Deepwater oil and gas exploration is getting ever deeper; wells are already being drilled at mud-line depths of up to 10,000ft and will
go deeper in the next five years. This big challenge can only be achieved using dynamically positioned vessels with the ability to quickly disconnect in an emergency, which in turn drives the need for a fast-acting electro-hydraulic control system downhole.
To support these downhole electro-hydraulic control systems, expensive electro-hydraulic umbilical and surface reelers are required, and these have added operational difficulties and are vulnerable to damage running into or out of the hole.
In an ideal world, the downhole control system would not need an expensive umbilical/reeler package, but how viable is an umbilical-free system?
A futuristic conceptual design in development by the Subsea Deep Ocean group is trying to resolve this very question. Its name is Deep-Remote.
This involves a design concept of a string-mounted downhole electro-hydraulic control system made up of several modules, providing control for various downhole tool functions, either for marine risers or open seawater applications. Capable of reaching mud-line depths in excess of 10,000ft, it would be used to control existing oil and gas well testing, completion and servicing tools, without the support of an umbilical system.
The system would achieve this through the use of existing and newly developed technology. Hydraulic power would be produced by a battery-powered downhole hydraulic power unit, while the control signals would be provided by a bespoke method of communicating with the surface vessel. The system would also use a unique method of preventing hydrate formation. Patents and trademarks have been applied for.