Classification of Commonly Used Valves in Oil Fields
1, Gate valve
Main Characteristics:
-The opening and closing part is a gate plate,
-Full bore, low flow resistance,
-Suitable for high-pressure large diameters,
Main usage: (commonly seen in wellhead devices)
-Main valve and wing valve of Christmas trees,
-Main valve for manifold,
-Used in BOP systems,
2, Choke valve
Main Characteristics:
-Adjustable flow rate and pressure difference,
-There are two types: fixed throttling and adjustable throttling,
Main usage:(installed beside the wellhead wing valve)
-Throttling at the oil & gas wellhead,
-Fracturing and testing operations,
3, Globe valve
Main characteristics:
-The opening and closing parts rise and fall along the valve seat,
-It has good regulating performance,
-Relatively high resistance,
Main usage: (used for small flow regulation and cut-off)
-Wellhead auxiliary manifold,
-Oil & gas processing station regulation system,
4, Check valve
Main characteristics:
-Unidirectional flow of medium,
-Prevent back-flow,
-Automatic opening and closing,
Main usage:(installed at the outlet of the mud pump to prevent the back-flow of drilling fluid)
-Prevent high-pressure oil & gas from flowing back,
-Mud pump piping,
5, Ball valve
Main characteristics:
-Quick opening and closing(1/4 turn),
-Good sealing performance,
-Full bore design,
Main usage:(Flexible operation, controlled by hand wheel or hydraulic)
-Manifold system,
-Fracturing and acidizing operations,
-High-pressure pipeline,
6, Butterfly valve
Main characteristics:
-Easy to open and close,
-Compact structure,
-Suitable for low pressure and large diameter,
Main usage:(valve plate is disc-shaped and rotates to open and close)
-Import and export of oil tanks,
-Gathering and transportation pipelines(low pressure),
7, Safety valve
Main characteristics:
-Automatic activation when over pressure
- Prevent over pressure accidents,
Main usage:(Make sure safe operation of the system)
-Oil & gas processing station,
-Separators, pressure vessels,
According to pressure rating(API 6A commonly used)
2000psi: Low-pressure wellhead, gathering and transportation system,
3000psi: Medium-pressure oil & gas wells,
5000psi: High-pressure well head(common specifications)
10000psi: Ultra-high pressure gas wells, BOPS
15000psi: Deep wells, high-pressure wells with high sulfur content.
Conclusion
Wellhead/Christmas tree: Mainly composed of gate valves and choke valves, they can withstand high pressure and has strong corrosive resistance,
Drilling operations: Mainly using gate valves and check valves, to ensure well control safety,
Gathering and transportation network: Mainly composed of ball valves, globe valves and check valves, to ensure transportation and regulation,
Processing station/Ground system: Mainly equipped with safety valves and butterfly valves, emphasizing regulation and protection.
