Well logging while drilling device based on muon imaging technology

Abstract

The invention belongs to the field of geological exploration, and discloses a logging-while-drilling device based on the muon imaging technology. Comprising an outer shell, an inner cylinder and a muon detector, the inner cylinder is coaxially nested in the outer shell, and a relatively sealed detection space is formed between the inner cylinder and the outer shell; the muon detector is arranged in the detection space; the muon detector comprises a scintillator assembly and a photoelectric detector, the scintillator assembly is coaxially sleeved in the detection space, the photoelectric detector is arranged on the inner side of the scintillator assembly, the scintillator assembly is made of a scintillator material capable of resisting the high temperature of 140 DEG C or above, and a heat insulation layer is arranged on the inner wall of the detection space. The method can be widely applied to oil-gas exploration, mineral resource investigation and underground structure detection, and the detection depth and imaging precision of logging while drilling are improved.

Description

Technical Field

[0001] The present invention belongs to the field of geological exploration and relates to a logging while drilling technology, in particular to a logging while drilling device based on muon imaging technology. Background Art

[0002] Logging While Drilling (LWD) technology can provide formation information during the drilling process to assist in geological exploration and development. However, current mainstream LWD technologies mainly rely on resistivity, gamma rays, neutrons, acoustic waves, and other methods. These methods have problems such as limited detection penetration range, significant influence of formation density, and insufficient imaging accuracy, making it difficult to identify large-scale structures (such as faults). Muon imaging is a non-destructive testing technology based on cosmic ray muons. Due to their high penetration ability, muons can be used to image the interior of media with large density variations and have been applied in fields such as volcano monitoring and nuclear waste detection. However, traditional muon detectors are bulky and rely on large-area detection arrays; the detector electronic components are not able to withstand the high temperature, high pressure, and drilling vibration environment, and muon imaging measurements take a long time.

[0003] Therefore, muon detectors cannot be adapted to LWD drilling tools, making muon technology difficult to directly apply to downhole detection. Therefore, it is necessary to propose a muon detection system suitable for LWD that is miniaturized, resistant to high temperatures and pressures, resistant to vibrations, and capable of real-time imaging. Summary of the Invention

[0004] The purpose of the present invention is to provide a logging-while-drilling device based on muon imaging technology. Through innovative design, it solves the problems of large size, poor temperature and pressure resistance, and vibration interference of muon detectors, and realizes high-precision detection of the formation structure during drilling.

[0005] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows: A logging while drilling device based on muon imaging technology, comprising outer shell; The inner cylinder is coaxially nested in the outer cylinder, and a relatively sealed detection space is formed between the inner cylinder and the outer cylinder; and Muon detectors are set up in the detection space; The muon detector includes a scintillator assembly coaxially installed in the detection space and a photodetector arranged inside the scintillator assembly. The scintillator assembly is made of a scintillator material that can withstand high temperatures above 140°C, and the inner wall of the detection space is provided with an insulation layer.

[0006] Furthermore, the detection space is filled with a high melting point phase change material for preventing high temperature impact, and the melting point of the high melting point phase change material is not lower than 140°C.

[0007] Furthermore, a vibration suppression module is provided on the scintillator assembly, and the vibration suppression module includes a first piezoelectric conversion module and a second piezoelectric conversion module. The vibration signal of the scintillator assembly is monitored by the first piezoelectric conversion module, and a reverse driving signal is generated according to the vibration signal to drive the second piezoelectric conversion module to generate reverse vibration, thereby suppressing vibration.

[0008] Furthermore, the outer shell is a titanium alloy shell, and an incident port is provided on the side wall of the outer shell corresponding to the scintillator assembly. The incident port is sealed with a muon high-transmittance material to form a muon incident window.

[0009] Furthermore, the scintillator assembly includes a plurality of coaxially stacked annular scintillators, and each scintillator assembly is provided with at least one corresponding photodetector.

[0010] Furthermore, the scintillator assembly further includes a second scintillator array arranged circumferentially outside the scintillator assembly, and a photodetector is provided at an end of the second scintillator array.

[0011] Furthermore, the scintillator assembly and the second scintillator surface are both coated with a reflective layer.

