Electric pulse transient shock wave oil-water well resonance yield increasing method and system

Abstract

The invention relates to the technical field of oil exploitation, in particular to an electric pulse transient shock wave oil-water well resonance yield increasing method and system, and the method comprises the steps: analyzing the difference between the maximum amplitude and the average amplitude in each modal component, and combining the difference between the energy sum value of each modal component in the 3dB bandwidth and the total energy of the modal components, determining an energy characteristic value; comparing the difference between the energy characteristic values of all the high-energy components and all the low-energy components, and determining an energy concentration value; and determining a fixed frequency deviation value by measuring the difference of the fixed matching degree between each time period and the previous time period and combining the minimum fixed frequency matching degree of the vibration signals in all time periods so as to determine the initial discharge frequency of crack-induced blockage removal in the electric pulse blockage removal process. The problem that transient shock waves formed by the fixed discharge frequency are not beneficial to formation and development of oil layer cracks is solved, and the oil layer plug removal efficiency and the resonance yield increasing effect are improved.

Description

Technical Field

[0001] The present application relates to the technical field of oil extraction, and in particular to a method and system for increasing the production of oil and water wells by resonance using electric pulse transient shock waves. Background Art

[0002] After the oil field is put into production, as the oil and gas are produced, the oil layer pressure gradually decreases, and energy needs to be continuously added to the oil layer. As a very important exploitation method for oil field development, oil-water wells are an effective way to replenish oil layer energy and maintain long-term high and stable production of oil fields. Water is injected into the oil layer through water injection wells to maintain oil layer pressure and increase oil production rate and recovery rate. During the drilling, completion, production and implementation of production increase measures, oil-water wells may cause damage to the oil layer, causing the oil layer to be polluted by various factors, resulting in a significant reduction in the permeability of the near-well area, affecting the flow of bottom oil, and causing a decrease in oil well production. Therefore, it is necessary to unblock the oil layer, restore and improve the permeability of the oil layer, so as to maintain stable production and increase production of the oil field.

[0003] As a commonly used physical oil production technology, electric pulse unblocking technology releases high-voltage electric pulses at the oil layer position in the well to generate transient shock waves and cavitation, form microcracks, increase the seepage area, and thus achieve oil field production increase. At present, the discharge frequency of electric pulse unblocking technology is usually fixed. When unblocking oil layers with different natural frequencies, the transient shock waves formed by the fixed discharge frequency are not conducive to the formation and development of oil layer cracks. At the same time, during the unblocking process, as the transient shock wave changes the fracture structure of the oil layer, the natural frequency of the oil layer also changes, resulting in the transient shock wave formed by the fixed electric discharge frequency, which reduces the efficiency and rate of oil layer unblocking, and the production increase effect of oil and water wells is not good. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of this application is to provide an electric pulse transient shock wave oil and water well resonance production enhancement method and system, the technical scheme adopted is as follows: In a first aspect, an embodiment of the present application provides a method for increasing oil and water well production by resonance using an electric pulse transient shock wave, the method comprising the following steps: The fixed frequency detection and unblocking process of electric pulse unblocking is divided into a preset number of time periods, a discharge frequency is set for the electric pulse in each time period, and the vibration signal in the oil and water well under the discharge frequency of the electric pulse in each time period is obtained; Decompose the vibration signal of each time period into multiple modal components, determine the amplitude difference by analyzing the difference between the maximum amplitude and the average amplitude of each modal component, and determine the energy characteristic value of each modal component in each time period by combining the difference between the energy sum of each modal component within its 3dB bandwidth and the total energy of the modal component; Compare the difference between the energy characteristic value of each modal component in each time period and the average energy characteristic value of all modal components, divide all modal components into high-energy components and low-energy components, compare the difference between the energy characteristic values ​​of all high-energy components and all low-energy components, and determine the energy concentration value of the vibration signal in each time period; By comparing the difference between the discharge frequency in each time period and the maximum discharge frequency in all time periods, and combining the total energy and energy concentration value of the vibration signal in each time period, the fixed frequency matching degree of the vibration signal in each time period is determined; by measuring the difference between the fixed matching degree of each time period and the previous time period, and combining the minimum fixed frequency matching degree of the vibration signal in all time periods, the fixed frequency deviation value of the vibration signal in each time period is determined; Based on the difference in the natural frequencies of all high-energy components between the last period and the previous period in the fixed-frequency detection and unblocking process, the high-energy deviation is determined, and the initial discharge frequency of fracture-induced unblocking in the electric pulse unblocking process is determined by combining the discharge frequency and the fixed-frequency deviation value in the last period.

[0005] Preferably, the method for determining the amplitude difference is: The ratio of the maximum amplitude to the average amplitude in each modal component is taken as the amplitude difference of each modal component.

