Abstract
LD-N extra-heavy oil reservoir in Bohai Sea is characterized with deep burial and large bottom water. Horizontal-well steam huff “n” puff has been applied, yet due to water coning and serious heat losses, the oil recovery after three cycles turned out to be rather low (1.58%). To find an appropriate follow-up process, this study proposed and analyzed three different flooding schemes: steam flooding, multiple-thermal-fluid flooding, and foam flooding. Scaled 3D physical experiments and corresponding numerical simulation have been conducted to investigate the heating chamber development and fluid production. History match and parametric analyses have been carried out to optimize the well performance and operating conditions. The optimized results include 360 m3/d instantaneous steam injection rate, 1.3–1.4 production-injection ratio, and 13–16 m water avoidance height. In addition, the production well is recommended to be placed above the injection well. These findings provide a useful guidance for the design of thermal recovery schemes and the optimization of production processes for heavy oil reservoirs with bottom water.