Study on Wellsite Toxic Gas Leakage and Dispersion of High Temperature High Pressure Gas Wells with High Sulfur Content

During the drilling, completion and testing of gas well with high temperature, high pressure and high sulfur content, toxic gas leakage is dangerous and may bring severe consequences. It´s important for the safety of personnel and assets to ascertain the leaking position and research the leakage characteristics. Focusing on the wellsite-scale space, this paper discussed the key position of leakage for different well procedures, and calculated the dispersion of leaked gas with the software FLUENT based on three dimension methods of computational fluid dynamics. Characteristics of toxic gas dispersion is discussed, and influence of wind speed, toxic gas components, leakage flowrate, temperature and wellsite obstacles is considered, which would help to optimize the monitoring locations. New proposal was put forward in simulation of multi-component gas disperion on wellsite, as well as in explaination of toxic gas accumulation around obstacles.