Detection devices and methods for in-well tracers

Abstract

This application relates to the measurement of in-well fracturing parameters using radioactive tracers, specifically to a tracer detection device and method. The detection device includes a radiation detector and a gyroscope. The radiation detector comprises a housing and multiple detection crystals. The housing is configured to form a chamber, and the multiple detection crystals are disposed within the chamber. At least two detection crystals are positioned facing different circumferential directions of the housing to detect radiation emitted by the tracer in different circumferential directions within the well. The gyroscope is used to determine the orientation of each detection crystal within the well. The detection device provided in this application, by changing the arrangement of the detection crystals so that at least two detection crystals face different circumferential directions of the housing, enables the detection crystals to detect radiation emitted by the tracer in different circumferential directions, thereby determining the distribution of the tracer in different circumferential directions within the well.

Description

Technical Field

[0001] The embodiments of this application relate to measuring in-well fracturing parameters using radioactive tracers, specifically relating to an in-well tracer detection device and detection method. Background Technology

[0002] The statements herein are provided merely as background information in connection with this application and do not necessarily constitute prior art.

[0003] The technology of monitoring fractures with radioactive tracers in oilfields is a commonly used near-wellbore fracture monitoring technology. This technology involves injecting radioactive tracers into oilfield fractures and determining the distribution of the tracers by detecting the rays emitted by the tracers, thereby obtaining relevant data on oilfield fracturing. Summary of the Invention

[0004] A brief overview of this application is provided below to offer a basic understanding of certain aspects thereof. It should be understood that this overview is not an exhaustive summary of the application. It is not intended to identify key or essential parts of the application, nor is it intended to limit its scope. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0005] In a first aspect, embodiments of this application provide a wellbore tracer detection device, comprising a radiation detector and a gyroscope. The radiation detector includes a housing and a plurality of detection crystals, the housing being configured to form a chamber; the plurality of detection crystals are disposed within the chamber, wherein at least two detection crystals are positioned facing different circumferential directions of the housing to detect radiation emitted by the tracer in different circumferential directions within the well. The gyroscope is used to determine the orientation of the plurality of detection crystals within the well.

[0006] Secondly, embodiments of this application provide a method for detecting tracers in a well, comprising: placing the device of the first aspect of this application in a well and lowering it to an initial detection position, wherein multiple detection crystals are at different heights; determining the orientation of each detection crystal in the well; uniformly pulling the device upward from the initial detection position while recording the data detected by the multiple detection crystals, thereby obtaining detection data of the time change corresponding to each detection crystal; obtaining detection data of the depth change corresponding to each detection crystal in the well based on the initial detection position, the pulling speed, and the height of each detection crystal; thereby determining the distribution of the tracer at different depths in the well.

[0007] The detection device provided in the embodiments of this application changes the arrangement of the detection crystals so that at least two detection crystals face different circumferential directions of the shell, thereby enabling the detection crystals facing different circumferential directions of the shell to detect the rays emitted by the tracer in different circumferential directions, and thus to determine the distribution of the tracer in different circumferential directions in the well. Attached Figure Description

[0008] Other objects and advantages of this application will become apparent from the following description of embodiments of this application with reference to the accompanying drawings, and will help to provide a comprehensive understanding of this application.

[0009] Figure 1 This is a disassembled schematic diagram of a detection device according to an embodiment of this application.

[0010] Figure 2 This is a disassembly diagram of the radiation detector of the detection device according to an embodiment of this application.

[0011] Figure 3 This is a schematic diagram of the shielding component and the detector crystal assembled according to an embodiment of this application.

[0012] Figure 4 This is a schematic diagram of the structure of the detection crystal and support component of the X-ray detector of the detection device according to an embodiment of this application.

[0013] Figure 5 This is a schematic diagram of the structure of the ray detector of the detection device according to an embodiment of this application after the detection crystal and support are assembled.

[0014] Figure 6 This is a top view of the detection crystal and support of the X-ray detector of the detection device according to an embodiment of this application.

[0015] Figure 7 This is a schematic diagram of the detection device according to another embodiment of this application.

[0016] Figure 8 This is a schematic diagram of the detection device according to another embodiment of this application.

