Emissions Management and Reporting: Reducing Greenhouse Gas and other Emissions
We place high importance on achieving compliance with all applicable air quality rules and regulations. We have teams that work to interpret these regulatory requirements, implement them and achieve compliance.
Overall in 2017 our global direct greenhouse gas emissions decreased by four percent. During the year, we acquired Clayton Williams Energy, which had extensive holdings in Texas. Emissions from these operations have been added in our environmental database and emissions inventory. The newly acquired assets are being upgraded to comply with our standard operating practices (SOPs), which include an audit of all facilities, analysis and corrective planning and completion of all upgrades. Notably, these new operations have contributed to a 67 percent increase in our global indirect greenhouse gas emissions (a smaller measure driven primarily by higher electricity use). As a result, our total greenhouse gas emissions intensity, measured as tons of carbon dioxide equivalent per thousand barrels of oil equivalent production, rose slightly, from 13 to 14. We anticipate that our efforts - completed and ongoing - to bring the newly acquired assets up to our operating standards will bring reductions in these areas.
Global GHG Emissions
Reducing methane emissions continues to be a top environmental priority. To minimize these emissions, we employ best management practices such as using available direct pipeline take-away access and instrument air pneumatic devices. We also control emissions and minimize flaring of gas by recovering or re-injecting natural gas and actively pursuing sufficient take-away capacity for associated produced gas. In 2017, we prevented emitting more than 2 billion cubic feet of methane through increased use of vapor recovery units in the U.S.
Methane intensity (total methane emitted expressed as a percentage of natural gas production) held steady in 2017. Intensity was .18 percent compared to .15 percent in 2016. We will continue to update this measurement in our disclosures as part of the Carbon Disclosure Project.
We continue to evolve the design of our production facilities to produce oil and natural gas with fewer air emissions, including those emissions for which there are public health standards (e.g., ozone and particulate matter). In the DJ Basin, for example, the fourth-generation Econode consolidates wellpad operations by feeding production directly into a pipeline, thereby eliminating potential VOC, NOx and particulate emission sources such as trucks, tanks and combustion equipment that reduce visibility and contribute to ozone. Use of our Gen 4 EcoNodes in the DJ Basin contributed to a reduction of more than 30 percent in our onshore U.S. emissions of VOCs, an ozone precursor, in 2017. The lessons learned from this success are now being applied to our growing Permian Basin and Eagle Ford Shale operations in Texas.
Other Actions that Reduce Emissions
- In the DJ Basin, we implemented new environmental management software that enables us to better analyze emissions data and evaluate opportunities for minimizing burner downtime, which in turn reduces VOC emissions.
- We rely on a combination of diesel and natural gas to power our onshore drilling and well completion operations. Generating power by burning natural gas results in fewer air emissions, including greenhouse gas
- Where possible, we are replacing natural gas actuated pneumatic devices with air actuated devices, thereby reducing combustion emissions .