Earthquake characterization method and system for igneous rock intrusive fault zone structure

Abstract

The invention relates to an igneous rock intrusive fault zone structure seismic characterization method and system, and belongs to the technical field of oil and gas field exploration and development. The method comprises the following steps: loading geological data of a target area; constructing a fault plane of the magma intrusive target fault zone; according to the fault plane of the magma intrusive target fault zone, determining the spatial geometry and position of the fault zone in the target area; calculating seismic indication factors and distribution thereof of the fault zone in the target area according to the spatial geometric morphology and position of the fault zone in the target area; and counting the threshold value of the seismic indication factor of the igneous rock intrusive fault zone found in the exploration area, comparing the seismic indication factor of the fault zone to be evaluated with the threshold value of the seismic indication factor, and quantitatively evaluating the structure of the igneous rock intrusive fault zone according to the comparison result. Compared with a traditional SGR method and the like, the method does not need to count a large number of geological parameters, but directly carries out research on seismic data, and the implementation process is more intuitive and rapid.

Description

Technical Field

[0001] The invention belongs to the technical field of applied oil and gas field exploration and development, and in particular relates to a method and system for seismic characterization of an igneous rock intrusive fault zone structure. Background Art

[0002] Due to frequent tectonic activities in faulted lake basins, the coexistence of igneous rocks and clastic rocks in fault zones is very common, which poses a direct challenge to the exploration of clastic block oil and gas reservoirs and igneous oil and gas reservoirs. In the past, people paid attention to the structure of clastic fault zones, but did not consider the changes in the internal structure of the fault zones after magma intrusion, and could not quantitatively determine the location of oil and gas migration and drainage by faults. At present, the information mining in the use of seismic data is far from enough. However, seismic data contains rich information on fault zones and magma reflections. At present, it is not possible to use seismic data to directly predict the changes in the internal structure of the fault zone caused by magma intrusion. Summary of the invention

[0003] In view of the above problems, the present invention provides a method and system for seismic characterization of igneous intrusive fault zone structure, which can directly use geological data to identify the internal structure of the fault zone after magma intrusion, and quantitatively predict the structural differences of the fault zone for faults in clastic rock formations where magma intrusion occurs, thereby achieving quantitative determination of the impact of faults on the migration and drainage of oil and gas.

[0004] The first object of the present invention is to provide a method for seismic characterization of igneous intrusive fault zone structure, the method comprising:

[0005] Load geological data of the target area;

[0006] Construct the fault plane of the magma intrusive target fault zone based on the geological data of the target area;

[0007] Determine the spatial geometry and position of the fault zone in the target area based on the fault plane of the magmatic intrusion type target fault zone;

[0008] According to the spatial geometry and position of the fault zone in the target area, calculate the seismic indicator factors and their distribution in the fault zone in the target area;

[0009] The threshold value of the seismic indicator factor of the igneous intrusive fault zone found in the statistical exploration area is compared with the seismic indicator factor of the fault zone to be evaluated and the structure of the igneous intrusive fault zone is quantitatively evaluated based on the comparison results.

[0010] In an embodiment of the invention, the geological data includes seismic data, well logging data and fault interpretation data.

[0011] In this embodiment, the earthquake indicator factor is calculated according to the following formula:

[0012] S=R×w×f

[0013] Among them, S is the earthquake indicator factor of each point on a single seismic trace within the study time window, dimensionless;

[0014] R is the envelope of seismic reflection, specifically the envelope of each point on a single seismic trace within the study time window, and R = [x 2 (t)+y 2 (t)] 1 / 2 , x(t) is the displacement of a point on a single seismic trace in the x direction within the study time window, and y(t) is the displacement of a point on a single seismic trace in the y direction within the study time window;

[0015] w is a weighting coefficient, which is the proportion of the envelope of each point on a single seismic trace in the study time window, and w = R / sum(R), that is, the ratio of the envelope of a single point to the sum of the envelopes of all points in the time window;

[0016] f is the main frequency of the seismic data corresponding to each point in the study time window on a single seismic trace, HZ.

