Comprehensive evaluation method for selection of favorable zones of medium-order coalbed methane reservoirs in small and medium-sized fault-subsidence basins

Abstract

The invention relates to a comprehensive evaluation method for selection of favorable zones of medium-order coal bed gas reservoirs in small and medium-sized subsidence basins. The comprehensive evaluation method comprises the following steps: 1, evaluating the gas production capacity of a target coal seam; 2, evaluating the reservoir capacity of the target coal seam; 3, evaluating the storage condition of the target coal seam; 4, evaluating the permeability of the target coal seam; 5, defining coal bed methane accumulation main control factors of the target zone, predicting distribution characteristics of the main control factors by utilizing logging, earthquake and experiment analysis data of the research zone, superposing favorable zones of the main control factors, and comprehensivelyanalyzing and predicting favorable high-permeability enrichment zones. The method aims at the actual situation that the exploration degrees of a plurality of coal-bearing basins are different; according to the method, the parameters are reasonably classified, through comprehensive evaluation of the evaluation parameters, the coal bed methane reservoir area can be accurately and effectively judgedto the maximum extent, and the problems that according to an existing evaluation method, due to limitation of the evaluation parameters, evaluation is inaccurate, the selection target of coal bed methane is not clear, and manpower and material resources are wasted are solved.

Description

Technical field: [0001] The invention relates to a method for selecting areas for coalbed methane exploration, in particular to a comprehensive evaluation method for selecting favorable areas of middle-rank coalbed methane pools in small and medium-sized rift basins. Background technique: [0002] my country's prospective coalbed methane resources are 36.8 trillion cubic meters (Ministry of Land and Resources, Oil and Gas Resources Strategic Research Center, 2009), of which the recoverable resources are basically equivalent to my country's conventional natural gas resources, with great resource potential. Chinese scholars have innovatively developed the theory of high-rank coal CBM accumulation and successfully carried out commercial development (Song Yan, 2012). However, the medium and low-rank coalbed methane, which accounts for more than 40% of domestic resources, has not yet achieved a breakthrough. The development and utilization of coalbed methane has multiple effects...

AI Technical Summary

Problems solved by technology

[0003] An object of the present invention is to provide a comprehensive evaluation method for the selection of favorable areas of medium-rank coalbed gas reservoirs in small and medium-sized faulted basins, which is used to solve the problem of existing evaluation methods due to the The limitation of evaluation parameters leads to inaccurate evaluation, makes the selection target of coalbed methane unclear, and wastes manpower and material resources.

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