GB2358208A

GB2358208A - Liner setting tool with radial washout ports

Info

Publication number: GB2358208A
Application number: GB0100858A
Authority: GB
Inventors: Paul Howlett
Original assignee: SPS Afos Group Ltd
Current assignee: Schlumberger UK Holdings Ltd
Priority date: 2000-01-12
Filing date: 2001-01-12
Publication date: 2001-07-18
Also published as: GB0100858D0; US20010017210A1; GB0000497D0

Abstract

A liner setting tool (1) for running a liner (11) or casing into a borehole (9) has an elongate body (2) for attachment to the liner (11) or casing. Rotation of the body (2) relative to the liner (11) allows radial outlets (6) present on the body (2) to move from a position where they are closed by the liner (11) to a position where they align with ports (12) on the liner (11) and are therefore open. Such an arrangement allows cementing to occur in a conventional way, where cement is pumped through outlet (8) of the tool and also allows the bore (9) to be cleaned by pumping cleaning fluid through ports (6). Seal rings may also be present to restrict flow of fluid between the tool (1) and the liner (11).

Description

1 2358208 1 LINER SETTING TOOL 2 3 The present invention relates to a

liner setting tool as 4 may be typically used to introduce liner or casing into a 5 well bore. 6 7 It is conventional practice to drill a well bore in 8 sections, where a drill shoe mounted on the end of a 9 drill string is run to a predetermined depth and then 10 removed or "tripped". Structural casing is then 11 introduced and cemented in place in the newly formed 12 section in order to stabilise the bore to prevent 13 collapse of unstable sections and prevent contamination 14 of the oil or gas reservoir. Further sections of the 15 bore can then be drilled and cased off by further casing 16 or liner, the latter being typically used near the 17 production area of the bore. 18 19 In order to set liner, the drill shoe used to bore the 20 well is tripped from the well and the structural liner is 21 lowered into the bore on a work string through the 22 previously drilled and cased section of well. 23 Conventionally the liner is mounted on a hanger which is 24 adapted to temporarily hold the liner in place prior to 2 1 cementing. The liner can then be cemented in place by 2 pumping cement slurry to the bottom of the bore from 3 where it is displaced into the annular gap between the 4 outer wall of the lining and the external wall of the bore. The work string and hanger can then be removed 6 from the bore after the cement has set the liner in 7 place.

8 9 During the boring procedure, fluid is continuously passed through the section of well being bored to lubricate the 11 drill and wash out the bore by bringing drill cuttings to 12 the surface. However it is also advantageous to pass 13 fluid through the bore after the liner has been cemented 14 in place, to eliminate any foreign matter such as scale or burrs which may remain within the well and well wall.

16 This prevents any subsequent contamination of the oil or 17 gas reservoir.

18 19 It is uncommon for the cement which passes into the annulus to set entirely and evenly. In particular, fluid, 21 may leak into the annular area during the cementing 22 procedure and weaken sections of the cement. As a result:

23 it is common for the cement to have cracks or gaps within 24 it which can harbour foreign material.

26 To prevent contamination of the oil or gas reservoir it 27 is therefore advantageous to wash out the entire area 28 around the liner and work string, including the annular i 29 area which is cemented. This is difficult, however, as 1 conventional liner setting tools are configured to only 31 allow fluid flow in axial direction, as the standard 32 method for cementing the annular space between the liner 33 and bore wall is achieved by pumping cement axially to 3 1 the bottom of the section of well from where it is 2 displaced into the annulus. As a result, after the 3 cement sets, flow is restricted in the axial direction by 4 the cement itself. It would therefore be a distinct 5 advantage to provide a liner setting tool which allows 6 liner or casing to be run into a well bore and cemented 7 in place in the conventional manner, but which also 8 allows the flow of a cleaning fluid in a radial direction 9 after the cement has been set. 10 11 It is an object of the present invention to provide a 12 liner setting tool for running liner or casing into a pre 13 formed well bore. 14 15 It is a further object of the present invention to 16 provide a liner setting tool which facilitates both 17 cementing to set the liner or casing in place and fluid 18 by pass to allow cleaning of the bore. 19 20 It is a yet further object of the present invention to 21 provide a liner setting tool which in a first 22 configuration allows cement to flow in an axial direction 23 to the bottom of the section of well bore, and in a 24 second configuration allows fluid by pass in a radial 25 direction into the annulus between the liner or casing 26 and the bore wall. 27 28 It is a further object of the present invention to 29 provide a liner setting tool with superior mounting means 30 for attachment to liner. 31 32 According to a first aspect of the present invention 33 there is provided a liner setting tool for running liner 4 1 or casing into a well bore wherein said liner setting 2 tool is comprised of an elongate body with a number of 3 integral radial outlets and is adapted for attachment to 4 said casing or liner and wherein the liner setting tool 5 is moveable between a first and second position relative 6 to the liner or casing, wherein the radial outlets are 7 closed when the liner setting tool is in a first position' 8 relative to the liner or casing and open when the liner 9 setting tool is in a second position relative to the 10 liner or casing. 11 12 Preferably the radial outlets of the liner setting tool 13 are ports. 14 15 Preferably the liner has flow ports corresponding to the 16 ports of the liner setting tool. 17 18 Preferably movement of the liner setting tool relative to, 19 the liner or casing is provided by rotation of the liner 20 setting tool relative to the liner or casing. 21 22 Preferably when the liner setting tool is in a first 23 position the radial outlets are closed by virtue of the 24 liner or casing. 25 26 Preferably when the liner casing tool is in a second 27 position the radial outlets are open by virtue of them 28 communicating with the ports in the liner or casing. 29 30 Preferably the integral ports of the liner setting tool 31 are associated with seal rings which restrict the flow of. 32 fluid between the tool and the liner. 33 1 Most preferably said seal rings are made from a 2 relatively hard wearing but flexible material such as 3 rubber although any other suitable material may be used. 4 5 Preferably the elongate body of the liner setting tool is 6 cylindrical and hollow. 7 8 Preferably the liner setting tool is attached to the 9 liner by thread which is threadably engaged to the liner 10 or casing. 11 12 Preferably the liner setting tool has a first upper end 13 comprising attachment means for attaching the tool to a 14 work string. 15 16 Preferably the liner setting tool has a second 17 lower end formation which co-operates with a seat formed 18 in the casing or liner so as to restrict the axial 19 movement of the liner setting tool relative to the liner 20 or casing. 21 22 According to a second aspect of the present invention 23 there is provided a liner setting tool wherein said liner 24 setting tool is attached to the liner by threaded 25 connections. 26 27 Preferably the threaded connections are loosened by 28 rotation of the liner setting tool in an anti-clockwise 29 or left-hand direction. 30 31 According to a third aspect of the present invention 32 there is provided a method for lining a well bore, 33 comprising the steps of:

