WO1988000275A1

WO1988000275A1 - Cement control valve device

Info

Publication number: WO1988000275A1
Application number: PCT/GB1987/000460
Authority: WO
Inventors: Robert E. Bode
Original assignee: Bode Robert E
Priority date: 1986-07-01
Filing date: 1987-07-01
Publication date: 1988-01-14
Also published as: AU7649387A; CA1288685C

Abstract

A cement control device or sub (1) is provided for use in a well pipe (26) of a well and comprises a pipe assembly in the form of a pair of pipe sections (2A, 2B) which sandwich a central control member or ring (10) joined to the sections (2A, 2B), the assembly having ends (9A, 9B) adapted for fitting into a well pipe string as a section thereof. For control of fluid flow (e.g. cement) through the pipe assembly, a primary sleeve (5) is movably located within the pipe assembly (2A, 2B) while an additional fluid control sleeve (6) is movable with the primary sleeve (5). The primary sleeve (5) has a fluid inlet (8) at the upper end and a fluid outlet (7) at the bottom, together with a secondary outlet in the form of ports (13) in the wall of the sleeve (5). The primary sleeve (5) is movable from a closed to an open position. The outlet end (7) of the additional control sleeve (6) is closable by a ball (22) and the sleeve (6) is movable, with the primary sleeve (5) in the closed position to allow circulating fluid flow via ports (18, 19) on the primary sleeve and on the control member (10); and further when the primary sleeve (5) is then moved to the open position these ports (18, 19) are closed while cement can pass via the secondary outlet ports (13) to the discharge end (3) of the pipe assembly; the primary sleeve (5) is held in the closed position by shear pins (14).

Description

Cement control valve device.

The present invention relates to a cement contro valve sub for use in cementation operations in the well pipe assembly of oil wells, both on shore and off-shore oil wells.

The well pipe assembly of an oil well essentiall comprises a drill pipe located within a casing and the whole assembly structure is positioned in a well bore penetrating into the ground to a required depth. The tubular pipe is made up of a member of joined pipe sections and the arrangement is such that an annual spa exists between the drill pipe and the casing. It is o course known that various cementation operations can be called for with respect to the well pipe assembly, such as for example plugging the casing perforations.

In a method of cementation used up until now, th drill pipe or tubing was used as a squeeze string for squeezing cement to the casing perforat ons. It is vi however that cement does not become lodged in the annul between the tubing and the cas.ing since this could immo ably secure the tubing in position. Therefore prior t the cement squeezing operation the tubular pipe was sta into a packer (i.e. expandable ring device) by means of a stab sub (tool) fitted at the bottom end of the tubin In the cementation operation, the packer was set at the desired depth in the casing and cement was mixed at the surface and pumped to the stab sub. The cement was controlled in the squeeze string (tubing) by holdin back pressure on the annulus, and this was accomplished by closing a packer at the surface and controlling the amount of fluid allowed out of the annulus (e.g. via a choke line) to preclude cement from passing below the stab sub and into the annulus. The stab sub was then stabbed into the packer and the cement pumped (or squee into the formation via the casing perforations. A serious disadvantage was that if the annulus "wall" was weak it could not sustain the necessary back pressure s there was a considerable possibility of cement passing into the anulus prior to stabbing.

It is the main object of the present invention to provide a cement control valve device or sub for use in a drill pipe or tubing which will substant ally elimin¬ ate the risk of cement penetrating the annulus in the cementation operation.

According to the present invention there is provided a cement control device or sub use in a well i e of a well, said device comprising a pipe section adapted for fitting into a well pipe string as a section thereof, a primary sleeve movably located within said pipe section, said primary sleeve having a fluid inlet at an upper end and a first fluid outlet at the bottom end, a second fluid outlet in the form of port means on the primary sleeve wall, additional fluid control means selectably operable to control fluid flow through any one of said fluid outlets, said primary sleeve being movable between a closure position and an open position with the arrangement such that when in said open position with said additional fluid control means actuated, fluid e.g. cement can pass via said port means to a discharge end of the pipe section,- and releasable catch means for holding the primary sleeve in the closure position. Preferably the primary sleeve has an annular formation adapted to receive a further closure device, and preferably the catch means are overcome on the application of appropriate pressure on said further closure device when the device is positioned on said formation. The catch means preferably comprise primary shear pin means.

