PC Cluster-based Parallel Numerical Simulation Of The Low-permeability Reservoirs

The low permeability reservoirs will be the main object of the oil and gas exploration and exploitation of our country. Reservoir numerical simulation can provide the best theoretical guide and method support for the scientifically and effectively development of this kind of reservoirs. Based on the research and investigation of low permeability flow mechanism and affecting factors, this paper chose the pseudo-linear flow equation and firstly established the flow differential equations, considering the relationship between start-up pressure and permeability. Also the inner boundary condition was built considering the coordination of the flow from well to grids and flow between grids, as well as the start-up pressure. Then combined with the out-boundary condition and initiation condition, the numerical model of low permeability reservoir was established and solved by fully-implicit differential form. This paper used the region-decomposition parallel method, formed the parallel strategy, and produced low permeability reservoir simulation paralle software. Through the calculation of ideal five-spot well pattern and real reservoir of Daqing, it was proved that the parallel method based on PC cluster can greatly improve the calculation speed of the low permeability reservoir numerical simulation. The start-up pressure can influence the pressure transmission greatly. The bigger the start-up pressure is, the smaller the region which pressure transit and the bigger the pressure drop are in the early time. Meanwhile, the pressure drop also increases in the production tail. In the study of pressure distribution in injection-production pattern, in the same production and injection, the bigger the start-up pressure is, the bigger the pressure gradient between injection well and production well, which means that lower production well bottom hole pressure and high injection pressure are needed. The study results can be applied to low permeability reservoir simulation of the various development programs, for such a reservoir of scientific, rational and efficient development of important guiding significance.