Distributed optical fiber microseism event positioning method and device

Abstract

The invention relates to the technical field of hydrofracture micro-seismic event monitoring, in particular to a distributed optical fiber micro-seismic event positioning method and device, and the corresponding method comprises the steps: determining a vertical foot corresponding to a micro-seismic event according to the form of an event of the micro-seismic event in a seismic section corresponding to the micro-seismic event in a fractured well; determining the monitoring well and the perpendicular foot radius of the perpendicular foot in a cylindrical coordinate system; wherein the original point of the cylindrical coordinate system is the vertex of the event; and according to the radius of the perpendicular foot and the length of the fractured well, performing energy scanning on each grid under the cylindrical coordinate system in a plane which passes through the perpendicular foot and is perpendicular to the fractured well so as to position the microseism event. According to the method, the plane where the seismic source occurs is determined, and then seismic source scanning is performed only in the plane, so that the method has the advantages of high calculation precision and high calculation efficiency. And rapid real-time positioning of the distributed optical fiber fracturing microseism event can be ensured.

Description

Technical Field

[0001] This disclosure relates to the field of hydraulic fracturing microseismic event monitoring technology, and in particular to the field of detecting hydraulic fracturing microseismic events using distributed acoustic sensing technology. Specifically, it relates to a method, apparatus, equipment, storage medium, and computer program for locating distributed fiber optic microseismic events. Background Technology

[0002] Existing microseismic event monitoring methods are mainly divided into two categories: surface microseismic monitoring methods and well-drilled microseismic monitoring methods, specifically:

[0003] Ground-based microseismic monitoring methods have the advantages of wide monitoring range and high lateral imaging resolution; however, compared with well monitoring, the signal-to-noise ratio of the acquired data is low; at the same time, due to the long propagation path of seismic waves, the ability to detect weak and microseismic events is not as good as that of well monitoring, resulting in a relatively small number of detectable microseismic events.

[0004] In-well microseismic monitoring is suitable for situations where there are multiple wells in a development area. Due to the advantage of being close to the target fracturing layer, in-well monitoring results in a high signal-to-noise ratio and a large number of monitored microseismic events.

[0005] With the increasing demand for deep and ultra-deep fracturing microseismic monitoring, both of these monitoring methods face significant challenges. On the one hand, surface microseismic monitoring suffers from weak monitoring signals, making it difficult to identify and locate events. On the other hand, well-drilled microseismic monitoring faces challenges such as high formation temperatures and pressures, preventing geophones from getting close enough to the target layer. Furthermore, monitoring under prolonged high-temperature conditions carries the risk of burning out the geophones. Summary of the Invention

[0006] This disclosure provides a method, apparatus, device, storage medium, and computer program for locating distributed fiber optic microseismic events. By determining the plane of the seismic source and then performing source scanning only within that plane, it offers advantages in terms of high computational accuracy and efficiency. This, in turn, ensures rapid, real-time location of distributed fiber optic fracturing microseismic events.

[0007] Firstly, this disclosure provides a method for locating distributed fiber-optic microseismic events, including:

[0008] The foot of the microseismic event is determined based on the shape of the phase axis of the microseismic event in the seismic profile corresponding to the microseismic event in the fractured well.

[0009] Determine the monitoring well and the radius of the vertical foot in the cylindrical coordinate system; wherein the origin of the cylindrical coordinate system is the vertex of the phase axis;

[0010] Based on the vertical foot radius and the fractured well length, an energy scan is performed on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well to locate the microseismic event.

[0011] In some embodiments of this disclosure, determining the foot of the vertical corresponding to the microseismic event based on the morphology of the phase axis of the microseismic event in the seismic profile corresponding to the microseismic event in the fractured well includes:

[0012] The shape of the phase axis of the microseismic event is determined based on the seismic profile corresponding to the microseismic event in the fractured well, and the trace number corresponding to the vertex of the phase axis is determined.

[0013] The foot of the vertical for the microseismic event is determined based on the drilling trajectory of the fractured well and the tunnel number corresponding to the vertex.

[0014] In some embodiments of this disclosure, based on the perpendicular radius and the length of the fractured well, an energy scan is performed on each grid in the cylindrical coordinate system within a plane passing through the perpendicular and perpendicular to the fractured well to locate the microseismic event, including:

[0015] Based on the vertical foot radius and the fractured well length, each grid in the cylindrical coordinate system is imaged in a plane passing through the vertical foot and perpendicular to the fractured well to determine the image slice of each grid in the plane passing through the vertical foot and perpendicular to the fractured well.

[0016] The grid corresponding to the imaging slice with the highest energy is selected to locate the microseismic event.

[0017] In some embodiments of this disclosure, based on the perpendicular radius and the length of the fractured well, each grid in the cylindrical coordinate system is imaged in a plane passing through the perpendicular and perpendicular to the fractured well to determine an image slice of each grid in the plane passing through the perpendicular and perpendicular to the fractured well, including:

[0018] The scanning radius is determined based on the vertical foot radius and the length of the fractured well.

[0019] In the radius and angle domains, each grid in the cylindrical coordinate system is imaged in a plane passing through the foot of the vertical and perpendicular to the fractured well, based on the scanning radius, to determine the image slice of each grid in the plane passing through the foot of the vertical and perpendicular to the fractured well.

[0020] In some embodiments of this disclosure, based on the perpendicular radius and the length of the fractured well, each grid in the cylindrical coordinate system is imaged in a plane passing through the perpendicular and perpendicular to the fractured well to determine an image slice of each grid in the plane passing through the perpendicular and perpendicular to the fractured well, further comprising:

[0021] In a plane passing through the foot of the perpendicular and perpendicular to the fractured well, the seismic data recorded by all receiving points in the monitoring well are integrated to generate an integration result; wherein, the integration order is determined by the radius of the foot of the perpendicular, the length of the fractured well, and the cylindrical coordinate system;

[0022] Based on the integration result, the propagation time from the depth point in the plane passing through the foot of the plumb line and perpendicular to the fractured well to all receiving points is determined, so as to determine the imaging slice of each grid in the plane passing through the foot of the plumb line and perpendicular to the fractured well.

