煤系“三气”合采可行性及技术研究

Research on the Feasibility and Technology of Combined Production of "the Three Gases" in Coal Measures

以煤层气、页岩气和致密砂岩气共生叠置为特征的煤系"三气"是一类重要的非常规天然气资源。目前,煤层气、致密砂岩气合采在北美地区已经取得成功,且产量显著。我国煤系"三气"资源储量很大,而且分布范围广泛,但是对煤系地层中非常规天然气资源的认识和研究,以及勘探开发水平都处于起步阶段,国内尚未实现规模性共采。把煤系地层中的不同地层视为整体,利用单井进行综合勘探开发,不仅可以提高气井的使用效率,还可以降低开发成本和提高单井利润,延长气井开采寿命。国内的非常规天然气资源开发大多数仅限于两层不同介质合采,单层开采及同种介质多层合采的简单模式,且主要研究成果大多为理论方面的研究。本文主要从煤系地层中的页岩气、致密砂岩气和煤层气等非常规天然气资源的赋存情况及分布特征等方面,对煤系"三气"合采可行性以及合采技术进行阐述和分析。

Three gases in coal series,including coalbed methane (CBM),tight sandstone gas and shale gas,are important unconventional gas resources.At present,coal bed gas and tight sandstone gas combined production have been successfully achieved ill North America,and the production is significant.China's "the three gas"resources in coal reserves are large and widely distributed,but the understanding and research of unconventional natural gas resources in the coal measures strata,as well as the level of exploration and development are all in the initial stage,and domestic coproduction has not yet been achieved.Considering different strata in the coal stratum as a whole, comprehensive exploration and development by a single well not only can improve the efficiency of gas wells,but also can reduce the development cost and increase the profits of individual wells and prolong the life of gas wells.Most of the unconventional natural gas resources development in China is limited to the simple model of two-layer combined mining,single-layer mining and multi-layer combined mining of the same medium,and the main research results are mostly theoretical research.In this paper,based on the occurrence and distribution characteristics of unconventional natural gas resources including shale gas,tight sandstone gas and coalbed methane in the coal measures strata,the feasibility and commingled production technology of "the three gases"in the coal measure were expounded and analyzed.