Keeping the Flame Alive – Minimizing Emissions from Flares with Improved Flare DRE
As regulators increasingly restrict the practice of flaring in oil and gas operations, flares continue to serve a critical safety function. In the event of a production system upset, surge or sudden pipeline shut-in, associated gas and tank vent gas must be flared to avoid accumulation at the well site and creating a safety hazard to people and infrastructure.
Flaring of natural gas in production operations is considered an efficient method of destroying methane. The U.S. Environmental Production Agency (EPA) estimates the destruction removal efficiency (DRE) of flares at 98%.
But what happens when this safety measure becomes a significant source of emissions? Recent studies demonstrate that as a practical matter, flaring DRE is not as efficient as originally believed and that emissions from flaring in key oil and gas producing regions may be significantly understated.
This article explores various strategies and technologies that can be employed to reduce emissions from oil and gas flares and highlights the wide-ranging benefits of these efforts.
Flare Efficiency – How big of a problem are unlit flares?
For both safety and environmental performance reasons, the flare must always be ready to ignite, which means the pilot flame must always be lit. A reliable pilot flame is required to ensure uptime, efficient production flow and well site safety.
A key assumption behind the 98% flare DRE estimate is that the flare is always working when needed. However, if the pilot is blown out by high winds, a malfunction or another reason, the flare will emit raw natural gas to the atmosphere – defeating the very purpose of the flare and creating an environmental and safety risk.
In an article published in Science magazine (Science 377, 1566-1571, September 2022), researchers analyzed methane emissions in three large oil-producing areas the U.S., including the Permian Basin, Bakken and Eagle Ford. Collectively, these basins are estimated to represent 80% of flared gas volumes in the U.S. The researchers discovered that on average 4.1% of flares were unlit and the average effective DRE was only 91.1%.
Although a DRE above 90% might be considered “good,” the study puts the 91.1% observed DRE number in perspective: “If measures were taken to ensure that U.S. flares operated at 98% efficiency and remained lit, as current accounting assumes, this would be equivalent to removing 2.9 million cars from the road each year these mitigation measures were in place.” That is a lot of cars.
Strategies for Keeping the Pilot Flame Alive
Fortunately, oil and gas operators have several strategies for ensuring the flare pilot flame is always lit, and for demonstrating compliance.
Automated Burner Management Systems. The first line of defense against unlit pilot flames is an automated Burner Management System (BMS). If a pilot flame is extinguished, without a BMS unit the burner gas will continue to flow, creating a potentially dangerous situation by emitting raw gas to the atmosphere. An automated BMS unit prevents this situation by automatically detecting the absence of a flame and safely reigniting it, unattended. In many areas, automated BMS units like the Platinum-600 BMS have become essential components of fired equipment, including separators, heater-treaters, line heaters, downhole steam injectors, sulfur recovery units, tank heaters and other equipment that work with heat created by a burner.
Continuous Emissions Monitoring Systems (CEMS). There are several continuous emission monitoring systems (CEMS) for oil and gas operators to choose from, ranging from “blind” metal oxide sensors sitting at the fence line to lasers and OGI cameras. Each method has its pros and cons, however, they all serve the same purpose – to detect fugitive emissions between periodic well site inspections to mitigate methane emissions. If a flare pilot flame is unlit, a continuous monitoring sensor will likely detect it and provide a real-time alert to the appropriate personnel.
IR cameras. Optical Gas Imaging (OGI) using Infrared (IR) cameras are highly effective at visually confirming the presence and location of a leak at the well site. Fixed OGI cameras, like those provided by Kuva Gas Cloud Imaging, are able to monitor the entire well site. An IR camera at the well site or production pad can detect emissions on location and confirm that the leak is indeed coming from the operator’s site and not an adjacent one. That information provides the LDAR (Leak Detection and Repair) crew the specific location of the leak, saving them time, which may be the flare.