[0012] Furthermore, the logging while drilling device based on muon imaging technology also includes a posture sensor for monitoring the posture of the logging while drilling device.

[0013] Furthermore, the logging while drilling device based on muon imaging technology also includes a data processing system, which includes a downhole real-time processing module and a ground processing platform. The downhole real-time processing module divides the continuous drilling process into multiple time slices for data storage, and independently calculates the muon flux attenuation rate in each time slice, and then improves the signal-to-noise ratio through weighted fusion; the ground processing platform includes an industrial computer for processing and analyzing the collected data.

[0014] Furthermore, the detection space is filled with inert gas.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention creatively designs a detection space composed of an inner cylinder and an outer cylinder, passes the drill pipe through the hollow axis of the inner cylinder, and thus installs the while-drilling logging device on the drill pipe to realize while-drilling measurement. The present invention designs a muon detector with a unique structure composed of a scintillator assembly and a photodetector, and encapsulates it in the detection space to isolate the effects of high temperature and high pressure on electronic devices such as the scintillator assembly and the photodetector. In addition, a high-temperature resistant scintillator assembly is selected to meet the requirements of high-temperature and high-pressure resistance. Unexpectedly, this design of the present invention enables the present invention to install the muon detector in the while-drilling equipment for the first time and successfully realize logging. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the downhole muon imaging while drilling system of the present invention; Figure 2 It is a partial schematic diagram of the logging-while-drilling device in the downhole muon imaging-while-drilling system of the present invention; Figure 3 yes Figure 2 Middle AA section view; Figure 4 Schematic diagram of an axially stacked annular scintillator array according to a specific embodiment of the present invention.

[0017] Figure 5 The figure is a flow chart of a logging while drilling method based on muon imaging technology in a specific embodiment of the present invention.

[0018] Figure 6 Schematic diagram of a control module in an embodiment of the present invention.

[0019] Figure 7 Schematic diagram of a control module in another embodiment of the present invention.

[0020] 100 - Logging While Drilling Device, 110 - Outer Shell, 111 - Detection Space, 120 - Inner Cylinder, 130 - Muon Detector, 131 - Annular Scintillator, 132 - Annular Scintillator Array, 133 - Photoelectric Detector, 140 - Attitude Sensor; 150 - Vibration Suppression Module, 151 - First Piezoelectric Transformer Module, 152 - Second Piezoelectric Transformer Module; 210-drill pipe, 220-drill bit; 300-data processing system, 310-downhole real-time processing module, 320-ground processing platform. DETAILED DESCRIPTION

[0021] In order to more clearly illustrate the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and implementation examples.

[0022] It should be noted that the figures provided in the following embodiments are merely schematic illustrations of the basic concepts of the present invention. Obviously, the embodiments described are only a portion of the embodiments of the present invention, rather than all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0023] In existing technologies, logging temperatures are generally around 50-150°C, while ultra-deep well temperatures can reach over 200°C. The pressure range for normal-pressure wells is 10-30 MPa, for high-pressure gas wells is 30-70 MPa, and for ultra-high-pressure wells is around 70-140 MPa. Therefore, logging occurs in a typical high-temperature, high-pressure environment. Furthermore, the space for LWD is limited, making it difficult to design. Therefore, although muon logging has its own technical advantages, there is no precedent for combining it with LWD in existing technologies. The reason is that it is difficult to meet the high-temperature, high-pressure logging requirements within a limited space.

[0024] In order to solve the above technical problems, Figures 1 to 3 As shown, the present invention provides a logging while drilling device 100 based on muon imaging technology, comprising outer shell 110; The inner cylinder 120 is coaxially nested in the outer shell 110, and a relatively sealed detection space 111 is formed between the inner cylinder 120 and the outer shell 110; and The muon detector 130 is disposed in the detection space 111; The muon detector 130 includes a scintillator assembly coaxially mounted in the detection space 111 and a photodetector 133 disposed inside the scintillator assembly. The scintillator assembly is made of a scintillator material that is resistant to high temperatures above 140°C, and the inner wall of the detection space 111 is provided with a heat-insulating layer.

