Discrete fracture network modeling method, system and device based on microseismic event space-time distribution and medium

Abstract

The invention discloses a discrete fracture network modeling method, system and device based on microseism event time-space distribution and a medium, and the method comprises the steps: sorting microseism event points Pt in a microseism event point set M according to the time-space distribution characteristics of microseism events and the time t of the microseism event points; the distance from the microseismic event point set M to the fracture network N is 0 through the source point of the fracture network N; based on a connection criterion D of the microseismic event-fracture network, determining a connection point C from the event point Pt to the fracture network N at the t moment, establishing a connection path from the Pt to the N according to the selected connection criterion D, and removing the Pt from the event point set M; and removing Pt from the event point set M according to the sequence of the micro-seismic event points Pt until P does not appear in the event point set M, and obtaining a hydraulic fracturing fracture model. The defect that hydraulic fractures cannot be obtained in plane geometric distribution lineation when a discrete fracture network model is subjected to external interference is overcome.

Description

Technical Field

[0001] The present invention belongs to the technical field of reservoir transformation, and relates to a discrete fracture network modeling method, system, device and medium based on the temporal and spatial distribution of microseismic events. Background Art

[0002] In the process of hydraulic fracturing in oil fields, microseismic monitoring has gradually become a mainstream engineering monitoring and evaluation method. Since the scale of microseismic data is between the scale of drilling and seismic attributes, the fracture model of the fracturing reservoir obtained based on microseismic data can be used to accurately calculate the permeability of hydraulic fractures in the reservoir after fracturing operations, and can also be used to finely characterize the fracture morphology. The discrete fracture network model is a perfect method for evaluating the fluidity of reservoirs with fracture development. When facing complex fracture networks, the existing discrete fracture network model is often interfered by external human factors and cannot correctly obtain hydraulic fractures in the plane geometric distribution line drawing. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that the discrete fracture network model in the prior art is often interfered by external human factors when facing a complex fracture network, and cannot correctly obtain hydraulic fractures in the plane geometric distribution line drawing, and to provide a discrete fracture network modeling method, system, device and medium based on the spatiotemporal distribution of microseismic events.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] Discrete fracture network modeling method based on the spatiotemporal distribution of microseismic events, including:

[0006] Step 1: Based on inter-well microseismic monitoring, obtain a microseismic event point set M;

[0007] Step 2: Based on the time-space distribution characteristics of microseismic events, the microseismic event points Pt in the microseismic event point set M are sorted according to the time t of the microseismic event points;

[0008] Step 3: Based on the source point of the fracture network N, the distance from the microseismic event point set M to the fracture network N is 0;

[0009] Step 4: Based on the connection criterion D of the microseismic event-fracture network, determine the connection point C from the event point Pt at time t to the fracture network N, and establish a connection path from Pt to N based on the selected connection criterion D, and remove Pt from the event point set M;

[0010] Step 5: Repeat step 4, and remove Pt from the event point set M according to the order of the microseismic event points Pt, until P no longer appears in the event point set M, and obtain the hydraulic fracturing fracture model.

[0011] A further improvement of the present invention is:

[0012] Furthermore, based on inter-well microseismic monitoring, a microseismic event point set M is obtained, specifically: a microseismic event point set with time and space attributes obtained by using downhole microseismic and ground inter-well microseismic monitoring instruments during the repeated hydraulic fracturing of the oil field; the microseismic event point set represents the regular characteristics of fracture extension.

[0013] Furthermore, the microseismic event point set M is a collection of microseismic event points picked by purely manual interactive first arrival, and the picking principle is that the microseismic events collected by the geophone are visible on both the first arrival of the P wave and the S wave.

[0014] Furthermore, based on the source point of the fracture network N, the distance from the microseismic event point set M to the fracture network N is 0. Specifically, when the microseismic event point set M contains the wellbore, perforation, fracturing section, and perforation cluster information, the distance from M to N is defined as 0, and a relationship between the initial microseismic event point of the microseismic event point set and the orientation of the initial fracture, the fracture length, and the distance from the source point is established.

