art, providing a casing-out distributed optical fiber shooting-avoiding device, fixing a second light source emitting device at the toe end of the casing, fixing a plurality of first light source emitting devices at the non-toe end outside the casing, lowering together with the optical cable, obtaining the initial three-component azimuth angle of the optical cable by the second light source emitting device at the toe end of the casing and the three-component azimuth angle after the lowering of the optical cable is completed, recording the horizontal rotation angle of the second light source emitting device and each first light source emitting device by the light source receiving device at the wellhead, and finally obtaining the distribution of the optical cable along the surface of the casing, thereby providing a basis for the selection of the perforation angle, avoiding the damage of the perforation construction to the distributed optical fiber, improving the success rate of the distributed optical fiber shooting-avoiding, reducing the construction cost of the distributed optical fiber, and improving the utilization rate of the optical fiber.

[0008] The application is implemented by the following technical scheme:

[0009] One of the application purposes of the application is to provide a casing-out distributed optical fiber shooting-avoiding device, comprising:

[0010] The light source emitting device comprises a first light source emitting device arranged at the non-toe end of the casing and a second light source emitting device arranged at the toe end of the casing; a gyroscope is arranged on the second light source emitting device;

[0011] The light source receiving device is arranged at the wellhead, and an angle scale is arranged on the inner wall thereof; the light source receiving device is used for receiving the light source signals of the first light source emitting device and the second light source emitting device and recording the horizontal rotation angle thereof;

[0012] The terminal is in communication connection with the light source emitting device and the light source receiving device respectively, and is used for obtaining the relative position of the optical cable outside the casing.

[0013] In a preferred embodiment of the application, the light source receiving device is in the form of a circular ring, and the inner diameter of the circular ring is greater than the outer diameter of the casing; a plurality of optical sensors are arranged on the inner circle of the light source receiving device in equal intervals, and the plurality of optical sensors are all used for receiving the light source signals of the first light source emitting device and the second light source emitting device and recording the horizontal rotation angle thereof.

[0014] In a preferred embodiment of the application, the first light source emitting device is a plurality of first light source emitting devices, and the plurality of first light source emitting devices are arranged in equal intervals along the length direction of the casing.

[0015] In a preferred embodiment of the application, the interval between two adjacent first light source emitting devices is not greater than 1 / 2 of the length of each casing.

[0016] In a preferred embodiment of the present application, the communication mode between the second light source emitting device and the terminal is wired communication, preferably communication connection through the communication optical fiber reserved inside the optical cable.

[0017] In a preferred embodiment of the present application, the communication mode between the light source receiving device and the terminal is wired communication or wireless communication, preferably wired communication.

[0018] The second object of the present application is to provide a casing-out distributed optical fiber shooting avoidance method, which is implemented by using the casing-out distributed optical fiber shooting avoidance device of the first object of the present application. The method comprises

[0019] S1: installing the casing-out distributed optical fiber shooting avoidance device of the first object of the present application;

[0020] S2: starting to lower the casing, obtaining the horizontal rotation angle and the three-component azimuth angle of the second light source emitting device, and transmitting them to the terminal;

[0021] S3: gradually lowering the casing, obtaining the horizontal rotation angle of each first light source emitting device, and transmitting them to the terminal in sequence;

[0022] S4: lowering the casing to the position, again obtaining the three-component azimuth angle of the second light source emitting device, and transmitting it to the terminal;

[0023] S5: determining the relative position of the optical cable outside the casing according to the horizontal rotation angle and the three-component azimuth angle of the second light source emitting device in S2, the horizontal rotation angle of each first light source emitting device in S3, and the three-component azimuth angle of the second light source emitting device in S4.

[0024] In a preferred embodiment of the present application, in step S1,

[0025] S11: installing the second light source emitting device at the toe end of the casing;

[0026] S12: installing each first light source emitting device outside the middle section of the casing in sequence along the length direction of the casing;

[0027] S13: installing the light source receiving device at the wellhead.

[0028] In a preferred embodiment of the present application, in step S12,

[0029] Each first light source emitting device is arranged at equal intervals, and the interval between the adjacent two first light source emitting devices is not greater than 1 / 2 of the length of each section of the casing.

