The Feasibility Study of High Pressure Steam Flooding after Water Flooding for Common Heavy Oil Reservoir

Abstract

The buried depth of water flooded common heavy oil reservoir in Shengli oilfield is very deep, reservoir pressure and water cut are both high after long-term water flooding, which makes it difficult to carry out steam flooding after water flooding. In this paper the effects of reservoir pressure and steam quality on steam heating reservoir and steam expansion are studied through the numerical model, and the feasibility of high-pressure steam flooding is demonstrated. Finally, the development result of high pressure steam flooding is validated through the practice in Gudao Oilfield Zhongerzhong Ng5 pilot test area. The research result shows that when reservoir pressure is constant, the greater steam quality is, the better steam expands in vertical and horizontal direction, the faster temperature front and gas saturation front moves, the bigger heating radius is. When steam quality is constant, the greater reservoir pressure is, the higher steam chamber temperature is, the more slowly temperature front and gas saturation front moves, the smaller heating radius is. High steam quality can solve the problem of small steam chamber caused by high reservoir pressure due to its high specific volume and heat enthalpy, achieving the same effect of low reservoir pressure and steam quality. That’s “the same effect with the same specific volume” function.