[0017] Figure 9 The diagram schematically illustrates the distribution curves of the tracer over time detected by two detector crystals at different heights in the detection device of an embodiment of this application.

[0018] Figure 10 It shows that Figure 9 The distribution curve of the tracer over time is converted into the distribution curve of the tracer over depth in the well.

[0019] Explanation of reference numerals in the attached figures:

[0020] 1000. Detection device;

[0021] 100. X-ray detector; 10. Housing; 11. Chamber; 20. Detector crystal; 30. Shielding component; 40. Support component; 41. Connecting part; 50. Cover component;

[0022] 200. Gyroscope; 300. Magnetic positioning component; 400. Temperature and pressure detection component; 500. Data transmission component; 600. Storage component; 700. Power supply component.

[0023] It should be noted that the accompanying drawings are not necessarily drawn to scale, but are shown only in a schematic manner without affecting the reader's understanding. Detailed Implementation

[0024] Exemplary embodiments of this application will be described below with reference to the accompanying drawings. For clarity and brevity, not all features of actual implementations are described in the specification. However, it should be understood that many implementation-specific decisions must be made in the development of any such actual embodiment to achieve the developer's specific goals, such as complying with constraints related to the system and business, and these constraints may vary depending on the implementation. Furthermore, it should be understood that while development work can be very complex and time-consuming, such development work is merely a routine task for those skilled in the art who benefit from the content of this application.

[0025] It should also be noted that, in order to avoid obscuring this application with unnecessary details, only the equipment structure and / or processing steps closely related to the solution according to this application are shown in the accompanying drawings, while other details that are not closely related to this application are omitted.

[0026] In related technologies, the distribution of tracers is detected using a logging tool placed inside the well (bore). However, the logging tool can only detect all rays emitted by the tracer within a 360° circumferential range at any depth location, and cannot determine the circumferential distribution of the tracer at any depth location. Therefore, it cannot distinguish the tracer content and fracture opening direction in different circumferential directions within the well. In other words, related technologies cannot distinguish the circumferential distribution of the tracer at any depth in the well.

[0027] Therefore, embodiments of this application provide a device and method for detecting in-well tracers.

[0028] like Figure 1 The diagram shown illustrates a disassembled schematic of a detection device according to an embodiment of this application. This embodiment provides a wellbore tracer detection device 1000, which includes a radiation detector 100 and a gyroscope 200. As shown... Figure 1 and Figure 2As shown, the radiation detector 100 includes a housing 10 and a plurality of detection crystals 20. The housing 10 is configured to form a chamber 11. The plurality of detection crystals 20 are disposed within the chamber 11, wherein at least two detection crystals 20 are positioned facing different circumferential directions of the housing 10 to detect radiation emitted by tracers in different circumferential directions within the well. A gyroscope 200 is used to determine the orientation of the plurality of detection crystals 20 within the well.

[0029] The detection device 1000 provided in the embodiments of this application changes the arrangement of the detection crystals 20 so that at least two detection crystals 20 face different circumferential directions of the housing 10. This allows the detection crystals 20 facing different circumferential directions of the housing 10 to detect the rays emitted by the tracer in different circumferential directions, thereby determining the distribution of the tracer in different circumferential directions and thus determining the direction of the crack opening.

[0030] In some embodiments, any two detector crystals 20 are configured to face different circumferential directions of the housing 10, so that each detector crystal 20 can be used to detect tracers in different circumferential directions within the well.

[0031] In some embodiments, each detector crystal 20 is located at a different height; in other words, any two detector crystals 20 are located at different heights within the housing 10 to avoid different detector crystals 20 detecting rays emitted by the tracer at the same location, thus affecting the determination of the tracer distribution direction. In some embodiments, the height difference between two adjacent detector crystals 20 in the height direction can be 3cm-10cm, for example, 5cm.

[0032] In some embodiments, a plurality of detector crystals 20 may be spirally arranged within the housing 10. The angle between the detection directions (i.e., the directions that the detector crystals 20 face) of two adjacent detector crystals 20 may be 36°-90°, for example 45°.