[0030] In a preferred embodiment of the present application, in step S5,

[0031] S51: According to the horizontal rotation angle of the second light source emitting device in S2 and the horizontal rotation angle of the first light source emitting device firstly entering the well in S3, the horizontal angle difference when the two are lowered is calculated;

[0032] S52: According to the horizontal rotation angle of each first light source emitting device in S3, the horizontal angle difference generated when two adjacent first light source emitting devices are lowered is calculated in sequence to obtain a plurality of horizontal angle differences;

[0033] S53: The spatial position of the toe end of the optical cable is determined through the three-component azimuth angle of the second light source emitting device in S2 and the three-component azimuth angle of the second light source emitting device in S4;

[0034] S54: The relative position of the optical cable outside the casing is calculated through the horizontal angle difference in S51, the plurality of horizontal angle differences in S52 and the spatial position of the toe end of the optical cable in S53.

[0035] Compared with the prior art, the beneficial effects of the present application are:

[0036] The present application obtains the horizontal angle difference generated in the lowering process of the optical cable through a plurality of first light source emitting devices fixed outside the casing, and the relative position relationship between the optical cable at the toe end of the casing and the casing when the casing is lowered and after the lowering is completed, and transmits to the terminal, so that the distribution of the optical cable outside the casing can be accurately displayed, thereby providing a basis for the azimuth rotation of the perforation construction, avoiding damage to the optical cable by the perforation, protecting the observation length of the optical cable, reducing the construction cost and improving the utilization rate of the optical fiber. In addition, the present application uses high-density light source emitting devices for measurement, and the light source emitting devices can use devices with high beam light such as laser or radium light, which has low cost. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 It is a front view structural schematic diagram of the casing outside distributed optical fiber avoiding device of the present application.

[0038] Figure 2 It is a schematic diagram of the distribution of the optical cable outside the casing obtained by the casing outside distributed optical fiber avoiding method of the present application.

[0039] In the figure, M1 is a casing; M2 is an optical cable; M3 is an angle-scaled light source receiving device; M4 is a second light source emitting device; and M5 is a first light source emitting device. DETAILED DESCRIPTION

[0040] The present application will be further described in detail below in combination with the drawings:

[0041] As Figure 1As shown, the casing outer distributed optical fiber anti-shooting device of the present application is arranged outside the casing M1, comprising an optical source receiving device M3 with an angle scale, an optical source transmitting device and a signal transmission device. Among them, the optical source transmitting device comprises a first optical source emitting device M5 and a second optical source emitting device M4. Specifically, the optical source receiving device M3 with an angle scale is in the shape of a circular ring, the inner wall of which is provided with an angle scale, and the outer wall is mounted on the wellhead. The angle scale on the inner wall of the optical source receiving device M3 is 0-360°. The inner diameter of the optical source receiving device M3 with an angle scale is greater than the outer diameter of the casing M1, so that the casing M1 can pass through and extend downward into the well.

[0042] It should be noted that the angle scale on the inner wall of the optical source receiving device M3 of the present application is 0-360°, and 360 optical sensors are arranged at equal intervals along the inner wall of the optical source receiving device M3 on the same horizontal line, each optical sensor corresponds to a different angle, and the angle difference between adjacent two optical sensors is 1°, and each optical sensor is in communication connection with the terminal. However, this does not constitute a limitation on the present application, and in actual application, the number of optical sensors can be set by the technician according to the actual situation, for example, 240 optical sensors can be set, and the angle difference between adjacent two optical sensors is 1.5°; or 180 optical sensors can be set, and the angle difference between adjacent two optical sensors is 2°.

