GB2470763A

GB2470763A - Underwater drilling rig.

Info

Publication number: GB2470763A
Application number: GB0909617A
Authority: GB
Inventors: Lance Stephen Davis; Edward Docherty Scott
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-06-04
Filing date: 2009-06-04
Publication date: 2010-12-08
Also published as: GB0909617D0

Abstract

Underwater drilling system comprising a base plate 6 which is anchored to bedrock / seabed 7. Support structure 5 locked to the base plate supports a fluid powered drilling machine 3. There can be an axial loading system (9 and 10, fig 2) which is used to supply weight on bit by jacking the drilling machine. The fluid driven drilling motor 3 may be powered by fluid pumped from a surface vessel 1 via supply line 9. The base plate 6 can have a guide / template which is interchangeable for one of a larger diameter to allow opening up of a larger borehole.

Description

Title: Turbo-Borer Bore-Hole drilling machine In the task of drilling a bore hole in a flooded environment such as rivers, lakes & fast flowing tidal streams it is often required to construct an adequate anchor into the rock-bed strata for the deployment of new technology energy generation systems or other permanent installations.

The established technology in use today is e.g. drill ships, jack-up drilling rigs or other such systems for drilling bore holes where the logistics of deploying such equipment can become difficult and therefore prohibitively expensive.

In this application we will describe a simplified deployment method which will utilise a hydraulic powered drilling motor which can be used to drill welibores / boreholes into bedrock and other strata which is in a water flooded environment.

Abstract: A wellbore drilling machine deployed remotely from a floating vessel to drill a borehole into bedrock where the bedrock is in a flooded environment. The drilling assembly includes a column structure to support the welibore drilling machine, the column structure is locked in place to a base-plate support which is anchored to the bedrock. The base plate has a series of interchangeable drilling collars which may be replaced by incrementally larger collars to permit the opening up of a larger bore from the first or previous bore hole.

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Description * *5 * * I

In this development we have a system which is to be used for the boring of holes into submerged rock strata where this equipment is deployed from a floating structure (item 1) e.g. boat or barge or similar, this floating vessel being anchored (item 2) to the bedrock (item 7) or dynamically positioned during borehole drilling procedures. **5SS

The task of boring a hole is achieved by the deployment of a motor tubular support column (item 5) structure which will sit firmly on a subsurface landing (item 6) secured to the bedrock, this tubular being of sufficient weight and geometry to provide a firm anchor for the bore hole drilling machine and operations and streamlined for deployment in fast flowing river environments, this column may be further anchored to the subsurface landing.

The drilling motor system e.g. Axial flow Reaction Turbines, Vane Motors, Positive Displacement Motors etc (item 3) including drill-bit (item 8) is fluid powered, this fluid being taken from the surrounding water body (item 4) by the floating structure vessel and pumped into and through the Motor System.

The motor system is attached to the motor tubular support column and is configured in such a manner that the body of the drilling machine is index-able axially to permit forward movement of the drill bit during bit rotation. * 2

The floating vessel may also be configured to feed the motor tubular column through the hull of the vessel which can be lowered directly from the hull of a floating vessel to land on the surface of the bedrock or other similar landing surface.

A support base or template may also be incorporated to lock or latch the motor tubular support column in place for drilling ahead operations.

This drilling system may also potentially be configured to deploy other drilling machine systems e.g. electric motors or air / gas powered hammer drilling systems which would be deployed inside the tubular column acting as a caisson to exclude environmental fluid.

The floating vessel which we will refer to as the production vessel contains the pumping equipment which will take fluid from the water body to pump through to the drilling / boring machine by a connected pipe (item 9) and will in addition provide the separate hydraulic fluid power systems to incrementally jack the drilling machine into the rock structure the drill-bit rotates, this weight on bit is transmitted through a Rack & Pinion jacking arrangement or roller drive arrangement (items 9 & 10) or cylindrical hydraulic telescoping system. The jacking arrangement can also be used to reverse the Turbo-Borer machine from the borehole.

The used drilling water and cut bedrock is returned to the immediate water body as part of the normal drilling procedure by being discharged through the motor tubular support column.

*SS*..

* An advantage of having an hydraulically power rack and pinion axial drive system or : ** direct hydraulic axial ram pressure is that oscillating pressure can be applied directly through to the drill-bit and released as rotation of the drill bit is in process, this is not to * be confused with hammer drilling', this instead is a method of inducing harmonics to the cutting structure where a variable pressure is applied to the drill-bit but never fully removed from the drill-bit, this aids in breaking the rock structure.

:* In drilling a borehole into bedrock this system may also be configured as a slant bed configuration where bore-holes of various angles from the vertical may be drilled.

Explanation of figures 1 & 2 Fig 1: Shows the general layout of the production system.

Item 1: Floating production vessel.

Item 2: Anchor for floating production vessel.

Item 3: Turbo-Borer machine.

Item 4: Water body.

Item 5: Motor Tubular Support Column.

Item 6: Base Plate.

Item 7: Bedrock.

Item 8: Drill Bit.

Item 9: Fluid delivery pipe.

Fig 2: Shows a dual jacking Rack & Pinion method for providing weight to the drill bit during bore hole drilling.

Item 3: Turbo-Borer machine Item 9 & 10: Axial loading system.

Claims

Claims 1) A method of drilling bore holes from an off-shore or other floating vessel.

2) A method of providing a drilling support structure for drilling a bore-hole in a flooded environment.

3) A method of providing a column structure which acts as a drilling motor jacking support structure.

4) A method of hydraulically or mechanically jacking a drilling motor into bedrock.* 5) A method of drilling a vertical or angled from the vertical bore-hole in a flooded environment.

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* 6) A method of applying a variable oscillating on-off' pressure to the drill bit in : *** operation. ***S

7) A method of drilling an angled borehole from the vertical axis in a flooded environment.

8) A base plate for supporting a tubular motor support column.

9) A base plate designed to have a low profile or an aerodynamic profile to minimise the effect of tidal movement on the structure.

10) A base plate which allows by removing a collar subsequent larger diameter drilled boreboles to be made by opening out the first borehole.