[0023] In some embodiments of this disclosure, the propagation time from a depth point in the plane passing through the foot of the plumb line and perpendicular to the fractured well to all receiving points is determined based on the integration result, in order to determine an imaging slice of each grid in the plane passing through the foot of the plumb line and perpendicular to the fractured well, including:

[0024] The transmission coefficient of the transmitted wave at all receiving points is determined by superimposing the propagation times at all receiving points.

[0025] The imaging energy slice of each grid in a plane passing through the foot of the plumb line and perpendicular to the fractured well is determined based on the transmission coefficient.

[0026] Secondly, this disclosure provides a distributed fiber optic microseismic event location device, comprising:

[0027] The vertical foot determination module is used to determine the vertical foot corresponding to the microseismic event based on the shape of the phase axis of the microseismic event in the seismic profile corresponding to the microseismic event in the fractured well.

[0028] A cylindrical coordinate system establishment module is used to determine the monitoring well and the radius of the vertical foot in the cylindrical coordinate system; wherein, the origin of the cylindrical coordinate system is the vertex of the phase axis;

[0029] The microseismic event localization module is used to perform energy scanning on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well, based on the vertical foot radius and the length of the fractured well, in order to locate the microseismic event.

[0030] In some embodiments of this disclosure, the perpendicular determination module includes:

[0031] The trace number determination unit is used to determine the trace number corresponding to the vertex of the phase axis of the microseismic event based on the seismic profile corresponding to the microseismic event in the fractured well.

[0032] The vertical foot determination unit is used to determine the vertical foot corresponding to the microseismic event based on the drilling trajectory of the fractured well and the trace number corresponding to the vertex.

[0033] In some embodiments of this disclosure, the microseismic event localization module includes:

[0034] An imaging slice determination unit is used to image each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well, based on the vertical foot radius and the length of the fractured well, so as to determine the imaging slice of each grid in the plane passing through the vertical foot and perpendicular to the fractured well.

[0035] The microseismic event localization unit is used to select the grid corresponding to the imaging slice with the strongest energy to locate the microseismic event.

[0036] In some embodiments of this disclosure, the imaging slice determination unit includes:

[0037] A radius determination unit is used to determine the scanning radius based on the vertical foot radius and the length of the fractured well.

[0038] The imaging slice determines the inverted first sub-unit, which is used to image each grid in the cylindrical coordinate system in the radius domain and the angle domain according to the scanning radius in the plane passing through the foot of the perpendicular and perpendicular to the fractured well, so as to determine the imaging slice of each grid in the plane passing through the foot of the perpendicular and perpendicular to the fractured well.

[0039] In some embodiments of this disclosure, the imaging slice determination unit further includes:

[0040] An integration result generation unit is used to integrate the seismic data recorded by all receiving points in the monitoring well in a plane passing through the foot of the perpendicular and perpendicular to the fractured well, so as to generate an integration result; wherein, the integration order is determined by the radius of the foot of the perpendicular, the length of the fractured well, and the cylindrical coordinate system;

[0041] The imaging slice determines the penultimate sub-unit, which is used to determine the propagation time from a depth point in the plane passing through the foot of the plumb line and perpendicular to the fractured well to all receiving points based on the integration result, so as to determine the imaging slice of each grid in the plane passing through the foot of the plumb line and perpendicular to the fractured well.

[0042] In some embodiments of this disclosure, the imaging slice determining the penultimate subunit includes:

[0043] The reflection coefficient determination unit is used to superimpose the propagation time of all receiving points to determine the transmission coefficient of the transmitted wave at all receiving points.

[0044] A grid imaging slice determination unit is used to determine the imaging energy slice of each grid in a plane passing through the foot of the vertical and perpendicular to the fractured well, based on the transmission coefficient.

[0045] Thirdly, this disclosure provides a computer device including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method described in the foregoing aspects.

[0046] Fourthly, this disclosure provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of the method described in the above aspects.

[0047] Fifthly, this disclosure provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the methods described in the foregoing aspects.

[0048] This disclosure provides a method, apparatus, device, storage medium, and computer program for locating distributed fiber optic microseismic events.

[0049] The corresponding distributed fiber optic microseismic event localization method includes: First, determining the shape of the phase axis of the microseismic event and the corresponding vertical foot based on the seismic profile corresponding to the microseismic event in the fractured well; Next, determining the monitoring well and the vertical foot radius in the cylindrical coordinate system; wherein the origin of the cylindrical coordinate system is the vertex of the phase axis; Finally, based on the vertical foot radius and the length of the fractured well, performing an energy scan on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well to locate the microseismic event.

[0050] The corresponding distributed fiber optic microseismic event localization device includes: a vertical foot determination module, used to determine the shape of the phase axis of the microseismic event and the vertical foot corresponding to the microseismic event based on the seismic profile corresponding to the microseismic event in the fractured well; a cylindrical coordinate system establishment module, used to determine the vertical foot radius of the monitoring well and the vertical foot in the cylindrical coordinate system; wherein, the origin of the cylindrical coordinate system is the vertex of the phase axis; and a microseismic event localization module, used to perform energy scanning on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well, based on the vertical foot radius and the length of the fractured well, in order to locate the microseismic event.

[0051] In summary, the distributed fiber optic microseismic event localization method provided in this disclosure first determines the plane where the microseismic event is located. Then, within this plane, the microseismic event is scanned and imaged using cylindrical coordinates based on radius and azimuth to locate the spatial position of the seismic source. This method has low computational complexity, a simple and clear calculation process, and sufficient theoretical basis, and can meet the needs of real-time monitoring of distributed fiber optic microseismic events. Attached Figure Description

[0052] The present disclosure will be described in more detail below based on embodiments and with reference to the accompanying drawings:

[0053] Figure 1 This is a flowchart illustrating a method for locating distributed fiber-optic microseismic events, provided as an embodiment of this disclosure.

[0054] Figure 2 This is a flowchart illustrating step 100 of a distributed fiber optic microseismic event localization method provided in an embodiment of this disclosure.

[0055] Figure 3 This is a flowchart illustrating step 300 of a distributed fiber optic microseismic event localization method provided in an embodiment of this disclosure.

[0056] Figure 4 This is a flowchart illustrating step 301 of a distributed fiber optic microseismic event localization method provided in an embodiment of this disclosure.

[0057] Figure 5 This is another flowchart illustrating step 301 of a distributed fiber optic microseismic event localization method provided in an embodiment of this disclosure.

