Method for enhancing oil gas detecting accuracy using vibration amplitude with off-set distance variation characteristic

An amplitude-dependent offset, oil and gas detection technology, applied in the field of petroleum geophysical exploration, which can solve the problems of increasing the uncertainty of inversion results and reducing the approximate accuracy of reflection coefficients

Active Publication Date: 2008-10-08
BGP OF CHINA NAT GASOLINEEUM CORP
View PDF0 Cites 31 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, firstly, since the high-order term of the differential is ignored in the conversion of formation parameters, compared with (2), equation (6) reduces the approximation accuracy of the reflection coefficient (such as figure 2 shown); secondly, (6) is composed of three terms, and the third term reflects the contribution of the formation density with a small scale of change to the reflection amplitude. To obtain these three parameters reliably requires a variety of prior constraints , the data that needs to be involved in the inversion contains more remote information. With the increase of the incident angle (offset), the error of the reflection coefficient approximation formula and the distortion of the seismic amplitude (due to factors such as noise, data processing, wave field interference, etc.) is also larger, which inevitably increases the uncertainty of the inversion results

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for enhancing oil gas detecting accuracy using vibration amplitude with off-set distance variation characteristic
  • Method for enhancing oil gas detecting accuracy using vibration amplitude with off-set distance variation characteristic
  • Method for enhancing oil gas detecting accuracy using vibration amplitude with off-set distance variation characteristic

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0079] (1) Excite seismic waves and record seismic waves, perform high-fidelity processing with relative amplitude preservation according to the conventional seismic data processing flow, and form a normal moveout corrected gather that can be directly used for AVO analysis of amplitude variation with offset;

[0080] (2) Perform angle gather transformation on the input data, and the angle range is 0-30°.

[0081] (3) Constrained by the background mudstone line trend β=0.86α-1172 in the work area, use the formula (8) to perform AVO attribute fitting on the corner gather section in step (2), and get Δ(λ / μ+2) / (λ / μ+2) and Δ(μρ) / (μρ) property profiles.

[0082] (4) Use equations (11.1) and (11.2) to perform post-stack inversion on attributes Δ(λ / μ+2) / (λ / μ+2) and Δ(μρ) / (μρ), and perform step (3) The two attributes in are operated to obtain the AVO intercept attribute.

[0083] (5) Use the attributes obtained in step (4) to obtain the AVO intercept, and combine Δ(λ / μ+2) / (λ / μ+2) and ...

Embodiment 2

[0086] (1) Seismic data obtained by forward modeling using logging data and 20% noise added, and NMO correction was performed on the simulated data;

[0087] (2) Carry out angle gather transformation to the data obtained in step (1), and the angle range is 0~35°;

[0088] (3) Use formula (8) to perform AVO attribute fitting on the angle gather profile in step (2), and obtain Δ(λ / μ+2) / (λ / μ+2) and Δ(μρ) / (μρ) attribute profile, and use (11.1) and (11.2) to carry out post-stack inversion on attributes Δ(λ / μ+2) / (λ / μ+2) and Δ(μρ) / (μρ), and obtain LMR, velocity Compared with longitudinal and shear wave impedance data.

[0089] Image 6 The accuracy comparison results of the LMR parameters retrieved for noisy model data (noise is 20%), wherein the solid line represents the theoretical value, the dotted line represents the LMR parameters extracted by the present invention, and the dotted line represents the result extracted by the Fatti formula. As can be seen from the figure, the r...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention pertains to the oil geophysical prospecting technique, relates to a method using the characteristic the amplitude changes with the vibration of the bias distance to improve the oil gas testing accuracy, which includes: 1, exciting and recording the earthquake wave process into a trace gather for AVO analyzing after time difference correcting; 2, executing an angular trace gather transformation to the input data; 3, obtaining two property section planes: delta(lambada/mu+2)/ (lambada/mu+2) and delta (mu* rho) /(mu* rho), taking the work area argillite wire trend, beta=0.86alpha-1172 as a restriction; 4, inversion after stack; 5, combining delta(lambada/mu+2)/ (lambada/mu+2) and delta (mu* rho) /(mu* rho) to execute analyzing of unconventionality boundary containing oil-gas. The inventive AVO analysis has the approximately same accuracy with Fatti, reduces indeterminacy in routine inversion method, improves the feasibility and reliability, and reduces the irregularity of the inversion matrix. The invention is very sensitive to the formation lithology and small opening fluid constituents, which is convenient for directly recognizing formation lithology variation and small opening fluid constituents.

Description

technical field [0001] The invention relates to petroleum geophysical exploration technology, and is a method for improving the accuracy of oil and gas detection by using the characteristic of amplitude variation with offset (AVO) while improving the reliability of conventional amplitude variation with offset (AVO) inversion results. Background technique [0002] Seismic exploration is to excite seismic waves artificially (explosives, vibrators, air guns, etc.), and use single-component or multi-component sensors to record the vibration of the underground medium in a certain way on the surface or underground. The path, vibration intensity and waveform will vary with the properties of the media it passes through and the geometric shape of the interface. By processing and analyzing the seismic data recorded by the sensor, the properties of the underground medium and the geological structure can be obtained, and then minerals such as oil and gas can be found. Geophysical prospe...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): G01V1/30
Inventor 孙鹏远李彦鹏卢秀丽
Owner BGP OF CHINA NAT GASOLINEEUM CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap