WO2016041185A1

WO2016041185A1 - High-efficiency pre-stack time migration velocity analysis method

Info

Publication number: WO2016041185A1
Application number: PCT/CN2014/086902
Authority: WO
Inventors: 杨顺伟
Original assignee: 杨顺伟
Priority date: 2014-09-19
Filing date: 2014-09-19
Publication date: 2016-03-24
Also published as: CN104769459A

Abstract

A high-efficiency pre-stack time migration velocity analysis method. The method includes: applying for a plurality of processes, determining one of the processes to be a main process, and determining the rest of the processes to be sub-processes; determining allocation information; allocating a memory space to each sub-process; allocating, by the main process, a pre-stack time migration velocity analysis position and a pre-stack earthquake data track to each sub-process according to the allocation information; using, by each sub-process, the pre-stack time migration velocity analysis position and the pre-stack earthquake data track to perform pre-stack time migration, generating a pre-stack time migration result and sending the pre-stack time migration result to the main process; and obtaining, by the main process, a pre-stack time migration velocity analysis result according to the pre-stack time migration results sent by all the sub-processes, thereby remarkably improving the calculation speed and shortening the operation time.

Description

An efficient pre-stack time migration speed analysis method

Technical field

The invention relates to the field of petroleum exploration technology, in particular to an efficient pre-stack time migration speed analysis method.

Background technique

In the process of seismic exploration data processing of oil and gas resources, prestack time migration is a commonly used imaging method, which has become a routine processing method. The offset velocity field is an essential parameter when prestack time migration is performed. Therefore, the pre-stack time migration velocity analysis and the construction tools are efficient, convenient and practical, which is the decisive factor for the pre-stack time migration can be popularized.

The existing prestack time migration velocity analysis methods mainly include three methods: constant speed scanning method, stepwise correction method and edge velocity analysis method. However, these three methods have the disadvantages of large calculation amount, many processing steps and long consumption period. In order to overcome such shortcomings, other prestack time migration speed analysis methods have appeared in the prior art. For example, the Chinese patent No. 200910080622.9 proposes a method for determining the prestack time migration speed, which is only for The information that needs to be output at the speed analysis point is calculated, the implementation is simple and the calculation amount is significantly reduced, but since the memory occupancy and the calculation operation time are proportional to the number of speed analysis position points, for more speed analysis The application of large-area 3D seismic exploration sites will be limited. For example, if there are hundreds of speed spectra in a job, it may take up nearly 10 gigabytes of memory, which is beyond the configuration of most existing computers; such jobs may run for hundreds or even dozens of days. If an unexpected situation such as a computer failure occurs during the operation of the operation, the operation will be abandoned, and the risk that the processing contract cannot be completed on time cannot be ignored.

By analyzing the foregoing various prestack time migration speed analysis methods, the foregoing various methods are applied to the processing of a single computer device, and are limited by the processing capability of a single computer device. Therefore, the foregoing various methods are also different in degree. There is a defect in the calculation cycle that is long and it is a disadvantage to successfully complete the pre-stack time shift operation.

Summary of the invention

The main objective of the embodiments of the present invention is to provide an efficient pre-stack time migration speed analysis method to solve the problem of long calculation period existing in the existing pre-stack time migration speed analysis method.

In order to achieve the above object, an embodiment of the present invention provides an efficient prestack time migration speed analysis method, and an efficient prestack time migration speed analysis method, including:

Applying for multiple processes, determining one of the multiple processes as the primary process, and the rest as the child process;

Determining allocation information, the allocation information including a correspondence between each sub-process and a pre-stack time offset velocity analysis location to be assigned to the sub-process;

Allocate memory space for each child process;

The main process allocates a pre-stack time migration speed analysis position and a pre-stack seismic data track for each sub-process according to the allocation information;

Each pre-process uses the pre-stack time migration velocity analysis location and the pre-stack seismic data track to perform a pre-stack time offset, generates a pre-stack time offset result, and sends the result to the main process;

The main process obtains a prestack time migration speed analysis result according to a prestack time offset result sent by all the subprocesses, and the prestack time migration speed analysis result includes all prestack time migration speed analysis positions and all prestacks. The common reflection point CRP gather, the offset section and the offset velocity spectrum corresponding to the seismic data track.