[0033] In some embodiments, a plurality of detector crystals 20 are spirally arranged at equal intervals within the housing 10, that is, the height difference between two adjacent detector crystals 20 is the same, and the horizontal spacing is the same.

[0034] In some embodiments, the upper end of the housing 10 may have an opening, through which a plurality of detection crystals 20 may be inserted into the chamber 11. In some embodiments, the housing 10 may be cylindrical.

[0035] The outer diameter of the casing 10 can be 40mm-50mm, for example, 43mm. This configuration can meet the requirements of in-tubing logging, is suitable for logging in production conditions, is also suitable for horizontal well logging with the detection device 1000 carried by coiled tubing, and is also suitable for logging with larger diameter casing.

[0036] In some embodiments, the X-ray detector 100 may also include a cover 50, which may be disposed at the upper end of the housing 10 to close the opening at the upper end of the housing 10, thereby preventing impurities in the well from falling into the chamber 11 and affecting the normal use of the detector crystal 20.

[0037] In some embodiments, the number of detector crystals 20 can be 2-10, for example, 8.

[0038] In some embodiments, each probe crystal 20 is disposed adjacent to the peripheral wall of the chamber 11 (i.e., there is a gap between the probe crystal 20 and the peripheral wall of the chamber 11). In some embodiments, the width of the gap can be 1 mm to 5 mm, for example, 3 mm.

[0039] In some embodiments, the detector crystal 20 can be cadmium zinc telluride. Cadmium zinc telluride has the advantages of small size and high efficiency. Good detection effect can be achieved with a small volume of cadmium zinc telluride, which makes it easy to arrange multiple detector crystals 20 facing different circumferential directions of the housing 10 of the X-ray detector 100.

[0040] In some embodiments, a cubic cadmium zinc telluride crystal 20 can be selected as the detector crystal. The side length of the cubic cadmium zinc telluride crystal can be 3mm-8mm. For example, the detector crystal 20 is a cadmium zinc telluride crystal with dimensions of 5mm*5mm*5mm.

[0041] In some embodiments, the gyroscope 200 may be attached to the bottom of the housing 10 of the X-ray detector 100. The gyroscope 200 may be rigidly connected to the housing 10. When measuring horizontal wells, the gyroscope 200, positioned at the bottom of the housing 10 of the X-ray detector 100, can also provide a reference for the steering of the coiled tubing truck. The gyroscope 200 may be quickly detachably connected to the housing 10 of the X-ray detector 100.

[0042] The zero point of the gyroscope 200 is aligned with the detection direction of one of the detection crystals 20 of the ray detector 100, thus enabling the gyroscope 200 to determine the detection direction of that detection crystal 20. Then, based on the angles between the other detection crystals 20 and the first detection crystal 20, the detection directions of the remaining detection crystals 20 are determined.

[0043] The zero point position of the gyroscope 200 can, for example, be aligned with the detection direction of the lowest detection crystal 20 located along the height direction of the housing 10.

[0044] In a specific embodiment, the X-ray detector 100 includes eight detector crystals 20, which are spirally arranged at equal intervals within the housing 10. The angle between the detection directions of two adjacent detector crystals 20 is 45 degrees. Specifically, a detector crystal 20 is arranged at circumferential intervals of 45° within the housing 10, and each detector crystal 20 is spaced 5 cm apart along the height direction of the housing 10. The zero point position of the gyroscope 200 is consistent with the detection direction of the lowest detector crystal 20 in the height direction. After the detection device 1000 is lowered into the well to the initial detection position, if the zero point position of the gyroscope 200 is due east, then the detection direction of the lowest detector crystal 20 is due east. Based on the angle between two adjacent detector crystals 20, the detection directions of the remaining detector crystals 20 from bottom to top in the height direction can be obtained as northeast, north, northwest, west, southwest, south, and southeast, respectively. In this way, the detection direction of each detector crystal 20 is determined by the gyroscope 200.

