CN110261908A - Effective converted wave stacking image method - Google Patents

Abstract

The present invention provides a kind of effective converted wave stacking image method, comprising: step 1: input converted wave seismic data；Step 2: determining the range of P-S wave velocity ratio；Step 3: determining the gap size of P-S wave velocity ratio；Step 4: using the maximum value of P-S wave velocity ratio, minimum value and interval calculation P-S wave velocity ratio；Step 5: extracting the total asymptotic point trace gather of converted wave；Step 6: resetting to obtain new total asymptotic point trace gather using the total asymptotic point trace gather of friction speed ratio；Step 7: being overlapped imaging using new total asymptotic point trace gather and obtain the stacked section of converted wave.The effective converted wave stacking image method is total to asymptotic point trace gather than the converted wave of extraction using friction speed and determines that new converted wave is total to asymptotic point trace gather, realizes the stacking image of converted wave.

Description

Efficient Converted Wave Superposition Imaging Method

technical field

The invention relates to the field of oil and gas exploration seismic data processing, in particular to an effective converted wave superposition imaging method.

Background technique

It is an effective converted-wave imaging method to extract co-asymptotic point gathers by using the velocity ratio of P-to-S waves to superimpose converted waves. The common asymptotic point gathers of converted waves for stacking imaging is to select a velocity ratio with the best stacking effect through testing to perform stacking imaging of converted waves.

The general practice is that for the same P-wave velocity ratio converted wave seismic data, some stacked sections have better stacking effects, and some converted-wave stacked sections have poor stacking effects, and it cannot be guaranteed that the stacking effects of all stacked sections of converted wave seismic data are good. .

It is an inevitable requirement for converted wave stacking imaging to use a certain method to make the stacking effect of all seismic stacking segments of converted wave good. For this reason, we invented an effective converted wave superposition imaging method, which solved the above technical problems.

Contents of the invention

The purpose of the present invention is to provide an effective converted wave stacking imaging method which can make the stacking effect of all the seismic stacking sections of the converted wave good and realize the stacking imaging of converted wave seismic data.

The purpose of the present invention can be achieved by the following technical measures: an effective converted wave superposition imaging method, which comprises: step 1: input converted wave seismic data; step 2: determine the longitudinal and transverse wave velocity The range of the ratio; Step 3: Determine the interval size of the P-to-S wave velocity ratio; Step 4: Use the maximum value, minimum value and interval of the P-to-S wave velocity ratio to calculate the P-to-S wave velocity ratio; Step 5: Extract the co-asymptotic point channel of the converted wave Step 6: Use the co-asymptotic point gathers rearrangement with different velocity ratios to obtain a new co-asymptotic point gather; Step 7: Use the new co-asymptotic point gathers to perform stack imaging to obtain the stacked profile of converted waves.

The purpose of the present invention can also be achieved through the following technical measures:

In step 1, the input original converted wave seismic data is a seismic signal with certain morphological characteristics.

In step 2, the P-to-S wave velocity ratio is tested using the converted wave seismic data to determine the range of the P-to-S wave velocity ratio.

In step 3, the interval of the ratio of compressional and shear waves is determined according to the determined range of the ratio of compressional and shear waves.

In step 4, using the determined P-to-S wave velocity ratio range and P-to-S wave velocity ratio interval to calculate different P-to-S wave velocity ratios is completed by the following formula:

γ=γ _min +Δγ and γ≤γ _max calculate different P-to-S wave velocity ratios, where γ is the P-to-S wave velocity ratio to be calculated, γ _min is the determined minimum P-to-S wave velocity ratio, and Δγ is the determined P-to-S wave velocity ratio interval , γ _max is the determined maximum P-to-S wave velocity ratio.

In step 5, the co-asymptotic point gather is extracted using the calculated P-to-S wave velocity ratio by the following formula:

where x _acp is the coordinate of the co-asymptotic point, γ is the ratio of P-to-S wave velocity, and x _offset is the offset.

The effective converted wave stacking imaging method further includes, after step 7, outputting the final converted wave stacking seismic data.

The effective converted wave stacking imaging method in the present invention overcomes that the existing converted wave stacking method can make a certain section of converted wave stacking section effect good for the same speed ratio, but a certain section of converted wave stacking section has a bad effect and cannot make all The converted wave superimposition profile effect is good, and the converted wave common asymptotic point gathers extracted by different velocity ratios are used to determine a new converted wave common asymptotic point gather, so as to realize the superposition imaging of converted waves.

Description of drawings

Fig. 1 is the flowchart of a specific embodiment of the effective converted wave superposition imaging method of the present invention;

Fig. 2 is a superimposed cross-sectional schematic diagram of converted wave common asymptotic point gathers extracted by using a velocity ratio in a specific embodiment of the present invention;

Fig. 3 is a schematic cross-sectional view of a new converted-wave co-asymptotic point gather extracted by using different speed ratios to extract and rearrange converted-wave co-asymptotic point gathers in a specific embodiment of the present invention.

Detailed ways

In order to make the above and other objects, features and advantages of the present invention more comprehensible, the preferred embodiments are listed below and shown in the accompanying drawings in detail as follows.

