The effect of heterogeneity and well configuration on the performance of hot water flood

This study investigated the performance of hot water injection in several stochastically-generated permeable media using different well configurations and initial oil viscosity. The reservoir investigated is typical of a Middle Eastern heavy oil reservoir with heterogeneity and fluid properties that differ significantly from one location to another. The reservoir is a candidate for a thermal recovery method. However, due to the lack of fresh water to conduct steam flooding, only hot water flooding is considered in this study. Several three-dimensional heterogeneous permeability fields were generated geostatistically using the matrix decomposition method, to cover a wide range of permeability variation and correlation structure. Initially, simulations of hot water displacement were performed in all these permeable media with a multilateral horizontal well injector and a vertical producer. These results were then compared to those obtained with unheated conventional water flood. Investigations were then carried out to study the sensitivity of the displacement performance to the initial oil viscosity and to other well combinations. These well combinations consisted of vertical producer-vertical injector in a five-spot pattern and horizontal injector-vertical producer in a line-drive pattern. Results show that the performance of hot water injection is strongly affected by the degree and structure of reservoir heterogeneity. Regardless of the permeability variation and the correlation structure, the use of vertical wells in a five-spot pattern was found to be the most suitable well configuration to develop this reservoir. The combination of high permeability variation and high correlation length significantly reduces the displacement performance of horizontal or multilateral wells. (C) 2014 Elsevier B.V. All rights reserved.