[0006] Preferably, the method for determining the energy characteristic value of each modal component in each time period is: Calculate the ratio of the energy sum of each modal component of the vibration signal within the 3dB bandwidth and the total energy of the modal component in each time period, record it as the energy ratio of each modal component, and take the product of the amplitude difference of each modal component in each time period and the energy ratio as the energy characteristic value of each modal component in each time period.

[0007] Preferably, dividing all modal components into high-energy components and low-energy components comprises: Among all the modal components in each time period, the modal components whose energy eigenvalues ​​are greater than the average energy eigenvalue are recorded as high-energy components, and all the remaining modal components are recorded as low-energy components.

[0008] Preferably, the method for determining the energy concentration value of the vibration signal in each time period is: The sum of the ratios of the energy characteristic values ​​between each high-energy component and all low-energy components in each time period is taken, and the accumulated result of the sum of all high-energy components is taken as the energy concentration value of the vibration signal in each time period.

[0009] Preferably, the expression of the fixed frequency matching degree of the vibration signal in each time period is: ; In the formula, Indicates the fixed frequency matching degree of the vibration signal in time period i; Represents the total energy of the vibration signal in time period i; represents the discharge frequency in time period i; Indicates the maximum discharge frequency within a preset number of time periods; represents the energy concentration value of the vibration signal in time period i; ln( ) represents the logarithmic function with the natural constant as the base; Indicates a preset value.

[0010] Preferably, the expression of the fixed frequency deviation value of the vibration signal in each time period is: ; Indicates the fixed frequency deviation value of the vibration signal in time period i; , They represent the fixed-frequency matching degree in time periods i-1 and i respectively; max{} represents the maximum value function.

[0011] Preferably, the high energy deviation is: the average value of the natural frequency difference of all high energy components between the last time period of the fixed frequency detection and unblocking process and the previous time period.

[0012] Preferably, the expression of the initial discharge frequency of crack induced unblocking in the electric pulse unblocking process is: ; In the formula, It indicates the initial discharge frequency of crack-induced unblocking during the electric pulse unblocking process; Indicates the discharge frequency of the last period in the process of fixed frequency detection and unblocking; Indicates high energy deviation; Indicates the fixed frequency deviation value of the last period in the fixed frequency detection and unblocking process; ceil() represents the upward rounding function. In a second aspect, the embodiment of the present application also provides an electric pulse transient shock wave oil and water well resonance production enhancement system, including a memory, a processor, and a computer program stored in the memory and running on the processor, and when the processor executes the computer program, the steps of any one of the above-mentioned electric pulse transient shock wave oil and water well resonance production enhancement methods are implemented.

[0013] This application has at least the following beneficial effects: The present application constructs an energy characteristic value by analyzing the modal component characteristics of the vibration signal in each time period during the fixed-frequency detection and unblocking process, and can identify the frequency component that matches the natural frequency of the oil layer well, providing a basis for the subsequent adjustment of the discharge frequency of the electric pulse, so that it is closer to the natural frequency of the oil layer and achieves more effective resonance; further, by comparing the difference in energy characteristics between the high-energy component and the low-energy component, an energy concentration value is constructed, and the discharge frequency is optimized, so that the energy is more concentrated on the weak parts of the oil layer, thereby more effectively inducing the generation and development of microcracks and improving the production increase effect of oil and water wells; further, the present application constructs a fixed-frequency deviation value by comparing the difference in fixed-frequency matching in different time periods, so as to timely discover the degree of deviation between the discharge frequency of the electric pulse and the natural frequency of the oil layer, and can dynamically increase the discharge frequency of the positive electric pulse to keep it in the best match with the actual natural frequency of the current oil layer, avoiding the weakening of the resonance effect caused by the frequency deviation, thereby improving the oil layer unblocking efficiency and the resonance production increase effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 A flowchart of the steps of an electric pulse transient shock wave resonance production enhancement method for oil and water wells provided in one embodiment of the present application; Figure 2 A schematic diagram of a fixed frequency matching degree extraction process provided by an embodiment of the present application. DETAILED DESCRIPTION

[0016] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following is a detailed description of the electric pulse transient shock wave oil and water well resonance production enhancement method and system proposed in the present application, its specific implementation method, structure, features and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0017] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0018] The specific scheme of the electric pulse transient shock wave oil and water well resonance production enhancement method and system provided by the present application is described in detail below with reference to the accompanying drawings.

[0019] See also Figure 1 , which shows a flow chart of the steps of an electric pulse transient shock wave oil and water well resonance production enhancement method provided by an embodiment of the present application, the method comprising the following steps: Step S1: Divide the fixed frequency detection and unblocking process of electric pulse unblocking into a preset number of time periods, set the discharge frequency of the electric pulse in each time period, and obtain the vibration signal in the oil and water well at the discharge frequency of the electric pulse in each time period.

