WO2022075852A1

WO2022075852A1 - A lifting tool and a modularized lifting assembly

Info

Publication number: WO2022075852A1
Application number: PCT/NO2021/050201
Authority: WO
Inventors: Helge HOPE
Original assignee: Moonshine Solutions As
Priority date: 2020-10-05
Filing date: 2021-10-04
Publication date: 2022-04-14
Also published as: NO20201079A1

Abstract

A lifting tool (10) comprises an elongated body having a first end portion (11), a second end portion (12), and an intermediate portion (16). The first end portion is configured for connection to a lifting device, and the second end portion comprises a first connection device (12') for connection to a tool or structure or to an interface member (20). The intermediate portion comprises a outer surface (17) with a plurality of recessed portions (13) and an internal support structure (14). The lifting tool may be lifting sub formed of a low-density metal, such as aluminium. A modularized lifting assembly comprises the invented lifting tool and an interface member (20) releasably connected to the first connection device (12').

Description

A lifting tool and a modularized lifting assembly

Technical field of the invention

The invention concerns tools for handling objects, such as tool assemblies, tubulars, and the like, particularly in the oil and gas industry. Specifically, the invention concerns a lifting tool as set out by the preamble of claim 1, and a modularized lifting assembly as set out by the preamble of claim 10.

Background of the invention

A so-called “lifting sub” is generally a device that may be temporarily connected between a lifting apparatus (e.g. a rig elevator or top drive) and an object (e.g. a tool assembly or tubular) that is to be lifted vertically, such as when running or retrieving a tool string. One type of lifting sub is used for lifting objects between a drilling deck and an area adjacent to the drilling deck (e.g. a pipe deck). Lifting subs of this type are used for placing tool assemblies onto a drill string, and for removal of the same.

A prior art lifting sub of this type is typically between 70 cm and 110 cm long and is made of a stainless steel material. Typical weights range between 70 kg and 210 kg. The design and choice of material - and hence the weight - are specified by applicable rules and standards. For example API and NORSOK.

The prior art includes WO 2011/090390 Al, which describes a lifting object for a component for a bottomhole assembly. The lifting object is cylindrical and comprises a radially enlarged, first lift collar arranged at a first end portion of the lifting object, and also a threaded connector arranged at a second end portion of the lifting object. The cylindrical lifting object may be tubular and hollow, such as in conventional lift subs. Alternatively, the cylindrical lifting object may be massive, i.e. heavier and stronger than that of a corresponding, hollow object.

As the weights of prior art lifting subs of this type exceed what may be handled manually, the lifting subs themselves must be handled by cranes or other lifting equipment. Connecting and disconnecting a prior art lifting sub of this type to and from the intended equipment are therefore time-consuming operations. One object of the present invention is to facilitate manual handling of a lifting sub of this type, while maintaining the required structural integrity and load-bearing capabilities of the lifting sub.

Prior art lifting subs comprise an external profile on the upper section that is similar to that of the completion tubing, enabling the rig elevators to lift the assembled tool string safely. The external profile on the lower section of the prior art lifting sub is configured for connection to the object to be lifted, and may for example comprise an externally threaded section. Prior art lifting subs are therefore designed specifically for a given thread configuration and dimension. When the threads of a lifting sub are worn or damaged, the lifting sub must be replaced or refurbished. One object of the present invention is to provide lifting sub of the type described above, that may be connected to objects of varying diameter and thread configuration.

Summary of the invention

The invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the invention.

It is thus provided a lifting tool comprising an elongated body having a first end portion, a second end portion, and an intermediate portion, wherein the first end portion is configured for connection to a lifting device, characterized in that the second end portion comprises a first connection device for connection to a tool or structure or to an interface member; and the intermediate portion comprises an outer surface with a plurality of recessed portions and an internal support structure.

In one embodiment, adjacent recessed portions and a respective intermediate region of the outer surface form gripping regions, by which a human worker may lift and handle the lifting tool.

