A method and system for seismic characterization of igneous intrusive fault zone structure

Abstract

The present invention relates to a method and system for seismic characterization of the structure of an igneous intrusive fault zone, and belongs to the field of applied oil and gas field exploration and development technology. The method comprises loading geological data of the target area; constructing a fault plane of a magma intrusive target fault zone; determining the spatial geometry and position of the fault zone in the target area based on the fault plane of the magma intrusive target fault zone; calculating the seismic indicator factor and its distribution of the fault zone in the target area based on the spatial geometry and position of the fault zone in the target area; statistically analyzing the threshold value of the seismic indicator factor of the igneous intrusive fault zone that has been discovered in the exploration area, comparing the seismic indicator factor of the fault zone to be evaluated with the threshold value of the seismic indicator factor, and quantitatively evaluating the structure of the igneous intrusive fault zone based on the comparison result. Compared with traditional SGR and other methods, the present invention does not require statistical analysis of a large number of geological parameters, but directly conducts research on seismic data, making the implementation process more intuitive and rapid.

Description

Technical Field

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

[0002] Frequent tectonic activity in faulted lake basins often results in the coexistence of igneous and clastic rocks within fault zones, posing a direct challenge to the exploration of both clastic fault-block and igneous reservoirs. While previous research focused on the structure of clastic fault zones, it failed to consider the changes in the internal structure of fault zones following magma intrusion, making it impossible to quantitatively determine the impact of faults on the migration and distribution of oil and gas. Current information mining using seismic data is far from sufficient. While seismic data contain rich information about fault zones and magma reflections, it is currently not possible to directly predict structural changes in fault zones caused by magma intrusion using seismic data. Summary of the Invention

[0003] In response to 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. It is a quantitative prediction of the structural differences of the fault zone for faults in clastic rock formations where magma intrusion occurs, and thus realizes the quantitative determination of the location of oil and gas migration and drainage by faults.

[0004] A 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 intrusion target fault zone based on the geological data of the target area;

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

[0008] Calculate the seismic indicator factors and their distribution of the fault zones in the target area based on their spatial geometry and location;

[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 threshold value of the seismic indicator factor 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] Where 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 ratio 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 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 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 based on 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 based on 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 value of the seismic indicator factor of the igneous intrusive fault zone discovered 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 results.

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

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

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

[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 run 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. This method uses 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. Based on the seismic indicator factors of the fault zone in the target area, the structural characteristics of the magma intrusive fault zone are determined. This method solves the problem of quantitatively predicting the structural differences of igneous intrusive fault zones, provides guidance for the study of oil and gas migration and accumulation along magma-intrusive faults, and helps 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 magma intrusion bodies, and combined with the distribution characteristics of faults, propose a method for calculating the seismic indicator factors of the structure of igneous rock intrusion fault zones, so as to achieve the purpose of quantitatively predicting the oil and gas locations sealed by such fault zones. The prediction effect brought by this method is more in line with actual geological laws. Compared with traditional SGR and other methods, the present invention does not require the statistics of 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 in-depth mining process of seismic data.

[0030] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be 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 is a brief introduction to 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 any creative work.

[0032] Figure 1 A flow chart of 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 intrusion fault zone structure along the fault plane according to an embodiment of the present invention is shown;

[0034] Figure 3 A framework diagram of a seismic characterization system for 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 picture:

[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] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only 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 making creative efforts shall fall 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 based on geological data of the target area;

[0042] Step S3: determining the spatial geometry and position of the fault zone in the target area based on 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: 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.

[0045] In the embodiment of the present invention, for example, a 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 based on 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 geometry 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 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, namely:

[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 the 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 the 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 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;

[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 earthquake indicator factor S of the fault zone in the target area;

[0056] In step S5, the threshold value of the seismic indicator factor of the igneous intrusive fault zone found in the statistical exploration area is calculated, the seismic indicator factor of the fault zone to be evaluated is compared with the threshold value of the seismic indicator factor, and the structure of the igneous intrusive fault zone is quantitatively evaluated based on the comparison result, 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 assessed;

[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 assessed is less than the threshold value of S, then the fault zone is determined to be a magma intrusion type that is favorable for oil and gas sealing;

[0061] If the comparison result shows that the seismic indicator factor S of the fault zone to be assessed 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 Bayantala area of ​​Wuerxun Sag, Hailar Basin, Figure 2 It can be seen that there are obvious changes within the same fault zone. This change not only reflects the differences in its internal structure, but also reflects its lateral and vertical sealing capabilities for oil and gas and its favorable locations. Specifically, based on the results of exploratory well drilling in this area and the distribution of oil and gas wells, it was found that areas with an S index less than 28 (the threshold of S, derived from statistical data) are conducive to oil and gas sealing, which generally coincide with magma intrusion sites. Magma intrusions are a type of non-permeable rock that usually has a good ability to seal oil and gas; areas with an S index greater than 28 represent areas where sealing gradually deteriorates. Based on the results of exploratory well drilling in this area and the distribution of oil and gas wells, statistics show 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] Construction module 2 is used to construct a fault plane of a magma intrusion type target fault zone based on 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 based on 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 discovered 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 results.

[0070] like Figure 4 As shown, some embodiments of the present invention provide an electronic device, the electronic device 300 including: a processor 301, the processor 301 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. 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 storage medium, such as, but 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 that can be used by or in conjunction 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 replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to 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 intrusion target fault zone based on the geological data of the target area; Determine the spatial geometry and location of the fault zone in the target area based on the fault plane of the magma intrusion type target fault zone; Calculate the seismic indicator factors and their distribution of the fault zones in the target area based on their spatial geometry and location; 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 results; The earthquake indicator factor is calculated according to the following formula: Where S is the earthquake indicator factor of each point on a single seismic trace within the study time window; 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; w is a weighted 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 all points in the study time window; f It is the main frequency of the seismic data corresponding to each point in the study time window on a single seismic trace.

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. A seismic characterization system for igneous intrusive fault zone structure, characterized in that: include: The loading module is used to load geological data of the target area; The construction module is used to construct the fault plane of the magma intrusion type target fault zone based on 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 based on 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 value of the seismic indicator factor of the igneous intrusive fault zone discovered 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 results; The earthquake indicator factor is calculated according to the following formula: Where S is the earthquake indicator factor of each point on a single seismic trace within the study time window; 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; w is a weighted 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 all points in the study time window; f It is the main frequency of the seismic data corresponding to each point in the study time window on a single seismic trace.

4. 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 performs the method according to any one of claims 1 to 2.

5. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a program or instruction. When the program or instruction is executed on a computer, the computer is caused to perform the method according to any one of claims 1 to 2.

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