Study suggests offshore oil and gas production in Gulf of Mexico has higher methane loss rates than typical onshore production

Media Contact: Kelly Vaughn
Carbon Mapper Communications
kelly@carbonmapper.org
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New remote sensing methods shed light on large methane plumes from offshore oil and gas infrastructure that have previously been invisible.

August 11, 2022—Pasadena, CA—Today, Carbon Mapper released the findings of airborne observations in Spring and Fall 2021 of 151 shallow water offshore oil and gas platforms in U.S. state and federal waters in the Gulf of Mexico. Researchers found that the methane loss rate from these shallow water sources is significantly higher than typical onshore production and disproportionally contributes to climate change—providing a potential focus for sustained monitoring and mitigation efforts.

Specifically, the team calculated a methane loss rate (defined as the observed emissions normalized to reported natural gas production) of 23-66% from shallow offshore Gulf of Mexico operations compared to 3.3-3.7% reported by other studies of operations in the Permian basin. The team plans to conduct additional surveys of the broader population of plaforms in the Gulf and selected international offshore production areas with aircraft and satellites to assess overall methane loss rates.

This study penned by researchers at Carbon Mapper, University of Arizona, NASA’s Jet Propulsion Laboratory, University of Michigan, and Arizona State University is the first systematic application of a remote emissions-sensing technology that can detect methane emissions over water, and attribute methane emissions to specific infrastructure.

Offshore oil and natural gas platforms are responsible for about 30% of global oil and gas production. Despite the large share, few studies have directly measured atmospheric methane emanating from these platforms due to their remote location compared to onshore production, and technological challenges of observing methane emissions over water (the dark surface limits the sun’s reflection hindering methane measurements). These factors present unique challenges for oil and gas leak detection and repair programs and may undermine society’s ability to meet methane reduction targets such as the Global Methane Pledge. Remote sensing via aircraft or satellite—adapted for offshore conditions—may provide a powerful way to close this observational gap.

“Bottom-up estimates and gaps in observational data can result in significant undercounting of emissions from offshore oil and gas infrastructure,” said Dr. Alana Ayasse, Research Scientist with Carbon Mapper, and the University of Arizona. “This study underscores the importance of increased transparency and sustained remote monitoring in offshore oil- and gas-producing regions to inform mitigation action.”

Specific findings include:

• Many observed shallow-water offshore platforms and surrounding infrastructure exhibited super-emitter activity. Of the 151 targeted platforms and surrounding areas surveyed between Spring and Fall, 62 pieces of infrastructure had an observable methane plume (over 10 kg/hr).
• Emissions from observed offshore sources were highly persistent. The offshore sources measured in this study were over twice as persistent—meaning how frequently emissions were detected at a given location—as methane emissions from onshore oil and gas infrastructure reported by other studies. Researchers revisited many of these platforms multiple times in Spring and Fall of 2021 which provided an initial characterization of source persistence, and further observations will evaluate whether there is a long-term trend.
• Specific types of equipment were responsible for a disproportionate number of emissions. Using high resolution imaging, the researcher attributed observed emissions primarily to tanks, satellite wells, pipelines, and vent booms that were visually identifiable—showing that a small number of observable emissions sources were responsible for a majority of the methane released into the atmosphere.

The infrastructure observed were distributed evenly across state and federal waters, allowing the team to sample different regulatory structures.

“Remote sensing of methane over onshore oil and gas fields has transformed our understanding of emissions and highlighted mitigation possibilities,” said Eric Kort, Associate Professor of Climate and Space Sciences and Engineering University of Michigan. “By demonstrating these similar remote sensing capabilities for offshore infrastructure, this work opens the door to similarly impactful advances for this large and often neglected segment of the fossil fuel industry.”