[0020] The core of electric pulse plugging removal technology is to use transient shock waves to act on the oil layer, thereby forming new microcracks and improving seepage conditions. However, the natural frequency of the oil layer varies depending on the geological characteristics, and the natural frequency will change as the cracks expand during the plugging removal process. Therefore, if the discharge frequency is fixed, it is difficult to ensure that the transient shock wave always matches the natural frequency of the oil layer, resulting in a decrease in plugging removal efficiency.

[0021] In this embodiment, an electric pulse device is installed at the oil layer position, and a vibration sensor is installed inside the oil pipe of the same oil layer. Since this embodiment adopts electric pulse unblocking technology to unblock oil and water wells, it is divided into two processes: fixed frequency detection unblocking and fracture induced unblocking. The whole oil and water well unblocking takes 30 minutes, of which fixed frequency detection unblocking takes 1 minute and fracture induced unblocking takes 29 minutes. Therefore, the fixed frequency detection unblocking process of electric pulse unblocking is divided into a preset number of time periods. In this embodiment, the preset number is 10, and the length of each time period is 6s. The discharge frequency of the electric pulse device in each time period is set to 50Hz, 45Hz, 40Hz, 35Hz, 30Hz, 25Hz, 20Hz, 15Hz, 10Hz, and 5Hz in chronological order; further, the vibration signal in the oil and water well in each time period is obtained based on the above content.

[0022] It should be noted that the value of the preset number and the value of the length of each time period are all manually set, and the implementer can also set them according to the specific situation. This embodiment does not impose any special restrictions.

[0023] In addition, it should be noted that the sampling frequency of the vibration sensor used in this implementation is 10kHz, the electric pulse equipment is powered by three-phase AC, the input frequency is 50Hz, the input phase voltage range is 210~230V, the discharge voltage level is 7~25kV, the discharge frequency is adjustable, and the adjustable range is 0~60Hz. The discharge voltage of the electric pulse equipment in this implementation is set to 7.5kV.

[0024] Furthermore, during the discharge process of the electric pulse device, the high-frequency harmonics cause electromagnetic interference to the vibration sensor and the communication cable, and some high-frequency noise exists in the collected vibration signal. Therefore, this embodiment uses a median filtering algorithm to filter the collected vibration signal to remove the high-frequency noise in the vibration signal. In actual application, as other implementation methods, the implementer may also use other denoising methods such as Gaussian filtering or mean filtering algorithms according to the specific circumstances. Regarding the selection of denoising algorithms, this embodiment does not impose any special restrictions.

[0025] Among them, the median filtering algorithm is a well-known technology, and its specific principle process of signal denoising is not repeated here.

[0026] Step S2: Decompose the vibration signal of each time period into multiple modal components, determine the amplitude difference by analyzing the difference between the maximum amplitude and the average amplitude in each modal component, and determine the energy characteristic value of each modal component in each time period by combining the difference between the energy sum of each modal component within its 3dB bandwidth and the total energy of the modal component.

[0027] When the transient shock wave generated by the electric pulse resonates with the oil layer, the energy of the transient shock wave can be transferred to the oil layer to the greatest extent without being reflected or dissipated. At the same time, under the resonance state, the energy of the transient shock wave is concentrated on the weak parts of the oil layer, inducing the generation and development of microcracks, improving the efficiency and rate of the electric pulse equipment to remove plugging, and thus improving the production increase effect of oil and water wells.

[0028] During the electric pulse unblocking process, the high temperature, high pressure and strong magnetic field in the oil layer produce strong local pressure changes. When the static pressure in the oil layer liquid is lower than the saturated vapor pressure of the liquid, the liquid will be locally vaporized to form bubbles and produce cavitation. When the bubble bursts, the gas inside it is rapidly compressed and releases a large amount of energy, and a secondary transient shock wave is generated. At the same time, the bubble bursting process in the cavitation phenomenon is nonlinear, and the growth and rupture time of the bubble is shorter than the electric pulse cycle. Therefore, the frequency of the transient shock wave is often higher than the discharge frequency of the electric pulse device. By measuring the natural frequency of the oil layer and adjusting the discharge frequency of the electric pulse device accordingly, the transient shock wave and the oil layer will deviate from the resonance state, affecting the effect of electric pulse unblocking and resonance increase in oil and water wells.

