Abstract
Oil production is normally followed by water production in increasing rates, mostly when waterflooding is used as oil recovery mechanism. In order to minimize the impact that high rates of produced water causes to the topside facilities, Petrobras is working on the development of a subsea system for oil-water separation, so that most of the produced water can be separated on the mudline and reinjected in the reservoir or in a bearing formation. Besides the benefit of debottlenecking the production plant, there are gains in flowrate and flow assurance due to the less amount of water in the production stream.
The article also shows how this development has been carried on, the scenario definition for the pilot, the problems associated to an installation in a system already operating and the oil characteristics determination. These data constitute the base for the survey to detect the technologies with potential application on the separation system to be developed.
The special characteristic of the oil, with high tendency to form stable emulsions with water, are also analyzed, as well as the difficulties it brings to the process in the subsea environment, where there are vessel size and fluid heating limitations.