GB2265642A

GB2265642A - Improvements in or relating to down-hole locating tools

Info

Publication number: GB2265642A
Application number: GB9207123A
Authority: GB
Inventors: George Philip Brandie
Original assignee: BRANDIE MICHAEL
Current assignee: BRANDIE MICHAEL
Priority date: 1992-04-01
Filing date: 1992-04-01
Publication date: 1993-10-06
Anticipated expiration: 2012-04-01
Also published as: GB2265642B; GB9207123D0

Abstract

There are several disadvantages to presently known down-hole locating tools or stingers, for example excessive lowering speeds resulting in equipment damage. The present invention provides a down-hole locating tool (5) comprising a shaft (10) having a nose (15) at a first end (20) thereof, a second end (25) of the shaft (10) being held moveably and rotably within a first hollow elongate body (30), further comprising a second hollow elongate body 45 retained between the ends (20, 25) of the shaft (10). A first surface (65) of the second body (45) faces the first end (20) of the shaft (10) and is substantially complementary to a surface within a keyway of another tool in relation to which the tool (5) is to be located. A first surface (70) of the first body (30) faces the first end (20) of the shaft (10) and is substantially complementary to, and spacable from, a second surface (75) of the second body (45) facing the second end (45) of the shaft (10), such that, in use, the nose (15) can be located within the keyway in the other tool and the respective surfaces (65, 70, 75) brought into contact with one another. This arrangement allows the tool to pass obstructions without hanging-up but with a lower running speed than prior art tools. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO DOWN-HOLE LOCATING TOOLS This invention relates to down-hole locating tools usually referred to as stingers - and in particular, but not exclusively, to a down-hole locating tool for use in directional drilling which, in use, is run down the inside of a drill pipe string on the bottom of a gyroscope package by means of wireline, the tool then being seated into a down-hole orienting sub or Universal Bottom Hole Orienter (UBHO).

There are several disadvantages to presently known stingers. For example, the stingers used in most well site operations have to be run into the drill string at speeds in excess of 150 - 200 feet per minute so as to prevent the stinger from "hanging-up" in the inner surface of the drill string, ie. becoming stuck on obstructions, such as inclined lips. This lowering speed often results in expensive or irreparable damage to the gyroscope survey equipment run above the stinger.

Consequential downtime of the drilling rig is also highly costly.

It is therefore, an object of the present invention to obviate or mitigate the aforementioned disadvantages in the prior art.

Accordingly, a first aspect of the present invention provides a down-hole locating tool comprising a shaft having a nose at a first end thereof, a second end of the shaft being held moveably and rotably within a first hollow elongate body, further comprising a second hollow elongate body retained between the ends of the shaft, wherein , a first surface of the second body facing the first end of the shaft is substantially complementary to a surface within a keyway of another tool in relation to which the tool is to be located, and a first surface of the first body facing the first end of the shaft is substantially complementary to, and spacable from, a second surface of the second body facing the second end of the shaft, such that, in use, the nose can be located within the keyway in the other tool and the respective surfaces brought into contact with one another In use, normally, the nose of the tool will be oriented vertically downward.

The elongate first and second bodies are each preferably substantially cylindrical.

The first surface of the second body is preferably inclined at an acute angle to the central axis of the second body.

The second surface of the second body, and the first surface of the first body, are preferably inclined at substantially the same acute angle to the central axis of the second body and the first body respectively.

If the surfaces are so inclined, they may be termed "muleshoes n due to their shape. Hence, the second body may be termed as a "dual muleshoe'1 sub.

Preferably, the first and second surfaces of the second body are inclined at substantially the same acute angle to the central axis of the second body, but in opposing directions.

Biassing means are preferably retained on the second end of the shaft inside the hollow first body, the biassing means having no effect when the second surface of the second body and the first surface of the first body are distant from one another, but acting to urge the surfaces apart when the surfaces are brought together, in use.

In this way the biassing means prevents the second and first surfaces from the meeting while the tool is being lowered, even if the nose becomes snagged, and allows the second and first surfaces to meet when the tool is located, in use.

Preferably, a keyway slot is provided on the outer surface of the second body adjacent to the first surface thereof at a position on the surface furthest from the nose, an impression slug being provided within the slot, which slug also passes through the shaft and is retained therein.

Preferably, a further slot is also provided on the outer surface of the second body adjacent to the second surface thereof at a position on the surface closest to the nose, an further impression slug being provided within the further slot, which further slug also passes through the shaft and is retained therein.

