TATNEFT Apply Efficient Technologies to EOR

Pursuing the aim of enhancing oil recovery the specialists of OAO TATNEFT apply modern technologies such as EOR methods using xanthan biopolymer based composite systems ("Xanthan" technology).

The technology developed by the scientists of TatNIPIneft is applied in the Company's oil fields at the late stages of developing heterogeneous permeability reservoirs and has been designed to increase the current oil production through shutting off the watered out zones and re-distributing the routes of water injected in the reservoir.

The professionals of TATNEFT's oil and gas producing divisions achieve the results through alignment of the producing reservoir heterogeneity, as well as regulation of sweep efficiency and redistribution of the flows in the reservoir at the expense of the xanthan biopolymer based composition properties.

The technological process is carried out by injection of the gelling composition into injection wells, which is a xanthan exopolysaccharide based composition consisting of a microbial origin biopolymer and cross-linking agent.

The advantages of this technology include the use of solutions and gelling compositions resistant to mineralized water impact, as well as their resistance to shear deformations and biodegradation. The injected xanthan based injected compositions are characterized by low filtration resistance during migration in a porous medium up to the moment of gellation and after the gel is formed the filtration resistance of the isolated substratum increases hundreds of times. The low cost of the injection process and the high technological efficiency provide for high profitability of this development work.

An important advantage of the "Xanthan" technology is the environmental safety of the method. The biotechnologically produced polymer has no adverse impact on the environment.

The average increase in production rate of crude oil since the beginning of the commercial technology application has amounted to 3 tons per day. The technology of enhancing crude oil recovery by injection of biopolymer compositions has been protected by RF patent No.2347897 belonging to OAO TATNEFT.