Numerical Simulation Study On The Scheme Optimization Of Depth Profile Of S Block In Daqing Oilfield

The distribution of underground fluid is becoming more and more complicated after the more than 10 years cycle of water-flood development. Due to the homogeneity of reservoir development, injected fluid makes a breakthrough from high permeable area. With repeated erosion, the reservoir forms inefficient circulating paths, which increases heterogeneous contradiction of inter layer and inner layer so the exploitation become more and more difficult.The major reservoir has entered into high water-cut stage, the major reservoir of the watered-out degree is serious, most of the old oil wells composite water cut is more than 75%.New Wells have also exposed difficult question of water cut rising too fast, production falling fast.However, the oil recovery rate is only 19.2% in this oil field, there is still a large amount of remaining oil in the low physical area has not yet been affected.To solve these problems, we need to design a set of depth profile control scheme suitable for this block.Firstly, choose the suitable flooding system for this block according to the reservoir core composition and fluid physical properties: two kinds of particle system and four kinds of gel system. Two kinds of particle system are asphalt particles and suspended particles. Four kinds of gel are JLJ-2, Cape deep profile control gel, CNPC Tektronix gel, HLX-19 chromium system cross-linked polymer. There are eight kinds of system through orthogonal combination.Optimization of the best system combination by physical experiment method, afterward obtained the optimum number of slug and injection timing through optimization to lay the foundation for the subsequent numerical simulation.The next step,according to the geologic characteristics of the work area,using reservoir engineering method and collect fuzzy mathematics to establish the evaluation set of oil well and reservoir for the work area,and then use the main analytic hierarchy process to calculate the weight of each indicator,according to the calculation results to determine the profile wells and the target level.On the basis of fully understanding the geological characteristics of the S block, establish three - dimensional geological model and numerical model,and complete the historical fitting.Quantitative describe the remaining types of reserves of different types and causes and formulate the corresponding exploration.At last,on the basis of accurate numerical model,study on the effect of factors such as the concentration of modifying and flooding agent, plugging rate,profile control radius,profile control time.And provide technical reference for optimizing the flooding control,based on the established numerical model,forecast the target wells or blocks of Nissan oil, the cumulative oil production, transfer and control status and other indicators.Utilize the principles of technical economics,consider the S block drive transfer investment situation,combined with the numerical model of the output of the forecast results,finally considering from two aspects of technology and economy,give the best for the S oil field transfer program.