Water Alternating Gas Pilot Design and Results: Yaraktinskiy Field Eastern Siberia

The article describes the design of water alternating gas (WAG) project and the results of implementation within a portion of the Yaraktinskiy field. The technical applicability of using WAG to increase oil recovery was justified from core flood and slim tube experiments in conjunction with PVT fluid studies. The equation of state was tuned to the PVT data and slim tube experiments. Fully compositional modeling was used to generate type curves that demonstrated additional recovery from the WAG process. A systematic criterion was developed to identify and rank the best patterns for WAG response and therefore identify the optimal pilot area. For flood management performance ratios and efficiency criteria were defined. Pilot response has provided additional recovery, indicating mobilization of previously immobile oil. History matching the pilot response has improved the model and this has been used to justify further scaling of the process to more areas of the field. As well, the model is now used to establish requirements for piping, compressor and other surface upgrades.