Quantitative identification and three-dimensional characterization method for lithofacies classification of marine shale

Abstract

The invention discloses a method for quantitative identification and three-dimensional characterization of marine shale lithofacies classification, including: constructing a marine shale lithofacies composite triangular diagram classification method coupled with four elements, and using the method to obtain marine shale rocks Facies classification mode; on the basis of single well point-by-point sedimentary microfacies identification results and calculation of single well parameters, relying on sedimentary microfacies control and two-level segmental discrimination nested two-level fuzzy hierarchical comprehensive evaluation method, the marine shale Carry out quantitative identification of lithofacies single well; build a three-dimensional model of shale sublayer sedimentary microfacies, and use single well and single layer shale sedimentary microfacies constraints and control, and use truncated Gaussian simulation algorithm to perform three-dimensional visual representation of shale lithofacies. The present invention comprehensively considers differences in petrological characteristics and gas production potential of marine shale, characterizes the heterogeneity characteristics of shale lithofacies in three-dimensional spatial distribution, and reveals the spatial gas production of marine high-quality shale gas in production areas Potential differences provide models and technical support for optimizing production in production areas.

Description

technical field [0001] The invention relates to the technical field of petroleum exploitation, in particular to a quantitative identification and three-dimensional characterization method for classification of marine shale lithofacies. Background technique [0002] The research results of the Barnett shale and Horn River shale in North America show that the large-scale production of shale gas is not only affected by the level of engineering technology, but also controlled by the distribution of high-quality shale lithofacies. The research results of the Wufeng-Longmaxi marine shale in the Sichuan Basin, China, also confirmed that the heterogeneous distribution of shale lithofacies is an important factor causing the differential distribution of shale gas enrichment. Marine shale gas is often enriched in different shale lithofacies such as siliceous shale, calcareous shale, and argillaceous shale. Phases tend to have different shale gas development potentials. As a productio...

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Problems solved by technology

[0006] ②Large changes in lithofacies lead to large differences in single well gas production potential and serious heterogeneity

[0007] The mineral content, organic matter abundance, and physical properties of shale in the various marine shale gas production areas in the Sichuan Basin are quite different, and complex changes in lithofacies will lead to a rapid decline in single-well shale gas production (up to 20%~ 80%), and the difference in decline rate and output effect among individual wells is extremely obvious, which seriously restricts the smooth development of large-scale production construction

[0009] However, most of the existing shale lithofacies classifications focus on the sedimentary origin type, mineral content, and organic matter content, but do not consider the difference in gas production potential. Supporting technical methods for qualitative characterization

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