CN-121995457-A - Calibration and interpretation method based on depth domain seismic data

CN121995457ACN 121995457 ACN121995457 ACN 121995457ACN-121995457-A

Abstract

The calibration and interpretation method based on the depth domain seismic data comprises the steps of S1, performing speed structure analysis on VSP data and reliability evaluation, S2, performing well seismic calibration interpretation according to the VSP data, S3, analyzing deviation distribution characteristics in the longitudinal and transverse directions, exploring deviation distribution main control factors, and S4, obtaining a depth corrected interpretation result diagram according to the main control factors. According to the calibration result, analyzing the depth domain error characteristics, reducing the longitudinal deviation of depth domain interpretation, improving the depth domain structure interpretation precision, and solving the problem of difficult depth domain imaging depth error correction.

Inventors

SUI MINGYANG
YUAN HAIHAN
CHEN YUMAO
DING KUN
SUI XUQIANG
GAI PANPAN
WANG QIYUN

Assignees

中国石油化工股份有限公司
中国石油化工股份有限公司胜利油田分公司

Dates

Publication Date: 20260508
Application Date: 20241107

Claims (10)

1. The method for calibrating and explaining the seismic data based on the depth domain is characterized by comprising the following steps: s1, performing speed structure analysis on VSP data and performing reliability evaluation; s2, well earthquake calibration explanation is carried out according to the VSP data; S3, analyzing deviation distribution characteristics in the longitudinal and transverse directions, and exploring deviation distribution main control factors; and S4, obtaining a depth corrected construction interpretation result diagram according to the main control factors.
2. The method for calibrating and interpreting seismic data based on depth domain as defined in claim 1, wherein said step S1 comprises the steps of: Comparing the deep curve speed structure of all VSP wells in the work area with the general speed structure of the general speed in the work area, ensuring the normal change rule, good consistency and no abnormal value; Compared with the change of the acoustic wave curve of the well logging, the VSP speed structure is ensured to be consistent with the speed structure represented by the acoustic wave curve.
3. The method for calibrating and interpreting seismic data based on depth domain according to claim 1, wherein said evaluating reliability comprises: referring to logging coring data, observing whether the change amplitude of a speed curve is consistent with the lithology section change; And analyzing whether the speed relation provided by the VSP data accords with geological knowledge or not by combining the correspondence of the well layering and the seismic reflection, determining the quality of the VSP data, and providing a speed scale for subsequent well seismic calibration.
4. The method for calibrating and interpreting seismic data in depth domain according to claim 1, wherein said step S2 comprises the steps of: step 201, frequency-boosting the seismic data to obtain the seismic data of the superimposed section of the VSP corridor which is most matched with the seismic data; utilizing VSPLOG the same wavelet frequency band as the seismic data and the consistent waveform property; Comparing the VSP corridor superimposed profile reflection wave resistance with the depth domain seismic data profile reflection wave group to realize two sets of data matching imaging, and realizing accurate horizon calibration of the seismic profile according to known drilling geological stratification; Step 202, comparing the wave resistance characteristics of the depth domain seismic data of the VSP well with the wave resistance corresponding to the actual logging core data to obtain a corresponding relation, determining the longitudinal speed structure of the stratum and the wave resistance corresponding relation with the seismic section, giving the geological information revealed by the logging data to the seismic data, realizing the well earthquake interpretation of the surrounding well through the corresponding relation between the logging core data and the seismic wave resistance, and guiding the whole area interpretation work from a point strip line to a surface.
5. The method for calibrating and interpreting seismic data based on depth domain as defined in claim 1, wherein said step S3 comprises analyzing the distribution characteristics of the deviation in longitudinal and transverse directions, and exploring the main control factors of the deviation distribution specifically comprises: the research area has deviation rule characteristics according to geological conditions; and (3) counting imaging deviations of all well depth domains in a work area, analyzing deviation distribution characteristics in the longitudinal and transverse directions, and exploring deviation distribution main control factors.
6. The method for calibrating and interpreting seismic data based on depth domain according to claim 5, wherein said investigation region has deviation rule characteristics according to geological conditions, specifically comprising: acquiring a plurality of factors related to the deviation distribution characteristics of the work area according to geological awareness, wherein the factors comprise a first factor A, a second factor B and a third factor C; adopting a fitting correlation function to analyze the correlation between a single influence factor and imaging deviation; Classifying known correction amounts in a work area according to a first factor A, and fitting a correlation between imaging deviation and the first factor A to obtain a first regression coefficient R1; And analogically fitting the correlation between the imaging deviation and the second factor B and the third factor C to obtain a second regression coefficient R2 and a third regression coefficient R3.
7. The method for calibrating and interpreting seismic data based on depth domains as recited in claim 5, wherein said counting all well depth domain imaging deviations in the work area, analyzing the deviation distribution characteristics in the longitudinal and transverse directions, and exploring the deviation distribution master factors specifically comprises: classifying the parameters according to the regression coefficients of the corresponding correlation analysis; According to the consistency of the correlation between the single geological parameter and the deviation distribution and the actual geological rule, dividing the parameters into parameters conforming to the geological rule and parameters not conforming to the geological rule; And determining main control factors of imaging deviation distribution of the work area according to geological rule constraint on the basis of the relation between the specific deviation distribution and the influence factors.
8. The method for calibrating and interpreting seismic data based on depth domain as defined in claim 1, wherein said step S4 comprises the steps of: Dividing a work area into zones according to main control factors, excavating a functional relation existing in imaging deviation of depth domains of each zone, and establishing a theoretical model of a deviation rule; Obtaining a regional correction amount with low well control degree through the theoretical model simulation, taking an earthquake interpretation result as hard data, restricting the correction amount as soft data, and determining an optimal interval according to a variation function; And adopting a multi-grid approximation algorithm to spatially extrapolate and interpolate to obtain a corrected interpretation result, and obtaining a depth corrected construction interpretation result diagram.
9. The method for calibrating and interpreting seismic data based on depth domains as defined in claim 8, wherein said partitioning the work area according to the main control factors, mining the functional relation existing in the imaging deviation of the depth domains of each area, and establishing the theoretical model of the deviation rule specifically comprises: the existing wells in the research area are concentrated in the middle of the work area, the well control degree does not meet the correction requirement, and the correction values of the north and south with low well control degree are obtained to control the correction of the whole area; Assuming that the imaging deviation of the existing well is found to be Q1, Q2, Q3, Q4, Q5 and qn from A to B respectively after the partitioning, finding that consistent statistical rules exist in all layers from top to bottom under the partitioning condition according to the step S3, and fitting to obtain Q n ＝An 2 +/-Bn+/-C, so that R 2 is more than or equal to 0.8; Wherein Qn is a deviation value with a sequence number of n, and n is any value in an integer sequence; fitting theoretical model parameters A, B, C according to known well imaging deviation data to enable an R2 value to be close to 1, and establishing a deviation rule theoretical model of a certain partition of a work area; and simulating through the deviation rule theoretical model to obtain the area correction quantity with low well control degree.
10. The method for calibrating and interpreting seismic data based on depth domain as defined in claim 8, wherein said obtaining the area correction amount with low well control level by said theoretical model simulation specifically comprises: in the process of correcting the seismic interpretation result according to the real drilling correction amount, the density of the correction point determines the correction degree; By a variation function Determining an optimal interval of the correction points; wherein h is the number of intervals between 2 correction points, and 1 interval is 50m; The correction value of gamma (h) is smaller, the correction value of the two positions is closer, and conversely, the larger the difference is; the maximum interval is obtained through the variation function, the variation function value is not increased any more and is stabilized near a limit value, the correction amount in the range of hn has correlation, the correction amount outside the range of hn does not have spatial correlation any more, and hn is the optimal interval for interpolation of correction points.

