WO2008012580A1

WO2008012580A1 - Racking module

Info

Publication number: WO2008012580A1
Application number: PCT/GB2007/050442
Authority: WO
Inventors: Brendan Larkin
Original assignee: Ohs Group Limited
Priority date: 2006-07-25
Filing date: 2007-07-25
Publication date: 2008-01-31
Also published as: GB0614744D0; US20100143078A1

Abstract

A drilling derrick (2) comprises a lower section (4) and an upper section (6) separated by a racking module (8). The lower section (4) of the derrick (2) is constructed from a number of sections of metal scaffolding (10). The upper section (6) of the derrick (2) is constructed from a similar number of metal sections (12).

Description

RACKING MODULE

This invention relates to a racking module, more specifically to a racking module for an oil field/gas field drilling rig.

A drilling derrick is a structure which is mounted on a drilling rig. The derrick sits on the drill floor and lowers/raises a drillstring down/up a hole for drilling. The drillstring is usually supplied in sections 30 feet or 45 feet long and is stored within the derrick in 90 foot lengths known as stands or triples. Approximately 250 stands may be stored within a derrick.

The stands are usually stored in the derrick in racking boards. The racking boards are situated approximately 90 feet up the derrick and form the interface between the lower section of the derrick and the upper section thereof. Stands are usually stored in the racking boards such that the upper end is held by the racking boards and the lower end rests on the drill floor.

Stands are removed from and repositioned in the racking boards by specialised equipment or by a combination of machinery and manual manipulation. Such machinery and/or equipment must also be installed within the derrick. The majority of the action which takes place in the drilling derrick occurs at the racking boards.

A drilling derrick structure is typically constructed in a piecemeal fashion. Typically a derrick will be constructed from about 150 separate pieces which are fixed together to form a structure with a great deal of structural integrity. This method of construction is used for many practical reasons including ease of repair, avoidance of unnecessary welding and ease of calculation reasons .

During the construction of the derrick, the equipment necessary for drilling and handling the drillstring and stands must be carried up to and installed within the derrick at the racking boards. The upper section of the derrick can not be completed until all the necessary equipment is in place at the racking boards. The area surrounding the racking boards is the area where most of the action takes place.

This method of construction is disadvantageous because the erection of the derrick takes a long time and regulations often dictate that work cannot continue on the drill floor whilst the erection of the derrick is ongoing.

Further disadvantages lie in the fact that individual items of equipment must be hoisted up and manoeuvred into position at the racking boards, leading to a difficult, long and expensive construction process.

It is an object of the present invention to overcome these or other problems associated with the prior art.

According to a first aspect of the present invention, there is provided a racking module having a unitary construction comprising a framework fitted with drilling equipment and drill stand handling equipment, the module being securable to an upper part of a lower section of a drilling derrick and defining an interface between the lower section of the derrick and an upper section thereof.

Preferably, the framework is constructed from metal. The metal framework may be coated to prevent corrosion. Preferably, drilling equipment is installed within the framework of the racking module.

Preferably, the racking module comprises racking boards for storing drill stands.

Preferably, the racking module further comprises drill stand handling equipment. The drill stand handling equipment may be operable to move drill stands into and/or out of the racking boards. Preferably, the drill stand handling equipment comprises a bridge crane racker.

Preferably, the racking module has power supplies and control systems to control the equipment installed therein. These systems preferably comprise control solenoids. More preferably, the racking module also comprises a control station to allow a derrick worker to control the equipment installed therein.

The racking module may comprise further equipment or machinery. Preferably, the racking module contains an elevator .

Preferably, the equipment installed within the racking module may be altered depending on individual requirements . Preferably, the racking module has feet on the corners thereof to enable the module to be secured to a drilling derrick .

The racking module may be between approximately 10 feet and 50 feet tall, preferably, between 15 feet and 30 feet tall. Preferably, the racking module may be securable to any size of drilling derrick. Preferably, the positions of the feet may be altered to be secured to narrower and/or wider derrick structures.

According to a second aspect of the present invention there is provided a method of constructing a drilling derrick comprising the steps of :- a) constructing a lower section of the derrick; b) securing a racking module to the upper surface of the lower section of the derrick; and c) securing an upper section of the derrick to the upper surface of the racking module.

Preferably, equipment is installed within the racking module prior to its being secured in place on the lower section of the derrick. More preferably, equipment is installed within the racking module at ground level.

The upper section of the derrick may be constructed prior to its being secured in place. Alternatively, the upper section of the derrick may be constructed on site above the racking module.