[0017] A second object of the present invention is to provide a seismic characterization system for igneous intrusive fault zone structure, the system comprising:

[0018] The loading module is used to load the geological data of the target area;

[0019] The construction module is used to construct the fault plane of the magma intrusion type target fault zone according to the geological data of the target area;

[0020] The determination module is used to determine the spatial geometry and position of the fault zone in the target area according to the fault plane of the magma intrusion type target fault zone;

[0021] The calculation module calculates the seismic indicator factors and their distribution of the fault zones in the target area according to the spatial geometry and position of the fault zones in the target area;

[0022] The characterization module is used to statistically calculate the threshold of the seismic indicator factor of the igneous intrusive fault zone found in the exploration area, compare the seismic indicator factor of the fault zone to be evaluated with the threshold of the seismic indicator factor, and quantitatively evaluate the structure of the igneous intrusive fault zone based on the comparison results.

[0023] A third object of the present invention is to provide an electronic device, the electronic device comprising: a processor, the processor being coupled to a memory;

[0024] The memory is used to store computer programs;

[0025] The processor is used to execute the computer program stored in the memory so that the electronic device executes the method as described above.

[0026] A fourth object of the present invention is to provide a computer-readable storage medium, wherein the computer-readable storage medium stores a program or instruction, and when the program or instruction is executed on a computer, the computer executes the method as described above.

[0027] Beneficial effects of the present invention:

[0028] The present invention provides a method and system for seismic characterization of the structure of an igneous intrusive fault zone. The method and system utilize geological data (including seismic data, well logging data, and fault interpretation data) to calculate the seismic indicator factors of the fault zone in the target area. The structural characteristics of the magma intrusive fault zone are determined based on the seismic indicator factors of the fault zone in the target area. This solves the problem of quantitative prediction of the structural differences of the igneous intrusive fault zone, has guiding significance for the study of the migration and accumulation of oil and gas along the faults of magma intrusion, and helps to reduce geological risks in exploration and improve the success rate of fault block trap exploration and evaluation.

[0029] The method and system provided by the present invention take into account the seismic reflection envelope characteristics and frequency characteristics of the magmatic intrusion body, and combine the distribution characteristics of the fault to propose a calculation method for the seismic indicator factor of the structure of the igneous intrusion fault zone, so as to achieve the purpose of quantitatively predicting the closed oil and gas locations of such fault zones. The prediction effect brought by this method is more in line with the actual geological laws. Compared with traditional SGR and other methods, the present invention does not need to count a large number of geological parameters, but directly conducts research on seismic data. The implementation process is more intuitive and rapid, and it is a direct utilization and deep mining process of seismic data.

[0030] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A flow chart showing a method for seismic characterization of an igneous intrusive fault zone structure according to an embodiment of the present invention is shown;

[0033] Figure 2A diagram showing the distribution of the seismic indicator factor S of the igneous intrusive fault zone structure along the fault plane according to an embodiment of the present invention;

[0034] Figure 3 A framework diagram of a seismic characterization system for an igneous intrusive fault zone structure according to an embodiment of the present invention is shown;

[0035] Figure 4 A framework diagram of an electronic device according to an embodiment of the present invention is shown;

[0036] In the figure:

[0037] Loading module 1; establishing module 2; determining module 3; calculating module 4; characterizing module 5; electronic device 300; processor 301; memory 302. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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. 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.

[0039] like Figure 1 As shown, a method for seismic characterization of an igneous intrusive fault zone structure according to an embodiment of the present invention includes:

[0040] Step S1, loading geological data of the target area;

[0041] Step S2: constructing a fault plane of a magma intrusion type target fault zone according to geological data of the target area;

[0042] Step S3, determining the spatial geometry and position of the fault zone in the target area according to the fault plane of the magma intrusion type target fault zone;

[0043] Step S4, calculating the earthquake indicator factor and its distribution of the fault zone in the target area according to the spatial geometry and position of the fault zone in the target area;

[0044] Step S5, statistically analyzing the threshold of the seismic indicator factor of the igneous intrusive fault zone found in the exploration area, comparing the seismic indicator factor of the fault zone to be evaluated with the threshold of the seismic indicator factor, and quantitatively evaluating the structure of the igneous intrusive fault zone based on the comparison result.

[0045] In the embodiment of the present invention, illustratively, a certain fault in the Bayantala area of ​​the Wuerxun Depression in the Hailar Basin is taken as an example;

[0046] Specifically, in step S1, the geological data of the target area is loaded, wherein the geological data includes seismic data, well logging data and fault interpretation data;

[0047] In step S2, the fault plane of the target magma intrusion type fault zone is constructed according to the geological data of the target area, that is, seismic data, well logging data and fault interpretation data are loaded to construct the fault plane of the target magma intrusion type fault zone.