[0043] On the outer wall of the casing M1, along the axis direction of the casing M1, an optical cable M2 is arranged, and the optical cable M2 and the casing M1 are fixed by a fixing device. The optical cable M2 is an armored cable, and the first optical source emitting device M5 and the second optical source emitting device M4 are both fixed to the outer armor of the optical cable M2, but their fixed positions on the casing M1 are different. The second optical source emitting device M4 is arranged at the toe end of the casing M1, and the first optical source emitting device M5 is arranged at the non-toe end of the casing M1. The casing M1 is lowered through the wellhead, and the first to pass through the wellhead optical source receiving device M3 is the second optical source emitting device M4 located at the toe end of the casing M1. When the second optical source emitting device M4 passes through the optical source receiving device M3 with an angle scale, the horizontal rotation angle of the second optical source emitting device M4 is obtained, and is transmitted to the terminal through the signal transmission device. The casing M1 continues to lower, and when the first optical source emitting device M5 passes through the optical source receiving device M3 with an angle scale, the horizontal rotation angle of the first optical source emitting device M5 is obtained, and is transmitted to the terminal through the signal transmission device.

[0044] Specifically, when the first optical source emitting device M5 passes through the optical source receiving device M3 with an angle scale, the first optical source emitting device M5 will emit light rays with high light intensity, and the optical source receiving device M3 will receive the light rays. Figure 1 As shown, when the first optical source emitting device M5 passes through the optical source receiving device M3, it emits light rays ( Figure 1In the middle, the dashed line and arrow indicate the light rays), the light source receiving device M3 receives the light rays. Figure 1 In the middle, the position where the arrow arrives, i.e. the position where the light source receiving device M3 receives the light rays, the corresponding horizontal scale is the horizontal rotation angle of the first light source emitting device M5. The light source receiving device M3 obtains the corresponding horizontal scale at this position and transmits it to the terminal through the signal transmission device.

[0045] As mentioned before, the first light source receiving device M3 is the second light source emitting device M4 located at the toe end of the casing M1. When the light rays emitted by the second light source emitting device M4 located at the toe end of the casing M1 pass through the light source receiving device M3, the light rays point to a certain position, for example, 30°. Then the optical sensor at 30° in the light source receiving device M3 receives the light rays. Since the optical sensor corresponds to the angle of 30° and is in communication connection with the terminal, it records the horizontal scale as 30°, i.e. the horizontal rotation angle of the second light source emitting device M4 is 30°, and transmits it to the terminal. As the casing M1 continues to be lowered, assuming that the optical cable M2 rotates, when the first light source emitting device M5 passes through the light source receiving device M3, the light source points to a changed angle, for example, 36°. Then the optical sensor at 36° in the light source receiving device M3 receives the light rays. Since the optical sensor corresponds to the angle of 36° and is in communication connection with the terminal, it records the horizontal scale as 36°, i.e. the horizontal rotation angle of the first light source emitting device M5 is 36°, and transmits it to the terminal.

[0046] Preferably, the first light source emitting device M5 is multiple. It should be noted that several first light source emitting devices M5 are arranged along the track of the optical cable M2 in turn. More preferably, the multiple first light source emitting devices M5 are arranged at equal intervals, and the interval between two adjacent first light source emitting devices M5 is not more than 1 / 2 of the length of each section of casing. The smaller the interval, the more accurate the distribution of the optical cable M2 along the casing M1 obtained finally. It should be noted that the casing M1 is composed of multiple sections of casing, and the length of each section of casing is usually about 10 m. If the length of each section of casing is about 10 m, in order to determine whether the optical cable M2 has rotated around the outside of each section of casing, the interval between two adjacent first light source emitting devices M5 can be set to 2-3 m. With the gradual lowering of the casing M1, by recording the horizontal rotation angle of each first light source emitting device M5, the angle difference between two adjacent first light source emitting devices M5 can be calculated.

[0047] It should be noted that the rotation angle of the optical cable M2 between the two adjacent first light source emitting devices M5 does not exceed 360°. This is because the distance between the two adjacent first light source emitting devices M5 is designed according to the length of each section of the casing. In the actual casing M1 lowering process, as long as the distance between the two is not greater than 1 / 2 of the length of each section of the casing, the aforementioned situation that the rotation angle of the optical cable M2 between the two adjacent first light source emitting devices M5 exceeds 360° will not occur, the angle difference between the two adjacent first light source emitting devices M5 obtained is more accurate, and the distribution of the optical cable M2 on the surface of the casing M1 is also more accurate, and finally the accurate positioning of the optical cable M2 outside the casing M1 is achieved.