[0029] Therefore, based on the above analysis, in this embodiment, the vibration signal of each time period is decomposed into multiple modal components, and the amplitude difference is determined by analyzing the difference between the maximum amplitude and the average amplitude in each modal component, and the energy characteristic value of each modal component in each time period is determined by combining the difference between the energy sum value of each modal component within its 3dB bandwidth and the total energy of the modal component. The specific process is as follows: Oil layers are usually composed of multiple media, including rocks, fluids (oil, water), pores and cracks, etc. The elastic modulus, density and damping characteristics of these media are different, resulting in complex vibration behaviors of the oil layer. The coupling of multiphase media makes the oil layer exhibit multiple natural frequencies when subjected to transient shock waves.

[0030] Therefore, this embodiment uses the vibration signal of each time period as the input of the modal decomposition algorithm and outputs all modal components, wherein each modal component represents a natural vibration frequency mode of the vibration signal of the time period.

[0031] It should be noted that there are many commonly used modal decomposition algorithms. In this embodiment, the Hilbert-Huang transform is used to decompose the vibration signal into multiple modal components. In actual application, as other implementation methods, the implementer may also adopt other modal decomposition algorithms such as empirical mode decomposition according to specific circumstances. Regarding the selection of modal decomposition algorithms, this embodiment does not impose any special restrictions.

[0032] Among them, Hilbert-Huang transform is a well-known technology, and the specific process of decomposing the signal is not described in detail.

[0033] Furthermore, due to the multi-order natural frequencies of the oil layer, the oil layer will resonate at multiple frequencies when excited by transient shock waves. The modal components of the vibration signal correspond to different vibration modes of the oil layer, reflecting the resonant state of the oil layer at multiple natural frequencies under the current discharge frequency. When the frequency of the vibration signal is close to the natural frequency of the oil layer, the oil layer will produce a strong resonance effect on the vibration signal, resulting in a significant increase in the energy of the frequency component.

[0034] Therefore, this embodiment determines the amplitude difference by analyzing the difference between the maximum amplitude and the average amplitude in each modal component. Specifically: the ratio of the maximum amplitude to the average amplitude in each modal component is used as the amplitude difference of each modal component. The larger the amplitude difference, the stronger the resonance effect under the natural vibration mode caused by the transient shock wave generated by the current discharge frequency.

[0035] Furthermore, due to the influence of the coupling effect between different modes of the oil layer, the natural frequency is not a strict single value in the marginal spectrum of the modal component, but is usually expressed as a frequency band. Therefore, in this embodiment, based on the difference between the energy sum of each modal component within its 3dB bandwidth and the total energy of the modal component, and combined with the amplitude difference, the energy characteristic value of each modal component in each time period is determined, specifically: Calculate the ratio between the energy sum of each modal component of the vibration signal in the 3dB bandwidth and the total energy of the modal component in each time period, and record it as the energy ratio of each modal component. The higher the concentration of the energy of the corresponding modal component in the 3dB bandwidth, the stronger the resonance effect under the natural vibration mode. Furthermore, the product of the amplitude difference of each modal component in each time period and the energy ratio is taken as the energy characteristic value of each modal component in each time period.

[0036] The 3 dB bandwidth and the process of obtaining the modal component energy are both well-known technologies, and the specific concept of the 3 dB bandwidth and the process of obtaining the modal component energy are not described in detail.

[0037] According to the energy characteristic value of each modal component in each time period, it can be understood that the energy characteristic value reflects the intensity of the resonance effect under the corresponding discharge frequency. The larger the energy ratio, the higher the concentration of the energy of the corresponding modal component within the 3dB bandwidth, and the stronger the resonance effect. This means that the energy of the transient shock wave is more effectively transferred to the oil layer within this frequency range, which promotes the plugging removal and production increase effect of the oil layer. The larger the amplitude difference, the stronger the resonance effect caused by the transient shock wave generated by the current discharge frequency under this natural vibration mode, which helps to improve the plugging removal efficiency and rate. Therefore, the larger the energy ratio and amplitude difference, the larger the energy characteristic value finally obtained. On the contrary, the smaller the energy ratio, the lower the concentration of the energy of the corresponding modal component within the 3dB bandwidth, the weaker the resonance effect, which is not conducive to the unblocking and production increase of the oil layer. The smaller the amplitude difference, the weaker the resonance effect caused by the transient shock wave generated by the current discharge frequency in the natural vibration mode, which may reduce the unblocking efficiency and rate. Therefore, the smaller the energy ratio and the amplitude difference, the smaller the final energy characteristic value, which reflects that the intensity of the resonance effect under the corresponding discharge frequency is weaker.

