A production scheme for bitumen production from oil sands reservoir with forming emulsion by injecting hot surfactant solution

Alternative process of Steam-Assisted Gravity Drainage (SAGD) method for bitumen recovery from oil sands reservoirs has been studied to improve production cost, thermal efficiency and environmental issues. A new production process called as the Cyclic Huff & Puff method has been proposed in this study. The method uses injecting a hot surfactant solution using horizontal wells in a staggered arrangement. In this research, viscosity measurements of original oil and emulsion in type of oil-in-water (O/W) formed by the solution of Poly Vinyl Alcohol (PVA) were carried out in order to confirm the viscosity reduction of bitumen at relatively low temperature (<150ºC). The viscosity was apparently reduced to around 18cP from 100000cP of the original bitumen at 150ºC. It was also confirmed by the laboratory experiment that PVA solution and bitumen formed the emulsion within a half hour after contacting in the beaker. Those measurement results were applied to numerical simulations by CMG STARS^TM. The numerical model was assumed that horizontal wells are placed at upper oil sands reservoir and other horizontal wells are located at its bottom in the staggered arrangement. When the hot PVA solution is injected from the upper wells, other bottom wells produce fluids. After a certain period, upper and lower wells are operated as opposite functions. The simulations were carried out to simulate formation of bitumen emulsion with hot PVA solution of 100℃and the emulsion move to production wells in a typical oil sands reservoir. The simulation results show that the Cyclic Huff & Puff method has a potential to be a production scheme for oil sands reservoir with less cost and higher thermal efficiency than that of SAGD method.