Collection board and collection method for well logging

Abstract

The invention discloses an acquisition board and an acquisition method for well logging. The acquisition board comprises: a sampling module configured to compare the scintillation pulse with a preset threshold voltage to obtain a plurality of threshold voltage-time sampling points; the packaging module is configured to package the plurality of threshold voltage-time sampling points; the fitting module is configured to fit the waveform of the scintillation pulse according to the plurality of packaged threshold voltage-time sampling points to obtain energy information and time information of the scintillation pulse; and the summarizing module is configured to obtain an energy spectrum and a time spectrum of the scintillation pulse according to the energy information and the time information, and transmit the energy spectrum and the time spectrum to an upper computer. According to the invention, on the basis of an MVT sampling method, an existing mode of carrying out flicker pulse fitting by a server and a computer is abandoned, flicker pulse fitting is carried out on the acquisition board, and the method has the advantages of high speed, accurate result, stable system, high counting rate and the like.

Description

Technical Field

[0001] The present application relates to the field of material detection, and in particular to a collection plate and a collection method for well logging. Background Art

[0002] Introducing the multi-threshold voltage (MVT) digitization method into the field of oil exploration is a feasible method to solve the problem of oil logging pulse digitization. Compared with the traditional time interval sampling method such as analog-to-digital converter, MVT digital sampling fixes multiple threshold voltages and only digitally samples the time when the scintillation pulse passes through the threshold voltage, thereby obtaining multiple sampling points in the fast rising edge stage and the relatively slow falling edge. In specific use, after obtaining a series of time-voltage pair information, based on the prior scintillation pulse shape information, the scintillation pulse fitting method is used to achieve accurate acquisition of particle energy deposition information. At present, the Levenberg-Marquardt method is a scintillation pulse fitting optimization algorithm and the most widely used nonlinear least squares iterative algorithm. It uses the gradient to find the maximum (minimum) value, a nonlinear optimization method between the Newton method and the gradient descent method, and has the advantages of both the gradient method and the Newton method.

[0003] However, due to the limitation of chip computing power and the complexity of fitting methods, it is impossible to complete fitting in time on embedded chips such as field programmable gate arrays, STM32, and digital signal processing using iterative fitting algorithms. This requires that the original sampling points obtained by the MVT method must be transmitted to the computer through Ethernet, serial port, WiFi, etc., and then the energy is calculated through the software iteration algorithm. In the process of oil well logging, scintillation events show the characteristics of periodic outbreaks, and the data volume of the original sampling points will reach 10Mbps~1Gbps. However, due to the characteristics of the downhole depth of up to thousands of meters and high ambient temperature in the use scenario of oil exploration, the transmission method can only be transmitted by carrier communication, and the bandwidth is only about 100Kbyte. In the existing methods, the transmission of numerous original sampling points will undoubtedly occupy a very high bandwidth, resulting in a decrease in the count rate. When fitting on the host computer, due to repeated iterations, fitting each scintillation pulse requires ultra-high CPU time, which is intolerable in oil exploration.

[0004] The content of the background technology description is only for facilitating understanding of the relevant technology in this field and is not regarded as an admission of the prior art. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a collection plate and a collection method for well logging.

[0006] In a first aspect, a collection board for well logging is provided, the collection board comprising:

[0007] A sampling module, configured to compare the scintillation pulse with a preset threshold voltage to obtain a plurality of threshold voltage-time sampling points;

[0008] A packing module, configured to pack a plurality of the threshold voltage-time sampling points;

[0009] A fitting module, configured to fit the waveform of the scintillation pulse according to a plurality of packaged threshold voltage-time sampling points to obtain energy information and time information of the scintillation pulse;

[0010] The summarizing module is configured to obtain the energy spectrum and the time spectrum of the scintillation pulse according to the energy information and the time information, and transmit the energy spectrum and the time spectrum to a host computer.

