As water-alternating-gas (WAG) miscible flooding is the best method to enhance oil recovery for hydrocarbon reservoirs, recently there has been an increasing interest in the WAG processes. In the recent years some reservoirs suitable for miscible flooding have been discovered in the western part of China. The first WAG miscible flooding project, Pubei oil field in Xinjiang, was put into production and scheduled to initially inject miscible gas at the early development stage. One objective of this work is to describe the process of making the optimal field development strategies in this field by integrated technology.
Also presented are theoretical models for comprehensively evaluating and decision-making the oil well production operation methods. These models have been successively applied to thirty reservoirs or fault blocks in China. With consideration of the specialty of the WAG process, the models were developed by incorporating reservoir geologic research, reservoir engineering scheme, reservoir numeric simulation, production performance and surface facility performance. Meanwhile, a novel approach was introduced into the modeling process so that we can simulate the future production performance of oil producers under different conditions in the Pubei oil field.
It is shown that oil producers can maintain stable flowing and there still is potential for the reservoir pressure maintenance, and that gas lift, plunger lift and sucker-rod pumping can be efficient artificial lifting methods under different conditions.