Tatneft Implements New Enhanced Oil Recovery Technologies

February 24, 2014

The technology of controlled carbonate reservoir flooding through combined effects of sedimentation and gel-forming compositions (GEOS-K technology) is successfully implemented at Tatneft Company to increase the recovery factor of the carbonate reservoirs.

The technology developed by the experts of TatNIPIneft is applied at the late stage of developing deposits represented by permeability-wise heterogeneous carbonate reservoirs. The proposed method combines multiple mechanisms of impact and is carried out by injection into the injection wells of the sedimentation and gelling composition which is a cross-linked cellulose ethers and alkaline/polymer based composition.

The high strength gelling composition with a pronounced adhesion to the reservoir rock is used to block large fractures. This is necessary to preserve the isolating properties under the periodical change of the fractures size.

Following the treatment with the gelling composition the injection of the movable alkaline/polymer composition is performed. The presence of an alkaline agent results in hydrophilizing the surface of reservoir rocks, which were earlier not involved in the development. This in turn, together with a mechanism for in-situ formation of a surfactant improves the separation of oil from the rock and improves its mobility.

The advantages of the engineering development include the use of inexpensive domestic production reagents, possibility of using both fresh and saline waste water for the preparation of compositions, as well as possibility of implementation in any climatic conditions and high technological efficiency. The technological effect duration is up to 2 years.

Source: Tatneft