[0011] According to an embodiment of the present application, the number of the sampling modules is the same as the number of the preset threshold voltages, and the two input terminals of each of the sampling modules respectively input the preset threshold voltage and the flicker pulse.

[0012] According to one embodiment of the present application, the packing module is configured to sort a number of the threshold voltage-time sampling points according to the size of the threshold voltage. When the flash pulse only crosses part of the preset threshold voltage, the sampling points corresponding to the preset threshold voltage that do not cross the preset threshold voltage are configured as (threshold voltage, 0).

[0013] According to an embodiment of the present application, the acquisition board further includes: a shaping module, which is arranged at the front end of the sampling module, and the shaping module is configured to shape the scintillation pulse.

[0014] According to an embodiment of the present application, the packing module and the fitting module are integrated into the same field programmable logic gate array chip, and the sampling module includes a low voltage differential signal interface of the field programmable logic gate array chip.

[0015] According to an embodiment of the present application, the packing module is integrated into a field programmable gate array chip, the sampling module includes a low voltage differential signal interface of the field programmable gate array chip, and the fitting module includes a digital signal processing chip.

[0016] According to an embodiment of the present application, the acquisition board further includes: a memory disposed between the field programmable logic gate array chip and the fitting module, the memory being configured to store a plurality of packaged threshold voltage-time sampling points.

[0017] A second aspect of the present application provides a method for collecting data for well logging, the method comprising:

[0018] The sampling module on the board is used to compare the flicker pulse with the preset threshold voltage to obtain a number of threshold voltage-time sampling points;

[0019] Using a packing module on the board to pack a number of the threshold-time sampling points;

[0020] Using a fitting module on the board to fit the waveform of the scintillation pulse according to a plurality of packaged threshold-time sampling points, to obtain energy information and time information of the scintillation pulse;

[0021] The energy spectrum and time spectrum of the scintillation pulse are obtained according to the energy information and time information by using a summary module on the board, and the energy spectrum and time spectrum are transmitted to a host computer.

[0022] According to an embodiment of the present application, the step of packaging a plurality of the threshold-time sampling points includes:

[0023] The threshold voltage-time sampling points are sorted according to the magnitude of the threshold voltage. When the flash pulse only crosses part of the preset threshold voltage, the sampling points corresponding to the threshold voltage that does not cross the preset threshold voltage are configured as (threshold voltage, 0).

[0024] According to an embodiment of the present application, the comparing the flicker pulse with a preset threshold voltage also includes: shaping the flicker pulse.

[0025] The acquisition system for well logging provided in the embodiment of the present application is based on the MVT sampling method, abandons the existing way of fitting scintillation pulses by servers and computers, and instead fits scintillation pulses on an acquisition board, which has the advantages of fast speed, accurate results, stable system, and high counting rate.

[0026] The optional features and other effects of the embodiments of the present application are partially described below, and partially can be understood by reading this document. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The embodiments of the present application are described in detail with reference to the accompanying drawings. The elements shown are not limited by the proportions shown in the accompanying drawings. The same or similar reference numerals in the accompanying drawings represent the same or similar elements, wherein:

[0028] Figure 1 It is a structural schematic diagram of a collection board for well logging according to an embodiment of the present application;

[0029] Figure 2 The present invention is a flowchart of a method for collecting data for well logging provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0031] It should be noted that when an element is referred to as "fixed to" another element, it can be directly on another element or there can also be a centered element. When an element is considered to be "connected" to another element, it can be directly connected to another element or there may be a centered element at the same time. The terms "vertical", "horizontal", "left", "right", "top", "bottom", "upper", "lower" and similar expressions used herein are only for the purpose of illustration and are not limited to practical applications. The described features, structures or characteristics can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to give a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical solution of the present application can be practiced in the absence of some specific details, or the technical solution of the present application can be practiced in other ways, components, materials, devices or operations. In these cases, known structures, methods, devices, implementations, materials or operations will not be shown or described in detail.