[0048] The second light source emitting device M4 is provided with a gyroscope and belongs to the combination of a gyroscope and a light source emitting device. When the second light source emitting device M4 passes through the light source receiving device M3 with an angle scale, the three-component azimuth angle and the horizontal rotation angle of the second light source emitting device M4 are recorded. Specifically, similar to the first light source emitting device M5, the second light source emitting device M4 also emits light rays with high light convergence; when the second light source emitting device M4 passes through the light source receiving device M3 with an angle scale, the horizontal rotation angle of the second light source emitting device M4 is recorded and transmitted to the terminal through a signal transmission device. By recording the horizontal rotation angle of the second light source emitting device M4 and the horizontal rotation angle of the first light source emitting device M5 that first enters the casing M1, the angle difference between the two can be calculated.

[0049] The gyroscope is used to provide the three-component azimuth angle of the second light source emitting device M4, mainly including the three-component azimuth angle when the casing M1 passes through the wellhead and the three-component azimuth angle after the casing M1 is lowered into position. When the gyroscope passes through the light source receiving device M3 for the first time, the casing M1 is suspended, the three-component azimuth angle collected by the gyroscope in the second light source emitting device M4 is obtained, and is transmitted to the terminal through the communication optical fiber reserved inside the optical cable M2. When the casing M1 is lowered to the specified depth, i.e. the optical cable M2 is no longer moving and rotating, the three-component azimuth angle collected by the gyroscope in the second light source emitting device M4 is obtained and transmitted to the terminal through the communication optical fiber reserved inside the optical cable M2. The terminal can determine the relative position of the optical cable M2 at the toe end of the casing M1 and the casing M1 through the three-component azimuth angle when the casing M1 passes through the wellhead and the three-component azimuth angle after the casing M1 is lowered into position. Among them, the three-component azimuth angle specifically refers to the three angle values of X, Y and Z directions. The gyroscope is specifically an electronic gyroscope.

[0050] Specifically, when the casing M1 passes the wellhead, the gyroscope is used to provide the three-component azimuth angle of the second light source emitting device M4 to determine the initial orientation of the toe-end gyroscope, i.e. to obtain the initial orientation of the second light source emitting device M4 and the initial relative position of the optical cable M2 and the casing M1. The three-component azimuth angle of the second light source emitting device M4 when the casing M1 passes the wellhead is very important, especially in a horizontal well, if the initial orientation is not determined, even if the three-component azimuth angle after the casing M1 is lowered is obtained, the spatial position of the optical cable M2 on the surface of the casing M1 cannot be determined. For example, if the three-component azimuth angle of the second light source emitting device M4 when the casing M1 passes the wellhead is not obtained, only the three-component azimuth angle of the second light source emitting device M4 after the casing M1 is lowered in the horizontal well is obtained, specifically: the Z component is in the positive north direction, and the X component becomes vertically directed. Then there will be two results of deduction: the optical cable M2 is directly above or below the casing M1, and finally the relative position of the optical cable M2 and the casing M1 at the toe end of the casing M1 cannot be determined. If the initial orientation of the second light source emitting device M4 is obtained when the casing M1 is lowered, the relative position of the optical cable M2 and the casing M1 at the toe end of the casing M1 can be accurately deduced accordingly.

[0051] After the casing M1 is lowered in place, the gyroscope is used to provide the three-component azimuth angle of the second light source emitting device M4 to determine the specific position of the gyroscope on the surface of the casing M1, i.e. to obtain the specific position of the second light source emitting device M4 on the surface of the casing M1 and the specific position of the toe end of the optical cable M2 on the surface of the casing M1. If in a vertical well, the specific position of the toe end of the optical cable M2 on the surface of the casing M1 is obtained; if in a horizontal well, the specific position of the toe end of the optical cable M2 on the surface of the casing M1 is obtained, i.e. above, below or on the left or right side. After the casing M1 is lowered in place, the three-component azimuth angle of the second light source emitting device M4 is also very important, if the specific position of the toe end of the optical cable M2 on the surface of the casing M1 is not determined, the specific position of the first light source emitting device M5 after entering the well cannot be determined, and the distribution of the optical cable M2 on the surface of the casing M1 cannot be deduced. It should be noted that the second light source emitting device M4 is arranged at the toe end of the casing M1 and the optical cable M2 is arranged outside the casing M1, so the "toe end of the optical cable M2" in the present application refers to the small part of the optical cable arranged at the toe end of the casing M1.