An effective converted wave stacking imaging method of the present invention can make all converted wave stacking sections have good effects, and realize stacking imaging of converted wave seismic data. The main steps it includes are:

Step 1, the input original converted wave seismic data is a seismic signal with certain morphological characteristics;

Step 2, using the converted wave seismic data to test the P-to-S wave velocity ratio, and determine the range of the P-to-S wave velocity ratio;

Step 3, according to the determined P-to-S wave velocity ratio range, determine the interval of P-to-S wave velocity ratio;

Step 4, using the determined P-to-S wave velocity ratio range and P-to-S wave velocity ratio interval to calculate different P-to-S wave velocity ratios is completed by the following formula:

γ=γ _min +Δγ and γ≤γ _max calculate different P-to-S wave velocity ratios, where γ is the P-to-S wave velocity ratio to be calculated, γ _min is the determined minimum P-to-S wave velocity ratio, and Δγ is the determined P-to-S wave velocity ratio interval , γ _max is the determined maximum P-to-S wave velocity ratio;

Step 5, using the P-to-S wave velocity ratio calculated in Step 4 to extract the common asymptotic point gather is calculated by the following formula:

where x _acp is the coordinate of the co-asymptotic point, γ is the ratio of P-to-S wave velocity, and x _offset is the offset;

Step 6, using the co-asymptotic point gather rearrangement of different speed ratios to obtain a new co-asymptotic point gather;

Step 7, use the new co-asymptotic point gathers to perform stacking imaging to obtain the stacking section of the converted wave;

Step 8, outputting the final converted wave stacked seismic data.

As shown in FIG. 1 , FIG. 1 is a flow chart of an effective converted wave superposition imaging method of the present invention.

Step 101, input converted wave seismic data to be processed;

Step 102, using the converted wave seismic data to test the P-to-S wave velocity ratio, and determine the range of the P-to-S wave velocity ratio of the converted wave data;

Step 103, according to the determined range of the P-to-S wave velocity ratio, determine the interval of the P-to-S wave velocity ratio;

Step 104, using the determined P-to-S wave speed ratio range and P-to-S wave speed ratio interval to calculate different P-to-S wave speed ratios is completed by the following formula:

γ=γ _min +Δγ and γ≤γ _max calculate different P-to-S wave velocity ratios, where γ is the P-to-S wave velocity ratio to be calculated, γ _min is the determined minimum P-to-S wave velocity ratio, and Δγ is the determined P-to-S wave velocity ratio interval , γ _max is the determined maximum P-to-S wave velocity ratio;

Step 105, using the speed ratio calculated in step 104 to extract the common asymptotic point gather is calculated by the following formula:

where x _acp is the coordinate of the co-asymptotic point, γ is the ratio of P-to-S wave velocity, and x _offset is the offset;

Step 106, using the rearrangement of co-asymptotic point gathers with different speed ratios to obtain a new co-asymptotic point gather;

Step 107, using the new co-asymptotic point gathers to perform superimposed imaging to obtain the superimposed profile of converted waves;

Step 108, outputting the final converted wave stacked seismic data as shown in FIG. 3 . Figure 2 shows the section of superimposed imaging of converted wave co-asymptotic point gathers extracted using a velocity ratio.

The effective converted-wave stacking imaging method of the present invention is correct, and the stacking profile of the converted-wave co-asymptotic point gathers extracted by a velocity ratio does not obtain a new conversion by rearranging the converted-wave co-asymptotic point gathers extracted by different velocity ratios The effect of wave co-asymptotic point gather stacking section is good. The actual data converted wave stacking profile of the present invention has good effect. This is because the new converted wave common asymptotic point gathers obtained by rearranging the converted wave common asymptotic point gathers extracted by different speed ratios can make the superimposition effect of all superposition sections of converted waves good, and can realize the conversion wave Seismic data stacking imaging is superior to conventional converted wave co-asymptotic point gather stacking method in converted wave stacking imaging.

Claims (7)

1. effective converted wave stacking image method, which is characterized in that the effective converted wave stacking image method includes:

Step 1: input converted wave seismic data；

Step 2: determining the range of P-S wave velocity ratio；

Step 3: determining the gap size of P-S wave velocity ratio；

Step 4: using the maximum value of P-S wave velocity ratio, minimum value and interval calculation P-S wave velocity ratio；

Step 5: extracting the total asymptotic point trace gather of converted wave；

Step 6: resetting to obtain new total asymptotic point trace gather using the total asymptotic point trace gather of friction speed ratio；

Step 7: being overlapped imaging using new total asymptotic point trace gather and obtain the stacked section of converted wave.

2. effective converted wave stacking image method according to claim 1, which is characterized in that in step 1, input Original conversion wave seismic data is the seismic signal for having certain form law feature.

3. effective converted wave stacking image method according to claim 1, which is characterized in that in step 2, using turn Rolling land shake data test P-S wave velocity ratio is changed, determines the range of P-S wave velocity ratio.

4. effective converted wave stacking image method according to claim 1, which is characterized in that in step 3, according to true Fixed P-S wave velocity ratio range, determines the interval of P-S wave velocity ratio.

5. effective converted wave stacking image method according to claim 1, which is characterized in that in step 4, using true The fixed P-S wave velocity ratio range P-S wave velocity ratio different with P-S wave velocity ratio interval calculation is complete by following formula At:

γ=γ_min+ Δ γ and γ≤γ_maxDifferent P-S wave velocity ratios is calculated, wherein γ is calculative velocity of wave in length and breadth Spend ratio, γ_minIt is determining minimum P-S wave velocity ratio, Δ γ is determining P-S wave velocity ratio interval, γ_maxBe it is determining most Big P-S wave velocity ratio.

6. effective converted wave stacking image method according to claim 1, which is characterized in that in steps of 5, utilize meter The P-S wave velocity ratio of calculation extracts asymptotic point trace gather altogether and is calculated by the following formula:

Wherein x_acpIt is the coordinate of total asymptotic point, γ is P-S wave velocity ratio, x_offsetIt is geophone offset.

7. effective converted wave stacking image method according to claim 1, which is characterized in that the effective converted wave is folded Adding imaging method further includes after step 7, exporting final converted wave superposition seismic data.