Sulphate in Reservoir Rock

Waterflooding of Carbonate Reservoirs - Optimal composition of injected water

The project is divided into two main tasks.

First, the chemical wetting properties for crude oils with different AN/BN ratio will be studied using different carbonates, i. e. chalk, limestone and dolomite. The study will include effects of brine salinity and composition (especially potential determining ions) as well as temperature. Special focus will be made on the wetting properties of the main Norwegian chalk fields: Ekofisk, Valhall and Eldfisk. The wetting mechanism should be characterized, and the most promising chemical additives should be tested in spontaneous imbibition experiments. We will use the newly developed wettability test technique.

Secondly, for the different oil fields studied (Ekofisk, Valhall and Eldfisk) spontaneous imbibition of chemical modified water (e.g. adding or removing components) will be performed with the ultimate goal to increase the capillary forces and thereby enhance the displacement of oil. Also in this task, the salinity and composition of initial brine and injected fluid must be considered as well as temperature effects.