Preferably said additional fluid control means comprises a control device located within the primary sleeve and operable in conjunction with a closure element to close said first fluid outlet.

Preferably said fluid control device comprises a movable secondary sleeve held in position by a secondary catch, and preferably the associated closure element comprises a ball freely movable through the pipe string and the primary sleeve to a supporting formation on the secondary sleeve. Release of the secondary catch can be achieved by pressure application on the secondary sleeve located ball.

Preferably secondary port means are provided on the sleeve wall, fluid flow through the secondary port means being controlled by the position of the secondary sleeve, said secondary port means aligning with aperture means on the pipe assembly when the primary sleeve is in the "closure" position.

Preferably an additional control member is connected into said pipe assembly and carries said releasable catch means.

Preferably the control member is in the form of a sleeve through which the primary sleeve is slidable.

Preferably the pipe assembly comprises separate pipe sections, the control member being sandwiched between these pipe sections.

Said further closure device can comprise a dart movable under pressure through the pipe assembly.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings wherein:-

Figs. 1 and 2 show sectional elevational views of a cement control valve sub of the present invention in various stages of operation between open and closed conditions;

Fig. 3 shows a sectional elevation of part of the sub of Fig. 1 to a larger scale; and

Fig. 4 shows a sectional view of a dart launched sub for use in a pipe string containing the sub of Fig. 1. Referring to the drawings, a cement control valve device or sub 1 is fitted into a piping string (not shown) of a well pipe assembly in an oil well (either on-shore or off-shore) and is used for cementation operations in connection with the well. The sub 1 comprises an outer pipe assembly 2 having male and female connector ends 3 4 to facilitate fitment into the piping string, a primary sleeve valve 5 slidable within the pipe assembly 1, and a secondary sleeve member 6 within the sleeve valve 5. The pipe assembly includes pipe sections 2A, 2B having opposed ends attached to a central control member 10 by threads 10A, 10B so that the member 10 is sandwiched between the pipe sections 2A, 2B. The control member 10 is in the form of a sleeve through which primary sleeve valve 5 is slidable, seals 11 being provided at the interface of the sleeves and the member 10 carries a primary shear pin 14 serving to hold the sleeve valve 5 in an upper closure position (Fig. 1). The control member 10 has a wider diameter mid portion and this mid portion includes radial circulation ports 19 aligning with ports 18 in the sleeve 5 (in Fig. 1). The sleeve valve 5 includes an annular series of ports 13, and, in the sleeve closure position, ports 13 are located above the member 10 so that fluid flow from the ports 13 to the ports 19 via the annular space between sleeve 5 and pipe section 2A is precluded. The primary sleeve valve 5 is essentially a single integral member but includes a discharge nose part 5B defining a fluid outlet 7 while the upper end of the valve 5 defines a fluid inlet 8. The nose 5B is of inwardly turned flange form so as to be capable of holding shoulder 6B of the sleeve member 6.

The sleeve valve 5 sealingly engages the control member 10, and the valve 5 is radially supported through the member 10. Sealing rings 11 located on the control member 10 seal the sleeve 5, control member 10 interface while similar rings 12A are present between the sleeves 5/6. Further sealing rings 12B are present in the sub 1 and from a consideration of Figs. 1 and 2 their function and purpose should be fairly self-explanatory. The ports

18 of the sleeve valve 5 are closed by the secondary sleeve member 6 in the initial position shown in Fig. 1 and in this position the ports 18 align with the ports

19 in the control member 10. The sleeve member 6 is located in position by shear pins 25 carried by sleeve 5, which pins 25 are adapted to fail at a considerably smaller axial load than shear pins 14. Downward movement of sleeve member 6 opens ports 18 enabling fluid to flow through sleeve valve 5 and be discharged via the ports 19. The sleeve member 6 operates in conjunction with a steel ball 22 which can fall freely through the piping string and through the sleeve valve 5 to rest on a frusto-coni ca I shoulder 23 of the member 6. Expansion ring 21 engages recess 21A to hold the sleeve valve 5 in the open position.

