This article is part of our OGMP 2.0 Educational Series
View all the articles
- What Is OGMP 2.0?
- Emission Factors and Activity Factors Explained
- What Is a Methane Baseline?
- LDAR Programs for OGMP 2.0
- Operational vs. Fugitive Emissions
- Methane Quantification: Why It Matters
- Continuous Monitoring vs. Periodic Surveys
- What Are Fugitive Emissions?
- How to Detect Fugitive Emissions
- Upstream Methane Emissions Sources
- What Are Vented Emissions?
- Understanding Incomplete Combustion Emissions
- Achieving OGMP 2.0 Gold Standard
Emission Factors and Activity Factors and OGMP 2.0
As oil and gas operators work toward higher levels of methane transparency under OGMP 2.0, two concepts come up repeatedly—Emission Factors (EFs) and Activity Factors (AFs). While they may sound technical, these factors are fundamental to how methane emissions are estimated, quantified, and ultimately reduced.
Understanding how EFs and AFs work—and their limitations—is essential for companies aiming to progress from estimate-based reporting to the measurement-driven requirements of OGMP 2.0 Level 4 and Level 5.
What Are Emission Factors (EFs)?
An Emission Factor represents an average rate of methane emissions associated with a specific type of equipment or activity. In simple terms, it answers the question:
“On average, how much methane does this component emit?”
For example:
- A pneumatic controller might be assigned an EF expressed as kilograms of methane per device per year.
- A compressor seal may have an EF based on historical measurement data across similar assets.
Emission factors are typically derived from:
- Industry studies
- Regulatory datasets
- Historical measurement campaigns
- Engineering assumptions
EFs play an important role in early-stage reporting (OGMP 2.0 Levels 1–3), where direct measurements may be limited. They allow operators to estimate emissions across large asset portfolios when monitoring infrastructure is sparse.
However, emission factors are averages by design. They do not account for site-specific conditions, operational variability, equipment age, maintenance practices, or intermittent high-emission events—often referred to as super-emitters.
What Are Activity Factors (AFs)?
Activity Factors describe how often or how much an emitting activity occurs. They provide the scale needed to apply emission factors correctly.
AFs answer questions such as:
- How many pneumatic devices are installed at a site?
- How many valves, flanges, or thief hatches are present?
- How frequently does a specific operation occur?
Examples of activity factors include:
- Number of components per site
- Operating hours per year
- Number of maintenance or venting events
When combined, EF × AF = estimated emissions for a given source category.
This approach allows operators to build a methane inventory by summing emissions across multiple equipment types and activities. While practical, this method relies heavily on assumptions—and those assumptions can introduce uncertainty.
Why EF- and AF-Based Estimates Fall Short
- Averages mask leak variability Methane emissions are rarely uniform. A small number of leaks often account for a large share of total emissions.
- Static values can’t capture real-time changes Equipment failures, intermittent leaks, and operational upsets can significantly alter emissions between inspections.
- Limited ability to prioritize repairs EF- and AF-based inventories estimate what might be emitting, not what is emitting right now.
How EF and AF Data Fit into OGMP 2.0 Levels 4 and 5
At OGMP 2.0 Level 4, operators are expected to move beyond default values and begin developing company- and site-specific emission factors, supported by direct measurements. This may involve validating EFs using periodic surveys, drones, or fixed sensors.
At Level 5, reporting shifts decisively toward measurement-based inventories, where emissions are quantified continuously at the site level and independently verified.
In this context:
- EF and AF data still provide structure and context
- Continuous measurements reveal when assumptions break down
- Real-world data replaces averages with actual emissions behavior
EFs and AFs become inputs, not the final answer.
Why Continuous Monitoring Changes the Equation
Continuous emissions monitoring systems like MethaneTrack™ fundamentally improve how EFs and AFs are used. Instead of relying on static averages, operators gain:
- Real-time visibility into emissions events
- Site-specific data to validate or update emission factors
- Accurate baselines that reflect actual operating conditions
- Clear insight into which assets drive the majority of emissions
This shift enables operators to focus mitigation efforts where they matter most—improving both environmental performance and operational efficiency.
Building Better Methane Inventories
EFs and AFs remain an important part of methane accounting, especially for organizing inventories and meeting early reporting requirements. But as OGMP 2.0 expectations increase, so does the need for direct, continuous measurement.
By combining structured inventory frameworks with automated emissions monitoring, operators can:
- Reduce uncertainty
- Improve reporting credibility
- Demonstrate measurable emissions reductions over time
In the end, understanding emission factors and activity factors isn’t just about compliance—it’s about building a methane management strategy grounded in real data, not assumptions.
