Development of foam-breaking measures after removing liquid contamination from wells and flowlines by using surface-active substances

Abstract

The purpose is to consider the complications that arise during the operation of gas condensate wells, in particular, the accumulation of liquid contamination. Development of new approaches to improve the efficiency of the separation equipment performance of gas gathering and treatment systems when a multiphase flow enters. Development of a foam breaking method in a gas-liquid flow after removal of liquid contaminants from wells and flowlines using surfactants. An analysis was made of the complications that may arise when removing liquid contaminants from wells and flowlines using surfactants. Measures have been developed that will make it possible to timely prevent the ingress of foam into the separation equipment of gas gathering and treatment systems. Using computational fluid dynamics (CFD) modelling, an effective foam-breaking device was developed by supplying stable hydrocarbon condensate. A method to minimize the negative impact of foam on the operation of separation equipment after fluid removal from wells and gas condensate field flowlines using a surfactant solution was elaborated. A method for its breaking was proposed to prevent the flow of foam into the gas processing unit. This method foresees the application of the technological scheme layout for supplying a stable hydrocarbon condensate to a gas-liquid flow entering the separators of the first of separation, both the main line and the measuring line. CFD modelling was used to study the process of foam breaking by feeding hydrocarbon condensate into it. The influence of the hydrocarbon condensate supplying method on gas-dynamic processes (distribution of pressure, velocity, volumetric particles of phases), and the efficiency of foam breaking was estimated. It was established that the supply of hydrocarbon condensate from one branch pipe to the pipeline through which the foam moved did not ensure its complete breaking. To increase the efficiency of foam breaking, a device with designed four nozzles for supplying hydrocarbon condensate was developed. CFD modelling made it possible to substantiate that in this case, a pressure reduction zone appeared at the place of condensate supply. Because of a sharp change in pressure, a strong improvement in the effect of foam breaking occurred. The understanding of the regularities of foam breaking processes by hydrocarbon condensate was obtained, and the design of a device for the complete foam breaking was developed. The obtained results of laboratory studies have shown that a sharp decrease in the stability of the foam occurs under the condition of an increase in the volume of stable hydrocarbon condensate added to the studied model of mineralized formation water. Based on the results of CFD modeling, a device for breaking foam by stable hydrocarbon condensate has been worked out, the effectiveness of which will be confirmed experimentally and in field conditions. The results of the performed laboratory studies and CFD modelling allow a more reasonable approach to using various available methods and measures to prevent the ingress of foam with a gas-liquid flow into the separation equipment of gas gathering and treatment systems. This approach makes it possible to develop new effective ways and measures to prevent this complication. Based on CFD modelling, it was found that when a stable hydrocarbon condensate is supplied into a gas-liquid flow, foam breaks. A method for breaking foam in a gas-liquid flow has been developed, which is original and can be introduced in practice.