Velocity change along with frequency information-based oil-gas detection method

Abstract

The invention relates to the technology of geophysical exploration for oil, in particular to a velocity change along with frequency information-based oil-gas detection method. The velocity change along with frequency information-based oil-gas detection method starts from a post-stack seismic channel set, and comprises the following steps: firstly, adopting mathematical transformation to perform time-frequency analysis on each seismic channel signal of a target formation; then, extracting a group character parameter set of each seismic channel signal from a temporal frequency spectrum; and finally, extracting a group energy gradient attribute (GVF) from the group character parameter set to perform the oil-gas recognition. The velocity change along with frequency information-based oil-gas detection method improves the sensitivity and the reliability of the oil-gas recognition, reduces the uncertainty in conventional methods, obviously improves the capacity of separating the oil gas and water, and has high accuracy rate of recognizing oil-bearing reservoirs.

Description

technical field [0001] The invention belongs to petroleum geophysics exploration technology, and is an oil and gas detection method based on the information of the change of velocity with frequency. Background technique [0002] In petroleum geophysical exploration hydrocarbon detection technology, in addition to the commonly used "bright spot" technology, "AVO" technology, seismic wave absorption and attenuation technology, and spectral decomposition technology for oil and gas detection using seismic data, the research on the velocity dispersion characteristics of seismic waves is becoming more and more important. are getting more and more attention. [0003] Actual oil and gas reservoirs are composed of solid parts containing pores or fractures and fluids (including oil, gas, water, etc.) in pores or fractures, which belong to two-phase or multiphase media. Biot's theory (Biot, M.A., 1956) describes the propagation of elastic waves in saturated fluid porous media (or two-...

AI Technical Summary

Problems solved by technology

[0009] There are two defects in the current seismic attribute hydrocarbon detection technology: first, the commonly used oil and gas detection methods and technologies are strictly based on the theory of single-phase media, while oil and gas reservoirs are multi-phase media. The oil and gas detection results have multiple solutions and uncertainties; the second is that the existing oil and gas detection methods and technologies use seismic amplitude (or energy) or amplitude (energy) attenuation attributes for oil and gas detection. The detection of gas content has a certain effect, but the detection effect of oil content of the reservoir is not good

Images