Technical Screening Guides for the Enhanced Recovery of Oil

ABSTRACT The technical screening guides which are used to select enhanced oil recovery methods are described. The background and logic behind the various criteria are covered, and a brief description of each method is included. Economics are discussed, but the emphasis is on the technical guidelines. A distinction is made between the oil properties and reservoir characteristics required for each process. Generally, steamflooding is applicable for viscous oils in relatively shallow formations. At the other extreme, CO2, nitrogen, and hydrocarbon miscible flooding work best with very light oils at depths great enough for miscibility to be achieved. Both steamflooding and in-situ combustion require reservoirs of fairly high permeability. Chemical flooding processes (polymer, alkaline or surfactant) are applicable for low-to-medium viscosity oils where depth is not a major consideration. However, at great depths, the higher temperature may present problems in the degradation or consumption of some of the chemicals. Current values of the technical screening guides for the more common enhanced recovery procedures are given in tabular and graphical form. By the use of a simple graphical technique, it is shown that there is a complete spectrum of enhanced oil recovery methods available for all oils, ranging from the very lightest to the heaviest oil or tar sand.