Seismic identification method for complex fault block unconformity surfaces

Abstract

The invention provides a seismic identification method for complex fault block unconformity surfaces, comprising the following steps: S1, acquiring the initial time depth and structure features of a simple area, and grasping the structure initial form and features of the whole research area by constructing the structure features of the simple area; S2, for construction of a complex area, performing complex area fine synthetic seismogram calibration, and determining the time depth relationship and seismic reflection features of an unconformity surface; and S3, extrapolating a well-free area through connected well profile interpretation, and performing tracking interpretation of the unconformity surface of the complex area. The seismic identification method for complex fault block unconformity surfaces provides a foundation reference for residual oil distribution rule research and reserve calculation of the oil reservoirs in complex fault blocks, plays a guidance role in later development of oil reservoirs of the kind, has a broad popularization and application prospect and can bring remarkable economic and social benefits.

Description

technical field [0001] The invention relates to the field of fine reservoir description of complex fault block reservoirs, in particular to a seismic identification method for unconformity surfaces of complex fault blocks. Background technique [0002] The unconformity surface is a sedimentary discontinuity caused by the up-and-down movement of the crust. It is closely related to oil and gas accumulation, and can provide effective oil and gas accumulation places for buried hill type, stratum denudation type, and stratum overlying type oil reservoirs. Different types of oil and gas reservoirs develop above and below the buried hill draped structural accumulation belts such as Gudong-Zhuangxi, Chengdong, Chengdao, and Fangwang. Therefore, describing the structural characteristics of unconformities and describing their fracture patterns is very important for the reserve calculation and reservoir development of this kind of reservoirs. Due to the in-depth exploration and develo...

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Problems solved by technology

Due to the in-depth exploration and development, some unconformity reservoirs with simple structural forms have a higher degree of exploitation, the identification of unconformity surfaces is relatively simple, and the understanding and description are also very fine. characteristics, restricting its understanding of oil reservoirs and oil and gas development

The existing seismic description of unconformity is mainly based on the horizontal calibration of acoustic wave synthesis records through the wave group characteristics of the unconformity's upper and lower reflection coaxial axes. Velocity changes are large, faults are developed, and seismic resolution is limited. Seismic profiles cannot effectively reflect the shape of unconformities. Due to denudation or overlapping of unconformities, the upper and lower lithologies are complex. Conventional synthetic records and side-hole seismic The trace matching effect is poor, the horizon calibration near the unconformity is difficult, and the seismic description of the unconformity is difficult. Therefore, we invented a seismic identification method for the unconformity in complex fault-block reservoirs, which solved the above problems

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