摘要
镇原-泾川地区位于鄂尔多斯盆地西南缘,具有不同于鄂尔多斯地块的古应力场。通过三维地震资料解释发现:镇原-泾川地区发育NEE和NWW向2套断裂,总体表现为"上下分层、带状分布"的特点,断裂产状陡、近直立、铅直断距小。NEE向断裂多为走滑正断层样式,活动方式为张性走滑;NWW向断裂兼具走滑正断层与走滑逆断层样式,其中逆断层为压扭性走滑。NWW向断裂在延长组地层沉积前已形成,并一直以先存断裂的形式存在,喜山期至现今受NEE向挤压应力影响,NWW向断裂发生左旋走滑,先存断裂诱导形成NEE向的后期断裂。
The Zhenyuan-Jingchuan area is located in the southwest margin of Ordos Basin and has an ancient stress field different from the Ordos Block.Interpretation of 3D seismic data has clarified the development of Zhenyuan-Jingchuan area with both NEE and NWW directions of two strike fractures.The fractures are characterized by"upper and lower stratification,zonal distribution"with small vertical fault throws.The NEE faults are mostly strike-slip normal fault pattern with tensional and transtensional behavior,while the NWW faults are both strike-slip normal fault and strike-slip reverse fault pattern,in which the reverse faults are pressure twist.NWW faults are formed before Yanchang Formation deposition and exist in the form of deposit fractures.From the Himalayan period to present,the compressive stress in the NEE direction has caused the NWW faults to have a left-lateral slip so that they continue to play the role of preexisting fractures and induce the formation of NEE faults.
作者
王猛
WANG Meng(SINOPEC Geophysical Research Institute,Nanjing 211103,China)
出处
《断块油气田》
CAS
CSCD
北大核心
2019年第2期142-146,共5页
Fault-Block Oil & Gas Field
基金
中国石油化工股份有限公司科技攻关项目"鄂尔多斯盆地大中型气田目标评价与勘探关键技术"(P17009)
