Application of Risk Control Technology in CNPC Sichuan-Chongqing Region of High Sulfur Gas Field

This paper introduces two advanced technologies: 1) a controlling and monitoring system used in ground measurement and 2) a quantitative risk evaluation of high sulfur gas development under complicated 3D topographic conditions. Both of these technologies have been successfully used by the China National Petroleum Corporation (CNPC) in pipeline projects located in high sulfur gas fields. Overpressure safety release technology, emergency shutdown (ESD) technology, as well as the formation fluid hydrogen sulfide real time processing technology—were all used to assure a high level of security control. CNPC used real time monitoring of hydrogen sulfide content and real time image information to detect and transmit information by wired and wireless means via their monitoring system. A quantitative calculation method was used to determine the concentration and diffusion of hydrogen sulphide based on a 3D terrain model. This diffusion model helped eliminate the probability of a blowout incident and the probability of receptor lethality in the blowout of a sour gas well. It helped determine acceptable levels of individual risks, which were transferred to a determination of risks at a regional level. By introducing these two technologies, this paper provides new means to assure high sulfur gas fields safety.