[0038] At this point, the vibration signal is decomposed into multiple modal components by using the modal decomposition algorithm. Each modal component represents an inherent vibration frequency mode of the oil layer. By analyzing the amplitude difference and energy ratio of each modal component, the energy characteristic value of each modal component in each time period can be determined, reflecting the intensity of the resonance effect under the corresponding discharge frequency, thereby helping to adjust the discharge frequency of the electric pulse equipment to match it with the inherent frequency of the oil layer, achieving the optimal resonance state, and improving the efficiency of unblocking and the effect of increasing oil and water well production.

[0039] Step S3: Compare the difference between the energy eigenvalue of each modal component in each time period and the average energy eigenvalue of all modal components, divide all modal components into high-energy components and low-energy components, compare the difference in energy eigenvalues ​​between all high-energy components and all low-energy components, and determine the energy concentration value of the vibration signal in each time period.

[0040] Considering that the frequency components of the transient shock waves generated by the electric pulse device are relatively fixed, it is difficult to match multiple natural frequencies at the same time. Therefore, in this embodiment, among all the modal components in each time period, the modal components with energy eigenvalues ​​greater than the average energy eigenvalue are recorded as high-energy components, indicating natural vibration modes with strong resonance effects, which have a stronger effect on unblocking oil and water wells, and all the remaining modal components are recorded as low-energy components, indicating natural vibration modes with weak resonance effects, which have a weaker effect on unblocking oil and water wells.

[0041] Furthermore, this embodiment determines the energy concentration value of the vibration signal in each time period by comparing the difference in energy characteristic values ​​between all high-energy components and all low-energy components, specifically: As an implementation method, in this embodiment, the ratio of the energy characteristic values ​​between each high-energy component and all low-energy components in each time period is summed, and the cumulative result of the sum of all high-energy components is used as the energy concentration value of the vibration signal in each time period.

[0042] According to the energy concentration value of the vibration signal in each time period, it can be understood that the energy concentration value reflects the concentration degree of the energy generated by the transient shock wave near some natural frequencies under different discharge frequencies. The larger the energy concentration value, the larger the energy characteristic value of the high-energy component is compared with the energy characteristic value of the low-frequency component, which reflects that the energy generated by the transient shock wave at the current discharge frequency is more concentrated near some natural frequencies of the oil layer, and the stronger the improvement of the plugging relief and resonance production increase effect on oil and water wells; conversely, the smaller the energy concentration value, the smaller the energy characteristic value of the high-energy component is compared with the energy characteristic value of the low-frequency component, which reflects that the energy generated by the transient shock wave at the current discharge frequency is less concentrated near some natural frequencies of the oil layer, and the weaker the improvement of the plugging relief and resonance production increase effect on oil and water wells.

[0043] At this point, the energy concentration value of the vibration signal in each time period is determined by comparing the difference in energy characteristic values ​​between the high-energy component and the low-energy component. The larger the energy concentration value, the more concentrated the energy of the transient shock wave is near some natural frequencies of the oil layer, and the stronger the improvement in the effect of oil and water well unblocking and resonance production increase. Based on the energy concentration value, it is helpful to optimize the discharge frequency of the electric pulse equipment and improve the unblocking efficiency and oil well production increase effect.

[0044] Step S4: Determine the fixed frequency matching degree of the vibration signal in each time period by comparing the difference between the discharge frequency in each time period and the maximum discharge frequency in all time periods, and combining the total energy and energy concentration value of the vibration signal in each time period; determine the fixed frequency deviation value of the vibration signal in each time period by measuring the difference in fixed matching degree between each time period and its previous time period, and combining the minimum fixed frequency matching degree of the vibration signal in all time periods.

[0045] Due to the faster discharge frequency, the energy of the released transient shock wave is too concentrated, resulting in a large amplitude of the vibration signal at a higher discharge frequency, but a small amplitude at the natural frequency of the oil layer, which is not conducive to the formation and development of micro-cracks in the oil layer. Not only is the improvement of the oil layer unblocking rate limited, but the energy consumption of the higher discharge frequency is large, resulting in a decrease in the unblocking efficiency. At the same time, it affects the judgment of the transient shock wave generated by the current discharge frequency and the resonance state of the oil layer during the fixed frequency detection and unblocking process.

[0046] Therefore, based on the above analysis, this embodiment determines the fixed frequency matching degree of the vibration signal in each time period by comparing the difference between the discharge frequency in each time period and the maximum discharge frequency in all time periods, and combining the total energy and energy concentration value of the vibration signal in each time period, specifically: As an implementation method, in this embodiment, the fixed frequency matching degree of the vibration signal in time period i is The expression is: ; In the formula, Represents the total energy of the vibration signal in time period i; represents the discharge frequency in time period i; Indicates the maximum discharge frequency within the preset number of time periods; represents the energy concentration value of the vibration signal in time period i; ln( ) represents the logarithmic function with the natural constant as the base; Indicates a preset value.

