临兴区块煤系地层多层合压可行性研究  

Feasibility analysis of coal-measure strata multi-layer compression in Linxing block

作　　者：王波 吴鹏[1] 赵刚[1] 张迎春 崔树辉 WANG Bo;WU Peng;ZHAO Gang;ZHANG Ying-chun;CUI Shu-hui(China United Coalbed Methane Corporation,Ltd.,Beijing 100016,China)

机构地区：[1]中联煤层气有限责任公司,北京100016

出　　处：《煤炭工程》2022年第6期151-157,共7页Coal Engineering

基　　金：国家自然科学基金资助项目(42072194,U1910205);国家科技重大专项资助项目(2016ZX05066)。

摘　　要：针对煤系地层多层合压时煤与砂岩、页岩的差异较大,裂缝扩展针对煤系地层复杂,裂缝形态变化不可预知等问题,通过室内实验测量煤层顶底板地应力,建立多层有限元反演模型,进行煤层地应力反演计算,对不同类型地层合压的可行性进行分析。结果表明:反演计算结果误差小于5%,可信度较高;多层合压穿层条件为:裂缝为垂直缝、破裂压力相差小于5MPa、合压层相差小于18~20m;多储层合压时,上部储层条件较好,尽量避免压开下部煤层;下部煤层起裂时,支撑剂主要支撑下部煤层,对于上部地层而言,支撑效果相对差;煤层在上部,砂岩气层在下部,从煤层起裂可利用应力遮挡作用,增加在煤层中缝长。Aiming at the complicated propagation and unpredictable morphologic change of fractures in multi-layer commingled fracturing, caused by the lithology difference between coal, sandstone and shale, the peostress of coal seam roof and floor is measured in indoor experiments, a multi-layer finite element inversion model is established, the in-situ stress inversion of coal seam is conducted, and the feasibility of commingled fracturing for different formations is analyzed. The results show that the error of the inversion calculation result is less than 5%, the credibility is high;the conditions of the multi-layer commingled fracturing cross-layer are: the fracture is a vertical, the fracture pressure difference is within 5 MPa, and the vertical span of commingled fracturing layers is less than 18~20 m;in the commingled fracturing, when the upper reservoir is in better condition, it should be avoided to fracture the lower coal seam;when the lower coal seam cracks, the support of proppant mainly act on the lower coal seam, and the support is relatively poor on stratum above. When the coal seam is above sandstone reservoir, cracking from the coal seam can take advantage of the stress shielding effect to increase the crack length in coal seam when the coal seam.

关 键 词：煤系 多层合压 裂缝扩展 反演模型 可压性分析 压裂层位 

分 类 号：TD712[矿业工程—矿井通风与安全] P618.13[天文地球—矿床学]