Methane, ethane, and propane sensor for real-time leak detection and diagnostics

Proposal Technical Abstract: Methane is an important greenhouse gas with a global warming potential 25-35 times that of carbon dioxide. There are many anthropogenic and natural sources of CH4, but emissions from the oil and gas industry are the largest contributor to the overall US methane budget of 650 million metric tons of CO2 equivalent. Identifying sources of methane emissions from oil and gas facilities is complicated by the sheer number of possible emission points between the well and end user. It would therefore be of great value to use advances in methane sensor technology to aid and enhance leak detection and repair. Recent field measurements of downwind plumes from natural gas leaks have found that the chemical signatures of accompanying compounds can indicate the locations of these leaks. In particular, ethane and propane are frequently co-emitted with methane, and can be used to identify the specific equipment responsible for a downwind plume. We have previously demonstrated rapid measurements of ethane and methane with high sensitivity using high resolution infrared spectroscopy. We will extend this technology to include propane, thereby creating the first high sensitivity, real time gas monitor for this species. The sensor will be able to detect methane with a 1-second sensitivity of <500 parts per trillion, and ethane and propane with sensitivities <100 parts per trillion. This will allow for high precision remote sensing of all three compounds downwind of a facility. In addition to these novel sensing capabilities, the instrument will have a reduced electrical footprint such that it can be mounted in and powered from a vehicle. During phase I we will perform spectral analysis to determine the optimal spectral region for all three compounds, demonstrate detection of all three compounds in the laboratory, and explore options to reduce the sensor size and power requirements. We will design a final sensor to be built and tested during Phase II. Commercial Applications and Other Benefits: The proposed sensor will find application in the oil and gas industry as a tool to enhance existing leak detection and repair efforts. It will also be of great interest to the methane emission research community, where mobile detection of all three compounds can be used to estimate emissions from large regions, or remotely without crossing onto facility property. Key Words: Methane, natural gas, ethane, propane, leak detection, greenhouse gas, emissions, atmosphere, remote sensing, oil and gas, climate change, global warming.