Data log for continuous compliance. New Mexico recently instituted a new Ozone Precursor Rule (rule 20.2.50 NMAC Oil and Gas Sector – Ozone Precursor Pollutants) requiring “continuous compliance” and specifically mandates automated Burner Management Systems for all flares and combustors. An automated BMS with data recording and logging capability keeps track and records when a flare is on, off and how many times it may have been reignited. Effective compliance can help you avoid hefty fines and sell more natural gas, boosting ROI. As more states consider similar regulations and laws, reliable data will become increasingly important for evidencing continuous compliance.
Periodic inspections and proactive operations. Periodic well site inspections are required for compliance with NSPS OOOO/OOOOa (Quad-O, and Oa) compliance for gas plants, well sites and compressor stations, and different states have their own inspection requirements for oil and gas operations. In Colorado, Regulation 7, specifies that state’s requirements for inspecting tank batteries, air pollution control equipment (i.e., VRUs, enclosed flare, etc.) and other equipment.
Benefits of Keeping the (Pilot) Flame Alive
Environmental performance and economic performance are not mutually exclusive. In our experience a well site operating under compliance and at its full potential is more profitable than those that are not.
Maximize profitability. Well sites operating at their full potential and under compliance are typically more profitable. A reliable, “always-on” pilot flame increases well site safety and helps avoid fines. Combining multiple methods for reducing fugitive methane emissions keeps more product in the pipe and the incremental revenue typically more than outweighs the cost.
Meet environmental performance goals (reduce emissions). Leading oil and gas operators are committing to aggressive environmental performance goals as the industry moves towards greater decarbonization. Key initiatives typically involve reducing fugitive emissions, venting and flaring practices. A constant, reliable flare pilot flame ensures maximum flare DRE, prevents the venting of raw gas to the atmosphere.
Evidence compliance. Ideally, BMS units are equipped with an electronic means to capture data and connected to your SCADA system for remote monitoring. Platinum Control Flare Units, for example, as fitted with a USB port, so you can capture and download important data to a memory stick or flash drive. This data can be used to demonstrate continuous compliance.
Protect your reputation. Reducing the probability of flare pilot fuel gas venting to the atmosphere also decreases the opportunity for emissions from unlit flares to be detected by regulatory authorities and activists.
Summary
In summary, operators can employ several strategies to ensure compliance, maximize profitability and achieve environmental performance goals. When used in combination, burner management systems, periodic inspections, IR cameras and data can result in dramatic reductions in methane emissions, improve well site safety and help you harness the full potential of your well site(s).
Platinum is Your One-Stop Shop for Compliance
Platinum Control is your one-stop shop for environmental performance and regulatory compliance.
Our offerings include:
Proven and reliable automated Burner Management Systems equipped with data collection and reporting capability, to ensure active pilot flames on fired equipment with the data needed for continuous compliance.
Vapor Recovery Units (VRUs) that punch above their class and move 30% more gas volume for the same horsepower rating as competing units, helping you convert waste gas streams into revenue and reduce emissions.
Platinum uses area imaging technology from Kuva Systems to continuously monitor emissions for detecting and locating leaks, improving the efficiency and productivity of LDAR teams.
Flare Units based on our proven BMS units for dependable ignition and re-ignition of pilot flames on flares.
Periodic Method 22 AVO well site inspections to ensure compliance with federal and state air quality regulations.
Professional and timely Leak Detection and Repair (LDAR) services for compliance and emissions mitigation.
The Platinum Advantage
Our core competency in Facilities Optimization sets us apart. We work with operators in the Permian Basin of all sizes, from companies having only a handful of wells to supermajors. As a result, we leverage the experience gained with larger operators, build best practices into our products and services, and then disseminate that knowledge to our smaller customers.
A well site or facility with an optimized configuration will help you harness its full potential, maximizing its long-term economic value and environmental performance.
Contact us today at sales@platinumcontrol.com to learn how we can help you develop a comprehensive strategy for achieving compliance, environmental performance goals and harnessing the full potential of your well site.