According to a further aspect of the present invention there is provided a method of assembling a racking module including: - a) installing and securing drilling and stand handling equipment into the racking module framework; and b) securing the fully equipped racking module to the upper surface of a lower section of a drilling derrick.

Preferably, the installation and securing of the drilling and handling equipment is performed at ground level. The equipment may also be tested and commissioned at ground level. The equipped racking module may then be lifted in one piece to the upper surface of the lower section of the derrick and secured in place.

This unitary racking module allows the construction time of the drilling derrick to be greatly reduced. Individual pieces of equipment and machinery need not be carried up to the derrick one at a time as they are all first secured in place in the racking module which is lifted up to the derrick in one piece. Furthermore, testing of installed equipment at ground level allows any repairs and/or replacements to be dealt with before the equipment is raised up to the derrick.

All of the features described herein may be combined with any of the above aspects, in any combination.

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which:

Figure 1 is a schematic view of a drilling derrick; and Figure 2 is a schematic perspective view of a racking module .

Referring to figure 1, a drilling derrick 2 comprises a lower section 4 and an upper section 6 separated by a racking module 8. The lower section 4 of the derrick 2 is constructed from a number of sections of metal scaffolding 10. The upper section 6 of the derrick 2 is constructed from a similar number of metal sections 12.

The derrick 2 is situated on the drillfloor 14 of a drilling rig.

The lower section 4 of the derrick 2 is approximately 80 feet to 90 feet tall when measured from the drillfloor 14.

The upper section 12 of the derrick 2 extends substantially upwardly from the upper surface of the racking module 8 (approximately about 100 feet above the drillfloor) to approximately about 170 feet to 200 feet above the drill floor 14. The racking module 8 is approximately 20 feet tall.

The racking module 8 is located at, and forms, the interface between the lower section 4 and the upper section 6 of the derrick 2. The racking module 8 contains equipment for handling and storing sections of a drillstring 16.

The drillstring 16 comprises drill stands of 90 feet in length. The drill stands in turn comprise usually three 30 feet lengths of drill pipe connected together. The drill stands are stored in the racking module 8 within the derrick 2 prior to and after connection to the drillstring 16. This will be described in more detail below with reference to figure 2.

The drillstring 16 is raised and lowered by handling equipment located in the upper section 6 of the derrick 2.

The handling equipment comprises a fast line 18 which is connected to the upper end of the drillstring 16. The fastline 18 passes over a diverter sheave 20 and a crown block 22 which are located in the gin pole 24 of the derrick 2. The fastline 18 then passes down into the derrick structure through a water table 26 and under a travelling block 28 before returning up to the water table 26 where it is fixedly secured.

In use, the travelling block 28 is moved down the central line of the derrick 2 to raise the drillstring 16. The top drill stand is the removed from the fast line 18 and stored in the racking module 8, whilst the travelling block 28 moves back to its initial position and the fast line 18 is connected to the upper end of the next drill stand.

Referring now to figure 2, the racking module 8 comprises a framework 32 within which various equipment is secured.

On the lower surface of the racking module 8 there are situated racking boards 34. Drill stands are held in place in the gaps 36 between the racking boards 34. The racking boards 34 are controlled by control solenoids 38 located within the framework 32. A bridge crane racker 42 is provided in the racking module 8 to perform automated racking of drill stands. The bridge crane racker 42 is comprised essentially of three parts: a head portion 44, an arm portion 46 and a bridge portion 48.

The head portion 44 of the racker 42 is shaped to receive and hold an upper end of a drill stand. The head portion 44 is mounted on the arm portion 46 of the racker such that it is able to move in a substantially vertical direction along the arm portion 46, as denoted by arrow Z in figure 2.

The arm portion 46 of the racker 42 is situated substantially perpendicularly to the bridge portion 48 of the racker 42 and extends in a substantially vertical manner down from the bridge portion 48. The arm portion 46 is movably mounted on the bridge portion 48 such that it is operable to move along the bridge portion 48 in the direction denoted by arrow Y in figure 2, substantially parallel to the racking boards 34.

The bridge portion 48 of the bridge crane racker 42 is movably supported at both ends on the upper surface of the framework 32 of the racking module 8. The bridge portion 48 lies across the racking module 8 in a direction substantially parallel to the racking boards 34. Hydraulic pistons 50 are provided to move the bridge portion 48 along the upper surface of the framework 32 in a direction denoted by the arrow X in figure 2. Thus, the bridge crane racker 42 is operable to move a drill stand from the drill string to the racking boards 34 and vice versa.