6 2 a) running the liner on a work string attached to 3 the liner setting tool; 4 b) cementing the liner in place by introducing cement slurry axially into the bore, through the 6 tool, to the bottom of the section of bore, from 7 where the cement can flow into the annular space 8 between the external surface of the liner and the:

9 bore well wall; c) lifting the liner setting tool relative to the 11 liner by rotating the tool until the integral 12 ports of the liner setting tool are aligned with 13 the by pass port of the liner, and; 14 d) passing fluid through the bore, which flows in an, radial direction, through the newly aligned 16 integral ports of the liner setting tool and flow 17 ports of the liner, to clean the well bore.

18 19 Preferably the liner setting tool is lifted relative to 20 the liner by rotating the tool in an anti-clockwise 21 direction. 22 23 An example embodiment of the invention will now be 24 illustrated with reference to the following Figures in 25 which; 26 27 Figure 1 illustrates a liner setting tool in accordance 28 with the present invention, and; 29 Figure 2 shows the liner setting tool of Figure 1 30 attached to liner, being introduced into a pre formed 31 well. 32 1 1 I j 1 7 1 Referring firstly to Figure 1, a liner setting tool, 2 generally depicted at 1, is comprised of a cylindrical 3 body 2 with a first upper end with connection means 3 for 4 mounting the liner setting tool 1 on a work string (not 5 shown) and a second lower end with a seat conformation 4. 6 The liner setting tool 1 further comprises threaded 7 connections 5 for connecting liner (not shown) to the 8 tool 1. The cylindrical body 2 also has a plurality of 9 radial outlets or integral ports 6 and corresponding seal 10 rings 7, and an axial outlet 8. 11 12 Figure 2 shows the liner setting tool of Figure 1, 13 generally depicted at 1, as it is advanced through a 14 preformed section of well bore, which is generally 15 depicted at 9, and has already been lined with casing 10. 16 The liner setting tool 1, is attached to liner 11, by the 17 threaded connections 4. The tool 1 and liner 4 have a 18 smaller diameter than the well and can therefore be 19 passed through the preformed bore 9. 20 21 The tool 1 is advanced through the pre formed bore 9 on a 22 work string (not shown) to the section of drilled bore it 23 is intended to line. Upon reaching this section cement 24 is pumped into the well bore 9 from the surface. In a 25 first configuration (Position A), the axial outlet 8 of 26 the liner setting tool 1 allows the cement to pass down 27 the bore 9 and continue flowing in an axial direction 28 towards the bottom of the section of the well 9. The 29 cement passes to the bottom of the well bore 9 and is 30 displaced into the annular space between the external 31 surface of the liner 11 and the wall of the well bore 9. 32 In this first configuration (Position A) the integral 33 ports 6 of the cylindrical body 2 are closed by virtue of 8 1 the liner 11 which obstructs the ports 6 and therefore 2 prevents the flow of fluid in a radial direction. 3 4 After the cement has set within the annular space, the 5 liner setting tool 1 is lifted by a predetermined 6 distance relative to the liner 11. This is achieved by 7 rotating the tool 1 relative to the liner 11 in an anti8 clockwise, or left-hand direction. This loosens the 9 threaded connections 4 which attach the liner setting 10 tool 1 to the liner 11, thereby allowing the tool 1 to 11 move relative to the liner 11. The thread 4 which 12 attaches the liner setting tool 1 to the liner 13 11 is double start thread which allows the operator to 14 rotate the liner setting tool 1 relative to the liner 15 11 to a second configuration where the integral ports 6 16 of the cylindrical body 2 are aligned with corresponding 17 by pass ports 12 on the liner 11 (Position B). Therefore 18 in this second configuration the integral ports 6 of the 19 cylindrical body 2 are open and cleaning fluid can 20 be passed through the well bore 9. The fluid can pass in 21 a radial direction, through the integral ports 6 of the 22 cylindrical body 2, and the by pass ports 12 on the liner 23 11, into the annular space. Accordingly the fluid can be: 24 passed over the entire area around the liner 11 and the 25 work string (not shown) in order to wash out the bore 9. 26 27 Once the procedure is complete, the second 'start' of the:: 28 double start thread 4 can be initiated by setting down 29 weight or applying tension, thereby allowing further 30 rotation of the tool 1 relative to the liner 11 in an 31 anti clockwise direction, in order to remove the tool 1 32 from the liner 11 and subsequently from the well bore 9. 33 9 1 The present invention is described for use in setting 2 liner such as that typically used near the production 3 area of the bore, but could readily be adapted to be 4 suitable for use with any structural casing. 5 6 The advantage of the present invention is that in one 7 configuration the liner setting tool allows cement to be 8 passed axially into a well bore to allow the liner or 9 casing to be cemented in place as is conventional, and in 10 another configuration allows fluid to be passed from the 11 liner setting tool, in a radial direction to allow the 12 well bore to be washed out. 13 14 Furthermore the use of threaded connections as means for 15 attaching the liner setting tool to the liner or casing 16 provides greater control over the positioning and release 17 of the liner. 18 19 Further modifications and improvements may be 20 incorporated without departing from the scope of the 21 invention herein intended.

