Study on the coupling calculation model of dump flooding in Hala-hatang fracture-cavity reservoir

摘要

The dump flooding technology comes from offshore oil fields. It is necessary to increase the production of oil by water injection when fracture-cavity reservoirs in Xinjiang enter their middle and later stages. Lack of water sources in the desert area and the presence of heavy upper water layers encourage further research into the application of this technology. The dump flooding technology can eliminate the need for specialized injection wells and reduce the consumption of oil fields in the surface water sources, which may significantly aid in the development of the local economy and environment. In China, the research on dump flooding is still in its preliminary phase. Hence, there is no complete flow model for gravity flow and no optimization design software to optimize the development effect. This article sets up a flow model of a water layer-well-fracture unit by key local nodes. The key nodes, such as some perforating water layer, the bullet hole or the water valve, were simulated using the COMSOL software. The flow equations of each node were coupled together for the system-wide flow coupling model to verify the whole system by the numerical simulation, which needs Eclipse to run. The results of the research can be used to predict the water injection rates and formation pressures, and also provide a reference and a basis for the optimal design of water injection.