Research on technology to produce bitumen emulsion for water isolation in Lower Miocene production wells of Bach Ho oilfield

Abstract

There are several methods to treat flooded oil wells, using different kinds of chemicals and materials. However, most of them are unselective, meaning that the entire fluid in the reservoir will be completely isolated from the wells, including the crude oil. Many studies have used different residue fractions from crude oil distilation with high asphaltene and resin content to isolate water from the reservoir to the production well which allow the entire crude oil to penetrate through the isolation material. The disadvantage of this technique is that the viscosities of heavy crude oil fractions are too high, making it difficult to use them in oil wells. Therefore, using bitumen emulsion to isolate water from the resevoir is a highly potential technique. The authors have studied the technology to produce bitumen emulsion in lab scale. Bitumen emulsions later on were tested for their physicochemical properties to evaluate their abilities for injection into the production wells. The two most potential samples of bitumen emulsion were used for injection and isolation test at reservoir conditions (high pressure, high temperature) in the lab. The results of experiments showed that bitumen emulsions got a high water isolation ability (water permeability recovery coefficient was reduced by 96%). At the same time, they allow crude oil to penetrate through (crude oil permeability recovery coefficient was about 89%).