Petroleum reservoir simulation using 3-D finite element method with parallel implementation

Modeling fluid flow around wellbores with conventional reservoir simulators is inaccurate because radial flow occurs in the vicinity of the wellbore and these simulators use cartesian coordinates. In this research, we present a more accurate wellbore simulation by incorporating the finite element method (FEM) to simulate the radial flow in the vicinity of the wellbore and interfacing this finite element wellbore model with an existing finite difference method (FDM) reservoir simulator. Although this technique was developed for a vertical well, it could also be used to accurately model a horizontal wellbore. This “hybrid” solution is for three dimensional—triphasic fluid flow and allows a more rigorous treatment of the near-well flow. The reservoir region, where flow geometry is linear, is simulated with the cartesian grid using finite differences.; The reservoir simulator used for this research was the US Department of Energy's Black Oil Applied Simulation Tool (BOAST II). Two problems furnished by the Department of Energy were used to test the effectiveness of our solution. The first was a single stratum three phase system. The second was a three strata three phase gas injection problem.; Finally, our stand alone model could actually be interfaced with almost any other finite difference fluid flow simulator; whether it is for petroleum reservoirs, underground water, or hazardous waste management.