[0025] The present invention creatively designs a detection space 111 consisting of an inner cylinder 120 and an outer cylinder 110, and passes the drill rod 210 through the hollow axis of the inner cylinder 120, so that the downhole logging device 100 is installed on the drill rod 210 to realize downhole measurement. The present invention designs a muon detector 130 with a unique structure consisting of a scintillator assembly and a photodetector 133, and encapsulates it in the detection space 111 to isolate the influence of high temperature and high pressure on electronic devices such as the scintillator assembly and the photodetector 133, and selects a high-temperature resistant scintillator assembly to meet the high-temperature and high-pressure requirements. Unexpectedly, this design of the present invention enables the present invention to install the muon detector 130 in the downhole equipment for the first time and successfully realizes downhole logging.

[0026] It should be noted that the installation method of the inner cylinder 120 and the drill rod 210 can adopt the existing technology, and the present invention is not limited. For example, the inner cylinder 120 can be sleeved on the drill rod 210 using a high-temperature resistant bearing, and the drill bit 220, such as a PDC drill bit, is installed at the bottom of the drill rod 210. Generally, the drilling diameter of the drill bit 220 should be larger than the maximum diameter of the outer shell 110.

[0027] To meet the requirements of muon logging in high-temperature, high-pressure environments, the present invention fabricates outer shell 110 from a titanium alloy. Compared to other common metal materials, titanium alloys offer high muon transmittance, high strength, and high-temperature resistance, effectively meeting protection requirements. To further reduce muon loss from outer shell 110, the present invention provides a preferred method in which an entrance port is provided on the sidewall of outer shell 110 corresponding to the scintillator assembly. This entrance port is sealed with a high-muon-transmittance material to form a muon entrance window. This high-muon-transmittance material, which includes materials such as beryllium (Be), aluminum nitride (AlN), and silicon carbide (SiC), not only exhibits superior muon transmittance to titanium alloys (and most other metal materials) but also meets the requirements of high-temperature, high-pressure environments.

[0028] Generally, the inner cylinder 120 is generally made of high-strength stainless steel, which has a low cost. Of course, if the muon detector 130 needs to measure the muon scattering angle and azimuth, then it is necessary to measure the muon transmission path in the muon detector 130, then the inner cylinder 120 also needs to be made of a material with high muon transmittance, such as titanium alloy.

[0029] In order to further improve the high temperature resistance, the inner wall of the detection space 111 of the present invention is provided with a heat insulation layer ( Figures 1 to 3 The outer wall of the outer shell 110 is mainly provided with an insulation layer. Of course, the outer wall of the inner cylinder 120 can also be provided with an insulation layer. The insulation layer is made of alumina ceramics, zirconium oxide ceramics, silicon carbide ceramics, mullite fiber and other materials to provide excellent thermal insulation performance.

[0030] In order to further improve the high temperature resistance, the present invention fills the detection space 111 with a high melting point phase change material for preventing high temperature impact, and the melting point of the high melting point phase change material is not less than 140°C; exemplarily, the high melting point phase change material refers to a phase change material having a melting point 3-50°C higher than the normal working environment temperature, and more preferably, it can be a phase change material that exceeds the working environment temperature by 5-30°C, which can not only meet the working environment requirements, but also can cope with high temperature impact well. Exemplarily, some high melting point phase change materials and their characteristics are shown in Table 1.

[0031] Table 1. High melting point phase change materials that can be used for well logging

[0032] It should be noted that the high melting point phase change material is only used to prevent damage to the muon detector 130 and other electrical devices during high temperature shocks, such as sudden temperature rise in the wellbore, or extended operation time in a high temperature environment. When the wellbore operating temperature is significantly higher than the operating temperature of the muon detector 130 (in an abnormal situation), other measures should be taken to cool it down or the drill pipe 210 should be lifted to allow the logging while drilling device 100 to exit the high temperature zone.

[0033] In order to improve the compressive strength of the detection space 111 , an inert gas, such as argon, nitrogen or the like, may be added to the detection space 111 to increase the deformation resistance of the outer shell 110 by inflating the detection space 111 to a preset pressure.

