Thinking and discussion for some problems of geological survey of coal measures gas

This paper is the thinking and discussion on problems of geological survey of coal measures gas.

Objective The concept renewal drives the new geological survey plan of coal measures gas (CMG), and the new plan drives the breakthrough of geological survey of CMG.

Methods Review the geological survey process of CMG, differentiate the basic concept of CMG, summarize the key progress of CMG research and exploration, and then put forward suggestions for CMG geological survey.

Results (1) The geological survey of CMG in China has gone through four stages, there is no comprehensive and systematic understanding of CMG resources so far, and it is imperative to find out the situation through geological survey. (2) Five basic concepts of CMG are identified and analyzed to provide reference for accurately defining boundary conditions of geological survey. (3) Four key advances in the research and exploration of CMG are summarized, providing reference for the selection of geological survey basis. (4) Five principled suggestions for geological survey are put forward to provide reference for determining the key points of geological survey.

Conclusions The geological conditions of CMG are distinctive, and the geological survey plan strives to be targeted. The geological survey of shallow CMG mainly focuses on verification, while the deep CMG resource is the top priority of the survey. It is suggested to investigate the potential of deep coalbed methane resources and its scale release value, and establish a prediction and evaluation model for key attributes of deep coal reservoirs. The traditional constraints on the thickness of a single reservoir need to be broken, and attention should be paid to the ultra-large scale accumulation and high permeability conditions focusing on thin-interbed CMG. The gas volume test procedures and methods of coal measures reservoirs need to be improved, and the application scope of high reliability calibration method should be expanded to promote the geological survey of CMG to close to the development effect. The potential of CMG in some basins that have previously "leaked" should be paid attention to, and the potential of deep basins and basins with poor coal-bearing property should be investigated.