Method of evaluating and selecting an enhanced oil recovery strategy for fractured reservoirs

摘要

The invention is a method of evaluating a recovery potential for hydrocarbons contained in a fractured reservoir, using an enhanced recovery technique. Characteristic reservoir data, data obtained from well test results and data relative to the development conditions are acquired. A pressure gradient related to the flow of a fluid injected to improve recovery is then estimated from the previously acquired data. A recovery coefficient is calculated for the hydrocarbons initially in place in matrix blocks by estimating water saturation for a state of equilibrium of the matrix blocks. Finally, the oil recovery time under the effect of the fluid circulation in fractures is estimated by determining the required for the matrix blocks to change from the initial state to a state of equilibrium.

主权项

1. A method of evaluating a recovery potential of hydrocarbons contained in porous matrix blocks of a reservoir limited by fractures, using a recovery technique wherein a fluid is injected into the reservoir, for at least one matrix block comprising:
i) acquiring data characteristic of the reservoir, data obtained from well tests and data relative to development conditions of the reservoir; ii) estimating a pressure gradient related to a flow of the fluid in the fractures, from data acquired in i), iii) calculating a recovery coefficient for the hydrocarbons initially in place in the at least one block, by estimating a fluid saturation for a state of equilibrium of the a least one matrix block, from the pressure gradient and from data acquired in i); and iv) estimating a hydrocarbon recovery time under an effect of flow of the fluid in the fractures by determining a time required for changing from an initial state to an equilibrium state of the matrix block, by applying two-phase displacement laws, from the pressure gradient and from data acquired in i).