[0052] In one of the examples of the present application, when the casing M1 passes through the wellhead, the horizontal projection azimuth angle of the horizontal well trajectory is 0 degrees, and the light source receiving device M3 is perpendicular to the 0-degree azimuth of the horizontal well trajectory, and there is no azimuth difference. When the casing M1 passes through the wellhead, the first recorded three-component azimuth angle is "X: 0°, Y: 90°, Z: 0° (0° is vertically downward)". After the casing M1 is placed in position, if the second recorded three-component azimuth angle is "X: 0°, Y: 90°, Z: 70° (Z is a virtual value)", it can be inferred that the optical cable M2 is directly above the casing M1, and it can be inferred that the optical cable M2 outside the casing M1 has not been horizontally rotated. If the second recorded three-component azimuth angle is "X: 90°, Y: 180°, Z: 70° (Z is a virtual value)", it can be inferred that M2 is on the right side of the casing M1, and it can be inferred that the optical cable M2 outside the casing M1 has been horizontally rotated. It should be noted that the optical cable M2 is fixed outside the casing M1, so its Z component changes according to the direction of the casing M1, that is, the Z component is the inclination angle of the casing M1, and what we need to determine is the spatial position of the optical cable M2 outside the casing M1, so we mainly rely on the X and Y components to determine it.

[0053] The signal transmission device refers to a communication device, which is mainly used for communication between the light source receiving device M3 and the terminal, and is used for transmitting the horizontal scale of each first light source emitting device M5 recorded by the light source receiving device M3 and the horizontal scale of the second light source emitting device M4, and the three-component angle information of the second light source emitting device M4 when passing through the wellhead and when being placed in position. It should be noted that, as mentioned above, after the three-component azimuth angle is collected, the three-component azimuth angle can be transmitted to the terminal through the communication optical fiber reserved inside the optical cable M2, and the communication optical fiber belongs to part of the signal transmission device. In addition, since the light source receiving device M3 is arranged at the wellhead, the communication mode between the light source receiving device M3 and the terminal can be wired communication or wireless communication, and it is preferred that a communication cable is arranged between the light source receiving device M3 and the terminal to realize wired communication between them.

[0054] The specific embodiments of the present application are:

[0055] (1) Install the casing outside distributed optical fiber shooting avoidance device of the present application

[0056] The second light source emitting device M4 with a gyroscope is fixed to the toe end of the casing M1, specifically to the outer armor of the optical cable M2 at the toe end of the casing M1; along the length direction of the casing M1, a plurality of first light source emitting devices M5 are fixed at equal intervals to the outside of the middle segment of the casing M1, and also to the outer armor of the optical cable M2 at the outside of the middle segment of the casing M1, the interval between two adjacent first light source emitting devices M5 is 2-3 m; the light source receiving device M3 with an angle scale is installed at the wellhead.

[0057] (2) Measure the horizontal rotation angle of each first light source emitting device M5, the horizontal rotation angle of the second light source emitting device M4 and the three-component azimuth angle.

[0058] The casing M1 starts to be lowered, first, the three-component azimuth angle of the second light source emitting device M4 (with a gyroscope) and the horizontal scale when it passes through the light source receiving device M3 are recorded and transmitted to the terminal; second, the casing M1 is lowered step by step, during the lowering process of the casing M1, the casing M1 rotates, the horizontal scale when each first light source emitting device M5 passes through the wellhead light source receiving device M3 is recorded and transmitted to the terminal in turn; finally, when the casing M1 is lowered into place, the three-component azimuth angle of the gyroscope is obtained again and transmitted to the terminal.

[0059] (3) Determine the distribution of the optical cable M2 outside the casing M1

[0060] First, the terminal calculates the horizontal angle difference between the two when they are lowered according to the horizontal scale when the second light source emitting device M4 passes through the light source receiving device M3 and the horizontal scale of the first light source emitting device M5 that first enters the well.

