Recent regulations introduced by the Environmental Protection Agency (EPA) requires periodic leak detection surveys using optical gas imaging for petroleum and gas system facilities constructed on or after September 18, 2015. Numerous new technologies including satellite, airplane, drone, and ground-based fixed sensors demonstrate potential for providing quicker detection and detection at scale. However, minimal research has been conducted to systematically compare and quantify the methane reduction and the economic viability associated with the new detection technologies. Our study evaluates multiple technologies as potential applications for leak detection and repair (LDAR) programs, utilizing numerical simulation methods to quantify the methane reduction. Employing high-performance computing techniques and parallel algorithms, we performed probabilistic emission simulations and determined optimal emission detection strategies for oil and gas system facilities.
By analyzing the total emission rate across the simulated gas field, we identified two stages of time series data for methane emissions — an emissions creation stage and an emissions reduction stage. During the former, the volume of emissions is determined by the total number of components across the field and the rate of fugitive emissions. During the emissions reduction stage, the detection threshold of each technology and the frequency of deployed surveys determines the amount of emissions reduction. Conclusively, we combined the emissions reduction and survey frequency data for each technology, to allow for more informed decisions on optimal methane detection technology.
Oil and gas production operations involve drilling, extracting, storing and transporting oil, gas, and condensates. The U.S. EPA identifies oil and gas operations to be an important source of greenhouse gases such as methane and carbon dioxide. According to the US EPA Greenhouse Gas Inventory approximately one third of the of the 2019 total national methane emissions, a potent greenhouse gas, is emitted from petroleum and natural gas systems.
Emissions from oil and gas operating sites could be classified into two different categories. The first category would be intended emissions also referred to as process emissions, emitted from oil and gas equipment such as pneumatic devices and pressure relief valves and from emergency release of gas for safety reasons. The second category would be unintended emissions also referred as fugitive emissions that are emitted due to leaks from valves, connectors, malfunctioning equipment, etc. Whether intended or unintended, oil and gas operators are on the continuous lookout for solutions to mitigate emissions within their operations. With advent and availability of different types of methane detection methodologies and technologies, with different applications and effectiveness, oil and gas operators have several tools and options to choose from. However, they may be challenged with selecting an appropriate technology or combination of technologies for effective emissions reductions.