The determining allocation information is specifically:

According to the number of subprocesses applied, it is determined that all prestack time offset velocity analysis positions are evenly distributed to each subprocess.

Allocating memory space for each child process is specifically as follows:

For each sub-process, the memory space is calculated according to the pre-stack time migration speed corresponding to the pre-stack time, the number of samples of the pre-stack seismic data track, and the preset pre-stack time offset calculation parameter, and is allocated to the sub-process. process.

The main process allocates the pre-stack seismic data track for each sub-process, specifically:

The main process assigns all pre-stack seismic data tracks to the sub-process; or

The main process assigns a portion of the pre-stack seismic data track to the sub-process.

The main process allocates a part of the pre-stack seismic data track to the sub-process, specifically:

The main process determines a first set number of consecutive prestack seismic data tracks as a set of prestack seismic data tracks;

In all pre-stack seismic data tracks, a subsequent set of pre-stack seismic data tracks is assigned to the sub-process every second set number of consecutive pre-stack seismic data sets.

Each of the sub-processes uses the pre-stack time migration velocity analysis location and the pre-stack seismic data track to perform a pre-stack time offset to generate a pre-stack time migration result, specifically:

Each of the sub-processes determines a pre-stack time offset speed sequence, the pre-stack time allocated to the main process as each pre-stack time offset speed in the pre-stack time offset speed sequence The offset velocity analysis location and the pre-stack seismic data track perform prestack time migration, and generate CRP gathers, offset profile segments, and offset velocity spectrum data corresponding to the subprocess.

Each of the sub-processes generates CRP gathers, offset profile segments, and offset velocity spectrum data corresponding to the sub-process, specifically:

Each of the sub-processes generates a CRP gather corresponding to the sub-process, an offset profile segment lacking common information, and offset velocity spectrum data lacking common information, wherein the common information is a CRP gather and an offset profile segment Information that is common to the offset velocity spectrum data and that can be directly summed using the CRP gather;

Then, the main process obtains a prestack time migration speed analysis result according to the prestack time offset result sent by all the subprocesses. Specifically, it is:

For each sub-process, the main process directly calculates the common information by using the CRP gather corresponding to the sub-process, and utilizes the common information and the missing profile segment and the missing Offset velocity spectrum data of the common information, obtaining offset profile segments and offset velocity spectrum data corresponding to the subprocess;

The main process synthesizes the CRP gathers, offset profile segments and offset velocity spectrum data corresponding to all the sub-processes, and obtains all pre-stack time migration velocity analysis positions and CRP gathers and offsets corresponding to all pre-stack seismic data tracks. Section segment and offset velocity spectrum.

By means of the above technical solution, the invention distributes the pre-stack time migration speed analysis calculation to a plurality of sub-processes, fully utilizes the computer cluster technology, significantly improves the speed of the pre-stack time migration speed analysis and calculation, and greatly shortens the pre-stacking The working time of the time offset velocity analysis is especially suitable for large-area 3D seismic exploration sites with more velocity analysis locations, which has good practicability.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only the present invention. For some embodiments, other drawings may be obtained from those of ordinary skill in the art without departing from the drawings.

1 is a flow chart of an efficient pre-stack time migration speed analysis method provided by the present invention;

2 is a schematic diagram of a working cooperation relationship between a main process and a sub-process provided by the present invention;

3 is a partial view of an offset velocity spectrum on a time-speed plane according to Embodiment 1 of the present invention;

4 is a partial view of a CRP gather set at different offsets of different speeds on the in-phase axis of the reflected wave according to the first embodiment of the present invention;

5 is a partial view of an offset offset segment of a different speed versus a reflected wave in phase axis according to Embodiment 1 of the present invention;

6 is a partial view of an offset velocity spectrum calculated by using partial data according to Embodiment 1 of the present invention;

7 is a partial view of a CRP gather set calculated by using partial data according to Embodiment 1 of the present invention;

8 is a partial view of an offset section calculated by using partial data according to Embodiment 1 of the present invention;

FIG. 9 is a flowchart of a pre-stack time migration speed analysis and a field establishment process according to Embodiment 1 of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts, All fall within the scope of protection of the present invention.

