Located in the eastern Junggar Basin

the Huoshaoshan oil reservoir is characterized by complex fracture distribution and percolation mechanism. Due to the complexity of fractures

the effect of development was poor at the very beginning

the flow pattern of injected water is hard to understand

and the remaining oil distribution is difficult to predict. Based on analysis of the characters and orientation of the fractures and the reservoirforming patterns

we understood the distribution of the fractures in the reservoir. According to the water/oil displacement patterns of four matrixfracture combinations and in combination with the change of water cut of oil wells

we predicted remaining oil distribution in the reservoir through numerical simulation. It is concluded that tectonization and lithological change are the two major factors influencing three fracture development zones

including macro fracture zone

micro fracture zone and matrix zone. There are lots of remaining oil both in the macro fracture zone due to water channeling and in the matrix zone due to poor waterflooding efficiency. The remaining oil distribution is predicted through geologic modeling

reservoir engineering analysis and numerical simulation

laying a basis for reservoir adjustment in near future