[0015] Furthermore, the connection criterion D of the microseismic event-fracture network is that the microseismic event at time t is linked to the fracture network N along the shortest path or along the strike and dip in the focal mechanism interpretation, and each event point is connected according to the set geometric connection criterion to form a hydraulic fracture network.

[0016] Furthermore, a connection path from Pt to N is established based on the selected connection criterion D, and Pt is removed from the event point set M. Specifically, the event points in the microseismic event set M are processed in sequence according to the time and space characteristics, the direction and path of the expansion of the microseismic event points are obtained, the microseismic event points are connected to the fracture network system, and a hydraulic fracturing fracture network system with time and space characteristics that conforms to the law of fracture expansion is constructed.

[0017] Furthermore, according to the order of the microseismic event points Pt, Pt is removed from the event point set M until P no longer appears in the event point set M, and finally a complex hydraulic fracturing fracture model is formed. Specifically, the microseismic event points are processed cyclically to ensure that each time point meets the event-network connection criteria and the minimum path principle for the expansion of microseismic event points.

[0018] Discrete fracture network modeling system based on the spatiotemporal distribution of microseismic events, including:

[0019] An acquisition module, wherein the acquisition module acquires a microseismic event point set M based on inter-well microseismic monitoring;

[0020] A sorting module, wherein the sorting module sorts the microseismic event points Pt in the microseismic event point set M according to the time t of the microseismic event points based on the time-space distribution characteristics of the microseismic events;

[0021] A determination module, wherein the determination module is based on the source point of the fracture network N, and the distance from the microseismic event point set M to the fracture network N is 0;

[0022] A removal module, wherein the removal module determines the connection point C from the event point Pt at time t to the fracture network N based on the connection criterion D of the microseismic event-fracture network, establishes a connection path from Pt to N based on the selected connection criterion D, and removes Pt from the event point set M;

[0023] A model building module, wherein the model building module removes Pt from the event point set M according to the order of the microseismic event points Pt until P no longer appears in the event point set M, thereby obtaining a hydraulic fracturing fracture model.

[0024] A terminal device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0025] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] According to the time-space distribution characteristics of microseismic events, the present invention sorts the microseismic event points Pt in the microseismic event point set M according to the time t of the microseismic event points; and through the source point of the fracture network N, the distance from the microseismic event point set M to the fracture network N is 0; based on the connection criterion D of the microseismic event-fracture network, the connection point C from the event point Pt at time t to the fracture network N is determined, and the connection path from Pt to N is established based on the selected connection criterion D, and Pt is removed from the event point set M; according to the sorting of the microseismic event point Pt, Pt is removed from the event point set M until P no longer appears in the event point set M, and a hydraulic fracturing fracture model is obtained. The present invention determines the connection criterion according to the time-space distribution of microseismic events and the source mechanism information, and establishes a complex fracture network model based on the combination of the shortest distance of fluid migration, events and fracture network attributes, so that the shortest fracture connection path theoretically conforms to the fracture extension law. The present invention overcomes the shortcoming that hydraulic fractures interpreted by drawing lines of planar geometric distribution of microseismic event points are strongly interfered by human factors, and has the shortest distance of fluid migration, a combination of event and fracture network attributes or larger global scale attributes. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 A schematic flow chart of a discrete fracture network modeling method based on the spatiotemporal distribution of microseismic events of the present invention;

[0030] Figure 2 Another schematic flow chart of the discrete fracture network modeling method based on the spatiotemporal distribution of microseismic events of the present invention;

[0031] Figure 3 This is an example diagram of a discrete fracture network;

[0032] Figure 4 It is a structural schematic diagram of the discrete fracture network modeling system based on the spatiotemporal distribution of microseismic events of the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0036] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0037] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0038] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0040] See also Figure 1 and Figure 2 The present invention discloses a discrete fracture network modeling method based on the spatiotemporal distribution of microseismic events, comprising:

[0041] S101, based on inter-well microseismic monitoring, a microseismic event point set M is obtained;

[0042] During the repeated hydraulic fracturing process in the oil field, a microseismic event point set with time and space attributes is obtained using downhole microseismic and surface inter-well microseismic monitoring instruments; the microseismic event point set represents the regular characteristics of fracture extension.

