Development mechanisms and influencing factors of dump flooding

摘要

Aiming at the problem that the theory of dump flooding is not mature, this study examined the suitable reservoir conditions for dump flooding, defined the concept of “dump flooding threshold pressure” and its expression based on fluid mechanics and reservoir engineering fundamentals, and proposed the computing method of water injection rate, producing rate, water layer pressure, oil layer pressure, cumulative injection and cumulative production. It gave the corresponding computing program according to the proposed computing method, and made a case study and analyzed the factors affecting dump flooding using the program. The dump flooding computing methods are reasonable and applicable; when water reserve-oil reserve ratio is less than 60, production plateau extends with and oil recovery increases with the increase of water reserve-oil reserve ratio, when water reserve-oil reserve ratio is more than 60, the effect of the ratio of water reserve to oil reserve is negligible; the timing of dump flooding has a significant effect on production plateau and oil recovery, the later the dump flooding injection timing, the more completely the formation energy will be used, the longer the production plateau and the higher the recovery will be.