Influences of reservoir rock and fluid properties on cyclic steam stimulation efficiency in naturally fractured reservoirs

Steam injection in NFRs provides an extremely challenging problem as well as a potentially efficient EOR method. Coupling of the two distinct and contrasting matrices and fracture systems results in more complications as a result of steep changes in fluid properties due to the thermal effects of steam injection. In this research effort, attempts have been made to simulate the cyclic steam stimulation in NFRs containing heavy-oil and also analyse the influences and contribution of different reservoir parameters on oil recovery (RF), cumulative steam oil ratio (COSR) and cumulative water oil ratio (CWOR). The results obtained show the advantage of a fracture system in conducting heat into the rock matrix, because of the large surface area exposed to heating. The results obtained from the Sobol analysis show that oil viscosity, fracture horizontal permeability, matrix wettability and capillary pressure are the most effective reservoir parameter which affect the performance significantly. [Received: August 4, 2020; Accepted: October 17, 2020]