[0045] In some embodiments, the radiation detector 100 may further include a shielding member 30, which may be disposed within the chamber 11 to shield the multiple detector crystals 20 from each other. This facilitates the detection of the tracer-emitted radiation by each detector crystal 20 only through its surface facing the inner wall of the housing 10, preventing different detector crystals 20 from detecting the tracer-emitted radiation at the same location and affecting the determination of the tracer distribution direction. Specifically, the empty spaces between the detector crystals 20 and between the detector crystals 20 and the interior of the housing 10 are filled with lead blocks to shield tracer radiation in other circumferential and longitudinal directions, preventing radiation in these directions from affecting the detection accuracy.

[0046] like Figure 3 The diagram shows a schematic of the shielding member 30 and the detector crystal 20 assembled according to an embodiment of this application. In some embodiments, a groove can be formed on the surface of the shielding member 30 facing the peripheral wall of the chamber 11, and each detector crystal 20 can be embedded in the groove. The shielding element can shield rays from surfaces other than the side surface of the detector crystal 20 facing the inner wall of the housing 10, preventing rays in these directions from affecting the accuracy of the detector crystal 20 in the circumferential direction.

[0047] like Figures 4 to 6 As shown, in some embodiments, the X-ray detector 100 may further include a support 40, which may be disposed within the chamber 11, and a plurality of detector crystals 20 may be disposed on the support 40.

[0048] In some embodiments, the support member 40 includes a support rod located in the middle and a plurality of connecting portions 41. One end of the connecting portion 41 is connected to the support rod, and the other end extends away from the support rod. Each connecting portion 41 can be connected to a detection crystal 20.

[0049] See Figure 4 In some embodiments, multiple connecting portions 41 are spirally distributed at equal intervals along the circumference of the support rod, thereby allowing multiple detection crystals 20 to be spirally arranged at equal intervals within the housing 10. For example... Figure 6 As shown, multiple detection crystals 20 arranged in a spiral can be evenly distributed on the same circumference, which is beneficial for more accurate detection of the circumferential distribution of tracers in the well.

[0050] In some embodiments, the shielding member 30 may be composed of multiple shielding elements (not shown in the figure), which may be embedded in the space outside the multiple detector crystals 20 and the support member 40, so that each detector crystal 20 can only detect the rays emitted by the tracer through its side surface facing the inner wall of the housing 10, thus avoiding different detector crystals 20 detecting the rays emitted by the tracer at the same location, which would affect the judgment of the distribution direction of the tracer.

[0051] In some embodiments, the shielding element may be a lead block.

[0052] In some embodiments, a gap may exist between the shielding member 30 and the peripheral wall of the chamber 11. The width of the gap between the shielding member 30 and the peripheral wall of the chamber 11 may be 1mm-5mm, for example, 3mm. In some embodiments, the radiation detector 100 may further include a cooling member for cooling the chamber 11 to maintain the temperature inside the chamber 11 within a preset range. The cooling member may be disposed in the gap mentioned above. In some embodiments, the cooling member may maintain the temperature inside the chamber 11 at 20°C-30°C by electrocooling.

[0053] In some embodiments, the X-ray detector 100 may also include amplifiers, energy spectroscopy devices, etc., which may be disposed in the upper space of the chamber 11.

[0054] In some embodiments, the X-ray detector 100 may further include data lines connected to devices such as amplifiers or energy spectrometers and data lines connected to the detector crystal 20, and these data lines may be disposed in the gaps mentioned above.

[0055] like Figure 7As shown, in some embodiments, the detection device 1000 may further include a magnetic positioning element 300. The magnetic positioning element 300 may be connected to the X-ray detector 100 to determine the depth of the X-ray detector 100 within the well. In some embodiments, the magnetic positioning element 300 may be a modular design and can be quickly and easily connected to the X-ray detector 100. The magnetic positioning element 300 may be connected above the X-ray detector 100.

[0056] Specifically, couplings are usually installed at equal intervals along the depth direction inside the well. When the detection device 1000 is lowered into the well, the magnetic field lines detected by the magnetic positioning component 300 will change when it passes through each coupling, thereby enabling the depth of the position where the detection device 1000 is lowered into the well to be inferred.

[0057] See Figure 7 In some embodiments, the detection device 1000 may further include a temperature and pressure detector 400. The temperature and pressure detector 400 may be connected to the radiation detector 100, for example, via a magnetic positioning element 300, for detecting the temperature and pressure within the well.

