Gas condensate treatment: A critical review of materials, methods, field applications, and new solutions

Abstract

Recently, exploration operations for gas wells target deep reservoirs, where the temperature and pressure are very high. High temperature (more than 200 °C) and pressure (more than 5500 psi) result in degrading the complex organic molecules into dry gas or gas condensate. During gas production the reservoir pressure will decrease below the gas dew point and form a condensate bank near to the borehole. Condensate banking has been branded to cause serious drop in the gas effective permeability, gas productivity and results in formation damage. Numerous techniques have been adapted to mitigate gas condensate banking effects in gas wells. These approaches include the injection of solvents and chemicals to alter formation wettability to minimize condensate blockage. Other methods include acids injection, fracturing treatments, and drilling horizontal wells. These methods will lower the rate of pressure drop and permit the production of a single phase gas. This paper critically reviews the causes and instants of condensate banking in gas reservoirs. The developed models that capture and enumerate this phenomenon, and the most adapted mitigation techniques in accordance to the leading conditions are thoroughly discussed. The most successful agents for enhancing condensate production are reported and their effects on the condensate behavior is identified. Furthermore, novel and new technique for permanent condensate removal is presented in this paper. This review will fill the gap in the area of condensate removal treatments by critically analyzing and summarizing the techniques proposed in the literature.