The geological, economic, and strategic conditions which make the discovery of large petroleum reservoirs a more risky and costly undertaking has resulted in having to consider mature fields and to conclude that the geology and the properties of fluids have an incidence in the final recovery of each reservoir, and that by understanding these factors it is possible to improve the recovery factor. The Lisama Field is located in the basin of the Middle Magdalena Valley, in Colombia, and is operated by ECOPETROL S.A. It is characterized by a complex of fluvial channels with thicknesses of between 10 and 20 ft, a restricted lateral continuity, lateral and vertical changes in the type of rock and depleted producing sands; this resulted in the need for new exploitation strategies which would allow the optimum recovery of the remaining reserves of the field. From a technical screening based on the properties of the rock, fluids, and the reservoir, the review of analogue fields worldwide and the experimental feasibility evaluated in the laboratory, the implementation of a water injection process resulted in a favorable method to be applied to the Lisama Field.
Geological, petrophysical, fluids, and production information was integrated during the identification and selection of areas and stratigraphic intervals with the best characteristics for the implementation of the water injection process. Zone Quality Factor maps, isochors, average thickness and percentage of sand tied to stratigraphic correlations and reservoir rock-type thickness maps were analyzed to obtain the spatial distribution of the more powerful, continuous channels, with more effective pores systems, which, integrated with the production analysis, resulted in the delineation of the areas of interest.
The prediction of the behavior of the water injection and the expected recovery of oil was obtained by means of an analytical and numerical simulation of the injection patterns as established.