Author(s): WANG Cui-li, ZHOU Wen, LI Hong-bo, DENG Hu-cheng, LIU Yan, State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Tarim Oilfield Company of PetroChina
Pages: 596-603
Year: 2014 Issue:  5
Journal: Journal of Chengdu University of Technology
Keyword:  Zhenjing block; Yanchang Formation; fracture character; period; tectonic fracture; evaluation; distribution;
Abstract: According to the analysis and summary of outcrops,non-directional cores,imaging logging data,the measured results of the stable isotopes in fracture fillings,and the acoustic emission experiments of core samples,this paper analyses the characteristics and the formation periods and genetic types of the natural fractures in Ordos Yanchang Formation.The results show that there mainly are vertical fractures and high angle fracture in this block,whose main group system is S-N and N-E.There develops tension fractures and shear fractures.The fractures of the study area are thought to be 3rupture periods.The main rupture period is the second episode of Yanshan phase,whose corresponding depth is 1190 m.The results of the comprehensive analysis show that there are multiple phase regional fractures and fault symbiotic fractures.Using the fault symbiotic fracture evaluation software and the FLAC3 Drock fracture simulation software,the plane distribution of the fault symbiotic fractures and the multiple phase regional fractures can be predicted and evaluated.The results show that the regional tectonic fractures in the south of this block develop more than that in the north,and the more of sand bodies,the more of the fractures.The development degree of the fracture over the range of the fractured zone is generally higher than that of the non-fractured zone.