[0058] Figure 6 This is a flowchart illustrating step 3014 of a distributed fiber optic microseismic event localization method provided in an embodiment of this disclosure.

[0059] Figure 7 A flowchart illustrating a distributed fiber optic microseismic event localization method provided as an application example of this disclosure.

[0060] Figure 8 A schematic diagram of a microseismic event record profile provided as an application example of this disclosure.

[0061] Figure 9 A schematic diagram of the spatial range of the seismic source scan provided for this application example.

[0062] Figure 10 A schematic diagram of the imaging energy profile (P-wave spatial scanning energy spectrum) provided for an application example of this disclosure.

[0063] Figure 11 A schematic diagram of the imaging energy profile (S-wave spatial scanning energy spectrum) provided for an application example of this disclosure.

[0064] Figure 12 A schematic diagram of DAS microseismic event location results provided as an application example of this disclosure.

[0065] Figure 13 A block diagram of a distributed fiber optic microseismic event location device provided in an embodiment of this disclosure.

[0066] In the accompanying drawings, the same parts are referred to by the same reference numerals, and the drawings are not drawn to scale. Detailed Implementation

[0067] To enable those skilled in the art to better understand the technical solutions of this disclosure, and to fully understand and implement the process of how this disclosure applies technical means to solve technical problems and achieve corresponding technical effects, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, not all embodiments. The embodiments of this disclosure and the various features within them can be combined with each other without conflict, and the resulting technical solutions are all within the protection scope of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort should fall within the protection scope of this disclosure.

[0068] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0069] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0070] Unconventional reservoirs, due to their low permeability and high tightness, are economically viable using conventional development methods. With the rapid development of horizontal well completion and fracturing technology, unconventional reservoirs have been efficiently developed in the last decade. During fracturing, microseismic monitoring is primarily used to evaluate the fracturing effect and provide real-time reference for optimizing the fracturing process. Therefore, microseismic monitoring is crucial for fracturing.

[0071] Distributed Acoustic Sensing (DAS) is based on the principle of Optical Time-Domain Reflectometer (OTDR). It uses a high-power laser transmitter to send laser pulses to a connected optical fiber, while simultaneously collecting and analyzing Rayleigh scattering in the backscattered light, thus achieving distributed sensing of vibration signals. DAS-based wellbore microseismic monitoring not only boasts advantages such as high temperature resistance, high pressure resistance, and corrosion resistance, but also enables high spatial density sampling of vibration signals throughout the entire well section, making it a novel fracturing microseismic monitoring technology.

[0072] Essentially, distributed fiber optic microseismic monitoring is a type of borehole microseismic monitoring. However, unlike borehole detectors, distributed fiber optics are single-component, sensing vibrations only along the fiber's direction. Therefore, borehole microseismic event location methods are no longer applicable to distributed fiber optic microseismic location.

[0073] Example 1

[0074] For the reasons mentioned above, this disclosure provides a method for locating distributed fiber optic microseismic events. Figure 1 This is a flowchart illustrating a method for locating distributed fiber-optic microseismic events, provided as an embodiment of this disclosure. Figure 1 As shown, a method for locating distributed fiber-optic microseismic events includes:

[0075] Step 100: Determine the vertical foot corresponding to the microseismic event based on the shape of the phase axis of the microseismic event in the seismic profile corresponding to the microseismic event in the fractured well;

[0076] Step 200: Determine the monitoring well and the radius of the vertical foot in the cylindrical coordinate system; wherein the origin of the cylindrical coordinate system is the vertex of the phase axis;

[0077] Step 300: Based on the vertical foot radius and the fractured well length, perform an energy scan on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well to locate the microseismic event.

[0078] This disclosure provides a method for locating distributed fiber-optic microseismic events, comprising: first, determining the shape of the phase axis of the microseismic event and the corresponding vertical foot of the microseismic event based on the seismic profile corresponding to the microseismic event in the fractured well; next, determining the monitoring well and the vertical foot radius in a cylindrical coordinate system; wherein the origin of the cylindrical coordinate system is the vertex of the phase axis; finally, based on the vertical foot radius and the length of the fractured well, performing microseismic transmission energy scanning on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well to locate the microseismic event.

[0079] In summary, the distributed fiber optic microseismic event localization method provided in this disclosure is applicable to distributed fiber optic microseismic monitoring scenarios during hydraulic fracturing. First, the plane containing the microseismic event is determined. Then, within this plane, the microseismic event is scanned and imaged using cylindrical coordinates based on radius and azimuth to locate the spatial position of the seismic source. This method has low computational complexity, a simple and clear calculation process, and sufficient theoretical basis, and can meet the needs of real-time distributed fiber optic microseismic monitoring.

[0080] Example 2

[0081] For step 100, the vertical sections of the fractured well and the monitoring well are parallel to the y-axis in the Cartesian coordinate system.

[0082] The microseismic events in step 100 refer to low-energy seismic activity generated during hydraulic fracturing due to rock fracture. Additionally, a phase axis refers to a curve or surface formed by wavefronts or beams with the same phase during seismic wave propagation. In seismic records, this manifests as a collection of reflected or refracted waves with the same arrival time on the time axis. Characteristics of a phase axis:

[0083] Phase information: In-phase axes display wave phase information at a specific depth or interface, and are commonly used to identify and analyze underground geological structures.

[0084] Temporal and spatial relationships: The phase axis reflects the temporal and spatial relationships of seismic wave propagation in the underground medium, helping to explain the propagation paths of transmitted, reflected, and refracted waves.

[0085] Imaging and Inversion: In the process of seismic imaging and inversion, the identification of phase axes helps to determine the geometry of subsurface structures and assess the properties and distribution of the medium.

[0086] Understandably, the purpose of determining verticality in step 200 is to determine the plane in which the microseismic event is located, specifically, the plane in which the microseismic event is located, passing through the foot of the vertical and perpendicular to the plane in which the fracturing well is located.

[0087] Step 300 can obtain the imaging energy profiles of P-waves and S-waves respectively. Then, the point with the strongest energy is selected and its corresponding cylindrical coordinates are determined and converted to the corresponding Cartesian coordinates to determine the spatial location of the source of the distributed fiber optic microseismic event.

