Structural Evolution And Fracture Development Characteristics Of Zhongguai Uplift In The Western Margin Of Junggar

Jinlong 10 well area,located on Zhongguai uplift,is a structural-lithologic reservoir in the western of Junggar Basin.The favorable reservoir is located in Carboniferous.In this paper,the structural evolution and fracture development characteristics of Zhongguai uplift have been renewed through the reseach of reservoir based on Jinlong 10 well area.Based on the acquired seismic data,logging data,core data and logging production data,the structural characteristics and fracture characteristics of Carboniferous volcanic reservoirs in Jinlong 10 well area of Zhongguai uplift are studied by using the core technologies such as fine interpretation of three-dimensional seismic data and threedimensional geological modeling.Seismic interpretation shows that the tectonic evolution of the area can be divided into four stages: The Late Carboniferous NW-SE extensional fault depression,the Late Permian compression thrust,the Triassic-Jurassic compression-torsion thrust and the Cretaceous compression-torsion strike-slip.Early extensions formed horizontal extensional structural styles,including normal fault combinations such as stepped normal faults and graben horsts;mid-term contraction formed thrust and back thrust fault combinations;late strike-slip further affected the work area,forming normal flower strike-slip fault combinations.The formation of normal faults at the end of Carboniferous mainly controlled the distribution of igneous rocks and the formation of PALEOTECTONIC highs,while the boundary faults mainly controlled the migration of sedimentary centers after Carboniferous,that is,the distribution of strata after Carboniferous.Petrol comprehensive software is used to identify the fractures in the study area.The trend and dip angle of fracture development are counted from different scales.It is found that the reservoirs in Jinlong 10 well area of Zhongguai uplift mainly develop three main groups of fractures,i.e.NE,NW and near-EW trending.The types of fractures are lowangle and high-angle tension fractures,near-vertical tension fractures,high-angle pressure torsion fractures,etc.Comparing with the evolution of geotectonics,low-angle compressive fractures can be divided into three stages.Based on the previous structural interpretation data and fracture identification data,a three-dimensional structural model of Jinlong 10 is established.The three-dimensional geological model established by the random simulation technology of paleo-structural constraints and multi-scale fracture discrete technology can better reflect the physical characteristics of volcanic rocks in Jinlong 10 well area.Finally,the geological reserves are recalculated by the established dual porous medium model,and the recalculation results are in line with the real situation of the study area.