煤储层弹性能及其控藏效应：以沁水盆地为例

Flexibility energies of coal-bed gas reservoir and the controlling function on coal-bed gas reservoir formation:A case study from Qinshui Basin

煤层气成藏的主控因素包括合适的压力系统、运移系统以及相应的能量作用机制,其实质是煤储层有效压力系统和有效运移系统时空配置关系。而煤储层弹性能正是有效压力系统与有效运移系统之间的联系和作用纽带。文中提出了不同相态物质的弹性能模型,建立了煤层气成藏效应三元判识标志,并探讨了沁水盆地三元判识标志的展布特征。三元判识标志包括煤储层裂隙发育程度系数ζ1、煤储层裂隙开合程度系数Δ、煤储层压力系统发育程度系数ζ2。其中ζ1、Δ可以定量表示煤储层有效运移系统,ζ2可以定量表示煤储层有效压力系统。依据三元判识标志,分析了煤储层弹性能控藏效应,并提出判别煤层气成藏类型的三元模式。研究认为:煤层气成藏效应类型可分为27种,其中8种类型有利于煤层气富集高产。而沁水盆地实际上只存在2种有利类型,即有效压力系统-有效运移系统类型和较有效压力系统-较有效运移系统类型,分别分布于盆地南部大宁—潘庄—樊庄地区、沁水—郑庄—樊庄以及中部的沁源—安泽之间。

The main controlling factors of coal-bed gas reservoir formation include right pressure system,right transit system and corresponding energy mechanism,which is the space-time configuring relation of effective pressure system and effective transit system of coal-bed gas reservoir substantively.Flexibility energies of coal-bed gas reservoir are just about ties between the two systems.Different flexibility energy models are put forward in the paper,three-unit differentiate symbols of coal-bed gas reservoir formation function including crevice growth degree coefficient ζ1,crevice open and close degree coefficient Δ,and effective pressure system growth degree coefficient ζ2 are established,and their distributing laws in Qinshui Basin are discussed.ζ1 and Δ can show effective transit system quantificationally,while ζ2 can show effective pressure system quantificationally.According to three-unit differentiate symbols,the controlling function of coal-bed gas reservoir formation of flexibility energies is analysed,three-unit model on differentiating coal-bed gas reservoir formation style was advanced.The research results considered that there are 27 sorts of styles of coal-bed gas reservoir formation function,but just 8 sorts are propitious for coal-bed gas enrichment and high produce.Actually only 2 favorable styles in Qinshui Basin are effective pressure system and effective transit system distributing in Daning-Panzhuang-Fanzhuang zone of southern basin,and rather effective pressure system and rather effective transit system distributing in Qinshui-Zhengzhuang-Fanzhuang zone of southern basin and Qinyuan-Anze zone of middle basin.