[0034] It should be noted that the inert gas and phase change material do not conflict with each other and can be set separately or together. The inert gas itself does not affect the function of the phase change material. On the contrary, it can improve the durability of the phase change material and prevent the phase change material from being affected by the environment and undergoing chemical reactions that lead to changes in physical properties.

[0035] The outer shell 110 and the inner cylinder 120 may be connected and assembled by any one of threaded connection, welding, and clamping, and a sealing ring and other structures are provided to improve the sealing performance, thereby improving the pressure resistance of the logging while drilling device 100.

[0036] In order to further improve the high temperature resistance and reduce the size of the muon detector 130, the scintillator assembly adopts barium fluoride (BaF2), thallium-doped cesium iodide (CsI(Tl)), cerium-doped gadolinium aluminum gallium garnet (GAGG:Ce, Gd3Al2Ga3O 12 :Ce), lutetium aluminum garnet (LuAG:Ce, Lu3Al5O 12 :Ce)、yttrium lutetium silicate(LYSO:Ce,Lu2( 1-x )Y 2x SiO5:Ce 3+ ), ceramic scintillator (such as Gd2O2S:Pr, Ce, F) and any other materials.

[0037] Furthermore, an aluminum reflective layer (reflectivity ≥ 95%) can be plated on the surface of the scintillator to improve detection accuracy. Of course, the reflective layer material can also be TiO2 (sol-gel method) ceramic material.

[0038] The scintillator assembly of the present invention can be arranged in various forms, which can be selected according to the imaging mode; Figure 2 and Figure 3As shown, for example, if only muon flux attenuation calculation is performed and the muon flux attenuation rate is used to generate the density difference coefficient, then the scintillator assembly can be set as an annular scintillator 131. The annular scintillator 131 is coaxially installed in the detection space 111 (for example, it can be installed on the inner wall of the outer shell 110) by snapping, bonding or screwing, and the photodetector 133 is set close to the inner wall of the annular scintillator 131. If you need to calculate the incident trajectory of the muon, such as Figure 4 As shown, the scintillator assembly can be provided with a plurality of axially stacked annular scintillator arrays 132 , each annular scintillator 131 corresponds to at least one photodetector 133 , and the muon incident angle can be calculated through the annular scintillator array 132 .

[0039] If the incident azimuth angle of the technical muon is also required, a second scintillator array distributed circumferentially is provided on the outer layer of the annular scintillator array 132 ( Figure 4 (not shown in the figure, it is formed by a circumferential array of several types of prismatic scintillators. For details, please refer to the technology described in CN117724178A). A photodetector 133 is provided at the end of the second scintillator array. By numbering the second scintillators, the muon incident azimuth angle can be calculated. Combining the incident angle and azimuth angle, the spatial coordinates of the muon incident point can be determined, thereby determining the muon incident trajectory.

[0040] Exemplarily, the photodetector 133 can be a high-temperature resistant (temperature above 140°C) photodetector, such as a high-temperature optimized silicon photomultiplier (SiPM), a silicon carbide (SiC)-based photodiode, a gallium nitride (GaN)-based photodetector, etc., which can adapt well to high-temperature environments.

[0041] In order to reduce the impact of drilling vibration on muon monitoring, Figure 2 or Figure 4 As shown, a vibration suppression module 150 is provided on the scintillator assembly, and the vibration suppression module 150 includes a first piezoelectric conversion module 151, a second piezoelectric conversion module 152 and a control module. The control module is connected to the first piezoelectric conversion module 151 and the second piezoelectric conversion module 152 through signal lines, respectively. The first piezoelectric conversion module 151 monitors the vibration signal of the scintillator assembly and transmits the vibration signal to the control module. The control module has a built-in control algorithm, generates a reverse drive signal according to the vibration signal, and transmits the reverse drive signal to the second piezoelectric conversion module 152, driving the second piezoelectric conversion module 152 to generate reverse vibration, thereby suppressing vibration.

[0042] Specifically, the first piezoelectric conversion module 151 is a sensor-end piezoelectric ceramic used to collect vibration signals (monitoring end); the second piezoelectric conversion module 152 is an actuator-end piezoelectric ceramic used to generate reverse vibration (cancellation end); by setting a high-temperature resistant controller in the control module to process signals in real time and generate reverse excitation, and setting a high-temperature power supply and signal conditioning module to provide stable power supply and signal amplification.