[0032] The flowcharts shown in the accompanying drawings are only exemplary and do not necessarily include all the contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may change according to actual conditions.

[0033] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The term "and / or" or "and / or" includes any and all combinations of one or more related listed items.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0035] Well logging technology is a very important technical means in the field of oil exploration. It combines electronic technology and computer technology through various methods such as electricity, acoustics, and radiology to obtain various physical parameters of the formation, and further obtains oil and gas information through data analysis. Common well logging technologies include electrical logging, acoustic logging, nuclear logging, and nuclear magnetic logging. Among them, nuclear logging is based on the physical properties of the atomic nucleus of matter. It studies the drilling geological profile according to the nuclear physical properties of rocks, their pore fluids, and the medium in the well to find coal, oil and other mineral deposits. Nuclear logging includes natural gamma, density, neutron, formation elements and other logging technologies and supporting instruments and equipment.

[0036] Pulsed neutron logging is a type of nuclear logging. Its principle is to obtain the gamma rays released by the energy deposition of pulsed neutrons in the formation to obtain the corresponding energy spectrum information and time spectrum information. The main means of gamma ray detection is to use scintillation crystals coupled with photoelectric conversion devices. The scintillation crystals deposit the energy of gamma rays to generate visible light, which is converted into electrical signals by photoelectric conversion devices to obtain information such as the energy of gamma rays. At present, the scintillation crystals generally used are BGO, lanthanum bromide, sodium iodide, etc., and photomultiplier tubes (PMTs) that can work under high temperature conditions are usually used as photoelectric conversion devices. The corresponding scintillation pulses can be obtained through the scintillation pulse probe, and the energy spectrum and time spectrum of gamma rays can be obtained after digitization and subsequent signal processing.

[0037] There are two common traditional digitization methods. The first is the direct digitization method of high-speed analog-to-digital converter (ADC), which requires first shaping and widening the electrical pulse signal, and then using a high-speed ADC (1GSps) for digital sampling. However, in engineering practice, to digitize a pulse in order to obtain more accurate energy information, it is necessary to collect at least 20 sampling points. At the same time, the sampling rate performance of ADC chips working under high temperature (175°C) conditions is usually not very high, and the cost is very high. Therefore, it is impossible to complete the digitization of high-speed scintillation crystal pulse signals, making it difficult to apply to oil well logging. The second is the peak hold method, which uses a peak hold circuit The amplitude of the electrical pulse signal is locked, and then the ADC is used to collect the amplitude to obtain the energy information of the pulse. Although the peak hold method can process pulses of high-speed scintillation crystals, its dead time is very long due to the peak hold lock establishment and peak hold circuit recovery process, usually reaching hundreds of microseconds. This greatly limits the pulse throughput rate of the digitized part (the number of pulses processed per unit time). In oil well logging, the number of pulse events often grows explosively. In common neutron oil well logging, the instantaneous count rate of pulses can reach 1Mcps. The dead time of the peak hold method will cause the digitization process to lose many pulse signals, thereby causing deviations in the measurement results.

[0038] The multi-voltage threshold sampling (MVT) method is a flicker pulse digitization method based on prior information. The MVT flicker pulse digitization process can be roughly divided into two steps: (1) Sample acquisition. That is, n fixed threshold voltages V are pre-set. n Then, the time point information T of the preset threshold voltage when the rising edge of the flash pulse crosses positively (from low to high and finally higher than the threshold voltage) and the falling edge of the flash pulse crosses negatively (from high to low and finally lower than the threshold voltage) is recorded respectively. n1 、T n2 , thus obtaining the sampling sample S of the scintillation pulse 2n-1 (T 2n-1 , V n ), S 2n (T 2n , V n ). For N threshold voltages, 2n sample points will be obtained in the end. (2) Reconstruction and information extraction of scintillation pulses. Accurate reconstruction of scintillation pulses using the acquired sample points depends on an accurate mathematical model of scintillation pulses. A good mathematical model will make the reconstructed scintillation pulses closer to the real scintillation pulse shape, thereby improving the accuracy of the extraction of scintillation pulse time information and energy information.

