In development of hard-to-recover hydrocarbon reserves, enhanced oil recovery methods are applied on a massive scale, chemical methods being the most common ones. Each formation stimulation technology is associated with certain application conditions which depend on the initial geological and physical formation parameters and current state of its development. Methodological approach is provided for determination of permeability coefficient and coefficient of oil displacement from rock during testing of compositions of technologies of physical and chemical enhanced oil recovery methods on the basis of laboratory studies of rheological properties of various brands of acrylamide polymer. The methods have been developed according to the requirements to core analysis. The study provides a list of equipment and basic characteristics of the filtration system, as well as the procedure for preparation of working fluids and laboratory formation to laboratory study. Laboratory study of gel systems’ rheological properties is performed on the basis of the technological process for preparation of components of viscoelastic compound recipe at the wellhead and its further injection into the formation. To this end, in order to determine the rheological properties of gel systems, a special-purpose rheometer was used, with a capability to dynamically register the changing viscosity data of the tested polymer systems prepared on the analogues of fresh, produced and Cenomanian waters in “well – formation” thermobaric conditions. Based on the laboratory studies, it has been shown that trial injections of cross-linked compositions on the basis of polyacrylamide (PAA) of brands FP-107 and Ро1у-Т-101, possessing the capability of multifold increase of final viscosity of the polymer composition (by 2–3 times and more) in conditions of increasing temperature in low salinity waters (produced, Cenomanian), enable higher technological effectiveness compared to brand FP-307 polyacrylamide presently used in the company’s oilfields.
LABORATORY STUDY OF INFLUENCE OF RHEOLOGICAL CHARACTERISTICS OF CROSS-LINKED POLYMER SYSTEMS ON PERMEABILITY AND OIL DISPLACEMENT COEFFICIENTS
