摘要
柿庄北地区位于沁水盆地东南部,是我国重要的煤层气产区。煤层裂缝作为主要的渗流通道,对煤层气高产富集起到重要控制作用。该区山西组3号煤层中褶皱轴部走向为近南北向,野外露头区发育一组共轭剪裂缝,优势方位为NW与近EW向,其次是近SN向。根据构造形迹确定燕山期应力场以SEE105°挤压为主。利用水力加砂压裂法对现今井点目的层地应力进行计算,通过古地磁定向与声速各向异性确定现今最大水平主应力方向为NE55°。将煤层构造与地表起伏形态作为主要影响因素,采用有限元法对燕山期及现今地应力场进行数值模拟,利用弹性力学理论对裂缝参数进行计算,计算结果认为柿庄北3号裂缝孔隙度、渗透率普遍较小,整体上中部背斜区>中部平缓区>东部单斜区>中部向斜区>西部地区。模拟的裂隙特征与实测数据所反映的裂缝特征相近,单井产气量高的地区,裂隙较发育。
Northern Shizhuang,an important area for CBM production,is located in the southeast of Qinshui basin.As the primary seepage channel,fractures in coal seams make a great significance for the enrichment and productionof CBM.The direction of the fold axes in sem No.3is nearly NS,while a group of conjugate shear fractureswas developed in outcrops,of which the dominant direction is NW and nearly EW,followed by nearly NS.Accordingto the structural features,the stress field of Yanshanian was mainly compression from SEE105°.The stressin well points was calculated by using the hydraulic fracturing method,the direction of the maximum horizontalprincipal stress which is NE55°,was determined by restoring the original position through paleomagnetic and accordingto the velocity anisotropy.Considering the coal structure and surface topography as the main influencingfactors,using the finite element method to simulate Yanshanian and the present stress field,and the precision ishigh.By using elastic mechanics theory to calculate fracture parameters,the porosity and permeability of SEAMNo.3in northern Shizhuang is generally small.In general,the porosity and permeability in central anticlinal area>central flat area>eastern monoclinic area>central synclinal area>western district,the simulation results wereconsistant with the measured data and single well gas production line,the credibility was high.
作者
付晓龙
戴俊生
张丹丹
邹娟
徐珂
FU Xiaolong;DAI Junsheng;ZHANG Dandan;ZOU Juan;XU Ke(School of Geosciences, China University of Petroleum (East China), Qingdao 266580, China;Petrochina Daqing Oilfield Company, Daqing 163002, China;Research Institute of Exploration and Development, Petrochina Jidong Oilfield Company, Tangshan 063004, China)
出处
《煤田地质与勘探》
CAS
CSCD
北大核心
2017年第1期56-61,共6页
Coal Geology & Exploration
基金
国家科技重大专项课题(2011ZX05042-001)~~
关键词
柿庄北
裂缝
应力场
孔隙度
渗透率
northern Shizhuang
fracture
stress field
porosity
permeability
