Wettability alteration used for water block prevention in high-temperature gas wells

A gas flow analysis was conducted to evaluate the feasibility of a preventive chemical treatment to avoid water block formation with an aim to induce a long term wettability change. The wettability alteration is expected to increase the volume of brine displaced by gas. A mass flow controller was placed upstream of the core to measure the flowrate of the gas, and the core's gas permeability was calculated from the pressure drop across the core and mean gas flowrate in the core and mean gas flow rate in the core using Darcy's law. Three types of experiments- contact angle, imbibition, and core flow tests were conducted to test the wettability alteration produced by the chemical, the stability of the chemicals at high temperatures, and desorption and longevity of the treatment. The results show that the capillary forces are decreased and the clean-up of trapped water at low drawdown pressures is enhanced.