Efficient Injection-Production Optimization Theory Based On Reservoir Connectivity Model

In order to maximize the economic benefits of oilfield development,reservoir production optimization has become a research hotspot in the industry.However,the traditional reservoir production optimization method needs to establish a fine geological and numerical simulation model in the early stage of optimization,and needs to call the reservoir numerical simulator many times in the optimization process.The whole optimization process requires high technical requirements for engineers,and the optimization cycle is long,which limits its application in practical reservoir production optimization problems.In view of the above problems,this paper studies the efficient injection-production optimization theory based on the reservoir connectivity model.First of all,aiming at the time-consuming problem of traditional grid-based reservoir numerical simulation method,this paper investigates various reservoir proxy models.By ignoring the specific flow details between wells,small grids are integrated into large inter-well connectivity units,and combined with the automatic well pattern subdivision method,a reservoir connectivity model is formed.Compared with the traditional reservoir numerical simulation model,this model has the characteristics of less model parameters and fast calculation in the actual calculation process,and does not need complex modeling process,so it can greatly improve the calculation efficiency.Secondly,this paper studies the automatic history matching method of reservoir,and establishes the mathematical control model of automatic history matching of reservoir connectivity model according to the characteristics of reservoir connectivity model,and compares and analyzes various solving methods,forming an automatic solution method of parameters of reservoir connectivity model.Finally,based on the reservoir connectivity model after parameter inversion,two efficient injection-production optimization methods are proposed.The first method is an injection-production well control method based on reservoir engineering,which can increase oil production and control water in the whole block by increasing water injection in water injection intervals with high water injection efficiency,reducing water injection in water injection intervals with low water injection efficiency,and correspondingly adjusting the liquid production of production wells.The second method is the production optimization method based on the optimal control theory,which combines the reservoir connectivity model with the optimization theory,and realizes efficient reservoir injection-production scheme decision with the aid of the optimization algorithm.In addition to verifying the proposed method with theoretical model,in chapter 5,the establishment of reservoir connectivity model and automatic history matching in block x of Shengli oilfield are completed by using the proposed method.Finally,the production optimization of this block is carried out by using the two injection-production optimization methods.The results show that the production schemes obtained by the two methods have better development effects than the original scheme,which proves the effectiveness of the efficient injection-production optimization method based on reservoir connectivity model studied in this paper.