Method for forecasting TOC (Total Organic Carbon) content of shale reservoir stratum

Abstract

The invention provides a method for forecasting a TOC (Total Organic Carbon) content of a shale reservoir stratum. The method comprises the following steps: fitting a single well TOC content curve on the basis of a single well TOC content calculating equation; calculating a single well elastic parameter curve; establishing a relevance equation between the TOC content and the elastic parameter according to a crossing condition of the single well TOC content curve and the single well elastic parameter curve; inverting the elastic parameter on the basis of a three-dimensional earthquake pre-stack channel gathering elastic parameter inverting method; converting the inverted elastic parameter into TOC content data according to the relevance equation between the TOC content and the elastic parameter; applying the TOC content data and forecasting the TOC content horizontal distribution along a target layer of the shale reservoir stratum. According to the invention, the logging information, VSP logging achievement and three-dimensional earthquake data are comprehensively applied for quantitatively forecasting the TOC content horizontal distribution, so that the horizontal distribution of the TOC content in the shale reservoir stratum can be accurately evaluated. The method has the advantages of complete analysis, higher forecasting accuracy, lower cost, and the like.

Description

Technical field [0001] The invention relates to the technical field of applied geophysical prospecting, in particular to a method for predicting the TOC content of total organic carbon in shale reservoirs. Background technique [0002] Conventional Total Organic Carbon (TOC) content evaluation methods mainly have two forms. One is to use the laboratory test results of core sample data to evaluate the TOC content of the reservoir section. Although this method has high accuracy, it can only Obtain the TOC content at some specific points; the second is to use empirical formulas to calculate the TOC content through logging data to evaluate the target interval of the reservoir. This method can obtain the TOC content curve of the entire target interval, but it cannot describe the TOC content The plane distribution. In addition, the domestic use of logging data to calculate TOC content is mainly the ΔLgR method and some deformation methods. The ΔLgR method is to calculate the TOC cont...

AI Technical Summary

Problems solved by technology

However, the sampling interval of VSP logging is generally 5m or even 20m, and its resolution is low, which cannot meet the precision requirements of pre-stack gather elastic parameter inversion.

[0006] To sum up, some results have been achieved in the calculation of TOC content in China, but there is no method and process for quantitatively predicting the TOC content of shale reservoirs by comprehensive application of logging data, VSP data and seismic data, and there is no published page Detailed description and specific details of the quantitative prediction method of TOC content in rock reservoirs

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