Technical Articles
Designs and Applications of Ball Valves for Submarine Pipelines
Posted: 12/07/2017 10:55:52  Hits: 2
The Overview
With the rapid development of the offshore oil and gas industry and the demand for energy, the development of oil and gas fields in the deep water will become the focus of development of the offshore oil industry in the future. The manufacturing system of submarine oil and gas is hardly affected by severe weather and is highly reliable, which become one of the key facilities for exploitation of oil and gas fields in the deep water. Valves for submarine pipelines are the important parts for equipment of the manufacturing system in the deep water. This article introduces designs, land tests and submarine operation of the submarine valve based on the practical application of the two submarine ball valves in a production and development of offshore oilfield project.

The common standards
The submarine pipeline valve is a general designation for all the valves which are applied to submarine pipelines, and it is mainly used for terminals of submarine pipelines and oil and gas pipelines. The submarine pipeline valves are mainly the ball valve, the flat gate valve and the check valve. The submarine pipeline valve mainly adopts API6DSS, API6A, API17D and ISO13628-1 standards.

The operation modes
The main operation modes of the submarine pipeline valve are mainly hydraulic control, remote control (the ROV-remote Operated Vehicle) and diver operations.
 
The hydraulic control mode
The submarine pipeline valve, the hydraulic source, the hydraulic control unit and the umbilical cable form a system, and the hydraulic control unit is used for opening and closing the submarine valve. The advantage of this operation mode is that the submarine valve can be opened and closed automatically and real time monitoring of the submarine valve can be realized on offshore platforms. When the hydraulic control system fails, the submarine valve can be controlled by the ROV. However, the hydraulic control is complicated. It has relatively more potential leaks and higher investment costs.
 
The ROV mode
The submarine valve has the ROV interface, and it can be divide into top mounted and side mounted two types. The torque tool carried by the ROV open and close the submarine valve. The advantages of this kind of operation mode are that the structure of the submarine valve is simpler than that of the hydraulic control and the cost is relatively low. However, the ROV operation can not obtain an emergency shutdown when an offshore oil platform needs to shut down a submarine valve in case of an emergency, and the offshore oil platform can not monitor the status of the submarine valve.