[0047] It should be noted that the preset value To prevent the denominator from being 0, the preset value in this embodiment The value of is 10. Under the premise of ensuring that the denominator is not 0 and does not excessively affect the calculation result, the implementer can also set it according to the specific situation. This embodiment does not impose any special restrictions.

[0048] Among them, the method for obtaining the total energy of the vibration signal is a well-known technology, and its specific acquisition process will not be repeated here.

[0049] According to the fixed frequency matching degree of the vibration signal in each time period, it can be understood that the fixed frequency matching degree reflects the resonance matching degree between the transient shock wave generated by the current discharge frequency and the oil layer. The smaller the fixed frequency matching degree of the discharge frequency, the larger the ratio between the discharge frequency in the current time period and the maximum discharge frequency, which may mean that the discharge frequency is high, resulting in excessive concentration of energy, which is not conducive to the formation and development of oil layer cracks, and the energy concentration value and the total energy of the vibration signal are relatively small. The smaller the energy concentration value, the more dispersed the distribution of the energy of the vibration signal on the natural frequency of the oil layer, the weaker the resonance effect, which is not conducive to the formation and unblocking of micro-cracks in the oil layer. The smaller the total energy, the less energy the transient shock wave generates, and the limited impact on the oil layer, which may lead to unblocking and production increase effects. On the contrary, the greater the fixed-frequency matching degree of the discharge frequency, the smaller the ratio between the discharge frequency in the current period and the maximum discharge frequency, which may mean that the discharge frequency is more moderate and the energy distribution is more reasonable, which is conducive to the formation and development of oil layer cracks. At the same time, the energy concentration value and the total energy of the vibration signal are relatively large. The larger the energy concentration value, the more concentrated the distribution of the energy of the vibration signal on the natural frequency of the oil layer, the stronger the resonance effect, which is conducive to the formation and unblocking of micro-cracks in the oil layer. The larger the total energy, the more energy the transient shock wave generates, and the significant impact on the oil layer, which may lead to obvious unblocking and production increase effects.

[0050] Preferably, the schematic diagram of the fixed frequency matching degree extraction process provided in this embodiment is as follows: Figure 2 shown.

[0051] Furthermore, as the electric pulse device continues to unblock the oil layer, the blockage is removed, the porosity and permeability of the oil layer are improved, and the effective density of the medium is reduced. The above factors work together to cause the elastic modulus of the oil layer to be relatively reduced and the internal damping to increase, thereby reducing the natural frequency of the oil layer. Therefore, this embodiment determines the fixed frequency deviation value of the vibration signal in each time period by measuring the difference in fixed matching between each time period and its previous time period, and combining the minimum fixed frequency matching of the vibration signal in all time periods, which is specifically: As an implementation mode, in this embodiment, the fixed frequency deviation value of the vibration signal in time period i is The expression is: ; , They represent the fixed-frequency matching degree in time periods i-1 and i respectively; max{} represents the maximum value function.

[0052] In particular, for the first period of the fixed frequency detection and unblocking process, that is, when i=1, The value of is the fixed frequency matching degree corresponding to the maximum discharge frequency less than the optimal discharge frequency among the discharge frequencies in all time periods of the fixed frequency detection and unblocking process. If there is no discharge frequency less than the optimal discharge frequency, the fixed frequency matching degree of the optimal discharge frequency is taken as The value of .

[0053] Among them, the method for obtaining the optimal discharge frequency is: the binary group consisting of the fixed frequency matching degree and the corresponding discharge frequency in each time period in the fixed frequency detection and unblocking process is fitted to the binary group of all time periods in the fixed frequency detection and unblocking process to obtain a fitting curve, and the discharge frequency corresponding to the maximum value on the fitting curve is used as the optimal discharge frequency. In this embodiment, a polynomial linear regression model is used to fit the binary group of all time periods. In actual application, as other implementation methods, the implementer can also use the least squares method to fit the binary group according to the specific situation. Regarding the selection of the fitting method, this embodiment does not make any special restrictions.

[0054] Among them, the polynomial linear regression model is a well-known technology, and its specific fitting principle and process are not described in detail.

[0055] According to the fixed frequency deviation value of the vibration signal in each time period, it can be understood that it reflects the degree of decrease in the natural frequency of the oil layer. The greater the difference in the fixed frequency matching between time period i-1 and time period i is than the result of the fixed frequency matching of the previous time period i-1, it means that in time period i, the matching degree between the discharge frequency and the natural frequency of the oil layer becomes worse, and the energy distribution becomes unreasonable, which may lead to a decrease in the unblocking effect, and the corresponding fixed frequency deviation value is larger; conversely, the smaller the difference in the fixed frequency matching between time period i-1 and time period i is than the result of the fixed frequency matching of the previous time period i-1, it means that in time period i, the matching degree between the discharge frequency and the natural frequency of the oil layer is better, the unblocking effect is significant, and the corresponding fixed frequency deviation value is smaller. Therefore, the discharge frequency is adjusted according to the size of the fixed frequency deviation value.

