This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 205166, “Deployment of Methane Detection and Quantification Technologies,” by Noor A.A. Talip, Mohd H.M. Pikri, and Shahrul A.Z. Abidin, Petronas, et al. The paper has not been peer reviewed.
In supporting the energy transition, a need exists to improve accurate quantification and reduction of methane emissions and determine long-term reduction targets to drive the competitive advantages of natural gas as a low-carbon fuel. The complete paper reviews an initiative taken to measure baseline data for methane emissions for gas-processing facilities and gas-transmission and regasification units through the use of accurate measurement tools and methodologies.
A methane quantification tool has been developed in-house by Petronas, with two of the operator’s business units as the first users. Methane emission is quantified based on methane sources listed in the Oil and Gas Climate Initiative Guidelines. The quantification covers the following methane-emission sources based on applicability to sample plants:
- Unintended release (fugitive leaks, loss of primary containment)
- Intended release (venting and flaring of hydrocarbon, stationary combustion, compressor seals, and pneumatic controls and pumps)
Methane-emission volume from fugitive leaks, compressor seals, and pneumatic devices had not been quantified accurately by the operator until before the development of its methane-quantification tool. Much of the complete paper is dedicated to describing methodologies used to detect and quantify methane emissions; this synopsis identifies those methodologies but directs the reader to the complete paper for fuller discussions thereof, as well as equations used in those methodologies.
Fugitive Leaks. Global fugitive-emission standards for quantification are nonbinding, regardless of regulations or policies. Nevertheless, the oil and gas industry is still working to develop regulations for methane-emission measurements for effective monitoring and, ultimately, setting the targets for emission reduction. The choice of methods to estimate emission depends on how the estimates will be used and the degree of accuracy required. Methods using site-specific data from direct measurement are preferred. Table 1 of the complete paper shows the fugitive-emission-quantification methodologies sorted into inclining order with respect to accuracy.
The methodology-complexity level can be depicted per the terminology in Fig. 1. The five methods are described by the authors, and detailed in the complete paper, as the following:
- Method 1: Facility-/plant-level average emission factors
- Method 2: Equipment-level average emission factors
- Method 3: Device-component-level average emission factors
- Method 4: Alternative-leak/no-leak emission factors for optical-gas-imaging technologies
- Method 5: Screened value correlation approach