摘要
现今地应力场影响煤储层渗透率以及水力压裂裂缝的形成和扩展,在煤层气勘探开发过程中至关重要。我国滇东恩洪地区煤层气资源丰富,但目前该区现今地应力研究程度较低,限制着煤层气的高效开发。为解决上述问题,在研究区实测地应力参数综合分析基础上,选取区内稳定分布的上二叠统宣威组C16号煤层为研究对象,利用有限元数值模拟方法开展现今地应力分布特征研究。结果表明,研究区浅部煤储层为走滑型应力机制,深部转变为正断型应力机制。恩洪地区宣威组C16号煤层最大主应力为11.0~38.9 MPa,其中西南部应力较高,北部和东南部应力较低。现今地应力分布特征受构造影响,断层及褶皱发育区应力对比周围区域较小,不同性质的断层以及褶皱对应力的影响不同。现今地应力及其机制影响煤储层渗透率,有效应力对煤储层渗透性的影响不显著,应力机制对煤储层渗透率影响较大。
The present in-situ stress field is an important factor for exploration and development of coalbed methane(CBM),which affects the permeability of coal reservoirs and the formation and spreading of hydraulic fractures.A large volume of coalbed methane resources distributes in Enhong Basin of eastern Yunnan region in China.However,current studies on the in-situ stresses in this area are rare,which limits the efficient development of coalbed methane.In order to solve above problems,this paper studies the characteristics of present in-situ stress distributions in this area using the finite element numerical simulation method.The Upper Permian Xuanwei Formation No.16 coal seam was selected as the research target and comprehensive analysis of the measured in-situ stress in the study area was conducted.The results show that the shallow coal layers are in the stress region of strike-slip faults while the deep coal layers are in normal faults stress region.The maximum principal stress of No.16 coal seam of Xuanwei Formation in Enhong area is between 11.0 MPa and 38.9 MPa,with higher stress in the southwest and lower stress in the north and southeast.The distributions of presentin-situ stress are affected by tectonic movements,with lower value in fault and fold development area.Different faults and folds affect the distributions of in-situ stresses differently.It is also found that the present in-situ stress has in significant influence on the permeability of coal reservoirs while the stress mechanism has significant influence on the permeability of coal reservoirs.
作者
徐浩然
鞠玮
周阳
姜波
吴财芳
李明
XU Haoran;JU Wei;ZHOU Yang;JIANG Bo;WU Caifang;LI Ming(School of Resources and Geosciences,China University of Mining and Technology,Xuzhou 221116,China;Key Laboratory of Coalbed Methane Resources and Reservoir Formation Process,Ministry of Education,China University of Mining and Technology,Xuzhou 221008,China;School of Earth Sciences,China University of Geosciences(Wuhan),Wuhan 430074,China)
出处
《煤炭科学技术》
CAS
CSCD
北大核心
2019年第12期184-193,共10页
Coal Science and Technology
基金
国家科技重大专项资助项目(2016ZX05044)
中国博士后科学基金特别资助项目(2017T100419)
关键词
恩洪地区
地应力场
渗透率
应力机制
Enhong area
in-situ stress field
coal permeability
stress mechanism
