Recovery Correlations for In-Situ Combustion Field Projects and Application to Combustion Pilots

Abstract

This paper presents two correlations developed to predict the fieldwide oil recovery of dry in-situ combustion processes. The correlations are based on a combination of engineering and statistical approaches. This work also discusses extension of the second correlation to pilot projects and concludes that correlation parameters used for fieldwide projects seem reasonable for use in pilot projects. Introduction During the last three decades, the injection of heat-bearing fluid into a reservoir has gained considerable usage as an enhanced oil recovery mechanism. Crude oils with low API gravity and high viscosity do not respond satisfactorily to conventional recovery processes. Since oil viscosity is highly temperature dependent, the performance of these reservoirs can be improved significantly by raising the reservoir temperature through the addition of heat. In-situ combustion is one of the processes that can increase oil recovery through heat addition. Oil recovery predictions for in-situ combustion projects would provide a basis for calculating air-injected/oil-produced ratios (AOR's), oil rates, oil recovery, and economic limits. There is a possibility that such predictions could be achieved by describing the movement of heat and fluids analytically, and such approaches have been tried; however, no analytic model has been developed that completely describes the movement of heat and fluids.1 Numerical modeling has been an alternative way of describing in-situ combustion; however, due to the complexities of the process, the multidimensional geometry, and the cost of running the more complex models, no approach to recovery prediction has been entirely satisfactory. It appeared that the solution to this dilemma was to attempt to correlate field results. Our approach was to base our correlating parameters primarily on those terms that occur in heat and material balances of combustion and only then to add additional variables on a purely statistical correlation basis. Although some screening guides2–6 in the literature attempt to define which projects may be successes or failures, these guides make only a yes/no evaluation or apply only to certain fields. Therefore, there is a clear need to develop a simple model to predict the oil recovery to be expected from in-situ combustion.

In-Situ Combustion Handbook -- Principles and Practices

“…Oil recoveries in the field are much lower than laboratory oil recoveries due to lower horizontal and vertical sweep efficiencies. Graphical correlations have appeared in the literature to estimate oil recovery (Brigham et al, 1980). These correlations may be used in preliminary design work.…”

“…Several authors have presented procedures to engineer an in-situ combustion project (Nelson and McNeil, 1961;Gates and Rarney, 1980;Brigham et al, 1980;Fassihi et al, 1981;Naji and Poettmann, 1991). These were developed based on reported field performance data.…”

“…Satman and Brigham (Satman et al, 1981;Brigham et al, 1980) correlated the injection production history from 12 dry combustion projects and presented two correlation to predict the field wide oil recovery of dry in-situ combustion process. They developed an analytical model describing the heat transfer processes and movement of the steam plateau ahead of the combustion zone.…”

Reservoir Characterization, Production Characteristics, and Research Needs for Fluvial/Alluvial Reservoirs in the United States

“…The ICPM predicts oil recovery for in situ combustion projects based on the correlations developed by Brigham et al (1980). These correlations relate the volumes of oil burned and produced to the volume of air injected and the reservoir volume based on the analysis of the results of 12 field pilot tests.…”

Laboratory screening tests on the effect of initial oil saturation for the dynamic control of in-situ combustion

“…Thus, while the successful candidates, determined through laboratory-scale experiments, can give very promising results, the full-field application in general results in with unexpected outcomes [26]. Accordingly, there are only a few currently active and successful full-field-scale ISC projects [27].…”