NON-ROTATING WELLBORE TOOL AND SEALING METHOD THEREFOR
A wellbore tool, such as a cementing tool, configured for placement in a wellbore or drill string, and method of sealing the tool in the wellbore or drill string. The tool is lowered on a stem into the wellbore or drill string and contacts a downhole obstacle (the bit when lowered in a drill string), such that the downward pressure on the tool causes a shear pin to shear, resulting in upward movement of an outer sleeve relative to the central body of the tool. The outer sleeve, when upwardly displaced, pushes against a deformable sleeve, and the deformable sleeve then presses outwardly against the inner walls of the wellbore or drill string, sealing the tool therein. The deformable sleeve can be directed outwardly by contacting it during upward displacement of the outer sleeve with an angled surface of the central body.
This is a divisional application of copending U.S. patent application Ser. No. 14/033,754, filed Sep. 23, 2013, which claims priority to Canadian Patent Serial No. 2,790,548, filed Sep. 24, 2012; the entire contents of which are hereby incorporated by reference herein in their entireties.
FIELD OF THE INVENTIONThe invention relates to wellbore drilling technology, and specifically to tools and methods for cementing in a wellbore.
BACKGROUND OF THE INVENTIONIn the practice of borehole or wellbore drilling, a rotary drilling apparatus is employed to drill a hole downwardly into the ground, normally to either determine subsurface conditions, obtain samples of subsurface materials, or to extract natural resources located at depth. It is known to inject specialized cementitious material into the borehole to stabilize the hole walls or allow for isolation of certain subsurface strata.
Various cementing tools and methods have been developed over the years, often for mining or oil and gas drilling applications. While they have achieved generally widespread use and acceptance, it is known that certain drilling tools manifest potentially disadvantageous features. For example, some drilling tools are intended for deployment at a certain depth in the borehole, but locking them in place at that desired depth may require rotation of the tool and/or the string or stem used to deploy the tool, with the risk that threaded sections of drill pipe—in which the tool is being deployed—may be loosened at depth, a potentially serious occurrence. Also, some cementing tools can only be positioned when the drill string has first been removed from the hole, a practice known as tripping out the drill string. Tripping out the drill string can be time consuming and, in some contexts, otherwise unnecessary or undesirable.
It would therefore be desirable to have a wellbore cementing tool that could be employed without tripping out the drill string or requiring rotation that might destabilize the string in place.
SUMMARY OF THE INVENTIONThe present invention therefore seeks to provide a wellbore cementing tool and method for using same, where the tool can be deployed within an in-place drill string and locked in place at a desired depth without requiring tool rotation.
According to a first aspect of the present invention there is provided a sealable wellbore tool comprising:
-
- an inner body;
- at least one deformable member disposed adjacent an external surface of the inner body and configured for sealing engagement with an inner surface of the wellbore; and
- an outer sleeve slidably disposed adjacent the external surface of the inner body, the outer sleeve below and in operable communication with the at least one deformable member;
- wherein the outer sleeve is movable from a first downwardly disposed position relative to the inner body to a second upwardly disposed position relative to the inner body when the tool is lowered into the wellbore and the outer sleeve contacts a downhole obstacle;
- wherein when the outer sleeve is in the first position, the at least one deformable member is disengaged from the inner surface of the wellbore; and
- wherein when the outer sleeve is in the second position, the outer sleeve presses upwardly against the at least one deformable member causing the at least one deformable member to deform and engage the inner surface of the wellbore.
In exemplary embodiments of the first aspect of the present invention, the at least one deformable member is at least one deformable sleeve disposed around the inner body. Where the downhole obstacle is a drill bit, the at least one deformable member is configured to engage inner surfaces of a drill string within the wellbore. A bushing is preferably disposed between the outer sleeve and the at least one deformable member, the bushing configured to receive upward force from the outer sleeve and to transmit the upward force to the at least one deformable sleeve. The bushing may be secured to the inner body by a shear pin to hold the outer sleeve in the first position, the shear pin configured to rupture upon application of downward force to the tool. The at least one deformable member is also preferably held in place by a rupturable retention member positioned above the at least one deformable member, the retention member configured to rupture upon application of upward force when the at least one deformable member is pressed upwardly by the outer sleeve moving into the second position.