[0048] In step S3, the spatial geometric shape and position of the fault zone in the target area are determined according to the fault plane of the magma intrusion type target fault zone, that is, the spatial distribution shape of the fault plane of the magma intrusion type target fault zone is constructed according to the fault plane of the magma intrusion type target fault zone.

[0049] In step S4, the earthquake indicator factor and its distribution of the fault zone in the target area are calculated according to the spatial geometry and position of the fault zone in the target area, that is:

[0050] On the basis of step S3, the spatial geometry and position of the fault zone in the target area are determined, and then the position of each point on a single seismic trace in the study time window is determined, and the seismic indicator factor of the fault zone in the target area is calculated. The seismic indicator factor is calculated according to formula (1);

[0051] S=R×w×f (1)

[0052] In formula (1), S represents the earthquake indicator factor of each point on a single seismic trace within the study time window, which is dimensionless;

[0053] R is the envelope of seismic reflection, specifically the envelope of each point on a single seismic trace within the study time window, and R = [x 2 (t)+y 2 (t)] 1 / 2 , x(t) is the displacement of a point on a single seismic trace in the x direction within the study time window, and y(t) is the displacement of a point on a single seismic trace in the y direction within the study time window;

[0054] w is a weighting coefficient, which is the proportion of the envelope of each point on a single seismic trace within the study time window, and w = R / sum(R), that is, the ratio of the envelope of a single point to the sum of the envelopes of each point in the time window; f is the main frequency of the seismic data corresponding to each point in the study time window on a single seismic trace, HZ;

[0055] Specifically, the seismic indicator factor S value corresponding to each point on a single seismic trace within the study time window is calculated using formula (1), that is, the distribution of the seismic indicator factor S of the fault zone in the target area is calculated, that is, Figure 4 As shown, the gray area shows the distribution area of ​​the seismic indicator factor S of the fault zone in the target area;

[0056] In step S5, the threshold of the seismic indicator factor of the igneous intrusive fault zone found in the statistical exploration area is calculated, and the seismic indicator factor of the fault zone to be evaluated is compared with the threshold of the seismic indicator factor. According to the comparison result, the structure of the igneous intrusive fault zone is quantitatively evaluated, that is:

[0057] The threshold value of the seismic indicator factor S of the igneous intrusive fault zone found in the statistical exploration area;

[0058] Compare the threshold of S with the earthquake indicator factor S of the fault zone to be evaluated;

[0059] Based on the comparison results, the structure of the igneous intrusive fault zone is quantitatively evaluated, specifically:

[0060] If the comparison result shows that the seismic indicator factor S of the fault zone to be evaluated is less than the threshold value of S, then a magma intrusion type fault zone favorable for oil and gas sealing is determined;

[0061] The comparison result is that if the seismic indicator factor S of the fault zone to be evaluated is greater than or equal to the threshold of S, it is not conducive to oil and gas sealing, and it is used to determine the magma intrusion type fault zone that is conducive to oil and gas drainage;

[0062] Furthermore, based on the comparison results of each seismic indicator factor S on the fault zone in the target area and the corresponding S threshold, the structural characteristics of each point on the fault zone in the target area are determined, and then the structure of the entire igneous intrusive fault zone is quantitatively evaluated.

[0063] In a fault in the Bayantala area of ​​the Wuerxun Sag in the Hailar Basin, Figure 2 It can be seen that there are obvious changes within the same fault zone. This change not only reflects the difference in its internal structure, but also reflects its lateral and vertical sealing ability and favorable positions for oil and gas. Specifically, combined with the exploration well drilling results and the distribution of oil and gas wells in this area, it is found that the S index is less than 28 (the threshold of S, derived from statistical data) is conducive to oil and gas sealing, which is generally consistent with the magma intrusion site. The magma intrusion body belongs to a non-permeable rock and usually has a good ability to seal oil and gas; the area with an S index greater than 28 represents a gradually deteriorating sealing area. Combined with the exploration well drilling results and the distribution of oil and gas wells in this area, it is statistically believed that the larger the S index, the less conducive it is to fracture sealing of oil and gas; the drilling statistics show that the application effect of the present invention conforms to geological laws and is reliable.