The bridge crane racker 42 is powered by the control solenoids 52 situated within the framework 32 of the racking module 8. A derrickman's cabin 54 is provided within the racking module 8 with controls to enable the bridge crane racker 42 and other equipment to be operated from within the racking module 8. This allows the operator to control the equipment more accurately than is possible when controlling it from the ground.

A monkey board 40 is also provided for manual manipulation of the drill stands into and out of the racking boards 34 in case of power failure, machinery breakdown, and the like.

Other items of equipment, such as an elevator, may be provided within the racking module 8.

The lower corners of the racking module framework 32 are provided with feet 56 which enable the racking module 8 to be secured to the upper surface of the lower section 4 of a drilling derrick.

Similarly, the upper corners are provided with feet 58 which allow the upper section 6 of a drilling derrick to be constructed on the racking module 8.

A wall 60 is provided on the outer surfaces of the racking module 8 in order to protect the equipment and workers in the racking module 8 from wind and/or other adverse weather conditions.

In operation, the bridge crane racker 42 is moved in such a way that the head portion 44 engages with the upper end of the drillstring 16. The top drill stand is then removed from the drillstring 16 and is held by the racker

42. The bridge crane racker 42 is then moved such that the drill stand is received in the racking boards 34. This operation may also be carried out in reverse to move the drill stands out of the racking boards 34 to be connected to the drillstring 16.

The modular construction of the racking module of the present invention allows for the installation of handling equipment for drill stands, and/or other items of equipment to be installed within the racking module whilst it is still at ground level. This prevents the time consuming and difficult process of hoisting up individual pieces of machinery to the racking boards for installation. The present modular system also allows work to be continuing on the installation of equipment in the racking module at the same time as work is ongoing on construction of the derrick. Such concurrent work greatly reduces the length of time required to erect a derrick construction .

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s) . The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A racking module has a unitary construction comprising a framework fitted with drilling equipment and drill stand handling equipment, the module being securable to an upper part of a lower section of a drilling derrick and defining an interface between the lower section of the derrick and an upper section thereof.

2. A racking module as claimed in claim 1, in which the framework is constructed from metal.

3. A racking module as claimed in claim 1 or claim 2 , in which drilling equipment is installed within the framework of the racking module.

4. A racking module as claimed in any preceding claim, in which the racking module comprises racking boards for storing drill stands.

5. A racking module as claimed in any preceding claim, in which the racking module further comprises drill stand handling equipment.

6. A racking module as claimed in claim 5, in which the drill stand handling equipment is operable to move drill stands into and/or out of the racking boards.

7. A racking module as claimed in any preceding claim, in which the drill stand handling equipment comprises a bridge crane racker.

8. A racking module as claimed in any preceding claim, in which the racking module has power supplies and control systems to control the equipment installed therein.

9. A racking module as claimed in any preceding claim, in which the racking module also comprises a control station to allow a derrick worker to control the equipment installed therein.

10. A racking module as claimed in any preceding claim, in which the racking module contains an elevator.

11. A racking module as claimed in any preceding claim, in which the racking module has feet on the corners thereof to enable the module to be secured to a drilling derrick.

12. A racking module as claimed in any preceding claim, in which the racking module is between approximately 10 feet and 50 feet tall,

13. A racking module as claimed in any preceding claim, in which the racking module is securable to any size of drilling derrick.

14. A racking module as claimed in any preceding claim, in which the positions of the feet may be altered to be secured to narrower and/or wider derrick structures.

15. A method of constructing a drilling derrick comprises the steps of:- a) constructing a lower section of the derrick; b) securing a racking module to the upper surface of the lower section of the derrick; and c) securing an upper section of the derrick to the upper surface of the racking module.

16. The method of claim 15, in which equipment is installed within the racking module prior to its being secured in place on the lower section of the derrick.

17. The method of claim 16, in which equipment is installed within the racking module at ground level.

18. The method of any one of claims 15 to 17, in which the upper section of the derrick is constructed prior to its being secured in place.

19. A method of assembling a racking module including: - a) installing and securing drilling and stand handling equipment into the racking module framework; and b) securing the fully equipped racking module to the upper surface of a lower section of a drilling derrick.

20. The method of claim 19, in which the installation and securing of the drilling and handling equipment is performed at ground level.

21. The method of claim 20, in which the equipment is also tested and commissioned at ground level.

22. The method of claim 21, in which the equipped racking module is then lifted in one piece to the upper surface of the lower section of the derrick and secured in place.

23. A racking module substantially as described herein with reference to the accompanying drawings.

24. A method of assembling a racking module substantially as described herein with reference to the accompanying drawings .

25. A method of constructing a drilling derrick substantially as described herein with reference to the accompanying drawings.