中国煤层气资源控制程度及可靠性分析

Control degree and reliability of CBM resources in China

煤层气资源可靠性是产业持续发展的重要基础。为了客观认识和评价中国历次煤层气资源评价结果,从勘查控制程度的视角,基于煤炭资源、煤层含气性、煤层气可采性3个方面,研究了中国煤层气资源量控制程度,分析了提高煤层气资源可靠性待解决的关键问题,探讨了提高煤层气资源可靠性的措施与途径。研究结果表明:①当前全国煤层气资源评价结果具有全面性、系统性和客观性,也存在历史局限性,资源控制程度和潜力认识尚有极大提升空间;②基于所建立的勘查控制程度参数体系开展评价,二连盆地浅部煤层气资源可靠性极高,沁水盆地中等偏上,鄂尔多斯盆地和黔西—滇东地区相对较低,北疆地区很低,这些地区深部煤层气资源潜力可观;③已提交的全国2000 m以浅煤层气资源中,可靠的地质资源量介于11×10^(12)~14×10^(12)m^(3)之间,其中可采资源量约为4.5×10^(12)~6.3×10^(12)m^(3);④可采系数及可采资源量的认识具有高度不确定性,低估了全国2000 m以浅煤层气可采资源量;⑤讨论了评价方法现存关键问题,提出了解决问题的4条具体建议。结论认为,煤炭资源量控制程度很大程度上反映煤层气资源量可靠性,煤层气资源可靠性评价理论与方法尚待发展,资源控制程度和潜力认识尚有极大提升空间。

Reliability of coalbed methane(CBM)resources is an important foundation for the sustainable development of CBM industry.In order to understand and evaluate previous national CBM resource evaluation results objectively,this paper analyzes the control degree of CBM resources in China based on coal resources,CBM content and CBM recoverability from the perspective of exploration control degree.In addition,the pending key problems to improve the reliability of CBM resources are analyzed,and the measures and means to improve the reliability of CBM resources are discussed.And the following research results are obtained.First,the current evaluation results of CBM resources in China are generally comprehensive,systematic and objective,but due to historical limitations,there is still large room to improve the understanding of resource control degree and potential.Second,it is indicated by the evaluation based on the established parameter system of exploration control degree that the reliability of CBM resources is very high in the shallow part of the Erlian Basin,above medium in the Qinshui Basin,relatively low in the Ordos Basin and the western Guishou-eastern Yunnan area and very low in the northern Xinjiang,and the potential of deep CBM resources in these areas is considerable.Third,among the submitted CBM resources of less than 2000min depth in China,the amount of reliable geological resources is in the range of 11-14 trillion,of which the amount of recoverable resources is 4.5 trillion–6.3 trillion.The understandings on recoverable coefficient and recoverable resources are highly uncertain,which leads to the underestimate of the recoverable CBM resources of less than 2000 m in depth in China.Fifth,the existing key problems in evaluation methods are discussed,and four specific suggestions to solve the problems are put forward.In conclusion,the control degree of coal resources reflects the reliability of CBM resources to a great extent,the theories and methods for evaluating the reliability of CBM resources need developing,and the understandings on control degree and potential of CBM resources shall be improved greatly.