Logging information-based lithotype determining method

Abstract

The invention relates to a logging information-based lithotype determining method, which is characterized by comprising the steps of respectively collecting the parameter data of a coring well and an unknown well; selecting a compensated density logging curve, a compensated sound wave time difference logging curve, a compensated neutron logging curve and a borehole diameter logging curve, which are sensitive to lithotypes as basic parameters, counting the electrical parameter distribution intervals of different lithotypes by the true depth determination of core of the coring well, establishing a coal and rock logging classifying standard and a coal and rock identification plate, and determining the lithotype of the unknown well by adopting a plate method or a gray correlation statistical method. The logging information-based lithotype determining method has the advantages of solving the difficult problem that the lithotype can be determined by only rock coring, offsetting the defect that the cost for lithotype determining through naked eye observation is high, and realizing the fast and continuous identification on the lithotypes under the condition that a coal-bed gas well is not subjected to rock coring.

Description

technical field [0001] The invention belongs to the fields of coalfield exploration and coalbed methane exploration and development, and in particular relates to a coal rock type determination method based on logging data. Background technique [0002] Coal rocks can usually be divided into four types: bright coal, semi-bright coal, semi-dark coal and dull coal. Different types of coal rocks have different coal quality, different physical properties, porosity, permeability, and gas content. Gas production is different. Therefore, the identification of coal rock types is an important basic work in the process of coalbed methane exploration and development. [0003] At this stage, the identification of coal rock types is mainly through drilling core data or sampling through coal mine tunnels and visual observation. The method of coring observation is more accurate, but the cost of taking cores is very high. In a mining area, only a few wells take cores, and most of the wells...

AI Technical Summary

Problems solved by technology

The method of coring observation is more accurate, but the cost of taking cores is very high. In a mining area, only a few wells take cores, and most of the wells do not take cores. Therefore, the type of coal rock cannot be determined for wells that do not take cores, which affects coalbed methane. Design of development programs and implementation of measures

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