For technology marine oil and gas industry technology developing and demands for energy, development of deepwater oil and gas fields will become the key point of marine petroleum industry. Underwater water oil and gas production system is impacted less by disaster weathers and has strong reliability, having become one of key facilities for exploiting under oil and gas fields. Submarine pipeline valves are the important parts for production system. 

 

Submarine pipeline valves are a general term for all of valves used in submarine pipeline. The valves are mainly applied in underwater pipelines of marine oil and gas industry, submarine pipeline terminal and oil gas transmission pipeline, mainly including ball valves, flat gate valve and check valves.

 

Submarine pipeline valves mainly adopt API 6D SS, API 6A, API 17D and ISO 13628-1.

 

Operation modes of submarine pipeline valves are mainly classified into hydraulic control, ROV (Remote Operated Vehicle) and manual operation. 

 

Hydraulic control

Submarine pipeline valves, hydraulic source, hydraulic control units and umbilical cables consist of a system. The valve is controlled by control units equipped with hydraulic source. The advantage is that the valves are opened or closed automatically. Real time monitoring on submarine pipeline valves can be carried out on offshore oil platform. When hydraulic control system loses efficacy, the valves can be controlled through ROV. However, hydraulic control is complicated, having many potential leakage points and high investment costs. 

 

ROV

Submarine pipeline valves are equipped with ROV ports which are classified into top mounting and side mounting. The valves are operated through torque tools carried by ROV tower. The advantage is that the structure of valves are simpler compared with hydraulic control. Moreover, it has lower cost which can save costs in construction phase of engineering. But, ROV cannot realize emergency cutting-off when valves need to be closed under emergency circumstances. And real time monitoring cannot be carried out on offshore oil platform. 

 

Manual operation

For low depth of water, submarine pipeline valves are generally equipped with handwheel. The divers can operate by adopting air diving. What’s more, the valves with ROV ports can be operated by diver through appropriative operation tools and saturation diving when it is permitted.