In-situ combustion pilot basic design and laboratory experiments

Abstract

When it must be decided to develop a field with an enhanced oil recovery method, first it is needed to have a reservoir characterization model of high quality. Then the choice of the best suited method has to be carried out. For any method, a preliminary study has to be performed in order to help to decide. In the case of an in-situ combustion field development, various patterns are considered; at the same time, duration for the combustion front to move from the injector to a producer is analyzed. Field examples of various patterns are presented. The amount of air to inject in case of dry combustion and of air and water in case of wet combustion has to be determined in order to design air compressors and water pumps. The amount of air is a function of the volumetric sweep efficiency and of the oil and the matrix from the reservoir. Lab experiments must be performed in the reservoir matrix with the reservoir oil to determine the air requirement, which is the amount of air needed to burn a unit volume of reservoir. The amount of water is also determined by lab tests. Then the flows of air and of water are determined, which allows the design of compressors and pumps. The amount of oil produced is calculated taking into account the sweep efficiency in the different zones in front of the combustion. Production of oil, water and gas and their compositions obtained at the lab scale are presented. A scheme of the production, treatment and storage for a pilot field test is shown. In conclusion, a diagram shows the general guidelines for the preparation and implementation of field experiments using in-situ combustion.