It is a significant feature of operations with the present sub 1 that the pipe string is maintained in position throughout the various operations with the stab sub located in the relevant squeeze packer (not shown - but located at an appropriate depth in the casing⁾ It will be noted that the pipe sections 2A, 2B do not carry shear pins for the primary sleeve valve 5 or any other of the unique control fitments of the sub so that the pipe sections can be of straightforward standard design with internal threads at the ends. Further, the outer ends of the pipe section carry adapters 9A, 9B enabling the same cement control sub 1 to be used irrespective of the diameter of the fitting threads of pipes or fitments to be connected to the sub 1. A required amount of cement to squeeze into the formation at the external side of the casing (the casing being indicated at 26 in Figs. 1/4) is controlled by a drill pipe/tubing dart 27 (see Fig. 2). The dart 27 is moved down the pipe string to the sub 1 by means of a dual dart launching manifold or sub 29 shown in Pig_* 4. The launching sub 29 is positioned at the top of the string, having a male connector 30 to facilitate fitting, and the launching sub 29 is in the form of a pipe section having connected thereto a fluid pressure network 31 so that pressure can be applied in the sub 29 at three axially spaced points 32, 33, 34. Pressure fluid flow to the points 32, 33, 34 is controlled by valves 32A, 33A, 34A respectively. Further, throat members 35, 36 are supported on shoulders in the launching sub 29, and member 35 serves for initial support of the dart 27. In operation of the launcher, the throat member 35 is fitted in position with the dart 27 pushed into the member 35, and the launching sub 29 is fitted to the pipe string when the pipe string with the sub 1 attached has been moved down to the desired depth in the well bore. The bottom end of the string carries a stab sub. The inside diameter of the throat member 35, is slightly smaller than the outside diameter of the nose of the dart 27 and a fair degree of pressure Ceg. 300 P. Si) is required to force the dart 27 through the member 35. The dart 27 is launched by closing valve 32A and opening valve 33A so that pressure fluid is applied to the top of the dart 27, by closing valve 33A and opening valve 34A pressure fluid can be directed above the member 36 which is also capable of carrying a dart- The top end of the manifold 29 is closed by a removable plug 37 which also serves as a Lifting pin.

There will now be described a procedure for squeezing cement into the annulus 38 around the pipe string using the above sub 1 in conjunction with a cement retainer or squeeze packer. Firstly the sub 1 is made up to the stab sub of a cement retainer or squeeze packer and the assembly is fed down the bore hole to the desired depth. The dart launching sub 29 is installed at the top of the pipe string and the packer is then set. The cement injection rate is ascertained, and this can be achieved by displacing fluid through the valve 5 and the sleeve member 6 as positioned in Fig. 1 to the formation to be cemented via the casing perforations: the quantity of fluid displaced indicates the quantity of cement required. The top plug (cap) 37 is removed from the launching sub 29 and the steel ball 22 is dropped into the pipe string. A single (bottom) dart 27 is then loaded into the launching sub 29. When the ball 22 reaches the sleeve member 6 so as to rest on the shoulder 23, appropriate pressure is applied on the member 6 via the pipe string to shear pins 25 whereby the member 6 is moved downwardly to bring shoulder 6B onto nose 5B and the circulating ports 18/19 are consequently opened. It s now possible to c rculate fluid as desired through the pipe string and out via ports 18/19.

Cement is now mixed and pumped to the launcher with barrel of water behind the cement.. The dart 27 is displaced to the sleeve valve 5. The dart 27 moves down the sleeve valve 5 until it is arrested by shoulder 39 and in this position the ports 18 are sealed off by the dart 27. Further pressure is applied in the pipe string and on dart 27 to shear the shear pins 14 and the sleeve valve 5 moves to the open position shown in Fig. 2 viz fluid (eg. cement) can now pass down the string, flow through ports 13 and then pass in the annulus between valve 5 and pipe section 2B to the discharge 3. In this open position shoulder 17 of the valve 5 rests on a bearing ring 10<Tof the control member 10 The allocated cement (together with one additional barrel to clear the packer of cement) is now squeezed down the pipe string to the sub 1 whence it is discharged via discharge 3 to the casing perforations and to the formation. The packer will then be released or unstabbing effected from the cement retainer^, and the assembly can then be reversed out if required.

