Abstract
This work describes the results of laboratory experiments carried out on core samples and sandpack models as well as the field pilot tests conducted in October 2013 on 2 injection wells of Kumkol oilfield. The reduction of the permeability of porous space was achieved by injection of gellan solution, gelation of which is initiated by the following cations: Ba2+, Са2+, Мg2+, K+, Na+, containing in brine water. On the basis of laboratory experiments the suitable concentrations of polymer reagent for the pilot tests were selected. A series of laboratory experiments were carried out to reduce the amount of polymer reagent without detriment to the efficiency of the technology. Also the mixtures of polysaccharides gellan and xanthan in the weight ratios 1:2; 1:1; 2:1 were found to be more effective in comparison with separate components. One of the main features of this work is that polysaccharide gellan was used for the first time in oil industry, thus new application frontier for this polymer was found. The most remarkable feature of the proposed polymer is due to its gelation after contacting with brine water so no additives are needed to initiate the gelation process inside of the oil formation in contrast to polyacrylamide gels crosslinked by chromium ions which are widely used for conformance control operations.
