Hot-Water Flooding Investigation in Lithological Heterogeneous Reservoirs Associated with the Evolution of Fluid and Rock Properties

As an emerging energy demand owing to growth in industries and population, understanding hot water injection for the production performance in heterogeneous reservoirs becomes highly essential. The present investigation provides insights into the influence of reservoir rhythm and American Petroleum Institute (API) gravity on hot water flooding. A sensitive study on the order of permeability variation is also performed to understand the extent of hot water flooding. With this intent, we developed an improved fully coupled energy and multiphase flow model associated with the evolution of fluid and rock properties in two-dimensional reservoirs to evaluate hot water flooding scenarios. The lithological heterogeneity of the reservoirs degraded the total oil production rate in contrast to the homogeneous reservoir. Random rhythm reservoir effectively increases the total oil production and is observed to have a cumulative oil production of 338.62 m3, which is the highest among other rhythmic reservoirs. Waterfront advancement has reduced in higher API gravity reservoirs; however, more effective oil displacement than lower API gravity reservoirs is experienced, reducing the early water breakthrough phenomenon and increasing the total oil production. The largest cumulative oil production of 348.86 m3 is observed in the 21° API gravity oil reservoir. The wider variation of the permeability in the reservoir reduced the oil production significantly. The lowest cumulative oil production of 248.66 m3 is observed in the 2nd order reservoir in contrast to the reservoir, possessing permeability variation by scale factor and 1st order. From the present investigation, it can be interpreted that the lithological heterogeneity can influence the performance of hot water flooding by reducing 5.82%, 6.69%, 7.13%, and 7.91% in random rhythm, compound rhythm, negative rhythm, and positive rhythm reservoir in comparison to the homogeneous reservoir, which is required to design properly to reduce the drastic impacts on the hot water flooding project.