The Study On Fractured Horizontal Well Pattern Optimization Of The HEI A Block

China has very rich resources of low permeability reservoir. in recent survey, low permeability reservoirs reserves accounted for 60-70% of proven oil reserves, we can see, in the next period of time, increasing oil production mainly rely on low permeability reservoir, so the development of low permeability oil fields for exploration of the development of the oil industry is great significance. In this paper, the main purpose layer of the HEI A block is the third member of Nenjiang Heidimiao oil layer, the reservoir is a sheet of sand, and lithology is mainly dominated by silt or silty sand, the block is a low permeability reservoir. It can be seen from the data of the block over the years that the development effect of horizontal well in this area is good, but it is lack of theoretical basis for the reasonable well pattern, fracture parameters and energy supplement of the fractured horizontal wells.According to actual development situation in HEI A Block, comprehensive analysis of the advantages of horizontal wells and the current horizontal well pattern deployment problems. By using PETREL, combined with the software requirements and the actual characteristics of the research block, in order to establish the geological model, and design 22 kinds of spot well pattern include five-point method, the anti-seven law and anti nine law. According to the result predicted by simulation, the most suitable test block of well pattern could be selected. Then use orthogonal design optimization to select well parameter combination, the production wells and horizontal length of water injection wells and the well row spacing, in addition, it also optimize on the position of perforation fracturing, fracture length, fracture flow capacity and the number of fracturing. In oil extraction process, energy supply also affects the exploitation results, in order to develop the block to the best exploitation results, this paper also relatively optimize the timing of water injection, water injection, oil production rate and bottomhole pressure. Finally, the block productivity formula could be summed up, and study on the law of diminishing.The results show that: the HEI A block is suitable to use five-spot well pattern. The optimal production wells length is 700 m, the optimal length of horizontal injection wells is 450 m, the best crack length is 150 m, the best conductivity is 50d·cm, the optimal number of segments 12 and the best well spacing 200-400 m, the best row spacing is 300-350 m.According to the ways of adding energy, whether test block fracturing or not, both synchronous water injection development effect is best, and the later water injection, the worse the development effect, reasonable water injection rate of the block is 40m3/d, a reasonable time bottomhole pressure depletion is 6MPa, water injection bottomhole pressure 4MPa, optimum production rate for each crude oil prices have their different optimum production rate. In this paper, preferably a Li Hujun multistage fracturing productivity formula by calculating verify its accuracy was 93.56%, the law of diminishing satisfy hyperbolic decline index between 0.4 and 0.6.