With the development of computer technology, computer clusters have become the universally configured working platform for most petroleum exploration seismic data processing centers. It has many nodes and can undertake large-scale computing tasks in parallel. The invention utilizes the computer cluster technology to adopt a parallelized operation mode for the calculation process of the pre-stack time migration speed analysis, which improves the speed of the pre-stack time migration speed analysis and shortens the operation period.

As shown in FIG. 1, the present invention provides an efficient pre-stack time migration speed analysis method, including:

Step S11, applying for multiple processes, determining one of the multiple processes as the primary process, and the rest as the child process.

Specifically, the step applies for resources of multiple (at least three) processes in the computer cluster, one of which is the main process and the other is the child process; wherein the main process is responsible for distributing data to the child process, and calculating the process of recycling the child process. As a result, the child process is used to perform prestack time offset calculation using the data sent by the main process. Figure 2 shows the working relationship between the main process and the child process in the present invention.

This step can estimate the amount of job calculation in advance, and consider the process usage of the current computer cluster device, and then determine how many processes are applied in total.

In step S12, the allocation information is determined, and the allocation information includes a correspondence relationship between each sub-process and a pre-stack time offset speed analysis position to be allocated to the sub-process.

In order to ensure that the processing speed of each sub-process is equivalent, so as to complete the calculation task quickly without wasting the computing resources, in this step, each sub-process can be assigned a corresponding number of pre-stack time migration speed analysis positions. If the number of prestack time offset velocity analysis locations is an integer multiple of the number of subprocesses, this step determines that all prestack time offset velocity analysis locations are evenly distributed to each subprocess, and each subprocess is determined to be assigned to The pre-stack time migration speed of the sub-process analyzes the correspondence between the positions. If the number of prestack time offset velocity analysis locations is not an integer multiple of the number of subprocesses, then the number of velocity analysis locations on different subprocesses differs by no more than one.

In step S13, a memory space is allocated for each child process.

Specifically, the step is performed for each sub-process, and the memory space is calculated according to the pre-stack time migration speed corresponding to the sub-process, the number of positions, the number of samples of the pre-stack seismic data track, and the preset pre-stack time offset calculation parameter. And assigned to the child process.

When the amount of pre-stack time migration velocity analysis position data assigned to each sub-process is roughly equal, the memory space required for the pre-stack time offset calculation on each sub-process is mainly the number of samples of the pre-stack seismic data track. The preset prestack time offset calculation parameter is related.

Step S14: The main process allocates a pre-stack time migration speed analysis position and a pre-stack seismic data track for each sub-process according to the allocation information.

In this step, the main process allocates pre-stack seismic data for each sub-process, which can be divided into continuous and interval forms, wherein The continuous form means that the main process assigns all pre-stack seismic data tracks to the sub-process, and the interval form means that the main process allocates a partial pre-stack seismic data track to the sub-process.

When the continuous form is used, the data input from the main process to each sub-process is larger and takes longer, but the pre-stack time migration speed analysis result obtained by the sub-process is more realistic; when the interval form is used, the main process sends The data input to each sub-process is small and takes a short time, but the signal-to-noise ratio of the pre-stack time migration speed analysis result obtained by the sub-process will decrease. During the specific implementation, the operator can weigh the requirements of the actual operation on the amount of calculation, the length of calculation time, the high signal-to-noise ratio, etc., and determine whether to select the continuous form or the interval form.

In a preferred embodiment, when the interval form is selected, in order to ensure that the seismic data track allocated to the sub-process reflects the geological condition as accurately as possible, the main process will set the first number (such as the line and the common center). The continuous prestack seismic data track is determined as a set of prestack seismic data tracks; in the entire prestack seismic data track, every second set number of consecutive stacks The pre-seismic data channel group assigns a subsequent set of pre-stack seismic data tracks to the sub-process, for example, the main process is in all pre-stack seismic data tracks, each skips a plurality of pre-stack seismic data track groups, and the subsequent one stack The pre-seismic data track group is assigned to the sub-process.