Demonstrating the technical capabilities to remotely observe methane emissions from offshore oil and gas infrastructure is an important precursor to the future launch of the hyperspectral satellite constellation being developed in partnership with Carbon Mapper, Planet Labs PBC, and NASA JPL which will be able to provide more sustained and high frequency observations over wider geographic areas. Insights from emissions data captured from offshore oil and gas platforms will be increasingly relevant as global demand for liquified natural gas grows, and offshore oil and gas leases are expanded.

The imaging spectrometer used in the study, Arizona State University’s Global Airborne Observatory, is able to pinpoint methane sources to within about 15 feet (5m) while flying at 18,000 ft. When methane emission plumes were detected, researchers used a high-resolution camera to relate the plumes to individual pieces of equipment.

Download the full study: https://iopscience.iop.org/article/10.1088/1748-9326/ac8566

About Carbon Mapper

Carbon Mapper is a non-profit organization focused on facilitating timely action to mitigate greenhouse gas emissions. Its mission is to fill gaps in the emerging global ecosystem of methane and CO₂ monitoring systems by delivering data at facility scale that is precise, timely, and accessible to empower science-based decision making and action. The organization is leading the development of the Carbon Mapper constellation of satellites supported by a public-private partnership composed of Planet Labs PBC, NASA’s Jet Propulsion Lab, the California Air Resources Board, the University of Arizona, Arizona State University, and RMI, with funding from High Tide Foundation, Bloomberg Philanthropies, The Grantham Foundation, and other philanthropic donors. Learn more at carbonmapper.org and follow us on Twitter @carbonmapper.

About University of Arizona

The University of Arizona, a land-grant university with two independently accredited medical schools, is one of the nation’s top 50 public universities, according to U.S. News & World Report. Established in 1885, the university is widely recognized as a student-centric university and has been designated as a Hispanic Serving Institution by the U.S. Department of Education. The university ranked in the top 20 in 2020 in research expenditures among all public universities, according to the National Science Foundation, and is a leading Research 1 institution with $761 million in annual research expenditures. The university advances the frontiers of interdisciplinary scholarship and entrepreneurial partnerships as a member of the Association of American Universities, the 66 leading public and private research universities in the U.S. It benefits the state with an estimated economic impact of $4.1 billion annually.

About Arizona State University

Arizona State University’s Global Airborne Observatory (GAO) is owned and operated by the Center for Global Discovery and Conservation Science at Arizona State University. The GAO is made possible by support from private foundations, visionary individuals, and Arizona State University. ASU, ranked No. 1 “Most Innovative School” in the nation by U.S. News & World Report for seven years in succession, has forged the model for a New American University. ASU is a comprehensive public research institution, measured not by whom it excludes, but by whom it includes and how they succeed; advancing research and discovery of public value; and assuming fundamental responsibility for the economic, social, cultural, and overall health of the communities it serves.

About NASA Jet Propulsion Laboratory (JPL)

JPL is a federal-funded research and development center managed by Caltech for NASA. Since the start of the Space Age, JPL has developed and launched robotic missions to explore the solar system and beyond. NASA-JPL missions also monitor Earth from land, air, and space with a fleet of satellites and airborne and ground-based observation campaigns, collecting long-term data records that contribute to understand and protecting our home planet.

About University of Michigan

One of the nation’s top public universities, the University of Michigan has been a leader in research, learning and teaching for more than 200 years. With the highest research volume of all public universities in the country, U-M is advancing new solutions and knowledge in areas ranging from the COVID-19 pandemic to driverless vehicle technology, social justice, and carbon neutrality. Its main campus in Ann Arbor comprises 19 schools and colleges; there are also regional campuses in Dearborn and Flint, and a nationally ranked health system, Michigan Medicine. The university also boasts a world-renowned intercollegiate athletics program and has been the site of many important events in U.S. history, including JFK’s announcement of the Peace Corps, LBJ’s “Great Society” speech, and the clinical trials of the Salk polio vaccine. U-M’s alumni body is one of the largest in the world and includes a U.S. president, scientists, actors, astronauts, and inventors.