[0061] Second, the terminal calculates the horizontal angle difference generated when the adjacent two first light source emitting devices M5 are lowered according to the horizontal scale when each first light source emitting device M5 passes through the wellhead light source receiving device M3, and obtains multiple horizontal angle differences.

[0062] Third, the terminal determines the spatial position of the toe end of the optical cable M2 by the three-component azimuth angle of the second light source emitting device M4 when the casing M1 starts to be lowered and the three-component azimuth angle of the second light source emitting device M4 when it is lowered into place.

[0063] Fourth, the terminal calculates the relative positions of the second light source emitting device M4 and each first light source emitting device M5 outside the casing M1, and further obtains the distribution of the optical cable M2 outside the casing M1, by the horizontal angle difference of the first step, the multiple horizontal angle differences of the second step and the spatial position of the toe end of the optical cable M2 of the third step.

[0064] It should be noted that the "spatial position of the toe end of the optical cable M2" refers to the specific position of the toe end of the optical cable M2 outside the casing M1, such as directly above or obliquely above the casing M1.

[0065] For example, when it is determined that the toe end of the optical cable M2 is directly above the casing M1 of the horizontal well section, the spatial angle of the toe end of the optical cable M2 relative to the casing M1 is recorded as 0° (Note: Since the optical cable M2 is fixed outside the casing M1, the Z component varies according to the direction of the casing M1, that is, the Z component is the inclination angle of the casing M1, and the spatial position of the optical cable M2 outside the casing M1 needs to be determined, so the relative position of the optical cable M2 on the surface of the casing M1 is mainly determined by the X and Y components), and the clockwise rotation angle is positive; according to the time sequence, the horizontal scale recorded by the light source receiver M3 of the second light source emitting device M4 and each first light source emitting device M5 is A1, A2,..., A n respectively. The horizontal angle difference between the second light source emitting device M4 and the first first light source emitting device M5 entering the casing M1 can be calculated, and the angle difference between two adjacent first light source emitting devices M5 is t1, t2,..., t n-1 . That is, the relative angle between the first first light source emitting device M5 entering the casing M1 and the second light source emitting device M4 is t1, the relative angle between the first two first light source emitting devices M5 entering the casing M1 is t2, and so on, and the relative angle between the last two first light source emitting devices M5 entering the casing M1 is t n-1 . In the case where the spatial position of the toe end of the optical cable M2 has been determined, the relative positions of the first light source emitting devices M5 relative to the toe end of the optical cable M2 can be obtained in sequence by the above-mentioned angle difference, and the relative positions of the optical cable M2 on the surface of the casing M1 can be obtained, and the distribution of the optical cable M2 outside the casing M1 can be simulated (as shown in Figure 2 ), so as to provide the distribution angle of the optical cable M2 when perforating at different depths.

[0066] Therefore, by using the horizontal rotation angle of the second light source emitting device M4 when passing through the wellhead, the initial three-component azimuth angle, the three-component azimuth angle after the second light source emitting device M4 is positioned, and the horizontal rotation angle of each first light source emitting device M5, the distribution of the optical cable M2 outside the casing M1 can be simulated, so as to provide the distribution angle of the optical cable M2 when perforating at different depths.

[0067] In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "connected", "connected" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0068] In the description of the present application, unless otherwise specified, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0069] The technical solution described above is only one embodiment of the present application. For those skilled in the art, on the basis of the principles disclosed in the present application, various types of improvements or modifications can be easily made, and are not limited to the technical solution described in the above specific embodiments of the present application. Therefore, the foregoing description is only preferred, and is not limiting.

Claims

1. A distribution optical fiber shoot-through device outside a casing, characterized by: The application relates to a casing-out distributed optical fiber shooting-avoiding device. The casing-out distributed optical fiber shooting-avoiding device comprises a light source emitting device, a light source receiving device and a terminal. The light source emitting device comprises a first light source emitting device arranged at a non-toe end of a casing and a second light source emitting device arranged at a toe end of the casing; the first light source emitting device is multiple; and the second light source emitting device is provided with a gyroscope. The light source receiving device is arranged at a well head; an inner wall of the light source receiving device is provided with an angle scale; and the light source receiving device is used for receiving light source signals of the first light source emitting device and the second light source emitting device and recording horizontal rotation angles of the first light source emitting device and the second light source emitting device. The terminal is respectively in communication connection with the first light source emitting device, the second light source emitting device and the light source receiving device, and is used for obtaining a relative position of an optical cable outside the casing.

