Understanding Intermittent Emissions and How CM Technology Fills the Gaps
Emissions from oil and gas facilities are dynamic and often intermittent, meaning that standard measurement techniques may only capture a small portion of a facility's actual emissions. This is commonly known as intermittency, referring to the sporadic release of gases caused by operational changes or equipment issues. These intermittent emissions are typically only picked up when scheduled measurement activities take place daily, weekly, monthly etc. and can lead to emission events that are completely missed or estimated calculations that are inaccurate.
Intermittent emissions pose a challenge because they may not be captured during routine monitoring activities if these do not coincide with the intermittent release events. Therefore, continuous or highly frequent monitoring technologies are seen as another effective strategy in the toolbox in capturing the full scope of emissions, particularly those that are intermittent.
Continuous Monitoring (CM) offers an essential solution to the challenges of accurately capturing true field level emissions and addressing intermittency. Traditional methods may not always account for the variability of emissions. As a technology to enhance overall emissions quantification, CM provides a continuous, comprehensive stream of emissions data, ensuring the dynamic nature of operations and subsequent emissions, including sporadic emission spikes and drops, are captured accurately.
Figure 1 and Table 1 below represent a real-world scenario and the blind spots in intermittency. They highlight the discrepancies between intermittent and continuous emissions monitoring methods and represents the variability of emissions over time, showcasing instances where intermittent monitoring—due to its non-continuous nature—may at times miss emission events.
Figure 1: Intermittency Gaps and Continuous Monitoring Advantages
Table 1: Intermittent Measurements Gaps in Detection and the Value of Adding CM
| Date/Time | Intermittent Detection | Intermittent Emission Rate | Continuous Detection | Continuous Emission Rate | Total Emissions Detected (kg/hr) |
|---|---|---|---|---|---|
| April 26 | Detected | 6 kg/hr | Detected | 6 kg/hr | 6 kg/hr |
| April 28 | Detected | 0 kg/hr | Detected | 0 kg/hr | 0 kg/hr |
| May 1 | Detected | 2 kg/hr | Detected | 2 kg/hr | 2 kg/hr |
| Total Detected Rates Over 1 kg/hr | 2/22 Events Detected | 8 kg/hr (Over 3 Surveys) | 22/22 Events Detected | 8 kg/hr (Over 22 Events) | Intermittency Gaps in 20 Out of 22 Measurable Events |
Intermittent measuring technology can result in gaps between monitoring intervals, during which any emissions released are not detected or recorded. Consequently, intermittent monitoring may not always capture transient or sporadic emission events, leading to underestimations and depending on the time interval of data capture, intermittency may also lead to overestimations of actual emissions due to averages extrapolated over the measured time period. CM technology works well with intermittent measurements to fill in these gaps to provide a holistic view of true emissions quantification.
Table 2 below illustrates the high-level differences between intermittent and continuous emissions monitoring. Intermittent monitoring, conducted at daily, weekly, or monthly intervals without real-time data, may miss transient emissions, leading to inaccurate results. Continuous monitoring, operating 24/7 with real-time data, captures most emission events as they occur, providing accurate and precise emission estimates. This highlights the complimentary advantage of continuous monitoring when coupled with intermittent monitoring in delivering comprehensive and reliable emissions data.
Table 2: Comparing Intermittent vs. Continuous Emissions Monitoring
| Monitoring Type | Data Collection Frequency | Real-time Data | Potential for Emission Detection | Impact on Emission Estimates |
|---|---|---|---|---|
| Intermittent | Daily, weekly, or monthly | No | May miss transient and sporadic events | Can lead to underestimations or overestimations due to infrequent data points |
| Continuous | 24/7 continuous | Yes | Captures the majority of emission events as they occur | Provides accurate and real-time emission data, leading to precise estimations |
The benefits of CM paired with traditional methods like Optical Gas Imaging (OGI) are further evidenced by their ability to continuously monitor emissions, capturing transient events that periodic assessments might miss. This is crucial in industries like oil and gas, where the accurate and timely detection of emissions can lead to immediate corrective actions, reducing overall environmental impact and aiding compliance with stringent regulations.
Thus, CM not only enhance the understanding of emissions patterns but also equip facilities with the essential real-time data needed to proactively address and mitigate environmental impacts. This stream of information is vital for developing effective pollution reduction strategies, ensuring regulatory compliance, and fostering sustainable industrial practices. The integration of CM into standard operational protocols marks a significant advancement in emissions management, recognized increasingly as essential for the future of environmental stewardship in the oil and gas industry.