Coal-mining geological conditions and explorations of deep coal deposits: status and problems

Coal plays a leading role in both production and contribution of energy sources in China,and it provides guarantee for national economic and social development in excellent coordination.However,the shallow coal re-sources in the old coal mining areas of North and Northeast China have been nearly exhausted,and it is necessary to mine the deep coal resources.Deep coal mines are under the complex mining environment conditions of high in-situ pressure and geotherm,as well as high methane content in coalbed and pore pressure dissipation.Therefore,the exploration and development of the deep coal deposits are both the engineering and the geological problems.According to the analyses of the research status and problems in coal resource exploration and development in our country,the key scientific problems in term of the basic research of occurrence,coal mining-geological conditions and comprehensive exploration of the deep coal deposit are as follow:(i) formation,evolution and occurrence conditions of coal-bearing geological bodies;(ii) primary energy fields and coupling reaction of multiple energy-field in deep coal mine;(iii) the origin and source of fluid,permeable flow,occurrence and migratory concentration mechanisms,and the coupling action of multiphase mediums;and(iv) the geophysical anomaly response of the special geological bodies and multiphase mediums,and theory of comprehensive exploration.Constructing the exploration theory,technology-method system of deep coal deposits,will provide the scientific basis for exploiting deep coal resource with optimum beneficial result and safety,and promote the sustainable development of the old coal mining areas in North and Northeast China.