In one embodiment, an internal stem forms a core of the lifting tool. In one embodiment, the internal support structure comprises a core (stem) and non-recessed portions of the intermediate portion. In one embodiment, the support structure has a cruciform cross-section. In one embodiment, the cross-sectional area of the support structure is smaller than the sum of the cross-sectional areas of the recessed portions. In one embodiment, the lifting tool comprises four recessed portions. The lifting tool may be formed of a low-density metal, such as aluminium. The lifting tool may be a lifting sub.

It is also provided a modularized lifting assembly, characterized by a lifting sub and an interface member releasably connected to a first connection device of the lifting sub via a second connection device on the interface member; the interface member also comprising a third connection device for connection to a tool, tool string, or tubular.

The interface member may be formed of a stainless steel material, and may be a sleeve configured for mating engagement with the second end portion.

In one embodiment of the modularized lifting assembly, the lifting sub is the lifting tool according to the invention.

The invented modular sub may is light-weight and comprises gripping portions, whereby it may be handled manually, i.e. by an on-site worker. The modular design, with the replaceable interface member, makes the sub more versatile and robust, compared to prior art subs.

Brief description of the drawings

These and other characteristics of the invention will become clear from the following description of an embodiment of the invention, given as a non-restrictive example, with reference to the attached schematic drawings, wherein:

Figure l is a exploded perspective view of an embodiment of the invention, and illustrates the invented lifting tool and the invented interface member;

Figure 2 corresponds to figure 2, and shows the lifting tool and the interface member in an assembled state;

Figure 3 is a longitudinal sectional drawing of an embodiment of the interface member;:

Figure 4 is a cross-sectional drawing in the plane A-A in figure 5;

Figure 5 is a side view of the lifting tool;

Figures 6 and 7 illustrate the lifting tool at two different longitudinal sections. Detailed description of embodiments of the invention

The following description may use terms such as “horizontal”, “vertical”, “lateral”, “back and forth”, “up and down”, ’’upper”, “lower”, “inner”, “outer”, “forward”, “rear”, etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader’s convenience only and shall not be limiting.

Referring initially to figure 1, two different but related inventions are disclosed. The first invention comprises a lifting tool 10, and the second invention comprises a modular sub: a combination of a lifting tool 10 and an interface member 20. In the illustrated embodiment, the lifting tool 10 is a lifting sub having a first end portion 11, a second end portion 12, and an intermediate portion 16. The first end portion 11 is configured for connection to a lifting device, such as an elevator (not shown), which is commonly known in the art.

The second end portion 12 comprises a first connection device 12’ for connection to a tool or structure (e.g. a tool assembly or tubular as described above (not shown)) or the interface member 20. In the illustrated embodiment, the first connection device is helical threads 12’.

As shown in figures 1, 2, and 3, the interface member 20 is in the illustrated embodiment a sleeve 20 with a second connection device 22, here internally arranged helical threads 22 that are configured for connection with the helical threads of the first connection device 12’. The sleeve 20 may thus be screwed onto the second end portion 12, to a state illustrated in figure 2. Removable fasteners, here in form of set screws 23 which are extended through holes 24 and into recesses 15, prevent relative rotation between the lifting sub 10 and the sleeve 20. It should be understood that other types of fasteners may be used. Although not illustrated, other connection means between lifting sub 10 and sleeve 20 are conceivable, for example a J-slot connection.

In the illustrated embodiment, the interface member 20 is a sleeve externally shaped as a truncated cone. The external surface comprises a third connection device 21, here in the form of helical threads that are configured for connection to a tool, tool string, or tubular (not shown), for example in a conventional pin-and-box connection. The invention shall not be limited to this shape.

