Development Of Numerical Simulation System For Non-Darcy Flow In Low Permeability Reservoir

Computer programs are an integral part of a modern petroleum engineeringeffort. These days, reservoir numerical simulator is one of the most important toolsfor reservoir engineering. With the development of computer and petroleumengineering technology, more and more commercial simulators are applied toreservoir engineering. These programs are time-saving tools for performingevaluation and design work.With a lot of petroleum exploitation of low-permeability reservoirs, theyconfront some new problems such as low natural output capacity, highinjection-water pressure, difficulty to see injection-water effect of oil extraction welland low final recover of oil field. Because slow velocity flow of low permeabilityrock doesn't obey Darcy-Law, we can not go on using Darcy Law in flow equationsin low-permeability reservoirs simulation. And recently commercial simulatorsusually do not take those problems into account, or deal with it with adding thresholdpressure gradient in former model simply, up to the present. It is necessary to studynonlinear flow law and mechanism of low permeability rocks and developcorresponding simulator.Probably the most routinely used of the technically sophisticated programs is theblack oil simulator. The black oil simulator is the workhorse of modern reservoirengineering in particular. Therefore in order to solve the simulation problem ofpetroleum exploitation of low permeability, we use black oil model as the base forbetterment. With a view to nonlinear character of seepage experiment data graphdirectly, the paper puts forward Alterable Permeability Algorithm and ImitatingGrads Algorithm to deal with the nonlinear seepage phenomena. Then we try to solvethis problem by improving on black oil model with the two Algorithms. At last, onthe base of the improved black oil model, we developed a new simulator called afterDynamic Flow 1.0. It consists of five parts: pre-disposal, calculation, post-disposal,database, parameter disposal, and run well on the Windows operating system. Thesystem is manufactured by VC++ and Visual Fortran compiler, draws 3D graphics byOpenGL, and provides Oracle9i database support.This paper mainly introduces the whole process of development and theframework of the simulator. It includes that: the theory that the simulator based, thedesign process of the numerical system, the tools that we choose for development, thethe primary algorithms we used in the software, and brief introduction of oursimulator.The Dynamic Flow 1.0 system has put onto the oilfield side, which can providereferences for low-permeability reservoirs petroleum exploitation and can beperfected in the future.