[0039] In this regard, an embodiment of the present application provides a board-level fitting, in which the entire MVT steps are all completed in the printed circuit board, and the energy information of the scintillation pulse can be quickly, accurately and stably obtained on the hardware without the need for a server or computer.

[0040] Figure 1 FIG. 1 is a schematic diagram of the structure of a collection board for well logging according to an embodiment of the present application. Figure 1 As shown, the acquisition board for well logging provided in the embodiment of the present application generally includes: a sampling module 10, a packaging module 20, a fitting module 30 and a summarizing module 40.

[0041] Specifically, the sampling module 10 is configured to compare the scintillation pulse with a preset threshold voltage to obtain a plurality of threshold voltage-time sampling points.

[0042] In an embodiment of the present application, a scintillation pulse can be acquired through a probe, and the probe may include a scintillation crystal and a photoelectric conversion device, which are coupled together, wherein the scintillation crystal includes yttrium lutetium silicate or lanthanum bromide, etc., and the photoelectric conversion device includes a silicon photomultiplier tube (SiPM) or a photomultiplier tube (PMT), etc.

[0043] More specifically, the acquisition board also includes a shaping module, which is arranged at the front end of the sampling module 10, and the shaping module is configured to shape the flicker pulse. The shaping module can be a low-pass resistor-capacitor filter circuit composed of a simple resistor and a capacitor, or a more complex Gaussian shaping circuit. The Gaussian shaping circuit can be a multi-order resistor-capacitor low-pass filter. According to the circuit design convention of Gaussian shaping, these multi-order resistor-capacitor low-pass filters all use the same parameters, and considering the isolation problem between resistor-capacitor low-pass filters of each order, an amplifier is used to separate each low-pass filter like a fence to ensure that each resistor-capacitor low-pass filter does not affect other filters.

[0044] Regarding the preset threshold voltage, it is understood that there are generally multiple preset threshold voltages, and the settings of these threshold voltages are usually determined by simulation or other methods. For example, the baseline of the scintillation pulse is at 0V, and the amplitude of the scintillation pulse to be measured during logging is roughly 0-2V. According to previous simulation experiments, the starting point of the threshold is determined to be 50mV, and the step length is 50mV, so a total of 16 threshold voltages are preset. It is understood that the setting of the specific threshold voltage can refer to the actual use situation.

[0045] More specifically, the number of the sampling modules 10 is the same as the number of the preset threshold voltages, and the two input terminals of each sampling module 10 respectively input the preset threshold voltage and the flicker pulse. For example, in the above embodiment in which 16 threshold voltages are set, the number of the sampling modules 10 is also 16, and each sampling module 10 corresponds to one threshold voltage.

[0046] Specifically, the packing module 20 is configured to pack a plurality of the threshold voltage-time sampling points, and the packing method may have certain rules, for example, the sampling points are sorted according to the magnitude of the threshold voltage and then packed.

[0047] More specifically, the packaging module 20 is configured to sort the plurality of threshold voltage-time sampling points according to the magnitude of the threshold voltage, and when the flicker pulse only crosses part of the preset threshold voltage, the sampling points corresponding to the preset threshold voltage that have not been crossed are configured as (threshold voltage, 0). Exemplarily, the packaging module 20 arranges the sampling points from front to back according to the threshold voltage from small to large, in a row. Assuming that 16 threshold voltages are set, if the flicker pulse does not have a high enough amplitude to trigger all the threshold voltages, for example, only 3 threshold voltages are triggered, that is, 3 threshold voltages are triggered on the rising edge, and similarly 3 threshold voltages are also triggered on the falling edge, so there are only 6 sampling points (v, t), and at this time, the sampling points of the threshold voltages that have not been triggered are set to (v, 0). That is to say, for the sampling point of the trigger threshold voltage, the real sampling point (v, t) is used, and for the sampling point without triggering the threshold voltage, 0 is used as the sampling point time, and the following 32 sampling points (v1, t1), (v2, t2), (v3, t3), (v4, 0), (v5, 0), ... (v 16 ,0)、(v 16 ,0),...,(v5,0),(v4,0),(v3,t 30 )、(v2,t 31 )、(v1,t 32 ). In this way, the sampling point of each acquired scintillation pulse can be retained.

