Differences in structural deformation and its influence on shale gas preservation in Changning and Luzhou areas
Changning and Luzhou areas are key blocks for shale gas exploration in southern Sichuan Basin,which are located in different parts of the basin-mountain structure.Since the Proterozoic era,they have been subjected to multi-stage structural transformation,resulting in complex structural deformation characteristics.Through detailed analysis on the seismic fine structure and statistical analysis on the core fracture of the bottom boundary of Longmaxi Formation in the study area,the differences in structural deformation characteristics and multi-scale fault and fracture development characteristics between Changning and Luzhou areas are compared and the structural evolution process since the Paleozoic is restored,which provides a basis for the evaluation of shale gas preservation conditions.The research shows that the structural style of Changning area is mainly fault-propagation folds,with the main structural deformation period being the late Yanshanian period,and it has undergone large-scale uplift and denudation in the Himalayan period;Luzhou area is a typical barrier fold,of which the main structural deformation period is the early Yanshanian period,and its structural features were reformed to some degree in the Himalayan period.The deformation intensity of Luzhou area is generally lower than that of Changning area,having lower fault level,lower fracture development degree,and better shale gas preservation conditions.The above results enrich the theoretical research of shale gas preservation conditions and provide help for the next step of shale gas development in Sichuan Basin.
structural deformation characteristicsfaultfractureshale gas preservationChangningLuzhou
NETL
NSTL
万方数据
