Study on the effect of cetyltrimethylammonium bromide on gas-liquid flow characteristics at low gas flow rates and gas pressure

Abstract

Cenomanian gas deposits account for about 80% of natural gas production in Russia. Today, mature Cenomanian gas fields are depleted by more than 75% on average, the reservoir pressure in the productive formation zone has decreased by almost 90% compared to the initial pressure and in some places reaches 1.0-1.5 MPa. Reduction of pressure in the pay zone leads to active intrusion of water from the aquifer. The liquid is loading the well, and gas production decreases. The technology of gas well operation with foaming agent is widespread in the world, which is characterized by a high level of efficiency, including economic. The use of technology leads to a solution to the liquid loading and requires a preliminary selection of the optimal concentration of surfactants. The optimal concentration should ensure the creation of a relatively stable foam and provide a minimum pressure gradient in the production tubing. The article presents the results of studies of CTAB foaming agent influence on the process of liquid removal and pressure gradient in production tubing. Sequential studies to determine CMC, foamability, foam stability, and pressure gradient under foam flow were conducted on small-scale and large-scale facilities. These results can be reliable when using CTAB foaming agent, foaming agents based on it, or other cationic foaming agents in Cenomanian gas wells under the condition of reservoir water inflow. Besides, the effect of pressure on the optimal concentration of the foaming agent was also studied in this work.