[0088] Example 3

[0089] Based on the above embodiments, see Figure 2 Step 100 of a distributed fiber optic microseismic event localization method includes:

[0090] Step 101: Determine the shape of the phase axis of the microseismic event based on the seismic profile corresponding to the microseismic event in the fractured well, and determine the trace number corresponding to the vertex of the phase axis;

[0091] Specifically, select microseismic events with a hyperbolic phase axis, where the phase axes on the left and right sides of the hyperbola have opposite polarities. This trace is the vertex trace, and the corresponding trace number is recorded as ID.

[0092] In-phase axis polarity refers to the phase characteristic of a wavefront or beam along the in-phase axis, manifested as the positive or negative polarity of the wave. Polarity refers to the change in the initial waveform of a seismic wave relative to its source.

[0093] Positive polarity: When the amplitude of a seismic wave is in the same direction as the amplitude of the incident wave (i.e., the rising part of the waveform is reflected back to the rising part), it is called positive polarity. Positive polarity is manifested by the rising part of the waveform appearing above the reflection point.

[0094] Negative polarity: When the amplitude of a seismic wave is opposite to the direction of the amplitude of the incident wave (i.e., the rising part of the waveform is reflected to the falling part), it is called negative polarity. Negative polarity is manifested by the falling part of the waveform appearing above the reflection point.

[0095] Factors influencing polarity:

[0096] Medium properties: The polarity of the reflected wave is determined by the physical properties of the formation medium (such as density and elastic modulus). When a wave propagates from a low-density medium to a high-density medium, positive polarity reflection occurs; conversely, negative polarity reflection occurs.

[0097] Interface properties: The properties of an interface (such as roughness, tilt, etc.) also affect the polarity of the reflected wave. In some cases, complex interfaces may lead to changes in polarity.

[0098] Wave type: Different types of seismic waves (such as compression waves and shear waves) have different effects on polarity. Polarity analysis of compression wave reflections is more common.

[0099] Step 102: Determine the foot of the microseismic event based on the drilling trajectory of the fractured well and the trace number corresponding to the vertex.

[0100] Specifically, based on the information from the fiber optic observation system, the spatial coordinates (xID, yID, zID) corresponding to the ID trace are read. Based on the well trajectory of the fractured well, the point with the smallest difference between the y-coordinate and yID is found, and the coordinates (xC, yC, zC) of this point are determined; this point is the foot of the perpendicular. Microseismic events occur in the plane passing through this foot of the perpendicular and perpendicular to the fractured well.

[0101] Based on the above embodiments, see Figure 3 Step 300 of a distributed fiber optic microseismic event localization method includes:

[0102] Step 301: Based on the vertical foot radius and the fractured well length, image each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well to determine the image slice of each grid in the plane passing through the vertical foot and perpendicular to the fractured well.

[0103] Step 302: Select the grid corresponding to the imaging slice with the strongest energy to locate the microseismic event.

[0104] Example 4

[0105] Based on the above embodiments, see Figure 4 Step 301 of a distributed fiber optic microseismic event localization method includes:

[0106] Step 3011: Determine the scanning radius based on the vertical foot radius and the length of the fractured well;

[0107] Step 3012: In the radius and angle domains, image each grid in the cylindrical coordinate system according to the scanning radius in a plane passing through the foot of the vertical and perpendicular to the fractured well, so as to determine the imaging slice of each grid in the plane passing through the foot of the vertical and perpendicular to the fractured well.

[0108] In steps 3011 and 3012, the distance between the microseismic event and the fractured well is set to no more than Range. Therefore, the scanning radius is [Range+r, r-Range], where the scanning grid size is dx. The angular scanning range is [90°, 270°], and the scanning interval is dθ. With these parameter settings, imaging is performed on each grid within the plane z = yc (passing through the foot of the perpendicular and perpendicular to the fractured well) in both the radius and angular domains, yielding an in-plane imaging section.

[0109] Based on the above embodiments, see Figure 5Step 301 of a distributed fiber optic microseismic event localization method further includes:

[0110] Step 3013: Integrate the seismic data recorded by all receiving points in the monitoring well in a plane passing through the foot of the perpendicular and perpendicular to the fractured well to generate an integration result; wherein, the integration order is determined by the radius of the foot of the perpendicular, the length of the fractured well, and the cylindrical coordinate system;

[0111] Specifically, the integral formula is:

[0112]

[0113] Where u(x,t) is the value of the wave field at position x and time t. s represents a point on the integral surface. G(x,s;t-τ) is the Green's function, which describes the propagation of the wave from s to x. and ∫GL ∫SS ...

[0114] Step 3014: Determine the propagation time from the depth point in the plane passing through the foot of the plumb line and perpendicular to the fractured well to all receiving points based on the integration result, so as to determine the imaging slice of each grid in the plane passing through the foot of the plumb line and perpendicular to the fractured well.

[0115] By calculating the propagation time from each underground point (in the fracturing well) to each receiving point, the transmission coefficient of each underground point is reconstructed to determine the imaging slice of each grid in a plane passing through the foot of the plumb line and perpendicular to the fracturing well.

[0116] Based on the above embodiments, see Figure 6 Step 3014 of a distributed fiber optic microseismic event localization method includes:

[0117] Step 30141: Superimpose the propagation times of all receiving points to determine the transmission coefficient of the transmitted wave at all receiving points;

[0118] Calculate the propagation time from each underground point to each receiving point, and superimpose the signals from these times to obtain the reflection coefficient of that point.

[0119] Step 30142: Determine the imaging energy slice of each grid in the plane passing through the foot of the vertical and perpendicular to the fractured well based on the transmission coefficient.

[0120] The integral results from all receiving points are superimposed to generate an image of the subsurface geological structure, thereby determining the imaging slice of each grid in a plane passing through the foot of the plumb line and perpendicular to the fractured well.

[0121] This disclosure provides a method for locating distributed fiber-optic microseismic events, comprising: first, determining the shape of the phase axis of the microseismic event and the corresponding vertical foot of the microseismic event based on the seismic profile corresponding to the microseismic event in the fractured well; next, determining the monitoring well and the radius of the vertical foot in a cylindrical coordinate system; wherein the origin of the cylindrical coordinate system is the vertex of the phase axis; finally, based on the radius of the vertical foot and the length of the fractured well, performing an energy scan on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well to locate the microseismic event.