[0056] At this point, by calculating the fixed frequency matching degree and fixed frequency deviation value, the discharge frequency of the electric pulse equipment is dynamically adjusted to keep it in the best match with the natural frequency of the oil layer, optimize the energy distribution and resonance effect, effectively improve the efficiency of unblocking and the effect of increasing oil well production, and avoid the negative impact of excessive frequency.

[0057] Step S5: Based on the difference in the natural frequencies of all high-energy components between the last time period and the previous time period in the fixed frequency detection and unblocking process, the high-energy deviation is determined, and the initial discharge frequency of the fracture-induced unblocking in the electric pulse unblocking process is determined in combination with the discharge frequency and the fixed frequency deviation value in the last time period.

[0058] Based on the fixed frequency deviation value obtained in step S4, the discharge frequency in the crack induced unblocking process is set. In this embodiment, the high energy deviation is determined based on the difference in the natural frequencies of all high energy components between the last time period and the previous time period in the fixed frequency detection unblocking process, and the initial discharge frequency of the crack induced unblocking process in the electric pulse unblocking process is determined in combination with the discharge frequency and the fixed frequency deviation value in the last time period. The specific process is as follows: In this embodiment, the average value of the natural frequency difference of all high-energy components between the last time period of the fixed frequency detection and unblocking process and the previous time period is used as the high-energy deviation.

[0059] It should be noted that there are many methods for measuring the differences between data. In this embodiment, the absolute value of the difference between the natural frequencies of all high-energy components between the last time period and the previous time period is taken as the difference in the natural frequencies of all high-energy components between the last time period and the previous time period. In actual application, as other implementation methods, the implementer may also adopt other methods of measuring the difference, such as the square or ratio of the difference, according to the specific circumstances. Regarding the selection of the method for measuring the difference, this embodiment does not impose any special restrictions.

[0060] Furthermore, the discharge frequency is corrected based on the high energy deviation and the fixed frequency deviation, specifically: As an implementation method, in this embodiment, the initial discharge frequency of the crack induced unblocking during the electric pulse unblocking process is The expression is: ; In the formula, Indicates the discharge frequency of the last period in the process of fixed frequency detection and unblocking; Indicates high energy deviation; It indicates the fixed frequency deviation value of the last period in the fixed frequency detection and unblocking process; ceil() indicates the upward rounding function.

[0061] The larger the fixed frequency deviation value is, the greater the change in the natural frequency of the oil layer during this period is. Therefore, the discharge frequency of the electric pulse is reduced to maintain the oil layer and the shock wave generated by the electric pulse equipment in the optimal resonance state, thereby improving the effect of resonance production increase.

[0062] At this point, this embodiment obtains the energy characteristic value of each modal component in each time period by analyzing the amplitude difference and energy ratio of each modal component of the vibration signal, reflecting the intensity of the resonance effect under the corresponding discharge frequency; further, by comparing the energy characteristic value difference between the high-energy component and the low-energy component in each time period, the energy concentration value of the vibration signal is obtained, and combined with the difference between the discharge frequency and the maximum discharge frequency, as well as the total energy and energy concentration value of the vibration signal, the fixed-frequency matching degree and fixed-frequency deviation value of the vibration signal in each time period are determined, and the discharge frequency of the electric pulse equipment is dynamically adjusted to maintain the best match with the natural frequency of the oil layer, optimize the energy distribution and resonance effect, thereby effectively improving the efficiency of unblocking and the effect of increasing oil well production, while avoiding the negative impact of excessively high frequency.

[0063] Based on the same inventive concept as the above method, an embodiment of the present application also provides an electric pulse transient shock wave oil and water well resonance production enhancement system, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of any one of the above-mentioned electric pulse transient shock wave oil and water well resonance production enhancement methods are implemented.

[0064] It should be noted that the above sequence of the embodiments of the present application is for description only and does not represent the advantages and disadvantages of the embodiments. The above is a description of a specific embodiment of this specification. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0065] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0066] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present application should be included in the protection scope of the present application.