[0058] While performing tracer gamma spectroscopy logging using the detection device 1000 after fracturing, the temperature and pressure detector 400 simultaneously monitors downhole temperature and pressure data, which can replace the post-fracturing well temperature and pressure logging step in oilfields, saving one logging operation. In some embodiments, the temperature and pressure detector 400 can be modularly designed and can be quickly detached from the magnetic positioning device 300 above it.

[0059] See Figure 7 In some embodiments, the detection device 1000 may further include a data transmission unit 500. The data transmission unit 500 may be connected to the X-ray detector 100 (e.g., connected to the X-ray detector 100 via the temperature and pressure detector 400) for transmitting data detected by each of the detection crystals 20. In such embodiments, the data transmission unit 500 may be positioned at the top of the detection device 1000 for easy cable connection. In some embodiments, the data transmission unit 500 may be a modular design and may be quickly and easily connected to the temperature and pressure detector 400 above it.

[0060] See Figure 8In other embodiments, the detection device 1000 may further include a power supply unit 700 and a storage unit 600. The storage unit 600 may be connected to the X-ray detector 100 and is used to store data detected by multiple detection crystals 20. The power supply unit 700 can provide power to the detection device 1000. In some embodiments, the power supply unit 700 may include a battery compartment and a battery disposed within the battery compartment. The number of battery compartments may vary depending on energy consumption and the usage time of the detection device 1000. When energy consumption is high or the detection device 1000 needs to detect for a long time, two or more battery compartments may be used. For example, since the detection device 1000 of this application needs to locate the circumferential distribution of the tracer in the wellbore, the monitoring speed is slower than conventional logging. The power supply unit 700 may include two battery compartments, which can power the detection device 1000 for more than 20 hours.

[0061] In some embodiments, the power supply unit 700 and the storage unit 600 can be modularly designed and can be quickly connected to the temperature and pressure sensor 400 above the temperature and pressure sensor 400.

[0062] In some embodiments, the detection device 1000 can be used to detect the distribution of tracers within a vertical well. In other embodiments, the detection device 1000 can be used to detect the distribution of tracers within a horizontal well.

[0063] In some embodiments, when using the detection device 1000 to detect tracers in the well, the detection device 1000 needs to be lowered to the initial detection position in the well, and the detection device 1000 is pulled upward at a constant speed at the initial detection position, while recording the data detected by each detection crystal 20.

[0064] In some embodiments, a cable logging rig can be used to lower or raise the detection device 1000. The cable logging rig can be used to detect tracers in vertical or horizontal wells. When using the cable logging rig to detect tracers in a vertical well, the detection device 1000 can be selected to include a data transmission device 500. The data transmission device 500 can be connected to external equipment and can transmit detection data to the external equipment in real time. The detection device 1000 can also be connected to an external power source via the cable of the cable logging rig, thereby obtaining electrical energy from an external power source to support the normal operation of the detection device 1000.

[0065] In some embodiments, the external device can process data about the tracer detected by the detection device 1000. The external device can be a computer or other data processing device. In some embodiments, the external device can also process detection data stored in the storage device 600.

[0066] External equipment can be, for example, surface control equipment, which can integrate the power supply and control software functions of existing cable-type logging surface equipment and the time preset and depth correction functions of storage-type logging surface equipment. Both types of logging tools can be controlled and configured using a laptop computer.

[0067] In other embodiments, a coiled tubing truck can be used to lower or raise the detection device 1000, which can be used for the detection of tracers in horizontal wells. In some embodiments, since the coiled tubing truck cannot support the transmission of real-time detection data or supply power to the detection device 1000, when using the coiled tubing truck to lower or raise the detection device 1000 to detect tracers in vertical wells, a detection device 1000 including a storage unit 600 and a power supply unit 700 can be selected.

[0068] In some embodiments, when using the detection device 1000 to detect tracers within a horizontal well, before lowering the detection device 1000, the time required to reach the initial detection position and the time required for the detection process can be calculated based on the lowering or raising speed of the cable logging truck or coiled tubing truck. Using the calculated time required to reach the initial detection position and the time required for the detection process as a basis, the start and end times of the detection crystal 20 are appropriately extended to ensure that the detection device 1000 can reach the initial predicted position and that the distribution of tracers within the horizontal well can be completely detected. This extension can be appropriately 20-50 minutes, for example, 30 minutes.

