A choke is a device similar to a valve that is used to manage wellbore pressures and provide control over water and fluid loss. Oil and gas industries use this arrangement for lowering pressure from the wellhead so that flaring of retrieved gasses can be done on-site.
Two chokes are provided in order to keep the manifold functional at all times in case one choke is needed to be taken out of service for repair. The well flow can be directed through the other one. Chokes are also used in gas lift equipment for gas lift operations.
Trenchlesspedia Explains Choke
During a drilling operation, mud circulation is done through a choke manifold when the blowout preventers are closed. A choke manifold is an arrangement consisting of high-pressure valves and piping with two adjustable chokes.
There are two types of chokes namely, an adjustable choke and a fixed choke. The adjustable choke allows the fixed choke to be changed during operations and provides greater flexibility for wellbore cleanup rates. The fixed choke gives more accurate flow control at differing test conditions.
A choke manifold enables dual-flow paths in order to control flow to the downstream process equipment from the upstream control equipment. Choke changes can be done with the least interference to testing and operations.