Design of downhole oil-water separation device and study on separation mechanism based on rod pump heavy oil system

Abstract Downhole oil-water separation technology (DOWS) is a new type of separation technology, which can improve efficiency, reduce energy consumption, and can solve the problem of high water cut oilfield development. At present, there are only two separation methods in the same well injection-production separator, one is the swirl separation technology and the other is the gravity separation technology. Cyclone separation technology mainly relies on cyclone separators to separate oil and water, but it is affected by oil viscosity, water content, and temperature. The gravity separation technology mainly relies on the similar separation principle of a multi-cup equal-flow gas anchor to design a multi-cup equal-flow oil-water separator, but it requires the oil-water mixed production liquid to stay in the settling bowl for a long time. The centrifugal separator has the characteristics of a good separation effect, high efficiency, and low demand for oil. At present, the downhole centrifugal separator is not used in the same well injection-production technology, which mainly needs to solve the driving force problem of the centrifugal separator. The new injection-production device designed in this paper can better solve the driving problem of the centrifugal separator and meet the working requirements of the process.