[0122] Specifically, first, the foot of the microseismic event on the horizontal well trajectory of the fractured well is determined. Then, a cylindrical coordinate system is established, transforming the Cartesian coordinate system into a cylindrical coordinate system with the vertex of the microseismic event as the origin. Next, using a principle similar to Kirchhoff imaging, the spatial location of the microseismic event is determined. Finally, the system is transformed back from the cylindrical coordinate system to the Cartesian coordinate system to determine the location of the seismic source in the Cartesian coordinate system.

[0123] This disclosure offers the following advantages: In locating microseismic events, the plane of the seismic source is first determined, and then a source scan is performed only within that plane. This provides advantages in both high computational accuracy and efficiency. This invention ensures rapid, real-time location capabilities for distributed fiber-optic fracturing microseismic events.

[0124] Example 5

[0125] To further illustrate the solution, based on the above embodiments, this disclosure provides an application example using Basin A as an example to further explain a distributed fiber-optic microseismic event location method. See also... Figure 7 The method includes the following steps:

[0126] This disclosure pertains to the field of microseismic monitoring in hydraulic fracturing using distributed acoustic sensing capabilities of optical fibers. Specifically, it utilizes seismic records monitored by distributed optical fibers, combined with kinematic characteristics, to rapidly locate microseismic events in a cylindrical coordinate system.

[0127] Step S1: Determine the projection of the spatial location of the microseismic event onto the horizontal well trajectory of the fractured well.

[0128] Preferably, firstly, the vertex trace ID of the microseismic event phase axis can be determined through a human-computer interaction using the microseismic event profile. The determination method is as follows: the microseismic event phase axis has a hyperbola shape, and the polarities of the phase axes on the left and right sides of the vertex of the hyperbola are opposite. This trace is the vertex trace, and the corresponding trace number is recorded as ID.

[0129] Next, based on the information from the fiber optic observation system, the spatial coordinates (x, y, z) corresponding to the ID-th channel are read. ID ,y ID ,zID ).

[0130] Finally, based on the well trajectory of the fractured well, find the y-coordinate value and the y-coordinate value. ID Find the point with the smallest difference and determine the coordinates (x, y) of the corresponding point. C ,y C ,z C This point is the foot of the perpendicular. Microseismic events occur in the plane passing through this foot of the perpendicular and perpendicular to the fractured well.

[0131] Specifically, first, find the ordinates y and y in the well trajectory. ID The two closest points, A and B, are given, where the depth sound of point A is less than that of point B. Their coordinates are (x...). A ,y A ,z A ) and (x B ,y B ,z B If the perpendicular foot C is perpendicular to the point C, then the coordinates of the point C can be obtained using formulas (1) to (4):

[0132] k = (y ID -y A ) / ( y B - y A (1)

[0133] x C = k * (x B - x A ) + x A (2)

[0134] y C = y ID (3)

[0135] z C = k * (z B - z A ) + z A (4)

[0136] Step S2: Establish a cylindrical coordinate system.

[0137] A cylindrical coordinate system is a three-dimensional coordinate system used to describe objects or phenomena exhibiting cylindrical symmetry. In a cylindrical coordinate system, a point in space is represented by three parameters (r, θ, z):

[0138] r: Radial distance, which is the distance from the origin to the projection of the point onto the xy-plane. It is a non-negative real number.

[0139] θ: Azimuthal angle, which is the angle from the positive x-axis counterclockwise to the projection of the point onto the xy-plane. It is usually expressed in radians or degrees, and ranges between [0, 2π) or [0°, 360°).

[0140] z: Height, which is the projection of the point onto the z-axis. It is a real number and can be positive, negative, or zero.

[0141] The Cartesian coordinate system, also known as a rectangular coordinate system, is used to describe the position of points in space. In the Cartesian coordinate system, all axes are perpendicular to each other. The unit length on the axes is uniform, meaning that the unit length is the same on all coordinate axes.

[0142] In two-dimensional space, the Cartesian coordinate system consists of two mutually perpendicular axes, called the x-axis and y-axis.

[0143] These two axes define a Cartesian coordinate system on the plane.

[0145] The position of each point is represented by an ordered pair (x, y), where:

[0146] x: Represents the position of the point in the horizontal direction (x-coordinate).

[0147] y: Represents the position of the point in the vertical direction (ordinate).

[0148] In three-dimensional space, the Cartesian coordinate system consists of three mutually perpendicular axes, called the x-axis, y-axis, and z-axis. The position of each point is represented by an ordered triplet (x, y, z), where:

[0149] x: Represents the position of the point in the horizontal direction (x-coordinate).

[0150] y: Represents the position of the point in the vertical direction (ordinate).

[0151] z: Represents the position of the point in the depth direction (height coordinate).

[0152] Specifically, the monitoring well trajectory file is read to obtain the coordinates (x, y) of all points on the monitoring well trajectory. m， y m， z m By setting the vertex of the microseismic event as the origin, and using formulas (5) to (10), the coordinates of the monitoring well trajectory and the vertical foot coordinates under the new coordinate system are obtained.

[0153] x' m = x m - xID (5)

[0154] y' m = y m - y ID (6)

[0155] z' m = z m - z ID (7)

[0156] x' C = x C - x ID (8)

[0157] y' C = y C - y ID (9)

[0158] z' C = z C - z ID (10)

[0159] Based on this, the Cartesian coordinate system is transformed into a cylindrical coordinate system. The z-axis of the cylindrical coordinate system is the y-axis in the Cartesian coordinate system. Using formulas (11) to (13), the coordinates of each point in the monitoring well can be obtained. And the radius r of the foot of the perpendicular in the cylindrical coordinate system can be calculated using formulas (11) to (13).

[0160] z = y; (11)

[0161]

[0162] Step S3: Locate the spatial position of the earthquake source.

[0163] Specifically, if the distance between the microseismic event and the fractured well is set to no more than Range, then the radius scanning range is [Range+r, r-Range], where the radius scanning grid size is dx. The angle scanning range is [90°, 270°], and the scanning interval is dθ.

[0164] With the above parameter settings, in the plane of z=yc, in the radius and angle domains, for each grid, imaging can be performed using a principle similar to Kirchhoff's imaging to obtain the imaging slice in the plane. The point with the strongest energy in the slice is selected, and its corresponding radius r and angle θ are determined. The spatial location (x, y, θ) of the seismic source in the Cartesian coordinate system is obtained using coordinate transformation formulas (14) to (16). p y p , z p ).

