The flow description applied for double porosity reservoirs is of paramount importance for evaluating the performance of fractured turbidite reservoirs. Many authors have measured in the lab and formulated formulas describing the transfer function between the fracture and the contiguous less permeable porous media. Other authors using these transfer functions described the flow behavior in a system of double porosity and double permeability.
In this work, laboratory tests were performed in long cores with different fluids, diverse wettability condition and various flow rates. At first experiments were conducted on unfractured cores. Then, for the same core, geometry, flow pattern and fluids, the transfer function that occurred in a subsequent flow test for a double porosity system was measured. The saturation history during the test was measured with an X-ray scanning system. The experiments were conducted quite differently from those commonly used in imbibition experiments and provided additional insight into oil recovery from fractured reservoirs.
In order to describe the lab flow tests it was used three mathematical approaches, namely: a finite difference commercial reservoir simulator, a semi-analytical solution, and an analytical solution for the hyperbolic system of equations governing the process. The experimental results obtained were matched satisfactorily by the three mathematical approaches investigated. At the end, the first two mathematical methods were applied to predict the production behavior for an equivalent injection pattern in a Brazilian fractured turbidite reservoir.