Claims

1 CLAIMS: 2 3 1. A liner setting tool for running liner or casing

4 into a well bore wherein said liner setting tool is 5 comprised of an elongate body with a number of 6 integral radial outlets and is adapted for 7 attachment to said casing or liner and wherein the 8 liner setting tool is moveable between a first and 9 second position relative to the liner or casing, 10 wherein the radial outlets are closed when the liner1 11 setting tool is in a first position relative to the 12 liner or casing and open when the liner setting tool: 13 is in a second position relative to the liner or 14 casing. 15 16

2. A liner setting tool as claimed in Claim 1, wherein 1 17 the casing or liner has flow ports corresponding to 18 the outlets of the liner setting tool.

19

3. A liner setting tool as claimed in Claim 1 or Claim 21 2, wherein movement of the liner setting tool 22 between the first and second position is provided by 23 rotation of the liner setting tool relative to the 24 liner or casing. 25 26

4. A liner setting tool as claimed in any one of the 27 preceding Claims, wherein when the liner setting 28 tool is in the first position the radial outlets are:

29 closed by virtue of the liner or casing.

31

5. A liner setting tool as claimed in any one of Claims' 32 2 to 4, wherein when the liner setting tool is in a 33 second position the radial outlets are open by 11 1 virtue of them communicating with the ports in the 2 liner or casing.

3 4

6. A liner setting tool as claimed in any one of the preceding Claims, wherein the radial outlets are 6 associated with seal rings which restrict the flow 7 of fluid between the tool and the liner.

8 9

7. A liner setting tool as claimed in Claim 6, wherein the seal rings are made from a relatively hard 11 wearing but flexible material, such as rubber.

12 13

8. A liner setting tool as claimed in any one of the 14 preceding Claims, being adapted to threadably engage with the liner or casing.

16 17

9. A liner setting tool as claimed in any one of the 18 preceding Claims, comprising a first upper end 19 having attachment means for attaching the tool to a work string.

21 22

10. A liner setting tool as claimed in any one of the 23 preceding Claims, having a second lower end 24 formation which co- operates with a seat formed in 25 the casing or liner so as to restrict the axial 26 movement of the liner setting tool relative to the 27 liner or casing. 28 29

11. A liner setting tool attachable to an associated casing or liner by threaded connections.

31 32

12. A liner setting tool as claimed in Claim 11, wherein 33 the threaded connections may be loosened by rotation 12 1 of the liner setting tool in an anti-clockwise or 2 left-hand direction.

3 4

13. A method for lining a well bore, comprising the steps of:

6 7 a) running the'liner on a work string attached to 8 the liner setting tool; 9 b) cementing the liner in place by introducing cement slurry axially into the bore, through the 11 tool, to the bottom of the section of bore, from 12 where the cement can flow into the annular space 13 between the external surface of the liner and the 14 bore well wall; c) lifting the liner setting tool relative to the 16 liner by rotating the tool until the integral 17 ports of the liner setting tool are aligned with 18 the by pass port of the liner, and; 19 d) passing fluid through the bore, which flows in an radial direction, through the newly aligned 21 integral ports of the liner setting tool and flow 22 ports of the liner, to clean the well bore.

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