[0069] In some embodiments, when using the detection device 1000 to detect tracers within a horizontal well, the X-ray detector 100 may include eight detection crystals 20. The zero point of the gyroscope 200 coincides with the detection direction of the lowest detection crystal 20 along the height direction of the housing 10. Since the detection direction of this crystal 20 is upward, the detection direction of the second-to-last detection crystal 20 along the height direction of the housing 10 is upward to the right, and so on. Therefore, the detection directions of the remaining detection crystals 20 along the height direction of the housing 10 from bottom to top are, in order, right, downward to the right, downward, downward to the left, left, and upward to the left. The left and right directions can be determined based on the drilling direction of the horizontal well.

[0070] Embodiments of this application also provide a method for detecting tracers in wells, comprising the following steps S1-S4.

[0071] S1: The detection device 1000 of any embodiment of this application is placed in the well and lowered to the initial detection position, wherein each detection crystal 20 is at a different height.

[0072] S2: Determine the orientation of each detector crystal 20 within the well.

[0073] S3: Pull the detection device 1000 upward at a constant speed from the initial detection position, and record the data detected by multiple detection crystals 20 at the same time, so as to obtain the detection data of the time change corresponding to each detection crystal 20.

[0074] S4: Based on the depth of the initial detection position, the pulling speed, and the height of each detection crystal 20, obtain the detection data of the depth change in the well corresponding to each detection crystal 20, thereby determining the distribution of the tracer at different depths in the well.

[0075] In some embodiments, an initial detection location may be determined before placing the detection device 1000. In some embodiments, the depth of the initial detection location may be deeper than the predicted location of the crack.

[0076] In some embodiments, when measuring a vertical well, the detection device 1000 can be placed into the well by its own weight. In some embodiments, when lowering the detection device 1000, the distribution of rays emitted by the tracer detected by the detection crystal 20 can be used to determine whether the detection device 1000 has reached the initial predicted position. The initial predicted position can be at least 10m below the predicted position to ensure complete measurement of the tracer.

[0077] In some embodiments, step S4, obtaining detection data of the well depth corresponding to each detection crystal 20, includes: S41: determining the time difference Δt between each detection crystal 20 reaching the same depth position in the well based on the pulling speed and the height of each detection crystal 20; S42: obtaining detection data of the change in well depth corresponding to each detection crystal 20 based on the time difference Δt and the depth of the initial detection position.

[0078] Since each detector crystal 20 is located at a different height, the initial detection data of each detector crystal 20 corresponds to a different depth position in the well, meaning that each detector crystal 20 detects different depth positions at the same time. By determining the time difference Δt between each detector crystal 20 reaching the same depth position in the well, the data detected by each detector crystal 20 is corrected to obtain the detection data corresponding to the change in well depth for each detector crystal 20.

[0079] In some embodiments, in step S41, the time difference Δt between the height difference Δh of the probe crystals 20 and the pulling speed can be used to determine the time difference Δt between the probe crystals 20 and the same depth position in the well.

[0080] like Figure 9 As shown, Figure 9The figure shows the distribution curves of the tracer detected by two detector crystals at different heights over time. Curve 91 in the figure represents the distribution curve of the tracer detected by the lower detector crystal 20 over time, and curve 92 represents the distribution curve of the tracer detected by the higher detector crystal 20 over time. Curves 91 and 92 respectively represent the changes in the neutron count detected by the two detector crystals 20 within the same detection time period. Figure 9 In this context, t0 represents the same initial detection time, meaning that at time t0, both detection crystals 20 are in their respective positions and begin detection. The lower detection crystal 20 detects the same depth in the well as the higher detection crystal 20 at time t0+Δt.

[0081] like Figure 10 As shown, Figure 10 It shows that Figure 9 The tracer distribution curve over time is converted into a tracer distribution curve over depth. In the figure, curve 101 is the tracer distribution curve over depth detected by the lower detection crystal 20, and curve 102 is the tracer distribution curve over depth detected by the higher detection crystal 20. Figure 10 In this context, h0 represents the initial detection position of the lower detection crystal 20; Figure 10 In this context, h0+△h represents the initial detection position of the higher detection crystal 20.

