The Research On Well Pattern Optimization About Fractured Low Permeability Sand-Gravel Reservoir

Fractured low permeability sand-gravel reservoir is typical of plentiful sediment types, complicated lithology, low porosity and permeability. How to improve the development effectiveness of such reservoirs has become a recognized problem. Since Yan Jia oilfield carried out field trials of injecting water in 2007, the performance of this well group is not good due to inappropriateness of well pattern, large spacing and development of fractures. As a result, it is important to look for optimal well pattern which could improve the recovery of this oilfield.Beginning with research and analysis of the geological characteristics and production performance data of this oilfeild, the structure model, sedimentary facies model, matrix property model are established based on deterministic and stochastic modeling methods using previous research and awareness. In order to consider the impact of fracture system, Firstly, the response patterns on conventional log are established based on imaging logs and core observations. On this basis, application QiuckProp neural network model is used to identify fractures. Secondly, development of fractures on a plane.is predicted using the method of the principal curvatures which is more mature and reliable. Based on the above characterization and description of the resoivor, the discrete fracture network models are built combining the advantages of .petrel and fraca software. Finally, through the statistical (Oda) upscaling method, fracture attributes which is used in dual porosity/permeability reservoir model are generated.Taking into the flow characteristics of the reservoir account, the remaining oil distribution and control factors are analyzed based on the dual media model after history matching. On this basis, select group of factors typical well in low permeability fractured reservoir reservoir development conglomerate reservoir conditions, way of water injection, well pattern and injection ratio are carefully researched and analyzed by selecting typical well group. Finally, based on the existing well pattern of Yan 22, combining with factors research, the optimization programof well pattern is got after prediction of development performance and economic evaluation.