Preferably, a hole is provided through the shaft at or near the second end thereof, a further hole also being provided through a suitable position on the first body, such that the first and second bodies can be urged together against the force of the biassing means until the first surface of the first body and the second surface of the second body meet, the hole and further hole then being aligned with one another, and a locking pin subsequently passed therethrough.

According to a second aspect of the present invention there is provided a down-hole locating tool comprising a shaft having a nose at a first end thereof, a second end of the shaft being held moveably and rotably within a first hollow elongate body, further comprising a second hollow elongate body retained between the ends of the shaft, wherein a first surface of the second body facing the first end of the shaft is substantially complementary to a surface within a keyway of another tool in relation to which the tool is to be located, the first surface of the second body being inclined at an acute angle to the central axis of the second body, and a first surface of the first body facing the first end of the shaft is substantially complementary to, and spacable from, a second surface of the second body, the second surface of the second body and, the first surface of the first body being inclined at substantially the same acute angle to the central axes of the second body and the first body respectively, further comprising a biassing means retained on the second end of the shaft inside the first body, the biassing means having no effect when the second surface of the second body and the first surface of the first body are distant from one another, but acting to urge the surface apart when the surfaces are brought together, wherein further, in use, the nose can be located with the keyway in the other tool and the respective surfaces brought into contact with one another.

According to a third aspect of the present invention, there is provided a down-hole locating tool comprising a two-part tubular member having keying engageable surfaces therebetween and a shaft mounted at its upper end for rotatable and resiliently buffered longitudinal movement relative to a first upper part of the tubular member, a second lower part of the tubular member being fixedly attached towards the lower end of the shaft and being formed with keying surfaces for engagements with a lower tool, in use.

According to a fourth aspect of the present invention there is provided a down-hole tool assembly providing a down-hole locating tool, as defined in any of the previous aspects of the invention, at the downmost end thereof.

An embodiment of the present invention will now be described, by way of example only with reference to the accompanying drawings which are: Fig 1 - a schematic cross-sectional view from one side of a down-hole locating tool according to the present invention; and Fig 2 - a schematic view of a second body and partial schematic view of a first body for use in the down-hole locating tool of Fig 1 along direction 'A'.

Referring to the drawings, there is provided a down-hole locating tool, generally designated 5, comprising a shaft 10 having a nose 15 at a first end 20 thereof. A second end 25 of the shaft 10 is held within a first hollow substantially cylindrical body 30. The second end 25 has an upstanding threaded portion 35, so that the second end 25 can be held in the first body 30, by means of a threaded retaining nut 40 threadably attached to the portion 35.

In this way, the second end 25 can be moved within the first body 30 and also rotated about its own axis.

The first body 30 comprises first and second parts 31a, 31b detachably attachable to one another by means of a joint 32 having a lock ring.

The second portion 31b of the first body 30 has a plurality of holes 33 passing through the side wall thereof, the holes 33 providing means for fluid escape from the inside of the first body 30, in use. Further, the holes 33 ensure that the pressure inside and outside the first body 30 is substantially the same, in use.

At an end of the second portion 31b distant from the first portion 31a there is provided a vented upper body 34 connectable to further equipment, such as a gyroscope.

The upper body 34 is vented so as to allow hydrostatic pressure balance between the body 34 and the wellbore (not shown).

A second hollow substantially cylindrical body 45 is provided between the ends-of the shaft 10, the second body 45 being suitably positioned and retained thereon by means of a shoulder 50 on the shaft 10 which co-acts with a complementary reduced inner diameter portion 55 of the second body 45 to suitably position the second body 45, and by means of assembly pins 60 (in this embodiment three such pins 60 are provided) which pass through the second body 45 and shaft 10 via corresponding aligned holes in the second body 40 and shaft 10.

In this way the second body 45 is securely positioned on the shaft 10.

A first surface 65 of the second body 45 which faces the first end 20 of the shaft 10 is inclined at an acute angle to the central axis of the second body 45 and is substantially complementary to a surface within a keyway of another tool (not shown) in relation to which the tool 5 is to be located.

Also, a first surface 70 of the first body 30 facing the first end 20 of the shaft 10, and also a second surface 75 of the second body 45 facing the second end 25 of the shaft 10, are inclined at substantially the same acute angle as each other to the central axes of the second body 5 and the first body 30 respectively, the central axes being substantially co-incident with one another.

As can by seen from the drawings, in this embodiment, the first and second surfaces 65, 75 of the second body 45 are inclined to the central axis of the second body 45 in opposing directions.