[0043] The first piezoelectric conversion module 151 and the second piezoelectric conversion module 152 both need to use high-temperature piezoelectric ceramic materials, specifically bismuth layered high-temperature piezoelectric ceramics (such as Bi4Ti3O 12 Doping): Curie temperature> 600℃, piezoelectric coefficient d at 200℃ 33 >20 pC / N; or lithium niobate (LiNbO3) single crystal: temperature resistance up to 1200°C; or metal / ceramic composite packaging using an alumina ceramic substrate with high-temperature silver paste electrodes, covered with a stainless steel housing, and filled with high-temperature resistant silicone (temperature resistance up to 300°C) to meet the high-temperature and high-pressure requirements of underground mines. The first and second piezoelectric transducer modules 151, 152 are mounted at the upper and lower ends of the annular scintillator 131, respectively, primarily monitoring and eliminating axial vibration. Vibration in other directions can also be monitored with modifications as needed. Typically, the first and second piezoelectric transducer modules 151, 152 are paired.

[0044] For example, Figure 6 As shown, the control module ( Figure 2 This part of the structure is not shown in the figure. It can be distributed arbitrarily in the detection space and does not affect the solution of technical problems. It includes a high-temperature resistant controller, a signal conditioning module, an AD / DA conversion module (including an ADC module and a DAC module), a power amplifier and a high-temperature power supply. The connection relationship between each module is as follows: Figure 6 As shown, the arrow direction indicates the signal direction, and the control algorithm is built into the high-temperature resistant controller. For example, the high-temperature resistant controller uses a SiC-based MCU (such as Cree C3M0075120K): the operating temperature is -55℃~300℃, and it supports high-speed signal processing.

[0045] The signal conditioning circuit of the signal conditioning module uses a high-temperature operational amplifier (such as HT-AMP-200, based on GaN process): bandwidth 10 MHz, temperature resistance 250 ° C.

[0046] AD / DA conversion module: Uses SiC-based AD7980 high-temperature ADC (temperature resistance 225°C, 16-bit resolution) and DAC8775 DAC (temperature resistance 210°C, 16-bit resolution).

[0047] Power amplifier: A high-temperature amplifier with a ceramic sealed package, such as CISSOID's PAH200T power amplifier (temperature resistant to 225°C).

[0048] High-temperature power supply: The high-temperature power supply uses a high-temperature DC-DC converter (such as the VPT DV-285, input 28V, output ±15V, temperature resistance 200°C); cable: silver-plated copper core + polyimide insulation layer + stainless steel braided shield layer (temperature resistance 300°C).

[0049] The control algorithm uses an improved FXLMS algorithm. FXLMS (Filtered-X Least Mean Square) is a commonly used adaptive filtering algorithm for active noise (or vibration) control. Its core is to continuously adjust the filter coefficients so that the output signal can offset the interference signal; more optimally, a temperature drift compensation module can be introduced to correct the changes in piezoelectric ceramic parameters (such as d 33 fluctuates with temperature).

[0050] The specific execution of the control algorithm is as follows: Step 1: Signal acquisition: The piezoelectric ceramic at the sensor end (the first piezoelectric conversion module 151) collects vibration signals in real time and converts them into digital signals through the ADC (analog-to-digital converter); Step 2: Secondary Path Filtering Filter the vibration signal to generate secondary path filter ,in is the estimated model of the secondary path (the transfer function from actuator to sensor), is a discrete transfer function, and z is a complex frequency domain variable in the Z transform; For the n The vibration signal collected by the sensor at each moment; Step 3: Generate cancellation signal Compute the adaptive filter output:

[0051] is the first adaptive filter at the nth moment k coefficients, L is the filter order, k The indices of the filter coefficients, is the filtered input signal, is the output signal of the adaptive filter.