Claims

1. An electric pulse transient shock wave resonance production enhancement method for oil and water wells, characterized in that: The method comprises the following steps: The fixed frequency detection and unblocking process of electric pulse unblocking is divided into a preset number of time periods, a discharge frequency is set for the electric pulse in each time period, and the vibration signal in the oil and water well under the discharge frequency of the electric pulse in each time period is obtained; Decompose the vibration signal of each time period into multiple modal components, determine the amplitude difference by analyzing the difference between the maximum amplitude and the average amplitude of each modal component, and determine the energy characteristic value of each modal component in each time period by combining the difference between the energy sum of each modal component within its 3dB bandwidth and the total energy of the modal component; Compare the difference between the energy characteristic value of each modal component in each time period and the average energy characteristic value of all modal components, divide all modal components into high-energy components and low-energy components, compare the difference between the energy characteristic values ​​of all high-energy components and all low-energy components, and determine the energy concentration value of the vibration signal in each time period; By comparing the difference between the discharge frequency in each time period and the maximum discharge frequency in all time periods, and combining the total energy and energy concentration value of the vibration signal in each time period, the fixed frequency matching degree of the vibration signal in each time period is determined; by measuring the difference between the fixed matching degree of each time period and the previous time period, and combining the minimum fixed frequency matching degree of the vibration signal in all time periods, the fixed frequency deviation value of the vibration signal in each time period is determined; Based on the difference in the natural frequencies of all high-energy components between the last period and the previous period in the fixed-frequency detection and unblocking process, the high-energy deviation is determined, and the initial discharge frequency of fracture-induced unblocking in the electric pulse unblocking process is determined by combining the discharge frequency and the fixed-frequency deviation value in the last period.

2. The electric pulse transient shock wave resonance production enhancement method for oil and water wells according to claim 1, characterized in that: The amplitude difference is determined by: The ratio of the maximum amplitude to the average amplitude in each modal component is taken as the amplitude difference of each modal component.

3. The electric pulse transient shock wave resonance production enhancement method for oil and water wells according to claim 1, characterized in that: The method for determining the energy characteristic value of each modal component in each time period is: Calculate the ratio of the energy sum of each modal component of the vibration signal within the 3dB bandwidth and the total energy of the modal component in each time period, record it as the energy ratio of each modal component, and take the product of the amplitude difference of each modal component in each time period and the energy ratio as the energy characteristic value of each modal component in each time period.

4. The electric pulse transient shock wave resonance production enhancement method for oil and water wells as claimed in claim 1, characterized in that: The method of dividing all modal components into high-energy components and low-energy components includes: Among all the modal components in each time period, the modal components whose energy eigenvalues ​​are greater than the average energy eigenvalue are recorded as high-energy components, and all the remaining modal components are recorded as low-energy components.

5. The electric pulse transient shock wave resonance production enhancement method for oil and water wells as claimed in claim 1, characterized in that: The method for determining the energy concentration value of the vibration signal in each time period is as follows: The sum of the ratios of the energy characteristic values ​​between each high-energy component and all low-energy components in each time period is taken, and the accumulated result of the sum of all high-energy components is taken as the energy concentration value of the vibration signal in each time period.

6. The electric pulse transient shock wave resonance production enhancement method for oil and water wells as claimed in claim 1, characterized in that: The expression of the fixed frequency matching degree of the vibration signal in each time period is: ; In the formula, Indicates the fixed frequency matching degree of the vibration signal in time period i; Represents the total energy of the vibration signal in time period i; represents the discharge frequency in time period i; Indicates the maximum discharge frequency within a preset number of time periods; represents the energy concentration value of the vibration signal in time period i; ln( ) represents the logarithmic function with the natural constant as the base; Indicates a preset value.

7. The electric pulse transient shock wave resonance production enhancement method for oil and water wells as claimed in claim 1, characterized in that: The expression of the fixed frequency deviation value of the vibration signal in each time period is: ; Indicates the fixed frequency deviation value of the vibration signal in time period i; , They represent the fixed frequency matching degree in time periods i-1 and i respectively; max{} represents the maximum value function.

8. The electric pulse transient shock wave resonance production enhancement method for oil and water wells as claimed in claim 1, characterized in that: The high energy deviation is: the average value of the natural frequency difference of all high energy components between the last period of the fixed frequency detection and unblocking process and the previous period.

9. The electric pulse transient shock wave resonance production enhancement method for oil and water wells as claimed in claim 1, characterized in that: The expression of the initial discharge frequency of crack induced unblocking in the electric pulse unblocking process is: ; In the formula, It indicates the initial discharge frequency of crack-induced unblocking during the electric pulse unblocking process; Indicates the discharge frequency of the last period in the process of fixed frequency detection and unblocking; Indicates high energy deviation; It indicates the fixed frequency deviation value of the last period in the fixed frequency detection and unblocking process; ceil() indicates the upward rounding function.

10. An electric pulse transient shock wave resonance stimulation system for oil and water wells, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the electric pulse transient shock wave oil and water well resonance production enhancement method as described in any one of claims 1-9 are implemented.

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