Due to their inclined natures, the surfaces 65, 70, 75 can be termed "muleshoes", and the second body 45 therefore termed a "dual-muleshoe" sub. This "mule-shoe" shape is particularly advantageous in ensuring correct locating of the tools, in use.

A keyway slot 80 is provided on the outer surface of the second body 45 adjacent to, and extending from, the first surface 65 thereof at a position on the surface 65 furthest from the first end 20. A first hole 85 is provided through the shaft 10 and second body 45 at a position substantially corresponding to the end of the keyway slot 80, the first hole 85 being suitable for retaining a first slug 90, such as a lead impression slug, therein.

Further a slot 95 is provided on the outer surface of the second body 45 adjacent to, and extending from, the second surface 75 thereof at a position on the surface 75 closest to the first end 20. A second hole 100 is provided through the shaft 10 and second body 45 at a position substantially corresponding to the slot 95, the second hole 100 being suitable for retaining a second slug 105, such as a lead impression slug, therein.

Baissing means 110 in the form of a compression spring, are provided on the second end 25 of the shaft 10 inside the hollow first body 30. A first end 115 of the spring 110 is retained on the second end 25 of the shaft 10, while a second end 120 of the spring 110 is free within the hollow first body 30 when the second surface 75 of the second body 45 and the first surface 70 of the first body 30 are distant from one another, and abuts a second surface 125 of the first body 30, which surface 95 faces the shaft 10, so as to urge the surfaces 70, 75 apart if and when the surfaces 70, 75 are brought together.

A third hole 130 is provided at or near the second end 25 of the shaft 10. Further, a fourth hole 135 is provided at a suitable position in the side wall of the first body 30. The third and fourth holes 130, 135 can be aligned with one another, against the force of the spring 110 such that the surfaces 70, 75 meet, and a locking pin 140 passed therethrough. A grub screw 145 can then be used to secure the locking pin 140 in the third and fourth holes 130, 135.

In this way, the tool 5 can be configured for storage, or for use as a conventional down-hole locating tool. To prepare the tool 5 for use, the screw 145 and locking pin 140 are removed so that the shaft 10 can move and rotate freely within the first body 30 Once the tool 5 has been prepared for use, the upper body 34 can be attached to further equipment (not shown), such as a gyroscope, and the resulting assembly run down the inside of a drill pipe string on wireline. The tool 5 will then be configured substantially as shown in Fig 1.

On lowering, if the shaft 10 or second body 45 snag on any obstructions inside the drill pipe string, the shaft 10 will move and/or rotate within the first body 30. In this way, the effects of such snagging on the further equipment is reduced in comparison to conventional downhole locating tools. Further, if the shaft 10 or second body 45 snag such that the second end 120 of the spring 110 abuts the second surface 125 of the first body 30, the force exerted by the spring 110 upon the shaft 10 will tend to force the tool 5 past the obstruction, thereby aiding in the free running of the tool 5 down the drill pipe string.

Once the tool 5 has been lowered, the nose 15 is seated in a keyway of another tool in relation to which the tool 5 is to be located. This other tool may be a down-hole orienting sub or Universal Bottom Hole Orienter (UBHO), for example, provided at the top of a bottom hole assembly comprising a bit, motor, Measurement While Drilling (MWD) tool and UBHO. Once the nose 15 is seated in the keyway, the second body 45 is located in the UBHO due to the shape of the first surface 65, the shape of the first surface 65 being such that its mating with, and orientation in relation to, a corresponding surface in the keyway is ensured. Subsequently, the spring 110 compresses under the weight of the assembly thus allowing the mating of the second and first surfaces 75,70.The shapes of the surfaces 70,75 ensure that they mate, and also that the orientation of the gyroscope in relation to the first surface 70, second surface 75, first surface 65 and hence the corresponding keyway surface, is known.

On successful mating of the respective surfaces, the lead impression slugs 90, 105 will be indicatively marked by a marker means (not shown) within the keyway, and by a pointed portion 150 integral with a lowerermost edge of the first surface 70 of the first body 30.

On retrieval the lead impression slug 90, will give an indication of whether or not the first surface 65 correctly mated with the UBHO. Further, the lead impression slug 105 will give an indication of whether or not the first surface 70 and second surface 75 correctly mated.

The tool 5 can be retrieved by wireline. The surfaces 75, 70 will be moved apart until the second end 25 of the shaft 10 can move no further within the first body 30.

The first surface 65 will then be moved away from the corresponding surface in the keyway, and the nose 15 disengaged from the keyway.