[0165]

[0166] y = z; (15)

[0167]

[0168] Next, the spatial coordinates of the earthquake source in the original coordinate system are obtained using formulas (17) to (19).

[0169] x p =x p +x ID (17)

[0170] y p =y p +y ID (18)

[0171] z p =z p +z ID (19)

[0172] This completes the rapid calculation of the spatial location of distributed fiber optic microseismic sources.

[0173] The above method was applied to two horizontal wells of a fracturing platform (one a fracturing well, the other a monitoring well, with fiber optic cables installed in the monitoring well). The fiber optic cable was 5555 meters long, and the spatial sampling interval was 1 meter. A microseismic event was recorded as follows. Figure 8 As shown, there are two in-phase axes in the figure, namely P-wave and S-wave. From the waveform of the S-wave, it can be seen that the arrival time of the seismic wave is shortest at trace 4550, and the polarity of the waveforms on both sides of this trace is reversed. Therefore, through human-computer interaction, the trace number of the vertex of the microseismic event is determined to be 4550. The projection y-coordinate of the microseismic event in the fractured well is obtained using formulas (1) to (4). The radius scanning interval is set to 5 meters and the angle scanning interval is 0.1°. The source scanning space can be determined using formulas (11) to (13), such as Figure 9 As shown. Using a principle similar to Kirchhoff imaging, the imaging energy profiles of P-waves and S-waves were obtained, respectively. Figure 10 as well as Figure 11 As shown in the figure. The red * in the figure represents the location of the earthquake source. The spatial coordinates of the earthquake source can be determined using formulas (14) to (19), and the plotted results are shown in the figure. Figure 12 As shown, the spatial location of the earthquake source has been completed.

[0174] This disclosure provides a distributed fiber optic microseismic event localization method, comprising: first, determining the shape of the phase axis of the microseismic event and the corresponding vertical foot of the microseismic event based on the seismic profile corresponding to the microseismic event in the fractured well; next, determining the monitoring well and the vertical foot radius in a cylindrical coordinate system; wherein the origin of the cylindrical coordinate system is the vertex of the phase axis; finally, based on the vertical foot radius and the length of the fractured well, performing an energy scan on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well to locate the microseismic event.

[0175] To address the problem of locating microseismic events in DAS single-component full-well-section monitoring, this disclosure fully considers the characteristics of distributed fiber optic single-component and full-well-section monitoring, and assumes that the vertical well sections of the fractured well and the monitoring well are parallel to the y-axis. Then, a cylindrical coordinate system is established, and a rapid location method for distributed fiber optic microseismic events is provided through a method similar to Kirchhoff imaging.

[0176] Example 6

[0177] Based on the same inventive concept, this application also provides a distributed fiber optic microseismic event location device, which can be used to implement the method described in the above embodiments, as shown in the following embodiments. Since the principle of the distributed fiber optic microseismic event location device is similar to that of the distributed fiber optic microseismic event location method, the implementation of the distributed fiber optic microseismic event location device can refer to the implementation of the distributed fiber optic microseismic event location method, and repeated details will not be elaborated further. As used below, the terms "unit" or "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the system described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0178] This disclosure provides a specific implementation of a distributed fiber optic microseismic event localization device capable of realizing a distributed fiber optic microseismic event localization method, wherein, see [link to relevant documentation]. Figure 13 A distributed fiber optic microseismic event location device includes:

[0179] The vertical foot determination module 10 is used to determine the vertical foot corresponding to the microseismic event based on the shape of the phase axis of the microseismic event in the seismic profile corresponding to the microseismic event in the fractured well.

[0180] The cylindrical coordinate system establishment module 20 is used to determine the monitoring well and the radius of the vertical foot in the cylindrical coordinate system; wherein, the origin of the cylindrical coordinate system is the vertex of the phase axis;

[0181] The microseismic event localization module 30 is used to perform energy scanning on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well, based on the vertical foot radius and the length of the fractured well, in order to locate the microseismic event.

[0182] In some embodiments of this disclosure, the perpendicular determination module includes:

[0183] The trace number determination unit is used to determine the trace number corresponding to the vertex of the phase axis of the microseismic event based on the seismic profile corresponding to the microseismic event in the fractured well.

[0184] The vertical foot determination unit is used to determine the vertical foot corresponding to the microseismic event based on the drilling trajectory of the fractured well and the trace number corresponding to the vertex.

[0185] In some embodiments of this disclosure, the microseismic event localization module includes:

[0186] An imaging slice determination unit is used to image each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well, based on the vertical foot radius and the length of the fractured well, so as to determine the imaging slice of each grid in the plane passing through the vertical foot and perpendicular to the fractured well.

[0187] The microseismic event localization unit is used to select the grid corresponding to the imaging slice with the strongest energy to locate the microseismic event.

[0188] In some embodiments of this disclosure, the imaging slice determination unit includes:

[0189] A radius determination unit is used to determine the scanning radius based on the vertical foot radius and the length of the fractured well.

[0190] The imaging slice determines the inverted first sub-unit, which is used to image each grid in the cylindrical coordinate system in the radius domain and the angle domain according to the scanning radius in the plane passing through the foot of the perpendicular and perpendicular to the fractured well, so as to determine the imaging slice of each grid in the plane passing through the foot of the perpendicular and perpendicular to the fractured well.

[0191] In some embodiments of this disclosure, the imaging slice determination unit further includes:

[0192] An integration result generation unit is used to integrate the seismic data recorded by all receiving points in the monitoring well in a plane passing through the foot of the perpendicular and perpendicular to the fractured well, so as to generate an integration result; wherein, the integration order is determined by the radius of the foot of the perpendicular, the length of the fractured well, and the cylindrical coordinate system;

[0193] The imaging slice determines the penultimate sub-unit, which is used to determine the propagation time from a depth point in the plane passing through the foot of the plumb line and perpendicular to the fractured well to all receiving points based on the integration result, so as to determine the imaging slice of each grid in the plane passing through the foot of the plumb line and perpendicular to the fractured well.

