In the optimization of oil and gas production, the management of sand – a common byproduct resulting from the fracturing process – is a crucial aspect often overlooked. Sand management practices play a pivotal role not only in furthering operational efficiency but also provide an opportunity to make significant strides toward the mitigation of fugitive methane emissions. Understanding various oil and gas sand management equipment, technologies, and processes along with their correlation to methane emissions release and/or control is imperative in today’s pursuit of sustainable energy practices.
Types of Oil and Gas Sand Management Techniques
Cyclonic and Spherical Sand Separators
Cyclonic or Spherical sand control technology is designed to be most efficient during single phase & steady-state production scenarios (similar to off-shore parameters) and uses differential pressure to force solid particles to the outer edge of the internal components. By forcing the well stream into a confined space and narrowing the flow path the resulting differential can be as high as 200 – 400 psi (depending on the manufacturer and well flow characteristics). In reality, once multi-phase production (Gas & Liquids combined) is introduced, the cyclonic action can break down and cause performance fluctuations that affect separation efficiency as well as further increase differential pressure thereby holding back production at the well head. These units must be blown down frequently to remove sand from the internal holding volume (~100 lb) while the well continues to flow through the system.
Gravity desanding technology uses temporary phase separation, significant velocity reduction, and adequate retention time to remove the sand safely and efficiently from multi-phase well production. The vessel does not utilize baffles, plates, or screens that would otherwise slow down the flow which allows for a near-zero pressure drop across these vessels (excepting pipe friction). With the predictable leveraging of Stoke’s Law, the sand settles to the bottom of the vessel and is retained until the cleanout process is initiated (>700 lb). This process is performed while isolated from the well allowing for full operational control of the gas trapped in the system. Real-time monitoring of the sand in the desander yields additional gains in operations efficiency as well as new opportunities for data analytics.
Relationship with Methane Emissions
The management of sand in oil and gas operations is intricately linked to methane emissions. Methane, a potent greenhouse gas, is emitted at various stages of oil and gas production, including during the sand control process associated with well flow back and initial production. Operators and contractors alike have ownership of equipment and process selection in order to eliminate routine methane releases while continuing to achieve effective and operationally efficient well flowback/production best practices.
Associated Causes of Methane Emissions
- Open tanks used for blowing down sand control equipment.
- Open measurement tanks for externally weighing sand after vessel is blown down to atmosphere.
- Delayed closing of dump valve after blowdown of sand is complete resulting in well flowing directly to atmosphere.
- Uncontrolled pressure releases from equipment and piping washouts
- Inherent efficiencies of combustion equipment such as flares (91% efficient) or incinerators (99% efficient).
- Breaking containment to repair chokes, valves, washed out flow iron, production separation equipment, and/or facilities components.
Mitigating Methane Emissions Through Sand Management
Adopting efficient sand management practices, with the integration of technology and improved processes, can significantly reduce methane emissions in the oil and gas industry.
Advanced separation technologies and equipment can enhance sand removal efficiency and reduce the likelihood of methane release during flowback and initial production. Gravity Desanders provide an industry-leading advantage to make total fugitive methane emission elimination a reality.
- Sand-holding capacities are more than 15x a standard vertical “sand trap”
- Results in significantly fewer depressure events
- Finite and consistent gas volumes to manage providing options for control
- Put more gas in the pipeline resulting in additional revenue
Improved Sand Production Monitoring and Measurement
The ability to monitor sand being produced, in real time, without the release of well fluids to the atmosphere, provides an opportunity to realize significant advances in on-site operations efficiency and data-driven decision-making, all leading to improved methane emissions capture capabilities.
- Only clean out as needed using Sand Sentry Measurement System
- Know how much sand is in the Desander in real-time, monitor on-site and online
- Sand production data ensures cleanouts done only as required
Enhanced Health, Safety, and Environmental Practices
The process of reducing impact on the environment also improves our ability to ensure the health and safety of personnel on location as well as safeguard the communities in which we operate. Working with local, state, and federal regulatory bodies will create a positive operating climate where both business and community stakeholders benefit from these advancements.
- Remove manpower from location reducing exposure to possible safety and health hazards
- Eliminate routine flaring during flowback and initial production operations
- Avoid fines from state/local regulations as well as the “Inflation Reduction Act.”
- Fines start at $900/metric-ton in 2024 and increase to $1,200 in 2025 and $1,500 in 2026
In conclusion, an effective and comprehensive sand management strategy during oil and gas operations plays a critical role in mitigation or even the complete elimination of methane emissions. By employing technology-enhanced sand control processes, embracing real-time data and analytics, and fostering a commitment to strategic operational improvements, the industry can make significant strides toward reducing its environmental footprint while ensuring socially responsible and sustainable hydrocarbon resource extraction.