Structure Fracture Quatitative Estimation Of Fuyang Reservoir Of Chaochang Area In Songliao Basin

Fractures in the low permeability and dense reservoir are not only the accumulative bulk, but also can connect the other types of space of reservoirs, and improve the reservoir quality. Because of increase of the oil-gas production of fractural reservoir, fractural reservoir is more and more important in the petroleum industry in China. Fuyu and Yangdachengzi reservoirs are fractural glutenite reservoirs, and have the characters of low porosity, low permeability and well developed structure fractures. Structure fracture of Fuyu and Yangdachengzi reservoirs of Chaochang area in Songliao Basin is studied in this thesis, and it is important to improve the rate of oil exploration and development by studying fractures distribution and strain field.In this paper, structural geology, rock mechanics, geophysics, geostatistics and experimental method are integrated. Strike and azimuth of fractures are ascertained by studying and observing drilling cores and the paleo-magnetic data of drilling cores. Nowdays stress value is obtained by penetrating fluid method and direction of stress is ascertained by method of microseismogram log. Rock mechanics parameters are obtained by long-spaced sonic log. Based on the study of tectonic evolution of Fuyu and Yangdachengzi reservoirs, stress field and fracture distribution are simulated by bending flexure. The achievements are as follows.1. There are two groups of structure fractures, one is tensile fracture,and its strike is about N60°W, and is as same as the strike of structure, the other group is conjugate shear fractures.2. The direction of maximum stress is about NW60°, its range is from 28~52MPa, the direction of minimum is about NW150°, its range is from 14~26MPa, the medium stress is vertical stress, the type of stress field is the third type:σH>σv>σh。3. The distribution of structure fracture is very different, near the hinge of structure and fault, fracture is well developed. On the map, on the structure highpoint of Changchunling anticline and Chaoyanggou terrace fracture is well developed, and strike of fracture is NNW. On the structure low strike of fracture is WE and WN. At the end, bulge and joint of faults, fracture is well developed. In the vertical, fracture of layer FI is well developed, and it becomes worse with increasing depth.