Comprehensive evaluation method for selection of favorable areas for middle-rank coalbed methane reservoirs in small and medium-sized rift basins

Abstract

The present invention relates to a comprehensive evaluation method for selecting favorable areas of medium-rank coalbed gas reservoirs in small and medium-sized faulted basins, which includes: 1. evaluating the gas generation capacity of the target coal seam; 2. evaluating the storage capacity of the target coal seam; 3. carrying out preservation of the target coal seam Condition evaluation; 4. Evaluate the permeability of the target coal seam; 5. Determine the main controlling factors of coalbed methane accumulation in the target area, and use the logging, seismic, and experimental analysis data in the research area to predict the distribution characteristics of each main controlling factor and superimpose each main controlling factor. Favorable zones of factors, comprehensive analysis and prediction of favorable hypertonic enrichment zones. Aiming at the actual situation of different exploration degrees in many coal-bearing basins, the present invention classifies the parameters reasonably, and through the comprehensive evaluation of the evaluation parameters, the coalbed methane reservoir area can be judged accurately and effectively to the greatest extent, which solves the problem of existing evaluation Due to the limitation of evaluation parameters, the evaluation is inaccurate, which makes the selection target of coalbed methane unclear, and wastes manpower and material resources.

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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