[0194] In some embodiments of this disclosure, the imaging slice determining the penultimate subunit includes:

[0195] The reflection coefficient determination unit is used to superimpose the propagation time of all receiving points to determine the transmission coefficient of the transmitted wave at all receiving points.

[0196] A grid imaging slice determination unit is used to determine the imaging energy slice of each grid in a plane passing through the foot of the vertical and perpendicular to the fractured well, based on the transmission coefficient.

[0197] This disclosure provides a distributed fiber optic microseismic event location device, comprising: a vertical foot determination module, used to determine the vertical foot corresponding to the microseismic event based on the shape of the phase axis of the microseismic event according to the seismic profile corresponding to the microseismic event in the fractured well; a cylindrical coordinate system establishment module, used to determine the monitoring well and the vertical foot radius in the cylindrical coordinate system; wherein the origin of the cylindrical coordinate system is the vertex of the phase axis; and a microseismic event location module, used to perform energy scanning on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well, based on the vertical foot radius and the length of the fractured well, in order to locate the microseismic event.

[0198] In summary, the distributed fiber optic microseismic event localization device provided in this disclosure first determines the plane where the microseismic event is located. Then, within this plane, the microseismic event is scanned and imaged using cylindrical coordinates based on radius and azimuth to locate the spatial position of the seismic source. This method has low computational complexity, a simple and clear calculation process, and sufficient theoretical basis, and can meet the needs of real-time monitoring of distributed fiber optic microseismic events.

[0199] Example 7

[0200] Based on the above embodiments, this embodiment provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method described in the above embodiments.

[0201] In some embodiments of this example, a computer-readable storage medium is provided, on which a computer program is stored. When executed by a processor, the computer program implements the steps of the method described in the above embodiments, specifically including the following:

[0202] The foot of the microseismic event is determined based on the shape of the phase axis of the microseismic event in the seismic profile corresponding to the microseismic event in the fractured well.

[0203] Determine the monitoring well and the radius of the vertical foot in the cylindrical coordinate system; wherein the origin of the cylindrical coordinate system is the vertex of the phase axis;

[0204] Based on the vertical foot radius and the fractured well length, an energy scan is performed on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well to locate the microseismic event.

[0205] In some embodiments of this disclosure, determining the foot of the vertical corresponding to the microseismic event based on the morphology of the phase axis of the microseismic event in the seismic profile corresponding to the microseismic event in the fractured well includes:

[0206] The shape of the phase axis of the microseismic event is determined based on the seismic profile corresponding to the microseismic event in the fractured well, and the trace number corresponding to the vertex of the phase axis is determined.

[0207] The foot of the vertical for the microseismic event is determined based on the drilling trajectory of the fractured well and the tunnel number corresponding to the vertex.

[0208] In some embodiments of this disclosure, based on the perpendicular radius and the length of the fractured well, an energy scan is performed on each grid in the cylindrical coordinate system within a plane passing through the perpendicular and perpendicular to the fractured well to locate the microseismic event, including:

[0209] Based on the vertical foot radius and the fractured well length, each grid in the cylindrical coordinate system is imaged in a plane passing through the vertical foot and perpendicular to the fractured well to determine the image slice of each grid in the plane passing through the vertical foot and perpendicular to the fractured well.

[0210] The grid corresponding to the imaging slice with the highest energy is selected to locate the microseismic event.

[0211] In some embodiments of this disclosure, based on the perpendicular radius and the length of the fractured well, each grid in the cylindrical coordinate system is imaged in a plane passing through the perpendicular and perpendicular to the fractured well to determine an image slice of each grid in the plane passing through the perpendicular and perpendicular to the fractured well, including:

[0212] The scanning radius is determined based on the vertical foot radius and the length of the fractured well.

[0213] In the radius and angle domains, each grid in the cylindrical coordinate system is imaged in a plane passing through the foot of the vertical and perpendicular to the fractured well, based on the scanning radius, to determine the image slice of each grid in the plane passing through the foot of the vertical and perpendicular to the fractured well.

[0214] In some embodiments of this disclosure, based on the perpendicular radius and the length of the fractured well, each grid in the cylindrical coordinate system is imaged in a plane passing through the perpendicular and perpendicular to the fractured well to determine an image slice of each grid in the plane passing through the perpendicular and perpendicular to the fractured well, further comprising:

[0215] In a plane passing through the foot of the perpendicular and perpendicular to the fractured well, the seismic data recorded by all receiving points in the monitoring well are integrated to generate an integration result; wherein, the integration order is determined by the radius of the foot of the perpendicular, the length of the fractured well, and the cylindrical coordinate system;

[0216] Based on the integration result, the propagation time from the depth point in the plane passing through the foot of the plumb line and perpendicular to the fractured well to all receiving points is determined, so as to determine the imaging slice of each grid in the plane passing through the foot of the plumb line and perpendicular to the fractured well.

[0217] In some embodiments of this disclosure, the propagation time from a depth point in the plane passing through the foot of the plumb line and perpendicular to the fractured well to all receiving points is determined based on the integration result, in order to determine an imaging slice of each grid in the plane passing through the foot of the plumb line and perpendicular to the fractured well, including:

[0218] The transmission coefficient of the transmitted wave at all receiving points is determined by superimposing the propagation times at all receiving points.

[0219] The imaging energy slice of each grid in a plane passing through the foot of the plumb line and perpendicular to the fractured well is determined based on the transmission coefficient.

[0220] In some embodiments of this example, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the method described in the above embodiments, specifically including the following:

[0221] The foot of the microseismic event is determined based on the shape of the phase axis of the microseismic event in the seismic profile corresponding to the microseismic event in the fractured well.

[0222] Determine the monitoring well and the radius of the vertical foot in the cylindrical coordinate system; wherein the origin of the cylindrical coordinate system is the vertex of the phase axis;

[0223] Based on the vertical foot radius and the fractured well length, an energy scan is performed on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well to locate the microseismic event.

[0224] The processor may include, but is not limited to, one or more processors or microprocessors. Each processor may be implemented as an Application Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), controller, microcontroller, microprocessor, or other electronic component, for executing the methods in the above embodiments.

[0225] Computer-readable storage media can be implemented by any type of volatile or non-volatile storage device or a combination thereof. Computer-readable storage media may include, but are not limited to, random access memory (RAM), read-only memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, and computer storage media (e.g., hard disks, floppy disks, solid-state drives, removable disks, CD-ROMs, DVD-ROMs, Blu-ray discs, etc.).

