Author(s): ZHANG Ji-biao, YUN Jin-biao, ZHANG Zhong-pei, LIU Shi-lin, HUANG Wei, SINOPEC Petroleum Exploration and Production Research Institute, No. 6 Oil Production Plant, Changqing Oilfield, Petro China
Pages: 413-423
Year: 2014 Issue:  4
Journal: Journal of Geomechanics
Keyword:  fracture; development law; stress; numerical simulation; genetic mechanism; Yubei area;
Abstract: Based on the identifying of fractures by the use of FMI,cores and slides data,the development law of structural fractures were summarized. The stages of structural fractures were classified according to the cross relation,the characteristics of cathodeluminescence and inclusions,and then the finite element method was applied to simulating the tectonic stress field mathematically in each fracture developing periods,also the genetic mechanism of structural fractures controlled by fault-fold in different periods were analyzed combining with the mechanical mechanism. The results showed that the structural fractures mainly developed along the high-steep zone in Yubei area,and their development degree and occurrence were controlled by fault and fold. Four stages of structural fractures recognized in this area: the fractures developed in I and III activities of the Middle Caledonian were mainly controlled by fault,the fractures developed in the Late Caledonian-Early Hercynian were controlled by fault and fold,and the fractures were mainly controlled by fold in the Late Hercynian. The fractures with high angle and parallel with the fault gave more contributions to reservoir development, and the fractures which developed both in the Late Caledonian-Early Hercynian and the Late Hercynian gave more conducive atmosphere to oil-gas accumulation.