Numerical Simulation Research Of Uncompartmentalized Oilfields By Flow Field Reforming To Improve Oil Recovery

As many oilfields have stepped into the high water cut stage or the extra high wate-cut stage, great changes of reservoir flow field have taken place because of the long-term erosion of injected water. Therefore, the research on dicators which describe the reservoir flow field and establishing the evaluating system of reservoir flow field is very importment in practice and significant in technological progress. A new method on the development of evaluating system of reservoir flow field has been established based on the mathematical method and producing dynamic data in this paper. In the light of the reservoir with a serious original heterogeneity and predominant flow channels produced by water flooding, evaluating system of reservoir flow field are put forward to recognize predominant flow channels, and it provides the basis for flow field reforming to improve oil recovery. The research is combined with the project of one oilfield, there are several creative contents:1. On the basis of the principles of streamline numerical simulation technology, the streamline integration software is improved. Its characteristics are taking into consideration the roles of gravity and capillary force, and the slightly compressibility of rock and fluids. Implicit method is used to solve the pressure field, with the Darcy's equation to solve the velocity field, and Pollock method is used to trace the streamline. Thus, a complete set of numerical streamline simulation method is formed, and is applied to actual region.2. On the basis of the formation and evolution mechanism of the predominant flow channels, conceptual Models are established to study the efect of various properties of the channel on the developmental effectiveness of water flooding. The results show that the existence and development of predominant flow channels have significant effect on water breakthrough time and the ultimate recovery. So it is necessary to identify predominant flow channels, and then a comprehensive management is done to enhanced oil recovery.3. Evaluating system of reservoir flow field are established. Logical analysis method and empirical methods are adopted to screen the indicators which describe the reservoir flow field. On this basis, according to AHP and fuzzy comprehensive evaluation methods, evaluation system of reservoir flow field is established and to grade flow field strength: absolute predominant flow field, predominant flow field, non-predominant flow field and absolute non-predominant flow field.4. Evaluating system of reservoir flow field are adopted to the actual region. Fine reservoir simulation model of Chengdong oilfields is established, and proceed accurate history matching. According to evaluating system of reservoir flow field, predominant flow field are determined and then reform the flow field, the layer system and well pattern optimization is performed, designing different adjustment programs, and making the program predicted, and at last choose the optimized program as the next program.