Abstract
To accurately capture the flow behavior and dynamics in fractured reservoirs, a theoretically sound, and practically robust boundary element method (BEM) numerical algorithm has been developed and successfully implemented. Explicit and discrete fracture description is adopted in this approach, and the complex fracture settings and interactions can be effectively simulated. Modules characterizing the transient flow dynamics and the flow dependence on matrix heterogeneity, which are seldom studied by previous researchers through a BEM approach, have also been established and investigated.
Specifically, our model starts from two simplifications: the flow inside the fractures is treated as twodimensional, and the fractures can be equivalently seen as planar source or sink entities interacting with the matrix. In our approach, only the matrix boundaries and fractures are discretized into small elements, and each element associates with either one or two unknowns. Two sets of equations generated from the above two simplifications are used to relate these unknowns and solve the problem. And when the flow transientness and matrix heterogeneity are concerned, additional internal matrix points are selected and taken into computation, following the procedure of the dual reciprocity boundary element method (DRBEM).
Several case studies have been conducted, and result comparison indicates the validity of this approach. Finally the strength and weakness of our approach are also discussed in this paper.