Air

Natural gas is a cleaner-burning fuel that plays an important role in reducing greenhouse gas (GHG) emissions and other air-quality impacts from power generation and other industrial sectors. However, methane, the primary component of natural gas, is a GHG when emitted, and excessive methane leakage can partially offset the benefits of natural gas as a lower-carbon fossil fuel. Reducing methane emissions is part of SWN’s corporate strategy of operational efficiency and environmental sustainability, and we are a proponent of innovative, performance-based programs to address methane emissions. In 2017, we continued to exceed our science-based goal to maintain a 0.36 percent or less methane leak/loss rate as a percentage of gross production (for combined production and midstream operations), achieving a rate of 0.221 percent.

SWN voluntarily participates in scientific studies with regulatory agencies, academia and nongovernmental organizations on a variety of topics, including methane emissions. We provide access to SWN operating sites for research purposes, facilitating the collection of robust, real-world data and providing a clear picture of actual operating practices. These research efforts – which have resulted in more than a dozen peer-reviewed papers to date on methane emissions from oil and gas operations – are driving significant advances in science-based knowledge and technology across the industry and underpin our internal management approach and performance improvements. SWN brought this science-based approach to the Our Nation’s Energy (ONE) Future coalition, a group that SWN helped to found and that is made up of companies dedicated to reducing methane emissions across the natural gas value chain.

0.221%

methane leak/loss rate in 2017 for SWN’s combined production and midstream operations, exceeding our target of 0.36 percent

0.171%

methane leak/loss rate for production operations alone in 2017

12.5%

reduction in GHG emissions intensity in 2017

Emission-Reduction Efforts

SWN proactively implements methane mitigation technologies – including reduced emissions completions, pneumatic device replacement, liquids unloading, and leak detection and repair (LDAR) programs – well in advance of U.S. regulatory requirements. We do not have high-bleed controllers in our current facilities and do not use them in new facility design or installation.

We developed a voluntary LDAR program to find and fix methane leaks across our operations.

Our program goes beyond current regulatory requirements by including certain nonfugitive equipment sources – such as pneumatic controllers – and by addressing all potential sources, not just new sources. The elements of our LDAR program are as follows:
  • Ongoing remote monitoring: Equipment is remotely monitored for pressure, temperature and flow rate, to identify any changes that may indicate methane leaks.
  • Frequent audio, visual and olfactory (AVO) inspections: AVO assessments are conducted by field personnel at least monthly to identify leaks that have not already been identified through remote monitoring.
  • Leak detection surveys: As illustrated in the photo above, we perform instrument leak detection surveys of existing wells and compressor stations using optical gas imaging cameras or laser-based analyzers at least annually. New wells and new compressor stations are assessed within 60–180 days of commencing operation. We utilize Bacharach Hi-Flow measurement devices to quantify the emissions detected.
  • Repair and re-survey: Leaking component repairs are made immediately if practical and safe. Leaks that cannot be repaired immediately are repaired within 15 days of obtaining the replacement component or equipment. Once repairs are completed, the component or equipment is re-surveyed to confirm the leak has been fixed.
  • Recordkeeping and reporting: We track and report data on leak detection surveys to help ensure repairs are made effectively and to drive improvements in maintenance and repair practices.
  • Training: All personnel engaged in implementing the LDAR program receive initial in-house training supplemented with training by third-party experts. The training covers regulatory requirements, SWN’s LDAR monitoring requirements, and instruction in infrared (IR) camera operation. Some SWN LDAR team members have also attended FLIR® training.

99%

of our total well count surveyed for
potential methane leaks in 2017

100%

of our Midstream-operated compressor stations surveyed for potential methane leaks in 2017

100%

of identified leaks were repaired

We also avoid or minimize emissions from venting, including during planned events such as liquid unloading and blowdown. We implement the applicable U.S. Environmental Protection Agency Natural Gas STAR recommended technologies for minimizing methane venting. Similarly, flare use is limited to stand-by for upsets in the early stages of the drilling process, emergency conditions or as otherwise required by federal or state regulations.

48 billion

cubic feet in cumulative methane emissions
reductions since 2006

724,000

the equivalent number of American homes whose average annual gas consumption has been eliminated by SWN’s methane reduction efforts

Methane Reductions Achieved, by Technology1

Technologies/Practices SWN Uses to Minimize Emissions, by Operational Phase

Well Drilling
  • Catalytic converters
  • Low-sulfur diesel fuel
  • Engines that run on a mixture of diesel and natural gas
Well Completions/Workovers
  • Catalytic converters
  • Low-sulfur diesel fuel
  • Green completions and re-completions
Production Activities
  • Maintenance practices
  • Low NOx burners
  • Vapor recovery
  • Leak detection, including use of infrared cameras to identify leaks
  • Low-emitting gas lift systems
  • Solar-powered instruments
  • Intermittent-bleed pneumatic controllers
Gas Gathering/Treatment
  • Lean burn engines
  • Catalytic converters
  • Vapor recovery
  • Leak detection, including use of infrared cameras to identify leaks
  • Closed-loop systems on compression equipment
  • Flash tank vessels on glycoil reboilers
  • Air/fuel ratio controllers
Miscellaneous
  • Conversion of fleet vehicles (field trucks) from gasoline/diesel to compressed natural gas (CNG)
  • Installation of CNG refueling stations for public use
  1. SWN’s cumulative methane reductions since 2006 according to the U.S. EPA’s 2016 Natural Gas Star Summary Report