[0048] Specifically, the fitting module 30 is configured to fit the waveform of the scintillation pulse according to a plurality of packaged threshold voltage-time sampling points to obtain energy information and time information of the scintillation pulse.

[0049] Exemplarily, the fitting module 30 may obtain the energy information and time information of the scintillation pulse by using the least square method, or may obtain the energy information and time information of the scintillation pulse by using other existing methods. This process may refer to the existing technology and will not be described in detail here.

[0050] More specifically, in an example of the present application, the packing module 20 and the fitting module 30 are integrated in the same field programmable gate array chip (FPGA), and the sampling module 10 includes a low voltage differential signal interface (LVDS) of the field programmable gate array chip (FPGA). In this example, the use of FPGA for packing and fitting can directly avoid the problem of low counting rate caused by communication bottlenecks and large amount of data at the transmitted sampling points. LVDS has a function similar to that of a comparator, and its number is the same as the number of preset threshold voltages. One end of each LVDS is connected to the preset threshold voltage, and the other end is uniformly connected to the flicker pulse, so that the flicker pulse can be collected into the FPGA through the LVDS interface.

[0051] More specifically, in another example of the present application, the packing module 20 is integrated in a field programmable gate array chip (FPGA), the sampling module 10 includes a low voltage differential signal interface (LVDS) of the field programmable gate array chip (FPGA), and the fitting module 30 includes a digital signal processing chip (DSP). Different from the above example, in this example, the fitting work is performed by the DSP. Compared with the above example, the solution is easier to implement. The counting rate of the entire acquisition board is generally about 25kcps. Under the architecture of MVT sampling, the counting rate is not as good as the above example.

[0052] More specifically, in the example where the fitting work is performed by DSP, the acquisition system also includes: a memory, which is arranged between the field programmable gate array chip (FPGA) and the fitting module 30, and the memory is configured to store a packaged number of the threshold voltage-time sampling points. The memory serves to temporarily store a number of the threshold voltage-time sampling points, which can improve the counting rate of the entire acquisition board.

[0053] Specifically, the summary module 40 is configured to obtain the energy spectrum and time spectrum of the scintillation pulse according to the energy information and the time information, and transmit the energy spectrum and the time spectrum to the host computer. Exemplarily, the summary module 40 includes a digital signal processing chip (DSP). It can be understood that in the example where the DSP performs the fitting work, there are two DSPs, one DSP performs the fitting work, and the other DSP performs the summarization work. The DSP that performs the summarization work integrates the energy information and the time information into an energy spectrum and a time spectrum, and uploads the energy spectrum and the time spectrum to the host computer after summarizing them. The DSP and the host computer can be connected via a CAN bus to achieve the transmission of the energy spectrum and the time spectrum.

[0054] The acquisition system for well logging provided in the present application is based on the MVT sampling method, abandons the existing way of fitting scintillation pulses by servers and computers, and instead fits scintillation pulses on an acquisition board, which has the advantages of fast speed, accurate results, stable system, and high counting rate.

[0055] Corresponding to the above-mentioned acquisition system for well logging, the present application also provides an acquisition method for well logging. Figure 2 Flow chart of the acquisition method for well logging provided according to the embodiment of the present application. Figure 2 As shown, the collection method includes:

[0056] S10: using a sampling module on the board to compare the flicker pulse with a preset threshold voltage to obtain a plurality of threshold voltage-time sampling points.

