Enclosed Flares for Lean Produced Gas
Enclosed flares that burn lean, low calorific produced gas cleanly at oil and gas production sites.
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Clean combustion for low calorific gas
CRA's enclosed flares for lean produced gas keep a steady flame on gas with a high share of inert gases, with the combustion held inside the enclosure and a support fuel added only where the gas needs it.
Destruction efficiency
>98%
Visible flame
Zero
Gas
Low calorific produced gas
Standard
API 537
How does an enclosed flare burn lean produced gas?
Lean gas has too little energy to hold a steady open flame, so part of it can pass through unburned. An enclosed flare surrounds the burners with a combustion chamber, which keeps the heat in and gives the gas time to burn completely. The burners are chosen for the gas's low heating value.
How it works
Where the gas is too lean even for the enclosure, a support fuel such as natural gas is blended in to keep the flame stable.
The produced gas flows to the flare, where its flow and quality are monitored.
Burners designed for low calorific gas take the flow.
When the gas is too lean, support fuel is added to keep the flame steady.
The enclosure keeps the heat in and gives the gas time to burn completely.
The burner management system supervises the flame and shuts the flare down safely when needed.
Key Benefits
Burners designed for low calorific gas keep combustion steady as the gas quality changes.
The enclosure keeps the heat of combustion in, which helps methane and other hydrocarbons burn completely.
The design adds a support fuel only when the produced gas is too lean to burn on its own.
Combustion stays inside the enclosure, out of sight of the surrounding area.
The flare is designed to destroy more than 98% of the hydrocarbons in the gas.
Projects That Push Boundaries
Single enclosed flare for HP and LP associated gas, designed to meet the site's radiation, noise and emission limits.
Advanced combustion design maintaining stable operation on near-limit hydrocarbon concentrations.
The CRA Edge
CRA has more than 30 years of experience in gas handling and flare engineering.
Design, R&D and manufacturing are carried out under one roof.
ISO 9001 certified through TÜV NORD, with designs aligned with ASME, API and CE.
Designs are customised to the process needs and the regulations that apply at site.
Applications
Built to help you specify.
Sizing tools, decision guides, and technical references. Use them before, during, and after your evaluation.
Frequently Asked Questions
What makes produced gas lean?
Gas with a high share of carbon dioxide, nitrogen or other inert gases has a low heating value, which makes it harder to burn steadily.
Why use an enclosed flare for lean gas?
The enclosure keeps the heat of combustion in and gives the gas time to burn, which helps a lean gas burn completely.
Will the flare need a support fuel?
That depends on the gas. CRA assesses the heating value range and adds a support fuel only where the gas cannot burn reliably on its own.
What data does CRA need to size a flare for lean produced gas?
CRA needs the gas flow range, the composition range including inert gases, the supply pressure and the site conditions.
Can the flare cope with changing gas quality?
Yes. CRA designs the burners and controls for the range of gas quality the site expects, including the leanest case.