In-Situ Combustion Models for the Steam Plateau and for Fieldwide Oil Recovery

摘要

In this study, two interrelated parts of the in-situ combustion oil recovery process have been investigated. The steam plateau region of laboratory combustion tube experiments was studied and heat transfer modes describing the steam plateau were defined. The combustion parameters affecting the steam plateau were also studied and evaluated. An analytical heat model was developed which describes the movement of the steam plateau axially along a cylinder with heat loss through an annular insulation. The behavior of the solution was studied to determine the interaction of the heat transfer mechanisms in laboratory cores. The agreement between experimental laboratory temperature profiles and those computed by model were satisfactory. In the second part of the study, correlations were developed to predict field scale recovery of dry in-situ combustion processes. Basically, a case history analysis was made on field tests as a first step. The recovery histories of those field systems were studied. A combination of an engineering and a statistical approach was used to develop the correlations. The match between the correlations and field test results was also satisfactory. The study shows that the recovery correlations developed for dry combustion processes may be used for the recovery prediction of the wet combustion test in which the air-water injected ratio is high. This study also indicated that air injection and/or oil migration losses are important factors affecting the recovery mechanisms of a pilot project. Thus in pilot projects, for the same air injection, the recovery is somewhat less than found in fieldwide cases. The extension of one of the correlations to pilot dry in-situ combustion projects shows that the correlation parameters used to predict field scale recovery appeared to be reasonable as correlating parameters for dry pilot projects. (ERA citation 06:021570)