Oil and gas giant ExxonMobil has proposed a voluntary framework for the offshore industry to regulate its methane emissions.
The Model Regulatory Framework focusses on methane emissions in upstream operations. However, it says some of its mitigation proposals “could be applicable to emission sources […] such as distribution and storage”.
It also says emissions should be considered in the design of new facilities and in documentation.
ExxonMobil chairman and CEO Darren Woods said: “We offer this blueprint to companies across our industry as they consider how to make improvements to reduce the sector’s methane emissions.
“Our industry has developed high-tech advances to curb emissions, and we also hope this framework will be helpful for governments as they develop new regulations.”
The framework is based on the company’s own methane regulations. These focus on detecting leaks, minimising venting, actively controlling equipment and better record keeping.
Its proposed model looks at three areas prone to emissions and suggests a path forward for the industry.
Equipment to contain methane
The company proposes offshore operators have a detection and repair programme for leaks, with surveys repeated at least once a year. However, it asks regulators to consider whether low-producing wells should be exempted from this.
The framework says valves, screwed connections, flanges, pump seals and open-ended lines are frequent causes of “fugitive emissions” which go undetected. It calls on regulators to consider listing equipment to be considered.
Other pieces of equipment are known methane emitters, but ExxonMobil suggests changes to these.
It encourages companies to eliminate pneumatic pressure regulators that constantly release methane and replace components in piston compressors at least every three years. Capturing and using methane is suggested for storage, in pumping, or when releasing pipeline pressure.
At the wellhead, methane can escape when gas wells manually unload liquids to clean out the well. The framework proposes these manual unloadings are better supervised to prevent venting methane.
It suggests documenting these, as well as several other processes, to improve methane emissions reporting.
In hydraulic fracturing (“fracking”), the company says gas which escapes during completion should be collected and used. It says this can be done by using reduced emissions completion procedures and separators.