On the importance of gel rigidity and coverage in a smart water shutoff treatment in gas wells

Abstract

This paper addresses a conceptual study on different aspects of a novel smart treatment method for a relatively new challenge of saline water production from low permeability lenses of high flow gas wells. Selective sealing of such lenses along with minor effect on gas productivity usually faces practical difficulties due to the inherent permeability contrast. Engineered application of salt sensitive gellan biopolymer through a smart treatment scenario that includes a protective gas flow proved its ability for treating such challenge. This paper investigates the importance of the gel rigidity and its coverage in the smart treatment scenario through considering the brine salinity and the injected biopolymer concentration. It is illustrated that during low gas flow rates, the performance of the smart water shutoff treatment is mainly governed by the aptitude of the biopolymer for covering the low permeability medium while at higher gas flow rates the importance of the gel rigidity is noticeably increased. It is concluded that for appropriate treatment, the biopolymer concentration should be determined based on the production strategy and brine salinity.