[0226] Computer-readable storage media may also store at least one computer-executable program, such as computer-readable instructions. Computer-readable storage media include, but are not limited to, volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache memory. Computer-readable storage media may include, for example, read-only memory (ROM), hard disk, flash memory, etc. For example, a non-transitory computer-readable storage medium may be connected to a computing device such as a computer, and then, when the computing device executes the computer-readable instructions stored on the computer-readable storage medium, the various methods described above can be performed.

[0227] In addition, the computer device may include (but is not limited to) a data bus, an input / output (I / O) bus, a display, and input / output devices (e.g., keyboard, mouse, speakers, etc.).

[0228] The processor can communicate with external devices via the I / O bus through wired or wireless networks.

[0229] In one embodiment, the at least one computer-executable instruction may also be compiled into or comprise a software product / computer program product, wherein one or more computer-executable instructions are executed by a processor to perform the steps of the various functions and / or methods in the embodiments described herein.

[0230] In the embodiments provided in this disclosure, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0231] It should be noted that, in this disclosure, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element limited by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0232] While the embodiments disclosed herein are as described above, the foregoing content is merely for the purpose of facilitating understanding of this disclosure and is not intended to limit this disclosure. Any person skilled in the art to which this disclosure pertains may make any modifications and changes in form and detail of the implementation without departing from the spirit and scope of this disclosure; however, the scope of patent protection of this disclosure shall still be determined by the scope defined in the appended claims.

Claims

1. A method for locating distributed fiber-optic microseismic events, characterized in that, include: The foot of the microseismic event is determined based on the shape of the phase axis of the microseismic event in the seismic profile corresponding to the microseismic event in the fractured well. Determine the monitoring well and the radius of the vertical foot in the cylindrical coordinate system; wherein the origin of the cylindrical coordinate system is the vertex of the phase axis; Based on the vertical foot radius and the fractured well length, an energy scan is performed on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well to locate the microseismic event.

2. The method for locating distributed fiber-optic microseismic events according to claim 1, characterized in that, The step of determining the foot of the vertical corresponding to the microseismic event based on the morphology of the phase axis of the microseismic event in the seismic profile corresponding to the microseismic event in the fractured well includes: The shape of the phase axis of the microseismic event is determined based on the seismic profile corresponding to the microseismic event in the fractured well, and the trace number corresponding to the vertex of the phase axis is determined. The foot of the vertical for the microseismic event is determined based on the drilling trajectory of the fractured well and the tunnel number corresponding to the vertex.

3. The method for locating distributed fiber-optic microseismic events according to any one of claims 1 to 2, characterized in that, Based on the perpendicular radius and the length of the fractured well, an energy scan is performed on each grid in the cylindrical coordinate system within a plane passing through the perpendicular and perpendicular to the fractured well to locate the microseismic event, including: Based on the vertical foot radius and the fractured well length, each grid in the cylindrical coordinate system is imaged in a plane passing through the vertical foot and perpendicular to the fractured well to determine the image slice of each grid in the plane passing through the vertical foot and perpendicular to the fractured well. The grid corresponding to the imaging slice with the highest energy is selected to locate the microseismic event.

4. The method for locating distributed fiber-optic microseismic events according to claim 3, characterized in that, Based on the perpendicular radius and the length of the fractured well, each grid in the cylindrical coordinate system is imaged in a plane passing through the perpendicular and perpendicular to the fractured well to determine an image slice of each grid in the plane passing through the perpendicular and perpendicular to the fractured well, including: The scanning radius is determined based on the vertical foot radius and the length of the fractured well. In the radius and angle domains, each grid in the cylindrical coordinate system is imaged in a plane passing through the foot of the vertical and perpendicular to the fractured well, based on the scanning radius, to determine the image slice of each grid in the plane passing through the foot of the vertical and perpendicular to the fractured well.

5. The method for locating distributed fiber-optic microseismic events according to claim 3, characterized in that, Based on the perpendicular radius and the length of the fractured well, each grid in the cylindrical coordinate system is imaged in a plane passing through the perpendicular and perpendicular to the fractured well to determine the image slice of each grid in the plane passing through the perpendicular and perpendicular to the fractured well, further comprising: In a plane passing through the foot of the perpendicular and perpendicular to the fractured well, the seismic data recorded by all receiving points in the monitoring well are integrated to generate an integration result; wherein, the integration order is determined by the radius of the foot of the perpendicular, the length of the fractured well, and the cylindrical coordinate system; Based on the integration result, the propagation time from the depth point in the plane passing through the foot of the plumb line and perpendicular to the fractured well to all receiving points is determined, so as to determine the imaging slice of each grid in the plane passing through the foot of the plumb line and perpendicular to the fractured well.

6. The method for locating distributed fiber-optic microseismic events according to claim 5, characterized in that, Based on the integration result, the propagation time from depth points in the plane passing through the foot of the plumb line and perpendicular to the fractured well to all receiving points is determined, so as to determine the imaging slice of each grid in the plane passing through the foot of the plumb line and perpendicular to the fractured well, including: The transmission coefficient of the transmitted wave at all receiving points is determined by superimposing the propagation times at all receiving points. The imaging energy slice of each grid in a plane passing through the foot of the plumb line and perpendicular to the fractured well is determined based on the transmission coefficient.

7. A distributed fiber optic microseismic event location device, characterized in that, include: The vertical foot determination module is used to determine the vertical foot corresponding to the microseismic event based on the shape of the phase axis of the microseismic event in the seismic profile corresponding to the microseismic event in the fractured well. A cylindrical coordinate system establishment module is used to determine the monitoring well and the radius of the vertical foot in the cylindrical coordinate system; wherein, the origin of the cylindrical coordinate system is the vertex of the phase axis; The microseismic event localization module is used to perform energy scanning on each grid in the cylindrical coordinate system in a plane passing through the vertical foot and perpendicular to the fractured well, based on the vertical foot radius and the length of the fractured well, in order to locate the microseismic event.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the distributed fiber optic microseismic event localization method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the method for locating distributed fiber-optic microseismic events as described in any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method for locating distributed fiber-optic microseismic events as described in any one of claims 1 to 6.

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