Engineers monitor a flare stack at a wellsite. Photo by Shutterstock/think4photoop
ExxonMobil is taking fugitive methane emissions seriously with a program designed to lower the volume of the greenhouse gas that is released from the company’s production and midstream sites across the US.
The program, launched in September, prioritizes actions at US sites operated by the company’s shale-focused subsidiary XTO Energy. The effort includes phasing out high-bleed pneumatic devices, research into new technologies designed to detect and reduce facility emissions, staff training, and a leak detection and repair program.
“We are implementing an enhanced leak detection and repair program across our production and midstream sites to continually reduce methane emissions, and are also evaluating opportunities to upgrade facilities and improve efficiency at both current and future sites,” XTO President Sara Ortwein said in a press release.
The program goes beyond measures required by federal and state laws and represents a substantial move by Exxon — the largest natural gas producer in the US — to set a higher bar for the entire industry.
The multi-pronged approach to reducing methane emissions begins with a focus on the wellhead and associated midstream infrastructure; The leak detection and repair program requirse every XTO division to survey production and midstream sites with optical gas imaging camera technology for leaks. Data collected by these surveys will then analyzed for frequency, trends and patterns with facilities and equipment that are found to be more prone to leaking becoming top repair priorities.
XTO is also starting a three-year plan to phase out the use of 1,250 high-bleed pneumatic devices across its US operations. The valves, which are typically found at older sites, are designed to periodically vent pressure buildup to maintain safety, system integrity and efficient operations. The ones considered ‘high bleed’ vent more often and at higher volume
The practice of addressing the most leak-prone equipment and high-bleed pneumatic devices first suggests that XTO’s program could yield notable improvements early on. That’s because the largest portion of methane emissions appears to come from a small number of sources, in much the same way that a small percentage of older cars is responsible for the largest share of automotive-exhaust pollution, according to a 2014 study published by the University of Texas and the Environmental Defense Fund, with participation from Exxon.
The new program also calls for managing planned events in ways that are designed to reduce the release of methane emissions into the atmosphere. For instance, field personal will now monitor and remain nearby during the manual liquid unloading process at well sites to close off all wellhead vents to the atmosphere. Liquid unloading is a process that involves removing liquid that has collected in equipment tubing and prevents natural gas from flowing up through the well.
In addition, a training effort focused on management approaches to overall fugitive emissions is being launched and will consider topics like pneumatic device integrity, leak detection and repair practices, and the sharing of best practices across the company.
XTO will also continue its practice of using green completions to minimize methane emissions at wells during the completion process by capturing or burning off flowback emissions instead of venting them into the atmosphere. It is also working to minimize the need to burn off or flare this gas by maximizing gas capture via pipeline, although some flaring will still happen at new developments where infrastructure investments are contingent on successful hydrocarbon development.
West Texas and New Mexico
XTO has already begun putting some of these practices to use in prolific fields in West Texas and New Mexico. Last year, the company completed a pilot project in the Midland Basin that tested new low-emission designs that use compressed air instead of natural gas to operate the pneumatic equipment that helps to regulate conditions such as level, flow, pressure and temperature. It said the results demonstrated the feasibility of using similar designs for new and existing central tank batteries to further eliminate methane emissions.
The company is also collaborating with ExxonMobil Upstream Research Company and third-party equipment manufacturers to develop state-of-the-art, low-cost, minimum-emissions equipment that could be used for future developments, particularly in the Delaware Basin. Parent company Exxon is also participating in a methane measurement reconciliation study with the Department of Energy’s National Renewable Energy Laboratory, and supporting research underway at Harvard, the University of Texas Energy Initiative, and Stanford University’s Natural Gas Initiative.
Exxon’s expanded commitment to the environment comes as the company is facing an environmental legal battle in California. In July 2017, seven coastal communities filed suits in their local Superior Court systems alleging greenhouse gas emissions caused by Exxon and 17 other energy companies contributed to a warming planet, leading to coastal flooding, beach erosion and rising infrastructure costs. New York City followed California’s lead in January by filing its own lawsuit against the oil major and four other fossil fuel companies that seeks billions in damages to fund “climate change resiliency measures that the city needs to implement.”
Exxon’s Vice President of Public and Government Affairs for Suzanne McCarron addressed these global warming concerns in a January post on the company’s Energy Factor blog, saying “We believe the risk of climate change is real and we are committed to being part of the solution. That is why we have invested $8 billion since 2000 on energy efficiency and emissions reduction.”
In the meantime, the effort by these governmental bodies to wring money from the oil supermajor may ultimately be distracting from the bigger, overarching challenge we all face — that of securing energy to power a hungry world while coming up with technological solutions to reduce the risks posed by climate change.
The methane emissions reduction effort represents a step in the right direction for Exxon and serves as the latest indication that momentum to develop more sustainable oilfield practices is building across the industry.