[0057] In an embodiment of the present application, a scintillation pulse can be acquired through a probe, and the probe may include a scintillation crystal and a photoelectric conversion device, which are coupled together, wherein the scintillation crystal includes yttrium lutetium silicate or lanthanum bromide, etc., and the photoelectric conversion device includes a silicon photomultiplier tube (SiPM) or a photomultiplier tube (PMT), etc.

[0058] More specifically, the acquisition method is further configured to shape the flicker pulse. A shaping module can be used to shape the flicker pulse. The shaping module can be a low-pass resistor-capacitor filter circuit composed of a simple resistor and capacitor, or a more complex Gaussian shaping circuit. The Gaussian shaping circuit can be a multi-order resistor-capacitor low-pass filter. According to the circuit design convention of Gaussian shaping, these multi-order resistor-capacitor low-pass filters all use the same parameters, and considering the isolation problem between resistor-capacitor low-pass filters of each order, an amplifier is used to separate each low-pass filter like a fence to ensure that each resistor-capacitor low-pass filter does not affect other filters.

[0059] Regarding the preset threshold voltage, it is understood that there are generally multiple preset threshold voltages, and the settings of these threshold voltages are usually determined by simulation or other methods. For example, the baseline of the scintillation pulse is at 0V, and the amplitude of the scintillation pulse to be measured during logging is roughly 0-2V. According to previous simulation experiments, the threshold revelation point is determined to be 50mV, and the step size is 50mV, so a total of 16 threshold voltages are preset. It is understood that the setting of the specific threshold voltage can refer to the actual use situation.

[0060] More specifically, the number of the sampling modules is the same as the number of the preset threshold voltages, and the two input terminals of each sampling module respectively input a preset threshold voltage and the flicker pulse. For example, in the above embodiment in which 16 threshold voltages are set, the number of the sampling modules is also 16, and each sampling module corresponds to one threshold voltage.

[0061] S20: using a packing module on the board to pack a plurality of the threshold-time sampling points.

[0062] More specifically, the packaging module is configured to sort the plurality of threshold voltage-time sampling points according to the magnitude of the threshold voltage, and when the flicker pulse only crosses part of the preset threshold voltage, the sampling points corresponding to the preset threshold voltage that have not been crossed are configured as (threshold voltage, 0). Exemplarily, the packaging module arranges the sampling points from front to back according to the threshold voltage from small to large, in a row. Assuming that 16 threshold voltages are set, if the flicker pulse does not have a high enough amplitude to trigger all the threshold voltages, for example, only 3 threshold voltages are triggered, that is, 3 threshold voltages are triggered on the rising edge, and similarly 3 threshold voltages are triggered on the falling edge, so there are only 6 sampling points (v, t), and at this time, the sampling points of the threshold voltages that have not been triggered are set to (v, 0). That is to say, for the sampling point of the trigger threshold voltage, the real sampling point (v, t) is used, and for the sampling point without triggering the threshold voltage, 0 is used as the sampling point time, and the following 32 sampling points (v1, t1), (v2, t2), (v3, t3), (v4, 0), (v5, 0) ... (v 16 ,0)、(v 16 ,0),...,(v5,0),(v4,0),(v3,t 30 )、(v2,t 31 )、(v1,t 32 ). In this way, the sampling point of each acquired scintillation pulse can be retained.

[0063] S30: using a fitting module on the board to fit the waveform of the scintillation pulse according to the packaged plurality of threshold-time sampling points, to obtain energy information and time information of the scintillation pulse.

[0064] Exemplarily, the fitting module may use the least square method to obtain the energy information and time information of the scintillation pulse. This process may refer to the prior art and will not be described in detail here.