[0064] like Figure 3 As shown, a seismic characterization system for igneous intrusive fault zone structure according to an embodiment of the present invention includes:

[0065] Loading module 1 is used to load geological data of the target area;

[0066] The construction module 2 is used to construct a fault plane of a magma intrusion type target fault zone according to the geological data of the target area;

[0067] The determination module 3 is used to determine the spatial geometry and position of the fault zone in the target area according to the fault plane of the magma intrusion type target fault zone;

[0068] The calculation module 4 calculates the earthquake indicator factor and its distribution of the fault zone in the target area according to the spatial geometry and position of the fault zone in the target area;

[0069] Characterization module 5 is used to statistically calculate the threshold value of the seismic indicator factor of the igneous intrusive fault zone found in the exploration area, compare the seismic indicator factor of the fault zone to be evaluated with the threshold value of the seismic indicator factor, and quantitatively evaluate the structure of the igneous intrusive fault zone based on the comparison result.

[0070] like Figure 4 As shown, some embodiments of the present invention provide an electronic device, the electronic device 300, comprising: a processor 301, the processor 301 is coupled to a memory 302;

[0071] The memory 302 is used to store computer programs;

[0072] The processor 301 is configured to execute the computer program stored in the memory 302 so that the electronic device executes the method described in the above embodiment.

[0073] In certain embodiments of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a program or instruction. When the program or instruction is executed on a computer, the computer executes the method described in the above embodiments.

[0074] According to an embodiment of the present invention, the computer-readable storage medium may be a non-volatile computer-readable computer-readable storage medium, for example, may include but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, a computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, an electronic device or a device.

[0075] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for seismic characterization of igneous intrusive fault zone structure, characterized in that: include: Load geological data of the target area; Construct the fault plane of the magma intrusive target fault zone based on the geological data of the target area; Determine the spatial geometry and position of the fault zone in the target area based on the fault plane of the magmatic intrusion type target fault zone; According to the spatial geometry and position of the fault zone in the target area, calculate the seismic indicator factors and their distribution in the fault zone in the target area; The threshold value of the seismic indicator factor of the igneous intrusive fault zone found in the statistical exploration area is compared with the seismic indicator factor of the fault zone to be evaluated and the structure of the igneous intrusive fault zone is quantitatively evaluated based on the comparison results.

2. The method for seismic characterization of igneous intrusive fault zone structure according to claim 1, characterized in that: The geological data includes seismic data, well logging data and fault interpretation data.

3. The method for seismic characterization of igneous intrusive fault zone structure according to claim 1, characterized in that: The earthquake indicator factor is calculated according to the following formula: SS=R×w× Among them, S is the earthquake indicator factor of each point on a single seismic trace within the study time window, dimensionless; R is the envelope of seismic reflection, specifically the envelope of each point on a single seismic trace within the study time window, and R = [x 2 (t)+y2(t)]1 / 2, x(t) is the displacement of a point on a single seismic trace in the x direction within the study time window, y(t) is the displacement of a point on a single seismic trace in the y direction within the study time window; w is a weighting coefficient, which is the proportion of the envelope of each point on a single seismic trace in the study time window, and w = R / sum(R), that is, the ratio of the envelope of a single point to the sum of the envelopes of all points in the time window; f is the main frequency of the seismic data corresponding to each point in the study time window on a single seismic trace, HZ.

4. A seismic characterization system for igneous intrusive fault zone structure, characterized in that: include: The loading module is used to load the geological data of the target area; The construction module is used to construct the fault plane of the magma intrusion type target fault zone according to the geological data of the target area; The determination module is used to determine the spatial geometry and position of the fault zone in the target area according to the fault plane of the magma intrusion type target fault zone; The calculation module calculates the seismic indicator factors and their distribution of the fault zones in the target area according to the spatial geometry and position of the fault zones in the target area; The characterization module is used to statistically calculate the threshold of the seismic indicator factor of the igneous intrusive fault zone found in the exploration area, compare the seismic indicator factor of the fault zone to be evaluated with the threshold of the seismic indicator factor, and quantitatively evaluate the structure of the igneous intrusive fault zone based on the comparison results.

5. An electronic device, characterized in that: include: a processor coupled to the memory; The memory is used to store computer programs; The processor is configured to execute the computer program stored in the memory, so that the electronic device executes the method according to any one of claims 1 to 3.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a program or an instruction, and when the program or the instruction is executed on a computer, the computer is caused to perform the method according to any one of claims 1 to 3.

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