Distributed optical fiber ray avoiding device and method outside sleeve

Abstract

The invention provides a distributed optical fiber ray avoiding device outside a sleeve. The distributed optical fiber ray avoiding device comprises a terminal, a light source emitting device and a light source receiving device, the light source emitting device comprises a first light source emitting device arranged at the non-toe end of the sleeve and a second light source emitting device arranged at the toe end of the sleeve; a gyroscope is arranged on the second light source emitting device; the light source receiving device is arranged at the wellhead and provided with angle scales on the inner wall for recording the horizontal rotation angle of the light source emitting device; the terminal is used for obtaining the relative position of the optical cable outside the sleeve. The distribution condition of the optical cable outside the sleeve can be obtained through the horizontal angle difference generated in the lowering process of the optical cable and the relative position of the optical cable at the toe end of the sleeve and the sleeve when and after the sleeve is lowered, so that a basis is provided for perforation construction, damage to the optical cable caused by perforation is avoided, the observation length of the optical cable is guaranteed, and the construction cost is reduced. And fiber utilization rate is improved. In addition, the invention also provides a distributed optical fiber shielding method outside the sleeve.

Description

Technical Field

[0001] The invention belongs to the field of geophysical exploration seismic data collection and processing, and specifically relates to a casing outer distributed optical fiber radiation avoidance device and method, which is used for downhole microseismic monitoring during oil and gas well fracturing. Background Art

[0002] In recent years, with the breakthrough innovation of oil and gas geological theory and the progress of engineering technology, China has made major breakthroughs in the exploration and development of continental shale oil and gas and tight oil and gas. Hydraulic fracturing is an essential technology for transforming unconventional oil and gas reservoirs and increasing the production of single wells. In order to achieve safe and efficient fracturing, seismic detectors are usually used for microseismic monitoring and fracturing effect evaluation. In general, the number of geophones in the well is small and the acquisition azimuth is narrow, making it difficult to obtain accurate microseismic source locations, resulting in an inability to accurately evaluate reservoir transformation.

[0003] Distributed fiber optic monitoring technology has gradually become the mainstream mode of hydraulic fracturing detection due to its unique advantages. At present, the distributed fiber optic sensors used in hydraulic fracturing monitoring mainly include distributed temperature sensing (DTS), distributed acoustic sensing (DAS) and distributed strain sensing via Rayleigh Frequency Shift (DSS-RFS). They were first put into field application in hydraulic fracturing monitoring in 2006, 2014 and 2021, respectively. The physical quantities monitored have evolved from the initial temperature to acoustic waves (vibration) and strain signals, which can more directly reflect the crack expansion and crack impact in the hydraulic fracturing process. It can also monitor the transient strain at the perforation holes when the well is switched on and off during the post-fracturing production process to evaluate the degree of crack opening (closing), which is mutually verified with the crack monitoring of the fracturing process. As the latest developed distributed optical fiber sensing technology, distributed optical fiber acoustic wave sensing technology has been applied to hydraulic fracturing monitoring of shale and tight sandstone reservoirs in recent years, and has achieved good results.

[0004] Distributed fiber optic acoustic wave sensing technology mainly realizes distributed acoustic wave sensing based on horizontal well fiber optic by permanently laying optical fiber outside the casing of horizontal wells in shale gas reservoirs. However, it is precisely because the optical fiber is fixed outside the casing and the casing often rotates horizontally during the process of lowering into the well, causing the optical cable to deform outside the casing, which makes it impossible to determine the specific distribution of the optical cable outside the casing, that is, it is impossible to determine the relative position relationship between the optical cable and the casing. Therefore, it is impossible to avoid the optical fiber during perforation construction, which often causes the optical fiber to break, resulting in a reduction in the length of the optical fiber observation section, affecting the microseismic acquisition effect. Therefore, before perforating, it is necessary to locate the optical fiber, and select the perforation angle based on the positioning result to avoid damage to the optical fiber. The commonly used methods currently include: using logging tools to detect the fixture that fixes the optical fiber to the casing and the beacon positioning device. This method can determine the lowering position of the optical cable, but it cannot determine the distribution of the optical cable attached to the outer layer of the casing, and the success rate of avoiding perforation is low.