The above sub in accordance with the present invention has the advantage that by placing the sub above the cement retainer or squeeze packer, the possibility of cement getting into the annulus above the packer is eliminated. The sub 1 avoids the need for back pressure to be held on the annulus to regulate the flow of cement to the packer prior to cement squeezing. Consequently, costly cement problems can be avoided.

Claims

C l a i m s

1. A cement control device or sub for use in a well pipe of a well, characterised in that the device ⁽1⁾ comprises a pipe assembly (2A, 2B⁾ adapted for fitting into a well pipe string as a section thereof, a primary sleeve (5) movably located within said pipe assembly (2A, 2B), said primary sleeve (5) having a fluid inlet (8) at an upper end and a first fluid outlet ⁽7⁾ at the bottom end, a second fluid outlet ⁽13⁾ in the form of port means on the primary sleeve wall, additional fluid control means ⁽6, 22) selectably operable to control fluid flow through any one of said fluid outlets (7, 13) said primary sleeve (5) being movable between a closure position and an open position with the arrangement such that when in said open position with said additional fluid control means (6, 22) actuated, fluid eg. cement can pass via said port means (13) to a discharge end (3) of the pipe assembly (2A, 2B), and releasable catch means (14) for holding the primary sleeve (5) in the closure position. 2. A control device as claimed n claim 1, characterised in that the primary sleeve (5) has an annular formation (39) adapted to receive a further closure device (27 - Fig.

2).

3. A control device as claimed in claim 2, characterised in that the catch means (14) are arranged to be overcome on the application of appropriate pressure on said further closure device (27) when the device ⁽27) is positioned on said formation (39).

4. A control device as claimed in claim 3, characterised in that the catch means ⁽14) comprise pr ary shear pin means.

5. A control device as claimed in any one of the precedin claims,characterised in that said additional fluid control means ⁽6, 22⁾ comprises a fluid control device (6) located within the primary sleeve (5) and operable in conjunction with a closure element C22⁾ to close said first fluid outlet C7) .

6. A control device as claimed in claim 5, characterised in that said fluid control device ⁽6) comprises a movable secondary sleeve held in position by a secondary catch (25).

7. A control device as claimed in claim 5 or 6, characterised in that the closure element ⁽22) comprises a bal freely movable through the pipe string and the primary sleeve (5) to a supporting formation (23) on the secondary sleeve (6).

8. A control device as claimed in claim 6, characterised in that secondary port means (18⁾ are provided on the wall of sleeve C5), fluid flow through the secondary port means (18) being controlled by the position of the secondary sleeve (6), said secondary port means C18) aligning with aperture means (19) on the pipe assembly (2A, 2B, 10) when the primary sleeve (5) is in the closure position.

9. A control device as claimed in claim 1, characterised in that an additional control member ⁽10⁾ is connected into said pipe assembly (2A, 2B) and carries said releasable catch means (14).

10. A control device as claimed in claim 9, characterised in that the control member (10) is in the form of a sleeve through which the primary sleeve (5) is slidable.

11. A control device as claimed in claim 9 or 10, characterised in that the pipe assembly ⁽2A, 2B⁾ comprises separate pipe sections, the control member ⁽10⁾ being sandwiched between these pipe sections (2A, 2B) .

12. A control device as claimed in any one of claims 9 to 11, characterised in that the control member ⁽10⁾ includes radial, externally opening, port means (19) which are alignable with secondary port means (18) of the primary sleeve (5), the arrangement being such that fluid flow from said second fluid outlet (13) to said radial port means (19) is precluded by the control member (10) when the primary sleeve (5) is in the closure position.

13. A control device as claimed in claim 11, characterised in that at Least one end of the pipe section (2A, 2B) includes an adapter device (9A, 9B) to enable the pipe section to be coupled to a pipe or fitment.

14. A control device as claimed in claim 2, characterised in that said further closure device ⁽27⁾ comprises a dart movable under pressure through the pipe assembly.

15. A control device as claimed in claim 14, characterised in that pressure operable dart launching apparatus (29) is provided for delivery of the dart ⁽27⁾ to the pipe assembly.

16. A control device as claimed in any one of the preceding claims, characterised in that locking means (21, 21A) are provided to lock the primary sleeve (5) in the open position (Fig. 2).