Appropriate use of dissolved gas energy in fields at the final stage of development

Abstract

In order to improve the development of fields at a later stage, this article considered the use of water-gas repression together with the dissolved gas energy. The theoretical basis of the study is based on the application of the method of physical modeling of oil displacement by water. As a result, it was found that waterflooding would be more effective when such an activity is carried out in the early stages of development. Waterflooding can also be effective in old, depleted fields with shallow depths of oil-bearing horizons. The article states that in flooded deposits, where the reservoir pressure did not drop below the bubble point pressure, it is advisable to reduce the reservoir pressure to the bubble point pressure (to carry out forced withdrawal). After that, water injection should be resumed with 30-50% compensation. It has been established that in order to increase the efficiency of the development of fields developed in the dissolved gas mode, waterflooding must be started at a reservoir pressure that is 30–70% less than the bubble point pressure. The best option for the development of such deposits is the presence of active edge waters. If they are absent, it is advisable to end water in the aquifer with compensation of withdrawals from 20 to 40% after the start of gas extraction from oil.