PRCI Methane Control-Related Work


Tue, January 20, 2015

January 20, 2015 —

On January 14, 2015 the White House announced a variety of initiatives directed at reducing methane emissions in the Oil & Gas sector (including oil & gas transmission). These include new standards for methane emissions from new and modified sources that will be implemented via future U.S. Environmental Protection Agency (EPA) rulemakings, additional requirements for methane fugitive leak reporting, new DOE research initiatives for increased equipment efficiencies and additional leak detection concepts, and potential regulatory constructs (via FERC) that would serve to “modernize natural gas infrastructure.” While industry groups such as the One Future Initiative and the Downstream Initiative have been formed to support the industry’s response to this situation, and of course individual operators have been taking steps to minimize methane emissions, it is important to note that the PRCI research program has a meaningful methane control component.

PRCI research projects directed aimed at methane emissions characterization and reduction are conducted by the Compressor & Pump Station Committee as fugitive emissions from compressor stations has to this point been the primary focus of EPA and state regulations. Notable projects include updating the Greenhouse Gas (GHG) emissions factors used by the EPA for estimating emissions from gas transmission & storage operations. If these factors and their usage in emissions estimations is accepted by the EPA, this would reduce the effort required by operators to conduct redundant, low value added methane leak surveys on equipment where emissions are low and relatively constant. Since 2012 operators have been required to submit GHG emissions data to the EPA, from both combustion sources and fugitive leaks. Three years of this data has been amassed and data analysis/mining is underway to evaluate whether additional emissions factors can be reasonably developed and to obtain additional insight into the dominant root source of the reported fugitives. A PRCI report “Methods to Reduce the Greenhouse Gas Footprint from Pipeline Compressor and Pump Stations” was completed and is available for purchase through the PRCI website. This catalogues the opportunities to reduce GHG emissions at compressor stations, from both thermal (CO2) and fugitive (CH4) sources. A companion report organized a consistent nomenclature for work on this topic and is a particularly useful reference for those new to this issue. While much of the compressor station technology development work in recent years has focused on NOx and air toxics reductions, it is notable that the improved combustion characteristics of most engines with retrofit NOx controls means there are fewer misfires, which is a primary cause of exhaust stack methane emissions.

Apart from these direct efforts, the entire PRCI pipeline integrity program carries a significant indirect benefit – which is to keep the product in the line. Any developments that enable operators to avoid cutouts and blowdowns, and of course avoid leaks and ruptures, keep methane out of the atmosphere. Significant efforts for remote leak detection and pipeline right-of-way surveillance contribute to the industry’s ability to rapidly respond to situations or threats that add to released methane volumes. Improved in-line inspection technologies that result in fewer cutouts and blowdowns will provide an important capability to help manage overall system GHG emissions as any new regulations are implemented. Finally, advanced repair techniques that facilitate the expanded use of composite repairs and sleeves avoid blowdowns and cutouts, as does improved feature characterization that avoids unnecessary and overly conservative repairs.

In 2015 PRCI will be developing a GHG technology roadmap that will examine, across all pipeline operations and all of its Technical Committee, what additional methods may be developed to reduce GHG emissions and improve the means to characterize and report those emissions. PRCI will be coordinating these future efforts with the various industry initiatives and individual operators who are in the vanguard for implementing cost-effective GHG emissions control.