Analysis on capillary pressure curves by wettability modification through surfactants

Abstract

Wettability of a reservoir rock is closely related to capillary pressure curves. The status of wettability is an important factor for oil recovery, can be clearly seen through the variations in capillary pressure curves. The aim is to analyze the changes in capillary pressure curves and saturations by altering wettability. An oil wet core sample was tested to alter wettability. During alteration process it is difficult to analyze the status of wettability. Surfactants were applied to modify wettability. Additionally, parameters like connate water saturation, spontaneous oil and water saturations, residual oil saturation and type of wettability can be analyzed. The concentration of surfactants was selected by conductivity test. The changes in saturations with variations in capillary pressure curves were stated.