In step S15, each of the sub-processes uses the pre-stack time migration speed analysis position and the pre-stack seismic data track to perform a pre-stack time offset, and generates a pre-stack time offset result and sends the result to the main process.

Step S16, the main process obtains a prestack time migration speed analysis result according to the prestack time offset result sent by all the subprocesses, and the prestack time migration speed analysis result includes all prestack time migration speed analysis positions and all stacks. The common seismic data corresponding to the common reflection point CRP gather, the offset profile and the offset velocity spectrum.

In steps S15 and S16, each sub-process performs calculation in parallel, and each sub-process performs a pre-stack time migration position on the pre-stack time migration velocity analysis position and the pre-stack seismic data track assigned to the main process by the main process, and passes all the sub-processes. Parallel operation, the whole pre-stack time migration velocity analysis position and the calculation task of all pre-stack seismic data tracks are completed as a whole, the efficiency of pre-stack time migration velocity analysis is improved, and the operation cycle is shortened; finally, the main process is further Summarize the results of the prestack time migration results sent by all the subprocesses, and obtain the prestack time migration velocity analysis results, that is, the total prestack time migration velocity analysis position and the CRP gathers and offsets corresponding to all prestack seismic data tracks. Section segment and offset velocity spectrum.

By using the CRP gathers, offset profile segments and offset velocity spectra obtained by the present invention, an optimal prestack time migration velocity can be determined, and the present invention can significantly improve the calculation speed of the prestack time migration velocity analysis. The short operating period and the risk of failure in the middle of the calculation process are reduced, which provides favorable conditions for the prestack time migration during the seismic exploration data processing of oil and gas resources.

In a preferred embodiment, step S15 is specifically as follows: each sub-process determines a pre-stack time offset speed sequence, and uses each speed function in the pre-stack time offset speed sequence as the pre-stack time offset speed , the pre-stack time migration velocity analysis position assigned to the main process and the pre-stack seismic data track are pre-stack time offset, and the CRP channel corresponding to the sub-process is generated. Set, offset profile segments, and offset velocity spectrum data. In this embodiment, the calculation process performed by each sub-process is as follows: scanning each speed function in the pre-stack time migration speed sequence, using the scanned velocity function as the pre-stack time migration speed, based on the pre-stack time The offset velocity is calculated by prestack time migration velocity analysis position and prestack seismic data track assigned to itself, and all speeds in the prestack time migration velocity sequence to be scanned are obtained. Pre-stack time migration velocity sequence and pre-stack time migration velocity analysis location and pre-stack seismic data channel CRP gathers, offset profile segments, and offset velocity spectrum data, wherein the offset velocity spectrum data Is the basic data information required for the main process to generate the offset velocity spectrum in subsequent steps. In addition, the tasks of the main process in this embodiment are as follows: comprehensively summarize the CRP gathers and offset profile segments calculated by all the sub-processes, and obtain all the pre-stack time migration velocity analysis locations and the CRP lanes corresponding to all pre-stack seismic data lanes. The set, offset section segments, and the offset velocity spectrum data calculated by all the sub-processes are used to generate the full pre-stack time migration velocity analysis position and the offset velocity spectrum corresponding to all pre-stack seismic data tracks.