[0005] CN112068267A relates to a method and system for avoiding radiation of downhole casing optical cables. The position information of the optical cable on the circumference of the casing is obtained by combining the optical cable's own acquisition information with a positioning device, mainly the light source reception and temperature information of the optical cable itself. This technology is greatly affected by factors such as cementing quality, and positioning is prone to errors. CN111425188A relates to a casing outer armored optical cable orientation 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 optical cable angle difference between two adjacent sound source transmitters is not greater than 360°, that is, the optical cable's rotation outside the casing is less than one circle; however, during the casing lowering process, the casing often rotates, and it is difficult to ensure that the casing rotation angle is less than 360°. Under such conditions, the method based on the variable frequency sound source has a large error, and it is difficult to achieve 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 avoidance, reducing optical fiber loss, and reducing construction costs. Summary of the invention

[0007] The purpose of the present invention is to solve the difficulties existing in the above-mentioned prior art, and to provide a distributed optical fiber radiation avoidance device outside the casing, wherein the second light source emitting device is fixed at the toe end of the casing, and multiple first light source emitting devices are fixed at the non-toe end of the outer side of the casing, and are lowered together with the optical cable, and the second light source emitting device at the toe end of the casing is used to obtain the initial three-component azimuth of the optical cable and the three-component azimuth after the optical cable is lowered, and the light source receiving device at the wellhead is used to record the horizontal rotation angle of the second light source emitting device and each first light source emitting device, and finally obtain 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 to the distributed optical fiber caused by the perforation construction, improving the success rate of the distributed optical fiber radiation avoidance, reducing the construction cost of the distributed optical fiber, and improving the utilization rate of the optical fiber. The "three-component azimuth" in this section refers to the specific orientation of the second light source emitting device on the casing surface, and the specific orientation of the optical cable at the position of the second light source emitting device on the casing surface, that is, the three angle values ​​in the X, Y, and Z directions.

[0008] The present invention is achieved through the following technical solutions:

[0009] One of the purposes of the present invention is to provide a distributed optical fiber radiation avoidance device outside a casing, 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; the second light source emitting device is provided with a gyroscope;

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

[0012] The terminal is respectively connected to the light source transmitting device and the light source receiving device for communication, and is used to obtain the relative position of the optical cable outside the casing.

[0013] In a preferred embodiment of the present invention, the light source receiving device is in a circular shape, and its inner diameter is larger than the outer diameter of the sleeve; the inner circle of the light source receiving device is provided with a plurality of optical sensors arranged at equal intervals, and the plurality of optical sensors are used to receive the light source signals of the first light source emitting device and the second light source emitting device and record their horizontal rotation angles.

[0014] In a preferred embodiment of the present invention, there are multiple first light source emitting devices, and the multiple first light source emitting devices are arranged at equal intervals along the length direction of the sleeve.

[0015] In a preferred embodiment of the present invention, the distance between two adjacent first light source emitting devices is no greater than 1 / 2 of the length of each section of the sleeve.

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

[0017] In a preferred embodiment of the present invention, 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 invention is to provide a method for avoiding radiation of a distributed optical fiber outside a casing, which is implemented by using the distributed optical fiber avoiding radiation of the first object of the present invention. The method includes

[0019] S1: Installing the outer-tube distributed optical fiber radiation avoidance device described in one of the purposes of the present invention;

[0020] S2: The casing starts to be lowered, and the horizontal rotation angle and three-component azimuth angle of the second light source emitting device are obtained and transmitted to the terminal;

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

[0022] S4: The casing is lowered into place, and the three-component azimuth angle of the second light source emitting device is obtained again and transmitted to the terminal;

[0023] S5: Determine the relative position of the optical cable outside the casing according to the horizontal rotation angle and 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 invention, in step S1,

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

[0026] S12: installing the first light source emitting devices in sequence on the outer side of the middle section of the sleeve along the length direction of the sleeve;

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

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

[0029] The first light source emitting devices are arranged at equal intervals, and the interval between two adjacent first light source emitting devices is no greater than 1 / 2 of the length of each section of the sleeve.

