A Study of Caustic Consumption in a High-Temperature Reservoir

Abstract

ABSTRACT This paper describes a procedure used for evaluating a high temperature reservoir for caustic flooding. A comprehensive feasibility study included reservoir rock and fluid characterization, laboratory measurements of parameters controlling caustic consumption and a process evaluation by simulation with a finite difference chemical model. A two phase, six component finite difference chemical model was modified to include the long term caustic consumption based on first order reaction kinetics. The model produced a satisfactory match of a laboratory experiment conducted for determining caustic consumption. The influence of ion exchange, slug size and flow rates on the propogation of an effective caustic concentration through the reservoir was also investigated. The study indicated that caustic flooding of a high temperature reservoir can be successful only if the reservoir has sufficient flow capacity. To overcome the large caustic consumption due to high temperature, a high velocity must be maintained. Concentration of the caustic is also critical. However, if the fluid cannot be propogated fast enough, the concentration becomes insignificant.