Considering that the center track of the offset profile segment can be directly calculated according to the CRP gather, and several pieces of information of the offset velocity spectrum data can also be directly calculated according to the CRP gather, in order to avoid double calculation, improve the calculation efficiency. In another preferred embodiment, the information shared by the CRP gathers and the offset profile segments and the offset velocity spectrum data that can be directly calculated from the CRP gathers can be marked as common information. Each sub-process no longer calculates the complete offset profile segment and offset velocity spectrum data in the specific calculation process, but only calculates the CRP gathers and the offset profile segments and the offset velocity spectrum data except the missing common information. Then, each sub-process sends the corresponding CRP gathers, the offset profile segments lacking the common information, and the offset velocity spectrum data to the main process; and then the main process uses the CRP gathers to directly calculate and obtain the common information, and utilizes The total information and the offset profile segment lacking the common information are combined to obtain the complete offset profile segment corresponding to each sub-process, and the offset velocity spectrum using the common information and the lack of common information. Combine the complete offset velocity spectrum data corresponding to each sub-process; finally, the main process also integrates the CRP gathers and the complete offset profile segments corresponding to all the sub-processes together to obtain the full pre-stack time migration velocity analysis position. And all the CRP gathers and offset profiles corresponding to the prestack seismic data track, and generate all prestack time migration velocity analysis positions and all prestack seismic data channel corresponding points according to the complete offset velocity spectrum data corresponding to all subprocesses. Offset velocity spectrum.

For example, in one embodiment, 61 pre-stack time offset speed sequences are formed using 61 scan speed functions, numbered -30, -29, ..., -1, 0, 1, ..., 29, 30, respectively. There are 9 CRP gathers and 9 offset profiles, which are calculated by the scan speed functions with serial numbers -8, -6, -4, -2, 0, 2, 4, 6, and 8. Each offset section has 11 lanes, indicating the velocity analysis position and 5 lanes before and after. When the sub-process performs the pre-stack time offset calculation, the above scanning speed function is cyclically used from the serial number -30 to 30, for the serial numbers of -8, -6, -4, -2, 0, 2, 4, 6, and 8. The scan speed function skips no calculation, skipping the center track (speed analysis position) in the calculation of the offset profile segment is not calculated. After the calculation of the sub-process is completed, the main process sums the CRP gathers, and the central track of the nine offset profile segments is formed, and further converted into the velocity spectrum vacancies, the serial numbers are -8, -6, -4, The calculation result of the scanning speed function of -2, 0, 2, 4, 6, and 8. This measure can The calculation amount of the scan speed prestack time shift is reduced by about 15%. The above figures are just examples, and the processor can specify other numbers according to the actual situation.

Since the calculation speed of the pre-stack time migration speed analysis can be significantly improved and the operation period is shortened, the present invention can be applied to a large-area three-dimensional seismic exploration work area having a plurality of speed analysis positions.

Embodiment 1

This embodiment illustrates the beneficial effects of the prestack time migration optimal velocity profile calculation method provided by the present invention in a specific embodiment. In this embodiment, the range of the input data is 871-900, the CMP range is 553-2130, a total of 4600323 channels, the sampling interval is 4ms, 2000 samples per channel, and the data size is 35115.23MB, which is the data in the 3D work area. portion. The speed analysis position is 42. The running time of the original mode is 151:16:11. The running time of the parallel operation of 6 processes and 6 processes is 9:43:36, which is shortened to 6.43% of the original mode; and each The node only needs the memory size of 7 speed spectra. Input 1 line for every 3 lines, and 1 CMP for every 3 CMPs. The parallel operation mode of 6 processes with 6 nodes is 1:02:14, which is further shortened to 0.69% of the original mode. . 3 is a velocity spectrum (partial) at the measurement line 890 and CMP 1500 calculated using all input data, FIG. 4 is a CRP gather (partial) corresponding to a plurality of scan speeds, and FIG. 5 is an offset profile corresponding to a plurality of scan speeds. (partial). 6 is a velocity spectrum (partial) at the measurement line 890 and CMP 1500 calculated using one-ninth of the input data, FIG. 7 is a CRP gather (partial) corresponding to a plurality of scan speeds, and FIG. 8 is a partial offset corresponding to the scan speed. Move the section (partial). It can be seen from the comparison of the corresponding drawings that the results calculated using one-ninth of the input data are basically the same, with only minor differences, indicating that this method is feasible.