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

[0031] S51: Calculate the horizontal angle difference between the two when they are lowered 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 that first enters the well in S3;

[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: determining the spatial position of the toe end of the optical cable by using 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 multiple 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 present invention has the following beneficial effects:

[0036] The present invention uses a plurality of first light source emitting devices fixed on the outside of the casing to obtain the horizontal angle difference generated by the optical cable during the lowering process, as well as the relative position relationship between the optical cable at the toe end of the casing and the casing when and after the casing is lowered, and transmits them to the terminal, so as to accurately display the distribution of the optical cable outside the casing, thereby providing a basis for the azimuth rotation of the perforation construction, avoiding damage to the optical cable caused by perforation, ensuring the observation length of the optical cable, reducing construction costs, and improving the utilization rate of optical fibers. In addition, the present invention uses a high-density light source emitting device for measurement, and the light source emitting device can use a device with high beam properties such as laser or laser light, which is relatively low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the main structure of the distributed optical fiber radiation avoidance device outside the casing of the present invention;

[0038] Figure 2 The figure is a schematic diagram of the distribution of the optical cable outside the casing obtained by using the distributed optical fiber radiation avoidance method outside the casing of the present invention.

[0039] In the figure, M1-sleeve; M2-optical cable; M3-light source receiving device with angle scale; M4-second light source emitting device; M5-first light source emitting device. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0041] like Figure 1As shown, the outer-casing distributed optical fiber radiation avoidance device of the present invention is arranged outside the casing M1, and includes a light source receiving device M3 with an angle scale, a light source sending device and a signal transmission device. Among them, the light source sending device includes a first light source emitting device M5 and a second light source emitting device M4. Specifically, the light source receiving device M3 with an angle scale is in a circular ring shape, and its inner wall is provided with an angle scale, and its outer wall is installed at the wellhead. The angle scale on the inner wall of the light source receiving device M3 is 0 to 360°. The inner diameter of the light source receiving device M3 with an angle scale is larger 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 of the inner wall of the light source receiving device M3 of the present invention is 0-360°. On the same horizontal line, 360 optical sensors are evenly spaced along the inner wall of the light source receiving device M3. Each optical sensor corresponds to a different angle. The angle difference between two adjacent optical sensors is 1°. Each optical sensor is connected to the terminal for communication. However, this does not constitute a limitation to the present invention. In actual application, technicians can set the number of optical sensors according to actual conditions. For example, 240 optical sensors can be set, and the angle difference between two adjacent optical sensors is 1.5°; 180 optical sensors can also be set, and the angle difference between two adjacent optical sensors is 2°.

[0043] An optical cable M2 is provided on the outer wall of the casing M1 and along the axial direction of the casing M1, 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 light source emitting device M5 and the second light source emitting device M4 are both fixed to the outer armor of the optical cable M2, but the fixing positions of the two on the casing M1 are different. The second light source emitting device M4 is arranged at the toe end of the casing M1, and the first light 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 light source emitting device M4 located at the toe end of the casing M1 passes through the wellhead light source receiving device M3. 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 obtained and transmitted to the terminal through the signal transmission device. The casing M1 continues to be lowered, and when the first light source emitting device M5 passes through the light source receiving device M3 with an angle scale, the horizontal rotation angle of the first light source emitting device M5 is obtained and transmitted to the terminal through the signal transmission device.

[0044] Specifically, when the first light source emitting device M5 passes through the light source receiving device M3 with an angle scale, the first light source emitting device M5 will emit a light ray with high light concentration, and the light source receiving device M3 will receive the light ray. Figure 1 As shown, when the first light source emitting device M5 passes through the light source receiving device M3, it emits a light ray ( Figure 1In the figure, the dotted line and the arrow indicate a light ray), and the light source receiving device M3 receives the light ray. Figure 1 In the figure, the position reached by the arrow is the position where the light source receiving device M3 receives the light ray, and the horizontal scale corresponding to the position is the horizontal rotation angle of the first light source emitting device M5. The light source receiving device M3 obtains the horizontal scale corresponding to the position and transmits it to the terminal through the signal transmission device.

