예비신랑19.10.22 09:20
What is natural gas flaring and why is it done?
Flaring is the controlled burning of natural gas and a common practice in oil/gas exploration, production and processing operations. A flare system consists of a flare stack and pipes that feed gas to the stack. Flare size and brightness are related to the type and amount of gas or liquids in the flare stack. Flares generate heat and noise. Large flares can be quite noisy because of the volume and velocity of the gas going through the flare stack.
Because natural gas is valuable, companies would rather capture than flare it. However, there are several reasons why it may be necessary to flare gas during drilling, production or processing.
During well production testing after drilling is completed
After a shale oil/gas well is drilled and hydraulically fractured, a temporary flare is used during well production testing. Testing is important in order to determine the pressure, flow and composition of the gas or oil from the well. Flaring at the well site can last for several days or weeks, until the flow of liquids and gas from the well and pressures are stabilized.
For safety and during emergencies and maintenance
A flare is an important safety device, particularly at gas processing plants. In an emergency situation where equipment or piping becomes over-pressured, special valves on the equipment automatically release gas through piping to flare stacks. In the absence of safety flares, plants would be at higher risk for fires and explosions.
Flares are also used as an outlet for gas during maintenance and equipment repairs (such as flaring during pigging events or flaring after cleaning wells). In these scenarios, the flare is operated temporarily until the emergency situation is resolved, or until maintenance activities have been completed.
For managing gas during compression and processing
Flare gas systems are used to manage waste gas that cannot be efficiently captured and returned to the system for processing. For example, some natural gas compressor stations have dehydrator units that remove water from the gas stream before it enters the pipeline system. There may be a flare at the compressor station to burn off gas vapors captured by the dehydrator unit. These flares are typically used as control devices when vapor recovery is impractical.
