Method of wave impedance curve decompaction suitable for logging constrained inversion

Abstract

The invention provides a method of wave impedance curve decompaction suitable for logging constrained inversion. The method comprises the following steps: The lithology, the longitudinal wave impedance and the compaction tendency of each lithologic rock are calculated and eliminated; by using the logging data obtained by logging curves, the baseline of P-wave impedance is obtained and the lithology is evaluated by the baseline of the longitudinal wave impedance; thus, the logging impedance curve of de compaction is obtained and applied to log constrained inversion, and quantitative prediction of P-wave impedance is carried out in the whole work area. The method of wave impedance curve decompaction suitable for the logging constrained inversion can enlarge the P-wave impedance difference between reservoir and surrounding rock reasonably, and can reduce the multiple solutions of the inversion results of the reservoir and surrounding rock on the original log P-wave impedance curve due to the large overlap interval of the P-wave impedance values, thus the final P-wave impedance inversion results can accurately predict the reservoir distribution.

Description

technical field [0001] The invention relates to the technical field of geophysical exploration data processing, in particular to a logging compressional wave impedance decompression processing method suitable for logging constraint inversion. Background technique [0002] Logging-constrained inversion is an important method in reservoir prediction at present, and has a wide range of applications. It has played an important role in the exploration and development of lithology, structure-lithology reservoirs such as turbidite, glutenite body and beach bar sandstone. In the usual sense, the result obtained by logging-constrained inversion is the seismic P-wave impedance inversion body, which has a clear physical meaning. In reservoir prediction, the distribution characteristics of the reservoir on the logging P-wave impedance curve are used to guide Reservoir prediction for the entire work area. However, a large number of practical applications show that the P-wave impedance ...

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Problems solved by technology

According to the analysis, although the "pseudo-acoustic" curve obtained by this acoustic curve reconstruction method can amplify the velocity difference between the reservoir and the surrounding rock, the P-wave impedance inversion body finally obtained by adopting this "pseudo-acoustic" curve The prediction result is not accurate, because the "false acoustic wave" curve obtained by adopting this reconstruction method will seriously affect the reflection coefficient curve finally calculated from it, and this curve processing method will obviously change the reflection coefficient of well logging sequence, resulting in poor matching between the synthetic trace and the original seismic trace obtained when it is convolved with the wavelet, which affects the final inversion result

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