Reservoir Geology Model of Lithological Reservoir with Low Permeability in Xifeng Oilfield,Ordos Basin

Key words: 
• Ordos Basin /
• Xifeng oilfield /
• low permeablity lithological reservoir /
• stochastic simulation /
• diagenetic facies

Abstract: Taken Chang 81 reservoir of Baimanan area, Xifeng Oilfield, Ordos Basin as an example, established the geologic models of Chang 81 reservoir by using the stochastic methods of Sequence Guass Simulation and Sequence Indicator Simulation, and then discussed the controlling factors of relative high permeable layer that formed in very low permeable lighological reservoir. The research results indicated that the sedimentary process was the most important reason why Chang 81 reservoir was made. The diagenesis and the fractures had also great influence on improving the reservoir properties and the migration of petroleum. The 3D model of sandstone distribution revealed that the main sandbody which lied in the west of the region of interest appeared to be a band with the direction from southwest to northeast. The results of stochastic modeling of the reservoir property indicated that the distribution of highquality reservoir which was matched with the regions of feldspar dissolution diagenetic facies and chlorite film cementation diagenetic facies in the main sandbody was mainly controlled by the sedimentation and the diagenesis of the research area.