2. The casing-out distributed optical fiber shooting-avoiding device according to claim 1, wherein the light source receiving device is in a circular ring shape, an inner diameter of the light source receiving device is greater than an outer diameter of the casing; and an inner wall of the light source receiving device is provided with multiple optical sensors which are arranged at a same horizontal line and are equidistantly arranged; and the multiple optical sensors are all used for receiving the light source signals of the first light source emitting device and the second light source emitting device and recording the horizontal rotation angles of the first light source emitting device and the second light source emitting device.

3. The casing-out distributed optical fiber shooting-avoiding device according to claim 1, wherein the multiple first light source emitting devices are equidistantly arranged along a length direction of the casing.

4. The casing-out distributed optical fiber shooting-avoiding device according to claim 3, wherein a spacing between two adjacent first light source emitting devices is not greater than 1 / 2 of a length of each casing section.

5. The casing-out distributed optical fiber shooting-avoiding device according to claim 1, wherein a communication mode of the second light source emitting device and the terminal is wired communication.

6. The casing-out distributed optical fiber shooting-avoiding device according to claim 5, wherein the second light source emitting device and the terminal are in communication connection through a communication optical fiber reserved inside an optical cable.

7. The casing-out distributed optical fiber shooting-avoiding device according to claim 1, wherein a communication mode of the light source receiving device and the terminal is wired communication or wireless communication.

8. The casing-out distributed optical fiber shooting-avoiding device according to claim 7, wherein the communication mode of the light source receiving device and the terminal is wired communication. The method comprises S1: installing the casing-out distributed optical fiber shooting-avoiding device according to any one of claims 1 to 8; S2: starting to lower the casing, obtaining a horizontal rotation angle and a three-component azimuth angle of the second light source emitting device, and transmitting the horizontal rotation angle and the three-component azimuth angle to the terminal; S3: gradually lowering the casing, obtaining horizontal rotation angles of the first light source emitting devices, and sequentially transmitting the horizontal rotation angles to the terminal; S4: lowering the casing to a position, again obtaining a three-component azimuth angle of the second light source emitting device, and transmitting the three-component azimuth angle to the terminal; S5: determining a relative position of the optical cable outside the casing according to the horizontal rotation angle and the three-component azimuth angle of the second light source emitting device in S2, the horizontal rotation angles of the first light source emitting devices in S3, and the three-component azimuth angle of the second light source emitting device in S4.

9. An out-of-casing distributed optical fiber shot-avoidance method, characterized by: ​ ​ ​ ​ ​ ​ 10. The outside casing distributed optical fiber anti-shooting method according to claim 9, characterized in that: In step S1, S11: install the second light source emitting device at the toe end of the casing; S12: install each first light source emitting device at the outer side of the middle section of the casing along the length direction of the casing; S13: install the light source receiving device at the wellhead.

11. The outside casing distributed fiber launch avoidance method of claim 10, wherein: In step S12, Each first light source emitting device is arranged at equal intervals, and the interval between two adjacent first light source emitting devices is not greater than 1 / 2 of the length of each section of the casing.

12. The outside casing distributed fiber launch avoidance method of claim 9, wherein: In step S5, S51: calculate the horizontal angle difference between the second light source emitting device in S2 and the first light source emitting device entering the well first in S3 according to the horizontal rotation angle of the second light source emitting device in S2 and the horizontal rotation angle of the first light source emitting device in S3; S52: calculate the horizontal angle difference between two adjacent first light source emitting devices according to the horizontal rotation angle of each first light source emitting device in S3, and obtain multiple horizontal angle differences; S53: determine the spatial position of the toe end of the optical cable according to the three-component azimuth angle of the second light source emitting device in S2 and the three-component azimuth angle of the second light source emitting device in S4; S54: calculate the relative position of the optical cable outside the casing according to the horizontal angle difference in S51, the multiple horizontal angle differences in S52, and the spatial position of the toe end of the optical cable in S53.

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