Investigation of drive mechanisms in fractured oil reservoirs with tight matrix: a case study of an Iranian reservoir

Abstract

ABSTRACT Tight matrix oil reservoirs pose significant challenges for oil recovery due to their low permeability and intricate fracture networks. Effective reservoir development strategies require a thorough understanding of the recovery mechanisms; otherwise, it is difficult to maximize production rates and optimize the oil recovery factor. The reservoir examined in this study contains black oil within a tight matrix, complicating the planning and selection of appropriate recovery methods. Despite strong bottom water influence and high water-cut issues, the fractures in the reservoir facilitate economical extraction. However, the reservoir’s complexity, coupled with limited knowledge and experience in this area, further complicates recovery efforts. In this study, we investigated the multi-mechanistic flow dynamics within the porous media. Simulation results indicate that during the first month of production, the dominant recovery mechanism is rock expansion drive. Beyond this period, the water drive mechanism prevails. Over a ten-year period, oil recovery is distributed as follows: 13.1% from bottom water drive, 1.0% from gas cap drive, 0.2% from rock expansion, and 0.6% from oil expansion drive.