[0082] Specifically, by dividing the height difference Δh between each probe crystal 20 by the real-time lifting speed, the time difference Δt between each probe crystal 20 reaching the same depth position can be calculated. Taking the arrival time of the top probe crystal 20 as the reference, the time point of each subsequent probe crystal 20 reaching the same depth position is automatically determined according to the calculated time difference Δt. The data curves measured by each probe crystal 20 are aligned according to the same depth position. In the final data curve, the measurement data of each probe crystal 20 corresponds to the same depth position.

[0083] In some embodiments, the step of obtaining detection data corresponding to the well depth of each detection crystal 20 in step S4 may further include the following steps S43-S45.

[0084] S43: Determine the depth at which the X-ray detector 100 is lowered into the well based on the magnetic positioning component 300, thereby determining the depth of the initial detection position.

[0085] S44: Based on the natural gamma count detected by the detector crystal 20, the depth of the initial detection position is corrected to obtain the corrected depth of the initial detection position.

[0086] S45: Based on the correction depth of the initial detection position, the pulling speed, and the height of each detection crystal 20, obtain the detection data of the well depth change corresponding to each detection crystal 20.

[0087] In step S43, couplings are usually set at equal intervals along the depth direction inside the well. When the detection device 1000 is lowered into the well, the magnetic field lines detected by the magnetic positioning component 300 will change when it passes through each coupling, thereby enabling the inference of the depth at which the detection device 1000 is lowered into the well to the initial detection position.

[0088] In step S44, the correction depth of the initial probe position can be determined by software.

[0089] In some embodiments, the response count and depth value of each detector crystal 20 to the tracer can be corrected by software.

[0090] The following describes, with reference to specific embodiments, a method for detecting tracers in vertical and horizontal wells using the detection device 1000 of this application.

[0091] When probing a vertical well, the detection device 1000 is connected to the cable of the cable logging vehicle. The detection device 1000 is lowered into the vertical well by the weight of the logging instrument, reaching a position at least 10m below the predicted position (the predicted position can be determined by observing the tracer response in real time through the computer software on the surface equipment). The logging vehicle then begins to lift the detection device 1000, and simultaneously begins to monitor and save the monitoring data in real time. The eight detection crystals 20 can monitor the tracer response in eight directions within the wellbore. The direction of the lowest detection crystal 20 is determined by using a gyroscope, thereby obtaining the direction of each detection crystal 20. Each probe crystal 20 measures the tracer response count and depth value, which are automatically corrected by software. With a distance of 5cm between each crystal, the time difference Δt between each crystal reaching the same depth position can be calculated by dividing by the real-time lifting speed. Based on the calculated time difference Δt, the time when the top crystal arrives first is used as the reference to automatically determine the time point when each subsequent crystal reaches the same depth position. The data curves measured by the 8 crystals are aligned according to the same depth position. In the final data curve, the measurement data of the 8 crystals correspond to the same depth position.

[0092] When probing a horizontal well, before lowering the probe 1000 into the well, the time required to reach the predicted position and the time required to measure the predicted section are calculated based on the lowering and raising speed of the logging truck or coiled tubing truck and the predicted depth. An additional 30 minutes is added to ensure sufficient time to reach the predicted position and complete the measurement of the predicted section. Using surface equipment, the start and completion times of the probe 1000's measurement are set according to the calculated times. The probe 1000 is then carried by the logging truck and crawler or coiled tubing to a position at least 10 meters beyond the predicted position at the bottom of the horizontal section (the depth is determined by the cable (wire rope) depth or coiled tubing depth; since the cable (wire rope) or coiled tubing will stretch to some extent, experience is used to lower it approximately 5 meters further when the predicted position is reached to achieve the initial probe position). Upon reaching the measurement start time, the probe 1000 is raised using the logging truck or coiled tubing. The probe 1000 automatically begins measurement and stores measurement and speed data. Unlike vertical well logging, the orientation of the eight detector crystals 20 and the gyroscope is no longer based on cardinal directions (north, south, east, west). Instead, the gyroscope determines eight directions: up, upper right, right, lower right, down, lower left, left, and upper left. The left and right directions are then determined based on the drilling direction of the horizontal section of the well, thus identifying the location of the tracer within the wellbore monitored by each detector crystal 20. The automatic correction method for the tracer response count and depth value of the eight detector crystals 20 is the same as in vertical well logging.

