Methane Emissions Management

Occidental's ongoing efforts to capture methane emissions under the Environmental Protection Agency's (EPA) voluntary Natural Gas STAR Program have helped to reduce GHG emissions from our oil and gas operations. Occidental has implemented a broad spectrum of projects that reduced cumulative estimated methane emissions by more than 16.5 billion cubic feet from 1990 through year end 2015. This corresponds to almost 8.3 million metric tons of CO2 equivalents, which, according to EPA emission factors, is the same as the annual emissions from 2.4 coal-fired power plants.

State and Federal Regulation of Oil and Gas Operations

There are many state and federal regulations that address the emissions of methane from oil and gas operations.  Occidental, like many other companies in the upstream segment, continues to work diligently to comply with these rules.  Among these are recent Environmental Protection Agency (EPA) rules to control emissions of volatile organic compounds (VOCs), including methane, from new hydraulically fractured gas wells and from oil wells. The final rules, known as New Source Performance Standards – Subpart OOOO/OOOOa, rely on proven technologies and best practices that are in use today to reduce methane and VOC emissions from oil and gas operations, including hydrocarbon storage tanks, equipment/compression leaks and pneumatic controller emissions.  In the development of these regulations, EPA recognized that it is not possible to capture and sell all low volume gas streams. Flaring is the preferred control technology for emissions of VOCs and methane.

Operational and Emissions Control Enhancements

Occidental has an ongoing effort to maintain and improve the reliability of the equipment and facilities used in its oil and gas activities. Occidental employs cutting-edge technologies and processes to contribute to the decline in methane emissions. Among such efforts are:

  • Adopting lower emission thresholds to eliminate leaks and to repair connections (e.g., valves, flanges, pump seals).

  • Adopting "green completion" practices to capture gas at the wellhead during well completion and prevent its release to the atmosphere.

  • Replacing diesel generators and engines with electric drives, where feasible.

  • Installing air supply systems to control instruments, rather than using natural gas controls and instruments.

  • Installing Vapor Recovery Units (VRUs) to capture and recover gas from certain equipment, rather than venting to atmosphere.

  • Adopting better control devices (e.g., low-bleed or no-bleed pneumatic valves) to reduce methane emissions.

  • Adopting cutting edge monitoring systems to help identify and eliminate sources of fugitive emissions.

Infrared (IR) cameras use the infrared spectrum to visually identify possible emissions leaks. Equipment exhibiting possible leaks identified by IR cameras are further inspected and components are repaired or replaced, as appropriate. The IR camera approach is being used in Occidental's oil and gas segment to monitor fugitive emissions on equipment and components such as pneumatic valves, plunger lift systems, storage tanks, compressors, glycol dehydrators and similar components, especially where the equipment or components are geographically dispersed or difficult to access. 

Flaring

In its oil and gas business, Occidental strives to minimize flaring of natural gas by bringing natural gas to market. Methane, the major component of natural gas, is a clean-burning fossil fuel and has 40-percent lower greenhouse gas emissions relative to coal. Occidental devotes significant resources to capture emissions of methane and other organic compounds, both in design and construction of new facilities and in retrofitting existing facilities. However, in upstream oil and gas operations, gas streams are flared for safety reasons when gas processing plants have planned shutdowns or during turnarounds, enabling inspections, repairs and maintenance activities that cannot occur during operation to be performed safely.

Historically, Occidental's oil production operations in the Arabian Gulf offshore in Qatar were the largest source of gas flaring in the company's operations.  The co-produced natural gas, which is owned by Occidental's partner, Qatar Petroleum, was flared because there was no domestic or export market for the gas. Occidental of Qatar (Oxy Qatar), with the active support of Qatar Petroleum, has implemented significant projects at the Idd El Shargi North Dome field to reduce flaring. These efforts have included capturing a substantial portion of the produced gas and shipping it to Mesaieed for treatment and use by Qatar Petroleum as a feedstock or fuel, reinjecting it for enhanced oil recovery and using it to generate electricity for Oxy Qatar's operations. Oxy Qatar has successfully reduced flaring emissions by more than 98 percent since 2005 and continues to work at reducing flaring. In 2015, Oxy Qatar reduced flaring volumes by 19 percent compared to 2014, and reduced non-routine flaring by 35 percent as part of an overall initiative to reduce flaring.