Oil displacement efficiency, as an integral part of the recovery factor, is a very important input in reservoir modeling and simulation. Reliable field production prediction results largely depend, not only on simulation efficiency, but also on the quality of the input data obtained from laboratory tests. This article focuses on enhanced laboratory methods for determining oil displacement efficiency. For more adequate test results, different ways of improving upon conventional laboratory flow tests on low-permeability and complex reservoirs core samples are presented.
Analyses of the results of oil displacement efficiency obtained from flow tests on plugs of both sandstone and carbonate cores alike are presented. It is shown from the results that the characteristics of two phase fluid flow (oil and water) in the porous media of the above reservoir types are different. Further researches on core samples show that these distinctions in flow characteristics are more common in low-permeability reservoir rocks than in those of higher flow properties.
A number of factors influencing the results of displacement experiments (like core length and size, pore structure, core texture, core saturation methods used, oil samples, etc) are also considered. Some approaches designed to enhance core flow tests and produce more reliable input data for reservoir modeling are discussed.
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