The lifting sub 10 may be formed of a low-density (light-weight) metal, such as titanium or an aluminium alloy. The intermediate portion 16 is solid (i.e. not hollow as in prior art lifting subs) and comprises an outer surface 17 with a plurality of cut-outs, or recessed portions, 13. The recessed portions 13 effectively provide grooves in the intermediate portion, coaxial with an internal support structure. Adjacent recessed portions 13 and a respective intermediate region of the outer surface 17 form gripping regions 17’, by which a human worker may lift and handle the lifting sub. An internal stem forms a core 14 of the lifting sub 10. This is also illustrated in figure 4, where the core (stem) 14 and the non-recessed portions 18 of the intermediate portion form a support structure 14, 18. In the embodiment shown in figure 4, the support structure 14, 18 has a cruciform cross-section, and the cross-sectional area of the support structure (14, 18) is smaller than the sum of the cross-sectional areas of the recessed portions 13. Figure 4 shows an embodiments having four recessed portions 13.

The interface member 20 may be formed of a stainless steel, in order for the third connection device (e.g. external threads) 21 to be compatible with the connection device on the tool, tool string, or tubular. This modular sub (the combined lifting sub and interface member assembly) allows the sub to be used multiple times without excessive wear: the interface member 20 may be replaced as and when necessary.

In one embodiment, the lifting sub has a length of approximately 819 mm, a diameter of approximately 178 mm, and is formed of an aluminium alloy with a density of 2.89 cm³, giving a total weight 19.8 kg. The stainless steel sleeve may have a weight in the order of 4 to 5 kg. The invention shall not be limited to these dimensions and/or weights.

The invented assembly of the lifting sub 10 and interface member 20 may be designed to have a mass less than 25 kg, while still being operational as an offshore lifting sub. Tests have shown that an embodiment of the invented lifting sub with a weight of less than 25kg would be able to handle loads of 2000 kg while still performing as well as a traditional lift sub.

Claims

6 Claims

1. A lifting tool (10) comprising an elongated body having a first end portion (11), a second end portion (12), and an intermediate portion (16), wherein the first end portion is configured for connection to a lifting device, characterized in that

- the second end portion comprises a first connection device (12’) for connection to a tool or structure or to an interface member (20);

- the intermediate portion comprises an outer surface (17) with a plurality of recessed portions (13) and an internal support structure (14, 18).

2. The lifting tool of claim 1, wherein adjacent recessed portions (13) and a respective intermediate region of the outer surface (17) form gripping regions (17’), by which a human worker may lift and handle the lifting tool.

3. The lifting tool of any one of claims 1-2, wherein an internal stem forms a core (14) of the lifting tool (10).

4. The lifting tool of any one of claims 1-3, wherein the internal support structure (14, 18) comprises a core (stem) (14) and non-recessed portions (18) of the intermediate portion (16).

5. The lifting tool of claim 4, wherein the support structure (14, 18) has a cruciform cross-section.

6. The lifting tool of any one of claims 1-5, wherein the cross-sectional area of the support structure (14, 18) is smaller than the sum of the cross-sectional areas of the recessed portions (13).

7. The lifting tool of any one of claims 1-6, comprising four recessed portions (13).

8. The lifting tool of any one of claims 1-7, wherein the lifting tool is formed of a low-density metal, such as aluminium.

9. The lifting tool of any one of claims 1-8, wherein the lifting tool is a lifting sub.

10. A modularized lifting assembly, characterized by:

- a lifting sub (10); 7

- an interface member (20) releasably connected to a first connection device (12’) of the lifting sub via a second connection device (22) on the interface member; the interface member also comprising a third connection device (21) for connection to a tool, tool string, or tubular.

11. The lifting assembly of claim 10, wherein the interface member is formed of a stainless steel material.

12. The lifting assembly of claim 10 or claim 11, wherein the interface member is a sleeve configured for mating engagement with the second end portion (12).

13. The lifting assembly of any one of claims 10-12, wherein the lifting sub is the lifting tool (10) of any of any one of claims 1-9.