[0045] As mentioned above, the first light to pass through the wellhead 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 ray emitted by the second light source emitting device M4 located at the toe end of the casing M1 passes through the light source receiving device M3, the light ray points to a certain position, for example, 30°. Then, the optical sensor located at 30° in the light source receiving device M3 receives the light ray. Since the optical sensor corresponds to an angle of 30° and is communicatively connected to the terminal, its horizontal scale is recorded as 30°, that is, the horizontal rotation angle of the second light source emitting device M4 is 30°, and is transmitted to the terminal. As the sleeve M1 continues to be lowered, assuming that the optical cable M2 rotates, the angle of the light source pointing of the first light source emitting device M5 changes when it passes through the light source receiving device M3. For example, the angle is changed to 36°. Then, the optical sensor at 36° in the light source receiving device M3 receives the light ray. Since the optical sensor corresponds to an angle of 36° and is connected to the terminal for communication, its horizontal scale is recorded as 36°, that is, the horizontal rotation angle of the first light source emitting device M5 is 36°, and is transmitted to the terminal.

[0046] Preferably, there are multiple first light source emitting devices M5. It should be noted that several first light source emitting devices M5 are arranged in sequence along the trajectory of the optical cable M2. More preferably, 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 greater than 1 / 2 of the length of each section of the casing. The smaller the interval, the more accurate the distribution of the optical cable M2 along the casing M1 is. It should be noted that the casing M1 is composed of multiple sections of casing, and each section of the casing is usually about 10m long. If the length of each section of the casing is about 10m, in order to determine whether the optical cable M2 has been swung outside each section of the casing, the interval between two adjacent first light source emitting devices M5 can be set to 2 to 3m. As the casing M1 is gradually lowered, the angle difference between two adjacent first light source emitting devices M5 can be calculated by recording the horizontal rotation angle of each first light source emitting device M5.

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

[0048] The second light source emitting device M4 is equipped with a gyroscope, and is a combination of a gyroscope and a light source emitting device. When the second light source emitting device M4 passes through a 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 concentration; when the second light source emitting device M4 passes through a 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 sleeve 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 after the casing M1 is lowered into place. 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 the three-component azimuth angle is transmitted to the terminal through the reserved communication optical fiber inside the optical cable M2. When the casing M1 is lowered to the specified depth, that is, when the optical cable M2 no longer moves and rotates, the three-component azimuth angle collected by the gyroscope in the second light source emitting device M4 is obtained, and the three-component azimuth angle is transmitted to the terminal through the reserved communication optical fiber inside the optical cable M2. The terminal can determine the relative position of the optical cable M2 and the casing M1 at the toe end of the casing M1 through the three-component azimuth angle when the casing M1 passes through the wellhead and after the casing M1 is lowered into place. Among them, the three-component azimuth angle specifically refers to the three angle values ​​in the X, Y, and Z directions. The gyroscope is specifically an electronic gyroscope.

[0050] Specifically, when the casing M1 passes through 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 gyroscope, that is, 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 through the wellhead is very important, especially in horizontal wells. If the initial orientation is not determined, even if the three-component 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, the three-component azimuth angle of the second light source emitting device M4 when the casing M1 passes through the wellhead is not obtained, and only the three-component azimuth angle of the second light source emitting device M4 after the casing M1 is lowered into place in the horizontal well is obtained, specifically: the Z component is due north, and the X component becomes vertical. Then there will be two results of the deduction: the optical cable M2 is directly above or directly below the casing M1, and ultimately the relative position of the optical cable M2 and the casing M1 at the toe of the casing M1 cannot be determined at all. If the initial orientation of the second light source emitting device M4 is obtained when the sleeve M1 is lowered, the relative position of the optical cable M2 at the toe end of the sleeve M1 and the sleeve M1 can be accurately deduced based on the initial orientation.

[0051] After the casing M1 is lowered into 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, that is, 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 above, below or on the left and right sides of the casing M1 surface is obtained. After the casing M1 is lowered into 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 emitter M5 adjacent to it after entering the well cannot be determined, and thus the distribution of the optical cable M2 on the surface of the casing M1 cannot be superimposed and deduced. It should be noted that the second light source emitting device M4 is arranged at the toe end of the sleeve M1 and the optical cable M2 is arranged outside the sleeve M1, so the "toe end of the optical cable M2" in the present invention refers to the small part of the optical cable arranged at the toe end of the sleeve M1.