[0052] In another embodiment, error feedback and temperature compensation are introduced, and a temperature sensor (which can be installed in the detection space) and an accelerometer (which can be installed together with the first piezoelectric conversion module 151, or installed between the first piezoelectric conversion module 151 and the second piezoelectric conversion module 152) are added. Figure 7 As shown in the figure, according to the newly added speedometer, a signal conditioning module and an ADC module are added. The specific execution method of the corresponding control algorithm is as follows: Step 1: Signal acquisition: The piezoelectric ceramic at the sensor end (the first piezoelectric conversion module 151) collects vibration signals in real time and converts them into digital signals through the ADC (analog-to-digital converter); Step 2: Secondary Path Filtering Filter the vibration signal to generate secondary path filter ,in is the estimated model of the secondary path (the transfer function from actuator to sensor), is a discrete transfer function, and z is a complex frequency domain variable in the Z transform; For the n The vibration signal collected by the sensor at each moment; Step 3: Generate cancellation signal Compute the adaptive filter output:

[0053] is the first adaptive filter at the nth moment k coefficients, L is the filter order, k The indices of the filter coefficients, is the filtered input signal, is the output signal of the adaptive filter.

[0054] Step 4: Error feedback Acquire the error signal via an accelerometer or residual vibration sensor ,in For the n The original vibration signal at the moment; is the real secondary path.

[0055] Original vibration signal and vibration signals The relationship is as follows:

[0056] is the sensor transfer function (such as the frequency response characteristics of piezoelectric ceramics), To measure noise (thermal noise, electromagnetic interference, etc.).

[0057] Step 5: Coefficient update The improved LMS update formula (including temperature compensation) is as follows:

[0058] The adaptive filter at time n+1 k coefficients; is the step size factor related to temperature T, which can be obtained by looking up a table or online calculation; is the piezoelectric ceramic sensitivity compensation coefficient (from calibration data).

[0059] At the next moment, use the formula in step 3 to pass Calculate the adaptive filter output at time n+1 The second piezoelectric conversion module 152 is controlled to generate an excitation signal, and this process is repeated to achieve active control of vibration elimination.

[0060] In some embodiments, the present invention further includes a data processing system 300, which includes a downhole real-time processing module 310 and a surface processing platform 320. The downhole real-time processing module 310 divides the continuous drilling process into multiple time slices for data storage, and independently calculates the muon flux decay rate for each time slice, and then improves the signal-to-noise ratio through weighted fusion; the surface processing platform 320 includes an industrial computer for processing and analyzing the collected data; the downhole real-time processing module 310 calculates the muon flux decay rate in real time and generates a density difference coefficient ; Background cosmic ray subtraction (combined with the synchronous counting correction of the ground-based muon detector 130); the density difference coefficient ( ) and confidence parameters are transmitted to the surface via mud pulses (data volume <1kB / min). The data is transmitted to the industrial computer, and the ground processing platform 320 in the industrial computer is used to process and analyze the collected data.

[0061] In some embodiments, a posture sensor 140 for monitoring the posture of the logging while drilling device 100 is also included. The posture correction processing of the muon monitoring is performed by monitoring the posture of the logging while drilling device 100. The posture sensor 140 can be an accelerometer, a gyroscope or a north finder, etc., which is installed in the detection space.

[0062] The present invention also provides a logging while drilling method based on muon imaging technology to detect formation density information at a specific depth. The specific steps are as follows: Step S1: fix the processed muon detector 130 on the inner surface of the outer shell 110, and then fix the outer shell 110 on the inner cylinder 120 to complete the assembly of the logging while drilling device 100.

[0063] Step S2: Connect the inner cylinder 120 to the drill pipe 210, inject mud, and assemble the downhole muon imaging while drilling system; Step S3: Using ground power equipment, the drill bit 220 is driven into the formation. When the depth H0 of the formation to be measured is reached, the drilling is stopped, and the muon detector 130 begins to measure the change in the muon flux N at that depth. Step S4: Since muons are affected by density when penetrating the formation, their flux will decay. The downhole real-time processing module 310 pre-processes the raw data, including: calculating the muon flux decay rate and generating the density difference coefficient. : Muon flux decay rate Such as the formula:

[0064] Where, is the muon count at the downhole depth H0, is the ground background measurement value; Generate density variation coefficient According to the following formula:

[0065] Where μ is the muon attenuation coefficient, μ≈0.1 cm 2 / g.

