Continuous methane emission sensors could help the oil and gas industry more effectively limit unintended leaks, and the University of Texas at Austin is spearheading a project to evaluate the technology's viability and durability.
Project Astra will test various sensor technologies on Permian Basin oil and gas sites in West Texas and assess the amount of expected and unintended methane emissions in the area, according to David Allen, the project's lead investigator and director of the university's Cockrell School of Engineering's Center for Energy and Environmental Resources. Once researchers collect their data, they plan to create a network of sensors that could be deployed on a wide scale to constantly monitor the greenhouse gas emissions from oil and gas operations.
The university is working in conjunction with the Environmental Defense Fund, ExxonMobil, Pioneer Natural Resources Co. and the Gas Technology Institute on Project Astra, according to a news release. The industry has faced increasing pressure to limit methane emissions, which have a significantly stronger climate-warming effect than carbon dioxide.
Stages of Project Astra
Allen's team has worked on measuring, characterizing and modeling methane emissions for a decade, seeking to quantify the industry's emissions, which often stem from unlit flares and equipment failures.
"The end goal is to demonstrate this new type of emission measurement," Allen said in an interview. "We don't want to do this just as an academic experiment. We want to demonstrate something that could be potentially broadly deployed in lots of different areas."
Many of the new methane-sensing technologies have been tested in limited settings so Project Astra will determine how well and reliably they operate in the field for an extended period of time, Allen said. Depending on when the coronavirus threat subsides, the team hopes to begin testing and comparing sensors on oil and gas facilities owned by partner companies this summer.
The group will pick a region in the Permian that encompasses about 1,000 well sites and midstream facilities to deploy a sensor network in late 2021 that is fully operational by early 2022. Nearer term, researchers intend to create a "digital twin" simulation of the normal and unintended emissions in the test region by the end of 2020. Using the simulation, the team can determine where to place different types of sensors to design the sensor network.
'Next level of emissions sensing'
The industry now uses various measurement practices, from satellite-collected data to sending field personnel to sites. The sensor network Project Astra is assessing could prove to be more useful and efficient than current emission-detection methods, which offer only one-time measurements rather than continuous data, Allen said.
"In this case, what you're doing is you're trading off the costs of operating a network of sensors against not having to send out an operator to every single site with a very low probability of finding anything," Allen said.
While more intermittent measurement techniques commonly in use today may only measure methane emissions four times a year, an autonomous sensor might allow companies to record emissions data four times an hour, according to Ben Ratner, senior director with the Environmental Defense Fund. In the coming months, the environmental group hopes that the project identifies the "most promising technologies that can offer rugged and reliable methane detection in a stationary, fixed deployment," Ratner said.
"The success of this project depends on wide-scale deployment and use of these sensors to drive down emissions in a major way," Ratner said. "Technology is at the heart of a good methane regulation, so we want to support a virtuous cycle of stronger and tighter regulations that use and advance better, faster, cheaper technologies."
Dave Holland, Pioneer's senior director for environment and sustainable development, said Project Astra was a great opportunity for the Permian oil and gas producer to learn about cutting-edge technology. The company surveys emissions with flyovers a few times a year, but continuous, on-site methane sensors are the "next level of emissions sensing," Holland said. A network of sensors could help employees react faster to leaks as well.
"Right now, flyover seems to be the most operational for us as far as being able to cover a large area, but those are still just a snapshot in time," Holland said. "We may do those once, maybe twice a year, but ultimately to really cut down on our emissions to the point we hope to get to some day, we really need to get to something that's more continuous, more real-time."
Sensors could help minimize some of those emissions while keeping more product in the pipes and could help the industry improve its reputation with the public when it comes to venting and flaring practices, Holland said. Methane is a potent greenhouse gas, and while it has a shorter atmospheric life than carbon dioxide, methane's global warming potential far exceeds that of CO2. When burned, natural gas releases less CO2 than coal, but in uncombusted form, natural gas is predominantly composed of methane.
"If we're not keeping our emissions down below certain levels, then the efficiencies that we're gaining from natural gas over coal kind of go away," Holland said. "So, we've got to keep our emissions down and protect the environment."
Project Astra represents an example of the industry "investing in innovative programs to reduce emissions and improve the efficiency of their operations," Emily Smith, spokesperson for the American Petroleum Institute, said in a statement. The oil and gas sector has also invested in initiatives, such as the Environmental Partnership and the Texas Methane and Flaring Coalition, aimed at reducing its environmental impact.