[0065] More specifically, in an example of the present application, the packing module and the fitting module are integrated in the same field programmable gate array chip (FPGA), and the sampling module includes a low voltage differential signal interface (LVDS) of the field programmable gate array chip. In this example, the use of FPGA for packing and fitting can directly avoid the problem of low counting rate caused by communication bottlenecks and large amounts of data at the transmitted sampling points. LVDS has a function similar to that of a comparator, and its number is the same as the number of preset threshold voltages. One end of each LVDS is connected to a preset threshold voltage, and the other end is uniformly connected to a flicker pulse, so that the flicker pulse can be collected into the FPGA through the LVDS interface.

[0066] More specifically, in another example of the present application, the packing module is integrated in a field programmable gate array chip (FPGA), the sampling module of the field programmable gate array includes a low voltage differential signal interface (LVDS) of the field programmable gate array chip, and the fitting module includes a digital signal processing chip (DSP). Different from the above example, in this example, the fitting work is performed by the DSP. Compared with the above example, the solution is easier to implement. The counting rate of the entire acquisition board is generally around 25kcps. Under the architecture of MVT sampling, the counting rate is not as good as the above example.

[0067] More specifically, in an example in which the fitting work is performed by DSP, the acquisition system also includes: a memory, which is arranged between the field programmable logic gate array chip and the fitting module, and the memory is configured to store a packaged number of the threshold voltage-time sampling points. The memory serves to temporarily store a number of the threshold voltage-time sampling points, which can improve the counting rate of the entire acquisition board.

[0068] S40: using a summary module on the board to obtain an energy spectrum and a time spectrum of the scintillation pulse according to the energy information and the time information, and transmitting the energy spectrum and the time spectrum to a host computer.

[0069] Exemplarily, the summary module includes a digital signal processing chip (DSP). It can be understood that in the example where the DSP performs the fitting work, there are two DSPs, one DSP performs the fitting work, and the other DSP performs the summarization work. The DSP that performs the summarization work integrates the energy information and the time information into an energy spectrum and a time spectrum, and uploads the energy spectrum and the time spectrum to the host computer after summarizing them. The DSP and the host computer can be connected via a CAN bus to achieve the transmission of the energy spectrum and the time spectrum.

[0070] The acquisition method for well logging provided in the present application is based on the MVT sampling method, abandons the existing way of fitting scintillation pulses by servers and computers, and instead fits scintillation pulses on an acquisition board, which has the advantages of fast speed, accurate results, stable system, and high counting rate.

[0071] It should be noted that the above description of the modules is only for convenience of description and does not limit the present application to the scope of the embodiments. It is understandable that, after understanding the principle of the system, those skilled in the art may arbitrarily combine the modules or form a subsystem connected to other modules without deviating from the principle.

[0072] The basic concepts have been described herein. Obviously, for those skilled in the art, the above detailed disclosure is only for example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.

[0073] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or multiple times in different positions in the present application does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0074] In addition, it will be appreciated by those skilled in the art that various aspects of the present application may be illustrated and described by a number of patentable categories or situations, including any new and useful process, machine, product or combination of substances, or any new and useful improvements thereto. Accordingly, various aspects of the present application may be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software may all be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". In addition, various aspects of the present application may be represented as a computer product located in one or more computer-readable media, which includes computer-readable program code.

[0075] In addition, unless explicitly stated in the claims, the order of the processing elements and sequences described in this application, the use of alphanumeric characters, or the use of other names are not intended to limit the order of the processes and methods of this application. Although the above disclosure discusses some invention embodiments that are currently considered useful through various examples, it should be understood that such details are only for illustrative purposes, and the attached claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the essence and scope of the embodiments of this application. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0076] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more embodiments of the invention, in the above description of the embodiments of this application, multiple features are sometimes combined into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.

[0077] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±10%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values ​​is as accurate as possible within the feasible range.