In addition to the parallel computing, the pre-stack time migration velocity analysis and the construction process of the present invention are very similar to the overlay velocity analysis and the construction, as shown in FIG. Therefore, the processing personnel with conventional seismic data processing experience can also determine the pre-stack time migration speed parameters, making the pre-stack time migration more convenient for large-scale popularization.

The above described specific embodiments of the present invention are further described in detail, and are intended to be illustrative of the embodiments of the present invention. All modifications, equivalent substitutions, improvements, etc., made within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

An efficient pre-stack time migration speed analysis method, comprising:

Applying for multiple processes, determining one of the multiple processes as the primary process, and the rest as the child process;

Determining allocation information, the allocation information including a correspondence between each sub-process and a pre-stack time offset velocity analysis location to be assigned to the sub-process;

Allocate memory space for each child process;

The main process allocates a pre-stack time migration speed analysis position and a pre-stack seismic data track for each sub-process according to the allocation information;

Each pre-process uses the pre-stack time migration velocity analysis location and the pre-stack seismic data track to perform a pre-stack time offset, generates a pre-stack time offset result, and sends the result to the main process;

The main process obtains a prestack time migration speed analysis result according to a prestack time offset result sent by all the subprocesses, and the prestack time migration speed analysis result includes all prestack time migration speed analysis positions and all prestacks. The common reflection point CRP gather, the offset section and the offset velocity spectrum corresponding to the seismic data track.
The method according to claim 1, wherein the determining the allocation information is specifically:

According to the number of subprocesses applied, it is determined that all prestack time offset velocity analysis positions are evenly distributed to each subprocess.
The method according to claim 1, wherein said allocating a memory space for each child process is specifically:

For each sub-process, the memory space is calculated according to the pre-stack time migration speed corresponding to the pre-stack time, the number of samples of the pre-stack seismic data track, and the preset pre-stack time offset calculation parameter, and is allocated to the sub-process. process.
The method according to claim 1, wherein the main process allocates the pre-stack seismic data track for each sub-process, specifically:

The main process assigns all pre-stack seismic data tracks to the sub-process; or

The main process assigns a portion of the pre-stack seismic data track to the sub-process.
The method according to claim 1, wherein the main process allocates a partial pre-stack seismic data track to the sub-process, specifically:

The main process determines a first set number of consecutive prestack seismic data tracks as a set of prestack seismic data tracks;

In all pre-stack seismic data tracks, a subsequent set of pre-stack seismic data tracks is assigned to the sub-process every second set number of consecutive pre-stack seismic data sets.
The method according to claim 1, wherein each of said sub-processes uses said pre-stack time migration velocity analysis position and said pre-stack seismic data track to perform prestack time migration to generate prestack time offset Move the result, specifically:

Each of the sub-processes determines a pre-stack time offset speed sequence, the pre-stack time allocated to the main process as each pre-stack time offset speed in the pre-stack time offset speed sequence The offset velocity analysis location and the pre-stack seismic data track perform prestack time migration, and generate CRP gathers, offset profile segments, and offset velocity spectrum data corresponding to the subprocess.
The method according to claim 6, wherein each of the sub-processes generates CRP gathers, offset profile segments, and offset velocity spectrum data corresponding to the sub-process, specifically:

Each of the sub-processes generates a CRP gather corresponding to the sub-process, an offset profile segment lacking common information, and offset velocity spectrum data lacking common information, wherein the common information is a CRP gather and an offset profile segment Information that is common to the offset velocity spectrum data and that can be directly summed using the CRP gather;

Then, the main process obtains a prestack time migration speed analysis result according to the prestack time offset result sent by all the subprocesses, specifically:

For each sub-process, the main process directly calculates the common information by using the CRP gather corresponding to the sub-process, and utilizes the common information and the missing profile segment and the missing Offset velocity spectrum data of the common information, obtaining offset profile segments and offset velocity spectrum data corresponding to the subprocess;

The main process synthesizes the CRP gathers, offset profile segments, and offset velocity spectra corresponding to all the subprocesses. According to the data, the CRP gathers, the offset profile segments and the offset velocity spectra corresponding to all prestack time migration velocity analysis locations and all prestack seismic data lanes are obtained.