Study On The Structure Of The Xujiahe Formation In The Guankou Area Of ??western Sichuan

The Guankou area is located in the north of Sanhe field of the Depression low steep structural zone of the West of Sichuan area, After the Garito, Yanshan, Hercynian, Indosinian Himalayan and many other tectonic movements with different properties(tension and compression effect, etc.), it formed a rich and colorful structural style from the Cambrian to Jurassic.Especially the fracture superposition of different periods, on the one hand it makes Guankou area have a complex tectonic deformation,and on the other hand it formatted a large scale effective crack in the axis and wings of anticline, and the development of these fractures plays a key role in the oil and gas migration and accumulation of the Xujiahe formation of the Guankou area.Based on previous research, the paper according to the theory of tectonic geology, using 3D seismic profiles and drilling data, logging data, etc. and starting from the tectonic background, tectonic features, fault distribution, analyzed the fault distribution and local structural details and trap size of the study area. On this basis, this paper carried out the study of the fracture characteristics of the Xujiahe formation in Guankou area and made a detailed analysis of the characteristics of fracture distribution, and found the theoretical support for the feasibility of reservoir exploitation of Xujia formation in the late stage.Research shows that:(1)the Xujiahe Group of Guankou area has developed 29 faults, these faults is more distributed in the wings and axis of tectonic and control the structure shape of the Xujiahe Group of Guankou area.(2) the structure form of Xujiahe Group of Guankou area are similar to its formation, but comparing to the overlying strata, the fracture is more complicated and the fault block increased; (3) the Xujiahe formation development have 8 structural entrapment includes the latent structure of Qiongxi. these closed area is large and the amplitude ismoderate; (4)structural fractures constitute the main accommodation space for petroleum in the reservoir; (5) the Xujiahe formation fractures are well developed, and the reconstructive effect of crack on the reservoir one and Reservoir two is the most intense, the area which has a large density of fracture development can be formed in large and medium-sized reservoirs with good prospect.