[0078] Each patent, patent application, patent application disclosure, and other materials, such as articles, books, instructions, publications, documents, etc., cited in this application are hereby incorporated by reference in their entirety. Except for application history documents that are inconsistent with or conflicting with the content of this application, documents that limit the broadest scope of the claims of this application (currently or later attached to this application) are also excluded. It should be noted that if the descriptions, definitions, and / or use of terms in the attached materials of this application are inconsistent or conflicting with the content described in this application, the descriptions, definitions, and / or use of terms in this application shall prevail.

[0079] Finally, it should be understood that the embodiments described in this application are only used to illustrate the principles of the embodiments of the present application. Other variations may also fall within the scope of the present application. Therefore, as an example and not a limitation, the alternative configurations of the embodiments of the present application may be considered to be consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments explicitly introduced and described in the present application.

Claims

1. A collection board for well logging, characterized in that: The acquisition board comprises: A sampling module, configured to compare the scintillation pulse with a preset threshold voltage to obtain a plurality of threshold voltage-time sampling points; A packing module, configured to pack a plurality of the threshold voltage-time sampling points; A fitting module, configured to fit the waveform of the scintillation pulse according to a plurality of packaged threshold voltage-time sampling points to obtain energy information and time information of the scintillation pulse; The summarizing module is configured to obtain the energy spectrum and the time spectrum of the scintillation pulse according to the energy information and the time information, and transmit the energy spectrum and the time spectrum to a host computer.

2. The acquisition board according to claim 1, characterized in that: The number of the sampling modules is the same as the number of the preset threshold voltages, and the two input terminals of each sampling module are respectively input with the preset threshold voltage and the flicker pulse.

3. The acquisition board according to claim 1, characterized in that: The packing module is configured to sort the plurality of threshold voltage-time sampling points according to the magnitude of the threshold voltage, and when the flash pulse only crosses part of the preset threshold voltage, the sampling points corresponding to the preset threshold voltage that do not cross are configured as (threshold voltage, 0).

4. The acquisition board according to claim 1, characterized in that: The acquisition board further includes: a shaping module, which is arranged at the front end of the sampling module, and the shaping module is configured to shape the scintillation pulse.

5. The acquisition board according to claim 1, characterized in that: The packing module and the fitting module are integrated in the same field programmable logic gate array chip, and the sampling module includes a low voltage differential signal interface of the field programmable logic gate array chip.

6. The acquisition board according to claim 1, characterized in that: The packing module is integrated in a field programmable logic gate array chip, the sampling module includes a low voltage differential signal interface of the field programmable logic gate array chip, and the fitting module includes a digital signal processing chip.

7. The acquisition board according to claim 6, characterized in that: The acquisition board further includes: a memory, which is arranged between the field programmable logic gate array chip and the fitting module, and the memory is configured to store a plurality of the packaged threshold voltage-time sampling points.

8. A method for collecting data for well logging, characterized in that: The collection method comprises: The sampling module on the board is used to compare the flicker pulse with the preset threshold voltage to obtain a number of threshold voltage-time sampling points; Using a packing module on the board to pack a number of the threshold-time sampling points; Using a fitting module on the board to fit the waveform of the scintillation pulse according to a plurality of packaged threshold-time sampling points, to obtain energy information and time information of the scintillation pulse; The energy spectrum and time spectrum of the scintillation pulse are obtained according to the energy information and the time information by using a summary module on the board, and the energy spectrum and the time spectrum are transmitted to a host computer.

9. The collection method according to claim 8, characterized in that: The step of packaging a plurality of the threshold-time sampling points comprises: The threshold voltage-time sampling points are sorted according to the magnitude of the threshold voltage. When the flash pulse only crosses part of the preset threshold voltage, the sampling points corresponding to the preset threshold voltage that do not cross are configured as (threshold voltage, 0).

10. The collection method according to claim 9, characterized in that: The step of comparing the flash pulse with a preset threshold voltage also includes: The scintillation pulses are shaped.

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