This article is the first in our ongoing series looking at why adding quantitative OGI (QOGI) to a leak detection and repair (LDAR) regimine is critical to improving efficiency and safety, strengthening compliance, and optimizing methane monitoring programs. 

Leak Detection and Repair (LDAR) programs are no longer just a regulatory requirement. They are a core operational function for oil and gas and industrial facilities. As methane regulations tighten and emissions reporting becomes more data-driven, operators are being asked to do more with the same—or fewer—resources. This has put pressure on traditional LDAR workflows to become faster, safer, and more efficient without sacrificing measurement quality.

Quantitative Optical Gas Imaging (QOGI) is emerging as one of the most practical tools to meet this challenge. By enabling operators to both detect and estimate the size of gas leaks in the field, QOGI fundamentally changes how inspections are planned, prioritized, and executed. The result is an LDAR program that is not only compliant, but significantly more efficient.

The Efficiency Challenge in Traditional LDAR

Conventional LDAR programs were designed around component-by-component inspections, most commonly using EPA Method 21. While effective for confirming leaks at individual points, this approach introduces several inefficiencies:

• Every valve, flange, and connector must be physically accessed
• Technicians must work in close proximity to potential dangerous emissions
• Large facilities can require days or weeks to fully inspect
• Results often lack context (knowing that a leak exists but not how significant it is)

As facilities scale up and regulations expand to cover more infrastructure, these inefficiencies compound. The cost is not just labor hours, but delayed repairs, missed large leaks, and inspection fatigue that can undermine LDAR effectiveness.

Optical Gas Imaging (OGI) improved this situation by allowing inspectors to scan entire assets quickly and visually identify gas plumes. QOGI builds on this foundation.

What Is Quantitative Optical Gas Imaging (QOGI)?

Quantitative Optical Gas Imaging (QOGI) combines infrared gas visualization with physics‑based quantification models to estimate gas emission rates directly from video data. In simple terms, QOGI answers two questions at once:

• Where is the leak?
• How much gas is being released?

Rather than relying on default emission factors for estimates, QOGI allows operators to provide detailed measurement results by component, facility or overall operations. This rewards operators that are active in emission control by utilizing advanced technology like QOGI compared to their industry counterparts

Peer‑reviewed controlled‑release studies show that modern QOGI systems can quantify methane emissions with meaningful accuracy under field conditions, particularly for the leak sizes most relevant to LDAR prioritization.

How QOGI Improves LDAR Workflow Efficiency

1. Faster Facility Coverage

OGI allows inspectors to survey large sections of equipment in minutes, rather than checking components one at a time. Entire compressor skids, processing units, or tank farms can be scanned quickly, significantly reducing time on site.  When leaks are quickly identified with an OGI camera, QOGI technology allows users to efficiently measure these emissions. 

Unlike point-sampling tools, QOGI does not require prior knowledge of where leaks may occur. This allows LDAR teams to focus effort where emissions are actually present, rather than where they are expected.

EPA‑supported field studies show that optical gas imaging–based programs often identify significant leaks earlier than traditional approaches, reducing total inspection time over the life of a facility.

2. Immediate Leak Prioritization

Not all leaks are equal. In traditional LDAR, a small seep and a large release may initially receive the same attention because both exceed a detection threshold.

With QOGI:

• Larger leaks are highlighted and documented 
• Emission rate estimates provide immediate context
• Repair actions can be prioritized based on impact

Controlled testing of QOGI systems has shown that approximately 75% of quantified measurements fall within a factor of three of the true release rate, which is sufficient to distinguish high‑impact leaks from minor ones during inspections. 

This allows operators to:

• Fix the biggest problems first
• Allocate maintenance crews more efficiently
• Reduce total emissions sooner

3. Reduced Need for Follow-Up Measurements

In many LDAR programs, finding a leak is only the first step. Additional tools are often needed to measure concentration or estimate emissions, adding time and complexity.

QOGI reduces this need by producing inspect and estimate data in a single pass. While confirmatory tools may still be required for certain regulatory thresholds, QOGI can significantly reduce how often technicians must revisit the same equipment.

Studies conducted at controlled test facilities demonstrate that QOGI quantification improves when multiple video observations are averaged, reinforcing its role as an efficient screening and prioritization tool rather than a one‑off measurement technique. 

4. Safer and More Productive Inspections

Efficiency is closely tied to safety. QOGI allows inspectors to remain:

• At greater distances
• Out of confined spaces
• Off scaffolding or elevated structures
• Measure leaks inaccessible by other technologies

Remote inspection capability reduces exposure to operational hazards while allowing inspectors to cover more ground per shift. Over time, this translates into higher productivity and lower risk for LDAR teams.

Why Efficiency Matters More Under New Regulations

Regulatory programs increasingly reward early identification and accurate characterization of emissions, not just proof of monitoring.

In the United States, the EPA’s Greenhouse Gas Reporting Program Subpart W requires covered oil and gas facilities to report methane emissions using prescribed methodologies and supporting data. Recent revisions emphasize empirically derived measurements and improved transparency.

At the same time, EPA OOOOb and OOOOc rules are expanding LDAR requirements across new and existing sources. Faster, smarter inspections are necessary to keep pace with compliance obligations.

While QOGI is not currently a direct regulatory substitute on its own in the US, it supports these programs by:

• Improving detection efficiency
• Generating defensible emissions context
• Reducing reliance on generic emission factors

In other areas of the world, like the European Union, QOGI is central to the measurement of emissions to comply with regulations providing more efficient and effective measurement capabilities. 

The Science Behind the Efficiency

QOGI’s efficiency gains are rooted in physics rather than procedural shortcuts.

• Infrared absorption allows hydrocarbon gases like methane to appear clearly against appropriate backgrounds
• Radiative transfer models convert pixel intensity into plume concentration
• Optical flow algorithms estimate gas movement across frames
• Controlled‑release validation confirms performance under known conditions

Independent university‑led evaluations have shown that environmental factors—such as wind speed and thermal contrast — can play a role in accuracy, underscoring the importance of trained operators and proper deployment rather than over‑reliance on a single measurement.

When used as designed, QOGI delivers actionable insights quickly, exactly what an efficient LDAR program requires.

Efficiency Without Sacrificing Integrity

A key concern in emissions measurement is whether speed comes at the cost of credibility. The growing body of peer‑reviewed literature around QOGI suggests that this tradeoff is not necessary.

Multiple independent studies conducted by academic and research institutions have evaluated QOGI systems under blind, controlled conditions, providing transparency into both strengths and limitations. This level of scrutiny is critical as operators adopt new technologies within regulated environments.

Efficiency matters most when it enables better decisions, not just faster ones. This can have positive impacts on ROI but reducing losses. 

Read related case study

Looking Ahead

As LDAR programs evolve toward Leak Detection and Quantification (LDAQ), efficiency will increasingly be measured not in inspections completed, but in emissions reduced.

Quantitative Optical Gas Imaging does not replace good engineering judgment or sound maintenance practices. Instead, it improves the workflow, helping inspection teams move faster, work safer, and focus effort where it makes the greatest impact.

In the next article in this series, we’ll explore why QOGI compliance matters, and how quantification strengthens emissions reporting and regulatory confidence.