[0043] The microseismic event point set M is a collection of microseismic event points picked by purely manual interactive first arrival. The picking principle is that the microseismic events collected by the geophone are visible on both the first arrival of the P wave and the S wave.

[0044] S102, based on the time-space distribution characteristics of the microseismic events, sort the microseismic event points Pt in the microseismic event point set M according to the time t of the microseismic event points.

[0045] S103, based on the source point of the fracture network N, the distance from the microseismic event point set M to the fracture network N is 0.

[0046] When the microseismic event point set M contains the information of wellbore, perforation, fracturing section, and perforation cluster, the distance from M to N is defined as 0, and the relationship between the initial microseismic event point in the microseismic event point set and the orientation and length of the initial fracture and the distance from the source point (perforation point) is established.

[0047] S104, based on the connection criterion D of the microseismic event-fracture network, determine the connection point C from the event point Pt at time t to the fracture network N, and establish a connection path from Pt to N based on the selected connection criterion D, and remove Pt from the event point set M.

[0048] The connection criterion D of microseismic events and fracture networks is that the microseismic events at time t are linked to the fracture network N along the shortest path or along the strike and dip angle in the focal mechanism interpretation, and each event point is connected according to the set geometric connection criterion to form a hydraulic fracture network. The shortest path principle of the connection criterion D conforms to the physical principle of fracture extension to a certain extent, and can reflect the direction of fracture extension, thereby reflecting the path and angle at which the event extends or connects to the pre-existing fracture.

[0049] Based on the selected connection criterion D, a connection path from Pt to N is established, and Pt is removed from the event point set M. Specifically, the event points in the microseismic event set M are processed in sequence according to the time and space characteristics, the direction and path of the expansion of the microseismic event points are obtained, the microseismic event points are connected to the fracture network system, and a hydraulic fracturing fracture network system with time and space characteristics that conforms to the law of fracture expansion is constructed.

[0050] S105, repeat S104, remove Pt from the event point set M according to the order of the microseismic event points Pt, until P no longer appears in the event point set M, and finally form a complex hydraulic fracturing fracture model.

[0051] See also Figure 3 , the microseismic event points are processed cyclically to ensure that each time point meets the event-network connection criteria and the minimum path principle for the expansion of microseismic event points.

[0052] See also Figure 4 The present invention discloses a discrete fracture network modeling system based on the spatiotemporal distribution of microseismic events, comprising:

[0053] An acquisition module, wherein the acquisition module acquires a microseismic event point set M based on inter-well microseismic monitoring;

[0054] A sorting module, wherein the sorting module sorts the microseismic event points Pt in the microseismic event point set M according to the time t of the microseismic event points based on the time-space distribution characteristics of the microseismic events;

[0055] A determination module, wherein the determination module is based on the source point of the fracture network N, and the distance from the microseismic event point set M to the fracture network N is 0;

[0056] A removal module, wherein the removal module determines the connection point C from the event point Pt at time t to the fracture network N based on the connection criterion D of the microseismic event-fracture network, establishes a connection path from Pt to N based on the selected connection criterion D, and removes Pt from the event point set M;

[0057] A model building module, wherein the model building module removes Pt from the event point set M according to the order of the microseismic event points Pt until P no longer appears in the event point set M, thereby obtaining a hydraulic fracturing fracture model.

[0058] A terminal device is provided in one embodiment of the present invention. The terminal device of this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor executes the computer program, the functions of the modules / units in the above-mentioned device embodiments are implemented.

[0059] The computer program may be divided into one or more modules / units, and the one or more modules / units are stored in the memory and executed by the processor to accomplish the present invention.

[0060] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0061] The processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0062] The memory may be used to store the computer programs and / or modules, and the processor implements various functions of the terminal device by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory.

