Calculation of the Production Rate of a Thermally Stimulated Well

Abstract

This paper presents a method for calculating the pro-ducing rate of a well as a function of time following steam stimulation. The calculations have proved valuable in both selecting wells for stimulation alld ill determining optimum treatment sizes. The heat transfer model accounts for cooling of the oil sand by both vertical alld radial conduction. Heat losses for any number of productive sands separated by unpro-ductive rock are calculated for the injection. shut-in and production phases of the cycle. The oil rate increase caused by viscosity reduction due to heating is calculated by steady-state radial flow equations. The response of Sllcces-sive cycles of steam injection call also he calculated with this method. Excellent agreement is shown betweell calculated and actual field results. Also included are the results of several reservoir and process variable studies. The method is best suited for wells producing from a multiplicity of thin sands where the bulk of the stimulated production comes from the unheated reservoir. The flow equations used neglect gravity drainage and sall/ration changes within the heated region.