Abstract
In an earlier work, we presented a new, semi-analytical gravity drainage model to predict oil production of a horizontal well under cyclic steam stimulation. In this paper, the model for the horizontal well is extended from the gravity drainage representation to more accurately predict performance during the cyclic steam stimulation. The water–vapor equilibrium in the cylindrical chamber created by injected steam in the vicinity of the well, heat losses to surrounding oil, formation during the steam soaking stage, and oil production are now included in the modified model. The computation procedure consists of solving the transient heat conduction equations to obtain the temperatures in the chamber and surrounding oil during the soak period and determining the temperature decline during the oil production phase. By using the proposed model, one can optimize the soak time to maximize the cumulative oil production. A case stud is presented to illustrate this capability.
Sensitivity studies have also been conducted to better understand the impact of steam quality and steam injection volumes on well performance. The proposed model is employed on an example application to enhance cumulative oil production.