Professionals of the TATNEFT Company’s TatNIPIneft R&D Institute have developed an efficient technology that allows enhancing crude oil recovery.
The technology of steam gravity drainage with application of a thermal gel composition (TGC) allows improving the crude oil recovery from shallow deposits of high viscosity oil (HVO).
The TGC technology is predominantly implemented through horizontal production wells (implementation is also possible through horizontal injection wells) by pumping gel-forming compositions developed by the TatNIPIneft Institute’s Department for reservoir enhanced oil recovery.
New gel-forming compositions based on polymers of different nature and a combination of cross-linking agents possess improved structural and rheological characteristics in the temperature range from 20 to 150°C controlled by gelation time, thermal stability, as well as the specified parameters on the working solution filterability, depending on the reservoir oil/water saturation. This ensures maximum selectivity of the treatment.
The most important technological properties of polymer compositions, inter alia, include the ability to form a gel with a high shear gradient of at least 2 MPa/m; the possibility of forced destruction through the exposure to concentrated solutions of acids or peroxide compounds.
The change in concentration and the gel components composition ratio allow adjusting the working solution viscosity, its structural strength and thermal stability.
The cumulative current technological effect since the beginning of the technology testing at the production wells of the NGDU Nurlatneft and the NGDU Yamashneft has amounted to 37,268 tonnes. The specific technological efficiency is 932 tonnes per well/operation over the treatment period to 12 months.
The economic effect of the TGC technology is achieved at the account of the of HVO additional production.