[0052] In one of the examples of the present invention, when the casing M1 passes through the wellhead, taking the direction of the horizontal well trajectory (horizontal projection azimuth angle) as 0 degrees and the vertical 0-degree azimuth of the light source receiving device M3 and the horizontal well trajectory 0 degrees as an example, when the casing M1 passes through the wellhead, the three-component azimuth angle recorded for the first time is "X: 0°, Y: 90°, Z: 0° (vertically set to 0° downward)". After the casing M1 is lowered into place, if the three-component azimuth angle recorded for the second time 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 then it can be inferred that the optical cable M2 outside the casing M1 has not rotated horizontally. If the three-component azimuth angle recorded for the second time is "X: 90°, Y: 180°, Z: 70° (Z is a virtual value)", it can be inferred that M2 is on the right side outside the casing M1, and then it can be inferred that the optical cable M2 outside the casing M1 has rotated horizontally. 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 it is mainly determined by the X and Y components.

[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 to transmit the horizontal scales of each first light source emitting device M5 and the horizontal scales of the second light source emitting device M4 recorded by the light source receiving device M3, and the three-component angle information of the second light source emitting device M4 when passing through the wellhead and after being lowered into place. 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 is part of the signal transmission device. In addition, since the light source receiving device M3 is set at the wellhead, the communication method between the light source receiving device M3 and the terminal can be either wired communication or wireless communication. Preferably, a communication cable is set between the light source receiving device M3 and the terminal to realize wired communication between the two.

[0054] The specific implementation of the present invention is:

[0055] (1) Installing the outer-tube distributed optical fiber radiation avoidance device of the present invention

[0056] A 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 number of first light source emitting devices M5 are fixed at equal intervals to the outside of the middle section of the casing M1, and are also fixed to the outer armor of the optical cable M2 outside the middle section of the casing M1, and the interval between two adjacent first light source emitting devices M5 is 2 to 3 m; a 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. Secondly, the casing M1 is lowered step by step. During the lowering process of the casing M1, the casing M1 rotates. The horizontal scale of each first light source emitting device M5 when it passes through the wellhead light source receiving device M3 is recorded and transmitted to the terminal in sequence. 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 optical cable M2 outside casing M1

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

[0061] In the second step, the terminal calculates the horizontal angle difference generated when two adjacent 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] In the third step, the spatial position of the toe end of the optical cable M2 is determined by the three-component azimuth angle of the second light source emitting device M4 when the terminal starts to be lowered through the sleeve M1 and the three-component azimuth angle of the second light source emitting device M4 after being lowered into place.

[0063] In the fourth step, 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 through the horizontal angle difference in the first step, the multiple horizontal angle differences in the second step and the spatial position of the toe end of the optical cable M2 in the third step, and then obtains the distribution of the optical cable M2 outside the casing M1.

[0064] It should be noted that the above-mentioned “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 the specific position 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, its spatial angle relative to the casing M1 is recorded as 0° (Note: Since the optical cable M2 is fixed outside the casing M1, 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 needs to be determined is the spatial position of the optical cable M2 outside the casing M1, so the relative position of the optical cable M2 to the surface of the casing M1 is mainly determined by the X and Y components), with the clockwise rotation angle being positive; according to the recording time sequence, the horizontal scales of the second light source transmitting device M4 and each first light source transmitting device M5 recorded by the light source receiver M3 are A1, A2...A n , the horizontal angle difference between the second light source emitting device M4 and the first light source emitting device M5 entering the sleeve 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 light source emitter M5 entering the sleeve M1 and the second light source emitter M4 is t1, the relative angle between the first two first light source emitters M5 entering the sleeve M1 is t2, and so on, the relative angle between the last two first light source emitters M5 entering the sleeve M1 is t n-1 When the spatial position of the toe end of the optical cable M2 is determined, the relative position of each first light source transmitter M5 relative to the toe end of the optical cable M2 can be obtained in turn through the above angle difference, and then the relative position of the full-well section optical cable M2 on the outer surface of the casing M1 can be obtained, and the distribution of the full-well section optical cable M2 outside the casing M1 can be simulated (such as Figure 2 As shown), the distribution angle of the optical cable M2 is provided when perforating construction is performed at different depths.

