A New History-Matching Technique in Simulating Steam Injection Projects

Abstract

ABSTRACT As previously reported1,2,3, a scaled physical model was developed to study the oil recovery efficiency of steam injection into horizontal wells. Experimental performence evaluations were made with two types of synthetic oils with injection of steam at different qualities. In this paper, the results of these laboratory studies are compared to predicted performance using a three-dimensional, three-phase thermal simulator. Previously, most history matching studies have relied heavily upon adjustments to the relative permeability curves to obtain agreement between calculated and observed production data. In this study, to match production data we devised a new technique in which at elevated temperatures oil viscosity is lowered and water viscosity is increased so as to converge to a common value at steam temperature. Conceptually, this technique implies that at steam temperature oil and water tend to form as a combined emulsion phase. The presence of an emulsion phase is evidenced by experimental studies and thermal oil production in the field. We successfully used the proposed technique to match the oil and water production data obtained from laboratory experiments. The efficacy of the technique demostrated by comparing observations to three separate prediction runs; (1) base case using standard relative permeability and viscosity data (2) results computed with only relative permeability adjusted, and (3) results with only viscosity adjusted. The history matching studies include oil production from vertical wells in a five-spot pattern and horizontal wells in a trench pattern.