Abstract
The deep Lower Jurassic Ahe Formation(J1a)in the Dibei-Tuzi area of the Kuqa Depression has not been extensively explored because of the complex distribution of fractures.A study was conducted to investigate the relationship between the natural fracture distribution and structural style.The J1a fractures in this area were mainly high-angle shear fractures.A backward thrust structure(BTS)is favorable for gas migration and accumulation,probably because natural fractures are more developed in the middle and upper parts of a thick competent layer.The opposing thrust structure(OTS)was strongly compressed,and the natural fractures in the middle and lower parts of the thick competent layer around the fault were more intense.The vertical fracture distribution in the thick competent layers of an imbricate-thrust structure(ITS)differs from that of BTS and OTS.The intensity of the fractures in the ITS anticline is similar to that in the BTS.Fracture density in monoclinic strata in a ITS is controlled by faulting.Overall,the structural style controls the configuration of faults and anticlines,and the stress on the competent layers,which significantly affects deep gas reservoir fractures.The enrichment of deep tight sandstone gas is likely controlled by two closely spaced faults and a fault-related anticline.
基金项目
PetroChina Major Science and Technology Project(ZD2019-183-01-003)
Natural Science Foundation of Shandong Province(ZR2023MD069)
Training Program of Innovation for Undergraduates in Shandong Institute of Petroleum and Chemical Technology(2022084)
Science Development Foundation of Dongying(DJ2020007)
国家科技期刊平台
NSTL
万方数据