Controlling factor analysis of fracture density in the Bashijiqike Formation, Kuqa Depression
NIAN Tao, WANG Guiwen, XIAO Chengwen, LI Ruijie, ZHOU Lei, DENG Li, SONG Hongyu
1 College of Geosciences, China University of Petroleum-Beijing, Beijing 102249, China 2 State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum-Beijing, Beijing 102249, China 3 Tarim Oilfield Company of PetroChina, Korla 841000, China 4 China Petrochemical Press, Beijing 434000, China
Based on outcrop observation, drill cores, borehole imaging interpretation and section description, the factors affecting the fracture density in the Kuqa Depression were rock lithology, sedimentary microfacies, diagenetic facies, mechanical stratigraphy thickness, local structures and tectonic stress. Generally, environments for well-developed fractures include fine sandstone, sub-sea channels, strongly compacted diagenetic facies, thinner mechanical layers, distance to faults less than 1km and high paleo-tectonic stress. Furthermore, the calculation of the variable coefficient of fracture density indicates that mechanical stratigraphy thickness and tectonic stress significantly affect fracture density in contrast with diagenetic facies. Regionally, the paleo-tectonic stress has mainly controlled fracture density which gradually decreases from the Southern Tianshan Orogen to the depression. Meanwhile, rock lithology, sedimentary microfacies, diagenetic facies and mechanical stratigraphy thickness have simultaneously controlled the fracture density in the vertical direction. Additionally, shear fracture is the main fracture type in the Bashijiqike Formation, thus the principal structure curvature is not related to fracture intensity.
年涛,王贵文,肖承文,李瑞杰,周磊,邓黎,宋虹玉. 库车坳陷巴什基奇克组裂缝密度的控制因素分析[J]. 石油科学通报, 2016, 1(3): 319-329. NIAN Tao, WANG Guiwen, XIAO Chengwen, LI Ruijie, ZHOU Lei, DENG Li, SONG Hongyu. Controlling factor analysis of fracture density in the Bashijiqike Formation, Kuqa Depression. 石油科学通报, 2016, 1(3): 319-329.