Revolutionizing Liquid Unloading in Gas Wells: Maximizing Production with Self-Agitating Chemical Sticks

Abstract During a well's initial operation, high gas pressure and velocity lift water naturally. As the well ages, reduced pressure, and velocity cause water to accumulate, creating hydrostatic pressure that eventually blocks gas production. To resume gas flow, removing the accumulated water is essential. Many removal methods are costly and energy intensive. This paper presents a detailed analysis and evaluation of the technical performance of self-agitating chemical sticks, specifically designed for liquid unloading in gas wells. The operation of self-agitating chemical sticks is based on a reaction between a foam stick and an acid stick. This stoichiometric reaction generates N2 gas, leading to foam formation that lowers the hydrostatic pressure within the gas wellbore. Laboratory evaluations of these chemical sticks, including their unloading efficiency, solubility and the impact of condensate presence were conducted under various simulated conditions at different temperatures and salinity levels. Laboratory evaluation confirmed the superior performance of the self-agitating sticks. The unloading efficiency under various temperatures and salinity levels indicated that the chemical sticks were more efficient at high temperatures above 85°C, where the reaction between the foam stick and acid stick became more vigorous, unloading more than 50% of water under simulated conditions. However, salinity did not significantly affect the performance of the chemical sticks, indicating that they can be applied at any salinity level in the well. The presence of condensate was also tested at various levels, and the results indicated that the performance of the sticks is not significantly affected if the condensate level does not exceed 50% of the well. Solubility tests showed that the chemical sticks can dissolve completely without debris, even at low temperatures. This broadens the potential application of the sticks under any conditions in a gas well. The Self-agitating chemical stick presents a unique character as the gas produced from the reaction between foam sticks and acid sticks is N2 gas compared to typical gas produced by other foam sticks and gas sticks, which is CO2 gas. CO2 gas can alter the pH of the liquid in the wellbore to acidic, increasing the risk of corrosion in the casing and production tubing. Hence, the liquid unloading through the foam formation from the self-N2 gas-generating stick will reduce the risk due to the inert nature of the N2 gas.