The embodiment of the invention hereinbefore described is given by way of example only, and is not meant to limit the scope of the invention in any way.

It should particularly be understood that the tool 5 has been made to be run and seated at speeds not exceeding 50 feet per minute, thereby reducing the possibility of damaging the further equipment of the assembly.

It should also be appreciated that the biassing means 110 can be replaced, and that a choice of such can be provided, the choice of biassing means 110 used being dependent upon the weight of the assembly so as to ensure that the biassing means 110 does not force the first and second surfaces 70, 75 apart once the tool 5 has been seated.

Claims

1. A down-hole locating tool comprising a shaft having a nose at a first end thereof, a second end of the shaft being held moveably and rotably within a first hollow elongate body, further comprising a second hollow elongate body retained between the ends of the shaft, wherein , a first surface of the second body facing the first end of the shaft is substantially complementary to a surface within a keyway of another tool in relation to which the tool is to be located, and a first surface of the first body facing the first end of the shaft is substantially complementary to, and spacable from, a second surface of the second body facing the second end of the shaft, such that, in use, the nose can be located within the keyway in the other tool and the respective surfaces brought into contact with one another.

2. A down-hole locating tool as claimed in claim 1, wherein the elongate first and second bodies are each substantially cylindrical.

3. A down-hole locating tool as claimed in any preceding claim, wherein the first surface of the second body is inclined at an acute angle to a central axis of the second body.

4. A down-hole locating tool as claimed in any preceding claim, wherein the second surface of the second body, and the first surface of the first body, are inclined at substantially the same acute angle to the central axis of a second body and the first body respectively.

5. A down-hole locating tool as claimed in any preceding claim, wherein the first and second surfaces of the second body are inclined at substantially the same acute angle to a central axis of the second body, but in opposing directions.

6. A down-hole locating tool as claimed in any preceding claim, wherein biassing means are retained on the second end of the shaft inside the hollow first body, the biassing means having no effect when the second surface of the second body and the first surface of the first body are distant from one another, but act to urge the surfaces apart when the surfaces are brought together, in use.

7. A down-hole locating tool as claimed in any preceding claim, wherein a keyway slot is provided on the outer surface of the second body adjacent to the first surface thereof at a position on the surface furthest from the nose, an impression slug being provided within the slot, which slug also passes through the shaft and is retained therein.

8. A down-hole locating tool as claimed in claim 7, wherein a further slot is provided on the outer surface of the second body adjacent to the second surface thereof at a position on the surface closest to the nose, a further impression slug being provided within the further slot, which further slug also passes through the shaft and is retained therein.

9. A down-hole locating tool as claimed in claim 6, wherein a hole is provided through the shaft at or near the second end thereof, a further hole also being provided through a suitable position on the first body, such that the first and second bodies can be urged together against the force of the biassing means until the first surface of the first body and the second surface of the second body meet, the hole and further hole then being aligned with one another, and a locking pin subsequently passed therethrough.

10. A down-hole locating tool comprising a shaft having a nose at a first end thereof, a second end of the shaft being held moveably and rotably within a first hollow elongate body, further comprising a second hollow elongate body retained between the ends of the shaft, wherein a first surface of the second body facing the first end of the shaft is substantially complementary to a surface within a keyway of another tool in relation to which the tool is to be located, the first surface of the second body being inclined at an acute angle to the central axis of the second body, and a first surface of the first body facing the first end of the shaft is substantially complementary to, and spacable from, a second surface of the second body, the second surface of the second body and, the first surface of the first body being inclined at substantially the same acute angle to the central axes of the second body and the first body respectively, further comprising biassing means retained on the second end of the shaft inside the first body, the biassing means having no effect when the second surface of the second body and the first surface of the first body are distant from one another, but acting to urge the surfaces apart when the surfaces are brought together, wherein further, in use, the nose can be located with the keyway in the other tool and the respective surfaces brought into contact with one another.

11. a down-hole locating tool comprising a two-part tubular member having keying engageable surfaces therebetween and a shaft mounted at its upper end for rotatable and resiliently buffered longitudinal movement relative to a first upper part of the tubular member, a second lower part of the tubular member being fixedly attached towards the lower end of the shaft and being formed with keying surfaces for engagements with a lower tool, in use.

12. A down-hole tool assembly providing a down-hole locating tool, as claimed in any of claims 1 to 11 at the downmost end thereof.

13. A down-hole locating tool as hereinbefore described with reference to the accompanying drawings.

14. A down-hole tool assembly providing a down-hole locating tool as hereinbefore described with reference to the accompanying drawings.