Semester of Graduation
Master of Science in Petroleum Engineering (MSPE)
Craft and Hawkins Department of Petroleum Engineering
The mass transfer of a dissolved gas evolving to return to the gaseous phase from a liquid is governed by many parameters. This process affects the development of an oil and gas well due to the possibility of gas contamination occurring from either an influx entering the wellbore, or drilling through gas-bearing formations. Once this dissolved hydrocarbon gas circulates up the wellbore, it will begin to evolve from solution and poses a potential risk to drilling equipment, the environment, and personnel at a drilling rig. Being able to predict the behavior of gas desorption based on a known set of variables for a specific fluid/gas combination is critical. In this study, we investigated how changing the starting saturation pressure and fluid type have on the mass transfer coefficient for nonaqueous-based fluids commonly used in drilling operations.
The work in this thesis summarizes multiple investigations of these variables which affect the desorption kinetics and relate them to processes involved with well control operations. By designing and utilizing a custom apparatus, we have studied the desorption behavior of two different types of fluids in their pure form and each as an emulsion with water. During our preliminary testing and experimental development, it was determined that the starting pressure that the fluid had been saturated with methane at and the rate at which we allowed the fluid to desorb, through a pressure drop, had the most significant effect on the mass transfer coefficients of desorption. We observed strong relationships between the starting saturation pressure and oil/water ratio in emulsion fluids for the calculated mass transfer coefficients. These observations allow us to predict the coefficient at expanded pressures and different oil/water ratios. This study will lead to the development of more accurate models that will better predict the behavior of gas desorption from nonaqueous fluids for enhancing well control operations.
Nielsen, James Lee Jr., "The Desorption Kinetics of Methane from Nonaqueous Fluids for Enhanced Well Control" (2020). LSU Master's Theses. 5054.