Prediction Of Fractures In The Lower Cambrian Shale Reservoirs In The Northern Hebei Area

Shale gas as a new unconventional natural gas,gradually get the world's close attention.China's research on shale gas is entering a stage of rapid development.Guizhou belongs to the karst landscape,the geological structure is extremely complex,shale in the geological process will produce cracks.The northern Guizhou area is one of the most abundant shale gas resources in Guizhou,which contains a lot of organic black shale with low porosity and low permeability.Based on the basic project of basic research project of Guizhou Province,this paper studies the prediction of shale reservoir fractures in the Lower Cambrian region by means of geological survey,physical experiment and numerical simulation.The main research contents are as follows:(1)The geological reports and geological sections of Northern Guizhou were collected and analyzed,and the regional sedimentary background,structural features and evolution were analyzed.(2)Based on a large number of related information and research status of shale gas at home and abroad,the core samples of different locations in the study area were collected and analyzed macroscopically.The samples were analyzed by scanning electron microscopy,nuclear magnetic resonance,porosity test.The development characteristics and reservoir characteristics of shale fractures were analyzed.(3)According to the physical experiments of core samples in different regions of northern Guizhou,the paleo-tectonic stress field parameters were obtained by uniaxial compression and acoustic emission.The main factors controlling the development of shale reservoirs from lithology and tectonic movement were analyzed.(4)On the basis of the physical experiment,combined with the theoretical analysis of rock fracture criterion,ABAQUS simulation software was used to establish the stress distribution law and fracture prediction of 3D geological model.Finally,the favorable area of ??fracture area was evaluated.Based on the prediction of shale reservoir fractures in the Lower Cambrian Niutitang Formation of Northern Guizhou area,the characteristics and distribution regularity of reservoir fractures were discussed,which provides a technical reference for the future exploration and development of shale gas in Guizhou.