| dc.description.abstract | Heavy and extra heavy oil are fluids with high ranges of viscosity at both reservoir and surface conditions. These fluids have complex production processes due to factors such as high sulfide content, carbon dioxide (or other fluid injection reactions), flow assurance, and water breakthrough. The rheological properties of heavy and extra heavy oil modify the fluid in such a manner that these fluids cannot be treated as traditional Newtonian fluids. The behavior of such fluids is well documented in the petroleum industry and serves as the motivation for this work.
This work develops and presents a new reservoir model which accounts for the behavior of a non-Newtonian fluid within a double porosity reservoir. We propose a new interporosity function for "pseudosteady-state" flow with non-Newtonian phenomena. The non-Newtonian fluid type that we have chosen to use in this work is the "pseudoplastic" plastic fluid type.
We review and adopt certain aspects from the prior studies that have been performed to describe the behavior of a non-Newtonian fluid through porous media in a homogeneous reservoir system. We also provide an extensive literature review on this topic and the behavior of "double porosity" (or "naturally fractured") reservoir systems. In this work we only consider the classic case of "pseudosteady-state" interporosity flow introduced by Warren and Root as this represents the "base" case (or starting point).
Specifically, in this work, we derive the partial differential equation for non-Newtonian flow within a double porosity reservoir under pseudosteady-state interporosity transfer conditions. All solutions assume the "constant rate" inner boundary condition, the outer boundary conditions used in this work include the infinite-acting reservoir, circular reservoir with a "no flow" outer boundary, circular reservoir with a "constant pressure" outer boundary. "Type curve" plots are provided to illustrate the behavior of the dimensionless pressure and dimensionless pressure derivative behavior as a function of dimensionless time.
Illustrative examples are provided using synthetic cases. In these examples the entire workflow is illustrated, including diagnostic identification and radial flow analyses. | en |
