Process Controller Tagging and Methane Quantification
Trihydro supported an upstream oil and gas operator in Colorado with a large-scale process controller tagging, monitoring, and methane quantification program to meet greenhouse gas reporting and emissions intensity requirements. The operator needed defensible, facility-level emissions data to support reporting under EPA Mandatory Reporting Rule (MRR) Subpart W (Subpart W) and the Colorado Department of Public Health and Environment’s (CDPHE) Operator Greenhouse Gas Intensity Program while improving confidence in their existing process controller inventory.
The upstream operator had an existing process controller inventory but had not assigned each device a unique identifier. Trihydro designed and printed easily identifiable metal tags, which were hung on individual process controllers. The now tagged and field-verified inventory increased confidence in the current number, type, and condition of the process controller fleet. It also offered operations a clearer understanding of controllers eligible for removal or replacement.
Trihydro implemented a ground‑up monitoring program that combined inventory verification, optical gas imaging, and direct methane quantification. The integrated approach improved confidence in reported emissions, strengthened program defensibility, and provided the operator with clearer insight into their process controller fleet.
To support the scale and compressed schedule of the program, Trihydro mobilized certified optical gas imaging thermographers from Wyoming, Colorado, and New Mexico, completing field activities over a four‑month period while maintaining consistent methodologies and data quality across all locations.
Emissions Observation and Quantification Approach
Because the operator’s facilities included a mix of controller types, Trihydro conducted emissions observation and quantification based on designed bleed style in accordance with Subpart W requirements for both intermittent and low bleed process controllers.
Certified thermographers used FLIR optical gas imaging cameras to monitor 11,904 intermittent bleed controllers across 764 locations. Each device was observed for the prescribed two‑minute duration. Intermittent bleed controllers were classified as malfunctioning if visible emissions were observed outside of active actuation periods for longer than five seconds. Identifying malfunctioning devices allowed the operator to reduce actual greenhouse gas emissions and improve emissions intensity under both Subpart W and CDPHE reporting programs.
Trihydro also quantified low bleed process controllers using a Semtech HI‑FLOW 2 high‑volume sampler. Trihydro measured methane emissions from 1,013 low bleed controllers across 122 locations using 15‑minute measurement intervals. Collected data demonstrated that most controllers were emitting near anticipated rates based on make and model, providing equipment‑specific emissions data to support accurate reporting.
Delivering Defensible Results and Long‑Term Value
Trihydro compiled all inventory, monitoring, and quantification data into a comprehensive emissions report that satisfied Subpart W greenhouse gas reporting requirements and CDPHE operator-specific intensity program obligations. The resulting work product provided audit‑ready documentation and improved confidence in both the operator’s emissions inventory and reported methane intensity.
By pairing detailed field measurements with a verified process controller inventory, the program supported measurable improvements in emissions intensity while giving the operator a clearer understanding of their controller fleet. Following the initial engagement, the operator was able to transition process controller monitoring activities in house with limited ongoing support from Trihydro, demonstrating the value of a well‑designed, measurement‑informed optical gas imaging and methane quantification program.