[0066] It can be seen from this that by utilizing 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 in place, and the horizontal rotation angle of each first light source emitter M5, the distribution of the optical cable M2 outside the casing M1 can be simulated, thereby providing the distribution angle of the optical cable M2 when performing perforating construction at different depths.

[0067] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] In the description of the present invention, unless otherwise specified, the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0069] The above technical solution is only one implementation mode of the present invention. For those skilled in the art, it is easy to make various types of improvements or modifications based on the principles disclosed in the present invention, and it is not limited to the technical solution described in the above specific embodiments of the present invention. Therefore, the above description is only preferred and does not have a restrictive meaning.

Claims

1. A distributed optical fiber radiation avoidance device outside the casing, characterized in that: include: 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; the second light source emitting device is provided with a gyroscope; A light source receiving device is arranged at the wellhead, and an angle scale is arranged on the inner wall of the light source receiving device; the light source receiving device is used to receive the light source signals of the first light source emitting device and the second light source emitting device and record the horizontal rotation angle thereof; The terminal is respectively connected to the light source transmitting device and the light source receiving device for communication, and is used to obtain the relative position of the optical cable outside the casing.

2. The distributed optical fiber radiation avoidance device outside the casing according to claim 1, characterized in that: The light source receiving device is in a circular shape, and its inner diameter is larger than the outer diameter of the sleeve; the inner wall of the light source receiving device is provided with a plurality of optical sensors which are on the same horizontal line and arranged at equal intervals, and the plurality of optical sensors are used to receive the light source signals of the first light source emitting device and the second light source emitting device and record their horizontal rotation angles.

3. The distributed optical fiber radiation avoidance device outside the casing according to claim 1, characterized in that: There are multiple first light source emitting devices, and the multiple first light source emitting devices are arranged at equal intervals along the length direction of the sleeve.

4. The distributed optical fiber radiation avoidance device outside the casing according to claim 3, characterized in that: The distance between two adjacent first light source emitting devices is no greater than 1 / 2 of the length of each section of the sleeve.

5. The distributed optical fiber radiation avoidance device outside the casing according to claim 1, characterized in that: The communication mode between the second light source emitting device and the terminal is wired communication, preferably a communication connection through a communication optical fiber reserved inside an optical cable.

6. The distributed optical fiber radiation avoidance device outside the casing according to claim 1, characterized in that: The communication mode between the light source receiving device and the terminal is wired communication or wireless communication, preferably wired communication.

7. A method for avoiding radiation of distributed optical fiber outside a casing, characterized in that: The method comprises S1: Install the distributed optical fiber radiation avoidance device outside the casing according to any one of claims 1 to 6; S2: The casing starts to be lowered, and the horizontal rotation angle and three-component azimuth angle of the second light source emitting device are obtained and transmitted to the terminal; S3: lowering the casing step by step, obtaining the horizontal rotation angle of each first light source emitting device, and transmitting it to the terminal in sequence; S4: The casing is lowered into place, and the three-component azimuth angle of the second light source emitting device is obtained again and transmitted to the terminal; S5: Determine the relative position of the optical cable outside the casing according to the horizontal rotation angle and 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.

8. The method for avoiding radiation of distributed optical fiber outside the casing according to claim 7, characterized in that: In step S1, S11: Install the second light source emitting device at the toe end of the casing; S12: installing the first light source emitting devices in sequence on the outer side of the middle section of the sleeve along the length direction of the sleeve; S13: Install the light source receiving device at the wellhead.

9. The method for avoiding radiation of distributed optical fiber outside the casing according to claim 8, characterized in that: In step S12, The first light source emitting devices are arranged at equal intervals, and the interval between two adjacent first light source emitting devices is no greater than 1 / 2 of the length of each section of the sleeve.

10. The method for avoiding radiation of distributed optical fiber outside the casing according to claim 7, characterized in that: In step S5, S51: Calculate the horizontal angle difference between the two when they are lowered 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 that first enters the well in S3; 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; S53: determining the spatial position of the toe end of the optical cable by using 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: The relative position of the optical cable outside the casing is calculated through 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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