[0093] Regarding the embodiments of this application, it should also be noted that, without conflict, the embodiments of this application and the features in the embodiments can be combined with each other to obtain new embodiments.

[0094] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. The scope of protection of this application shall be determined by the scope of the claims.

Claims

1. A method for detecting tracers in a well, comprising: The detection device is placed inside the well and lowered to the initial detection position. The detection device includes a radiation detector and a gyroscope, wherein the radiation detector includes: The shell, which is configured to form a chamber; and Multiple detection crystals are disposed in the chamber, wherein at least two of the detection crystals are arranged to face different circumferential directions of the housing to detect the rays emitted by the tracer in different circumferential directions within the well; The gyroscope is used to determine the orientation of the plurality of detection crystals within the well. The plurality of detector crystals are located at different heights; Determine the orientation of each of the probe crystals within the well; The device is pulled upward at a constant speed from the initial detection position, while the data detected by the multiple detection crystals are recorded, thereby obtaining the detection data of each detection crystal corresponding to the time change. Based on the depth of the initial detection position, the pulling speed, and the height of each detection crystal, detection data of the well depth change corresponding to each detection crystal are obtained, thereby determining the distribution of the tracer at different depths in the well.

2. The method according to claim 1, wherein, The step of obtaining detection data on the change in well depth corresponding to each detection crystal based on the depth of the initial detection position, the pulling speed, and the height of each detection crystal includes: The time difference between the arrival of the plurality of probe crystals at the same depth position in the well is determined based on the pulling speed and the height of each probe crystal. Based on the time difference and the depth of the initial detection position, detection data of the depth change in the well corresponding to each detection crystal is obtained.

3. The method according to claim 1, wherein obtaining the detection data of the well depth change corresponding to each detection crystal based on the depth of the initial detection position, the pulling speed, and the height of each detection crystal includes: The depth at which the ray detector is lowered into the well is determined based on the magnetic positioning device, thereby determining the depth of the initial detection position; The depth of the initial detection position is corrected based on the natural gamma count detected by the detection crystal to obtain the corrected depth of the initial detection position; Based on the correction depth of the initial detection position, the pulling speed, and the height of each detection crystal, detection data of the well depth change corresponding to each detection crystal are obtained.

4. The method according to claim 1, wherein, The plurality of detector crystals are arranged in a spiral pattern within the housing.

5. The method according to claim 1, wherein, Each of the probe crystals is disposed adjacent to the peripheral wall of the chamber.

6. The method according to claim 1, wherein, The detector crystal is cadmium zinc telluride.

7. The method according to claim 1, wherein, The gyroscope is connected to the bottom of the housing of the ray detector.

8. The method according to claim 1, wherein, The radiation detector also includes: A shielding element is disposed within the cavity to shield the plurality of detector crystals from each other.

9. The method according to claim 8, wherein, The shielding member has a groove formed on the surface of the peripheral wall of the chamber, and each detection crystal is embedded in the groove.

10. The method according to claim 8, wherein, The radiation detector also includes: A support member is disposed within the cavity, and the plurality of detection crystals are disposed within the support member; The shielding component is composed of multiple shielding elements, which are embedded in the space outside the multiple detection crystals and the support component.

11. The method according to claim 1, wherein, The detection device also includes: A magnetic positioning element, connected to the ray detector, is used to determine the depth of the ray detector within the well; and / or A temperature and pressure detector, connected to the X-ray detector, is used to detect the temperature and pressure inside the well.

12. The method according to claim 1, wherein, The detection device also includes: A data transmission device, connected to the X-ray detector, is used to transmit data detected by the plurality of detection crystals; or A storage device, connected to the X-ray detector, is used to store data detected by the plurality of detection crystals.

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