[0063] If the module / unit integrated in the terminal device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0064] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A discrete fracture network modeling method based on the spatiotemporal distribution of microseismic events, characterized in that: include: Step 1: Based on inter-well microseismic monitoring, obtain a microseismic event point set M; Step 2: Based on the time-space distribution characteristics of microseismic events, the microseismic event points Pt in the microseismic event point set M are sorted according to the time t of the microseismic event points; Step 3: Based on the source point of the fracture network N, the distance from the microseismic event point set M to the fracture network N is 0; Step 4: Based on the connection criterion D of the microseismic event-fracture network, determine the connection point C from the event point Pt at time t to the fracture network N, and establish a connection path from Pt to N based on the selected connection criterion D, and remove Pt from the event point set M; Step 5: Repeat step 4, and remove Pt from the event point set M according to the order of the microseismic event points Pt, until P no longer appears in the event point set M, and obtain the hydraulic fracturing fracture model.

2. The discrete fracture network modeling method based on the spatiotemporal distribution of microseismic events according to claim 1 is characterized in that: The microseismic event point set M is obtained based on the inter-well microseismic monitoring, which is specifically: a microseismic event point set with time and space attributes obtained by using downhole microseismic and ground inter-well microseismic monitoring instruments during the repeated hydraulic fracturing of the oil field; the microseismic event point set represents the regular characteristics of fracture extension.

3. The discrete fracture network modeling method based on the spatiotemporal distribution of microseismic events according to claim 1 is characterized in that: The microseismic event point set M is a collection of microseismic event points picked by purely manual interactive first arrival, and the picking principle is that the microseismic events collected by the geophone are visible on both the first arrival of the P wave and the S wave.

4. The discrete fracture network modeling method based on the spatiotemporal distribution of microseismic events according to claim 3 is characterized in that: Based on the source point of the fracture network N, the distance between the microseismic event point set M and the fracture network N is 0. Specifically, when the microseismic event point set M contains information about the wellbore, perforation, fracturing section, and perforation cluster, the distance from M to N is defined as 0, and a relationship between the initial microseismic event point of the microseismic event point set and the orientation and length of the initial fracture and the distance from the source point is established.

5. The discrete fracture network modeling method based on the spatiotemporal distribution of microseismic events according to claim 4 is characterized in that: The connection criterion D of the microseismic event-fracture network is that the microseismic event at time t is linked to the fracture network N along the shortest path or along the strike and dip in the focal mechanism interpretation, and each event point is connected according to the set geometric connection criterion to form a hydraulic fracture network.

6. The discrete fracture network modeling method based on the spatiotemporal distribution of microseismic events according to claim 5, characterized in that: The method of establishing a connection path from Pt to N based on the selected connection criterion D and removing Pt from the event point set M is as follows: the event points in the microseismic event set M are processed in sequence according to the time and space characteristics, the direction and path of the expansion of the microseismic event points are obtained, the microseismic event points are connected to the fracture network system, and a hydraulic fracturing fracture network system with time and space characteristics that conforms to the law of fracture expansion is constructed.

7. The discrete fracture network modeling method based on the spatiotemporal distribution of microseismic events according to claim 6, characterized in that: The method removes Pt from the event point set M according to the order of the microseismic event points Pt until P no longer appears in the event point set M, and finally forms a complex hydraulic fracturing crack model. Specifically, the microseismic event points are processed cyclically to ensure that each time point meets the event-network connection criteria and the minimum path principle for the expansion of microseismic event points.

8. A discrete fracture network modeling system based on the spatiotemporal distribution of microseismic events, characterized in that: include: An acquisition module, wherein the acquisition module acquires a microseismic event point set M based on inter-well microseismic monitoring; A sorting module, wherein the sorting module sorts the microseismic event points Pt in the microseismic event point set M according to the time t of the microseismic event points based on the time-space distribution characteristics of the microseismic events; A determination module, wherein the determination module is based on the source point of the fracture network N, and the distance from the microseismic event point set M to the fracture network N is 0; A removal module, wherein the removal module determines the connection point C from the event point Pt at time t to the fracture network N based on the connection criterion D of the microseismic event-fracture network, establishes a connection path from Pt to N based on the selected connection criterion D, and removes Pt from the event point set M; A model building module, wherein the model building module removes Pt from the event point set M according to the order of the microseismic event points Pt until P no longer appears in the event point set M, thereby obtaining a hydraulic fracturing fracture model.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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