[0066] Step S5: Count the muon counts every 10 seconds, and use FPGA (Field-Programmable Gate Array) to perform vibration filtering and background subtraction on the original muon pulse signal to generate the depth The sequence is transmitted to the ground data processing platform; The present invention also provides another logging while drilling method based on muon imaging technology for continuous depth measurement and formation imaging method. Step M1: refer to step S1; Step M2: refer to step S2; Step M3: Use the ground power equipment to make the drill bit 220 drill into the formation, and stop after the drill bit 220 drills a certain distance (for example, about 1 meter). The muon detector 130 measures the muon flux of the current formation and calculates the density attenuation rate. .

[0067] Step M4: The downhole real-time processing module 310 performs background subtraction and transmits the data to the surface data processing platform, which calculates the formation density at the current depth and records the data; Step M5: Perform continuous depth measurement, add a certain length (eg, 1 meter) of drill rod 210, continue drilling, and stop again at a new depth to collect the density decay rate at the new depth.

[0068] Step M6: Repeat steps M3 to M5 to form a density profile of continuous depth by continuously measuring the muon flux at different depths.

[0069] Step M7: The ground data processing platform receives the density attenuation rate data at each depth and generates a continuous depth density profile.

[0070] Finally, it should be noted that the above-mentioned embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-mentioned embodiments within the technical scope disclosed by the present invention, or make equivalent replacements for some of the technical features thereof. However, these modifications, changes or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention. They should all be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0071] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A logging while drilling device based on muon imaging technology, characterized in that: include outer shell; The inner cylinder is coaxially nested in the outer cylinder, and a relatively sealed detection space is formed between the inner cylinder and the outer cylinder; as well as Muon detectors are set up in the detection space; The muon detector includes a scintillator assembly coaxially installed in the detection space and a photodetector arranged inside the scintillator assembly. The scintillator assembly is made of a scintillator material that can withstand high temperatures above 140°C, and the inner wall of the detection space is provided with an insulation layer.

2. The logging while drilling device based on muon imaging technology according to claim 1, characterized in that: The detection space is filled with a high melting point phase change material for preventing high temperature impact, and the melting point of the high melting point phase change material is not less than 140°C.

3. The logging while drilling device based on muon imaging technology according to claim 1, characterized in that: A vibration suppression module is provided on the scintillator assembly, which includes a first piezoelectric conversion module and a second piezoelectric conversion module. The first piezoelectric conversion module monitors the vibration signal of the scintillator assembly and generates a reverse driving signal according to the vibration signal to drive the second piezoelectric conversion module to generate reverse vibration, thereby suppressing vibration.

4. The logging while drilling device based on muon imaging technology according to claim 1, characterized in that: The outer shell is a titanium alloy shell, and an incident port is provided on the side wall of the outer shell corresponding to the scintillator assembly. The incident port is sealed with a muon high-transmittance material to form a muon incident window.

5. The logging while drilling device based on muon imaging technology according to claim 1, characterized in that: The scintillator assembly includes a plurality of coaxially stacked annular scintillators, and each scintillator assembly is provided with at least one corresponding photodetector.

6. The logging while drilling device based on muon imaging technology according to claim 5, characterized in that: The scintillator assembly further comprises a second scintillator array arranged on the outer side of the scintillator assembly and distributed circumferentially, and a photoelectric detector is provided at an end of the second scintillator array.

7. The logging while drilling device based on muon imaging technology according to claim 6, characterized in that: The scintillator assembly and the second scintillator surface are both coated with a reflective layer.

8. The logging while drilling device based on muon imaging technology according to claim 1, characterized in that: The device also includes an attitude sensor for monitoring the attitude of the logging while drilling device.

9. The logging while drilling device based on muon imaging technology according to claim 1, characterized in that: It also includes a data processing system, which includes a downhole real-time processing module and a ground processing platform. The downhole real-time processing module divides the continuous drilling process into multiple time slices for data storage, and independently calculates the muon flux decay rate for each time slice, and then improves the signal-to-noise ratio through weighted fusion; the ground processing platform includes an industrial computer for processing and analyzing the collected data.

10. The logging while drilling device based on muon imaging technology according to claim 1, characterized in that: The detection space is filled with inert gas.

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