Description

Calibration and interpretation method based on depth domain seismic data Technical Field The invention relates to the field of geophysical exploration, in particular to a calibration and interpretation method based on depth domain seismic data. Background The prestack depth migration is a migration method which is relatively accurate in homing in the current seismic data processing technology, has obvious advantages particularly in areas with complex speed or complex structure, and is mainly used for solving the wave field imaging problem of complex geologic bodies such as salt domes, complex substrates, complex broken blocks, biological reefs and the like. Compared with the time migration technology, the prestack depth migration improves imaging precision, on a time migration seismic section with good quality, the same phase axis can only truly represent the horizontal relative position of an underground structural surface, the vertical relative position is distorted, even serious distortion is caused, and particularly, the problems that the time domain section cannot overcome due to the relative structure such as igneous rock and other abnormal speed related structures, deep low-amplitude structures, the thrust and pushing complex structures in an extrusion basin and the like are solved, and the structural form of the reaction can be different from that of the underground structure. The depth domain seismic data has more visual advantage aiming at the problem, can obtain the correct space geometric position of the geologic body, including depth, occurrence, high points of construction, fault break points and the like, can truly reflect the construction form of the underground, and has more accurate geological significance. The domestic and foreign exploration practices prove that the prestack depth migration seismic imaging technology is one of key technologies for reducing exploration risks. Therefore, how to perform subsequent calibration and interpretation on the seismic data after the prestack depth offset becomes a problem to be faced. The former have conducted a great deal of research on the problems that exist in depth-domain seismic data interpretation. He Xinghua, starting from the seismic wave field descriptions in the time domain and the depth domain, prove that the geophysical concepts, principles and methods in the time domain and the depth domain are mutually related, the mathematical expression modes are similar, and reasonable explanation is provided for practical problems such as selection of sampling intervals in deep time conversion, relation between frequency spectrum and wave number spectrum data, video rate change on a deep time conversion section and the like. Zhang Xuejian, et al, consider that layer calibration in the depth domain should also use synthetic seismic records, and because of uncertainty in fourier transform in the depth domain, propose to use standard rake wavelets instead of statistical wavelets to make synthetic seismic records in the depth domain, and propose synthetic seismic record making methods applicable to the depth domain. Hao Xiaogong, etc., to explain and discuss the seismic data in the depth domain, to provide a method for explaining in the depth domain, to adapt to the working habit and thought of the present explanation system as much as possible, zhou Shang, etc., to explore the interpretation method and flow of the seismic data in the depth domain, to detect the oil-gas property by utilizing wave number type attribute, han Biwu, etc., to analyze the principal component by utilizing the extracted variance attribute, dip angle attribute, curvature attribute and coherence attribute of the depth domain, to fuse the result of the principal component analysis with the attribute of ant body, and to make construction explanation. Cao Danping based on the characteristic analysis of depth domain data, converting depth domain well-to-well seismic data into a time domain for research by using regional speed and tomography speed, establishing similarity connection between the well-to-well seismic data and the ground and the seismic data through coarsening and frequency reduction, obtaining knowledge of low-frequency reflection characteristics of the well-to-well seismic data, establishing reflection characteristics of the well-to-well seismic data by combining well side channel synthetic seismic record calibration, and accurately explaining reflection layers of the well-to-well seismic data, wherein the problem of accuracy of a depth domain structure after time-to-depth conversion is not solved effectively. Especially, in the shale oil exploration and development process at present, a three-dimensional development mode of a long horizontal well brings higher requirements on structural description precision, and the traditional depth domain interpretation method is difficult to meet the requirements of the shale oil exploration and development at present. Based on