The inner body may comprise an angled outer surface configured for the at least one deformable member or deformable sleeve to move against when the outer sleeve presses upwardly against the at least one deformable member or deformable sleeve, thus causing the at least one deformable member or deformable sleeve to move outwardly and engage the inner surface of the wellbore.
The outer sleeve preferably extends downwardly past a lowest extent of the inner body. The outer sleeve may also comprise an upper sleeve and a lower sleeve separated by a shear pin, the shear pin configured to rupture when the lower sleeve contacts the downhole obstacle and thereby allow upward movement of the upper sleeve into the second position.
According to a second aspect of the present invention there is provided a method for sealing a tool in a wellbore, wherein the method comprises the steps of:
-
- a. providing a tool comprising an inner body, an outer sleeve slidable relative to the inner body between first and second positions, and at least one deformable member configured for sealing engagement with the wellbore;
- b. lowering the tool with the outer sleeve in the first position into the wellbore until the outer sleeve contacts a downhole obstacle;
- c. forcing the inner body of the tool downward relative to the outer sleeve;
- d. allowing the outer sleeve to move to the second position, thereby pressing upwardly on the at least one deformable member;
- e. allowing the at least one deformable member to deform and press outwardly toward walls of the wellbore; and
- f. allowing the at least one deformable member to sealingly engage the walls of the wellbore.
In exemplary embodiments of the second aspect of the present invention, the outer sleeve is retained in the first position by a shear pin, the method further comprising the step of allowing the shear pin to rupture in response to the forcing of the inner body of the tool downward relative to the outer sleeve. The inner body preferably comprises an angled outer surface configured for the at least one deformable member to move against when the outer sleeve presses upwardly against the at least one deformable sleeve, thus causing the at least one deformable sleeve to press outwardly toward the walls of the wellbore and to sealingly engage the walls of the wellbore. Where the tool is lowered into a drill string in the wellbore and the downhole obstacle is a drill bit, the at least one deformable member deforms and presses outwardly toward inner walls of the drill string, and the at least one deformable member sealingly engages the inner walls of the drill string.
A detailed description of an exemplary embodiment of the present invention is given in the following. It is to be understood, however, that the invention is not to be construed as being limited to this embodiment.
In the accompanying drawings, which illustrate an exemplary embodiment of the present invention:
Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTIn the following description, an exemplary tool according to the present invention is identified by the numeral 10. Referring specifically to
The tool 10 is provided with a threaded section 22 for engagement with a hollow stem (not shown); the threaded section 22 is preferably a left-hand thread to help avoid unwanted rotation of the adjacent drill string connections when the hollow stem is disengaged from the tool 10 after use. The hollow stem or string is used to lower the tool 10 into position within the drill string (not shown) and to flow cementitious material to the tool 10. The tool 10 is provided with a central cavity 26 which extends from the upper end of the tool 10 to the lower body 16 where cementitious materials are allowed to exit through apertures 56, and the cavity 26 comprises a larger chamber 24 in the upper body 12. The chamber 24 is present to receive and retain a plug 64, as is discussed below.
The upper body 12 is threadably engaged with the middle body 14, as can be seen in
The securing means comprise four locking members 28 (two of which are visible in
In the position shown in
Turning now to
The lower body 16 is illustrated in
Turning now to
Use of the tool 10 will now be described. When a user wishes to cement a drilled borehole, the tool 10 is threadably connected to a hollow stem and then lowered into the interior of the drill string. When the tool 10 reaches the end of the drill string, the lower end 62 of the lower sleeve 20 strikes the drill bit. As downward force continues to be applied to the tool 10, however, the central body of the tool 10 (specifically the threadably connected upper body 12 and middle body 14) is pushed downward relative to the lower sleeve 20 and the bushing 42 on which the sleeve 20 is mounted. This causes the shear pin 40 to rupture, allowing movement of the lower sleeve 20 and bushing 42 relative to the middle body 14. As the bushing 42 has been freed to move upwardly relative to the middle body 14, the bushing 42 presses upwardly against the sleeves 44a,b. This upward movement is now applied to the sleeves 44a,b, causing the plastic ring 46 to rupture and drive the upper sleeve 18 upwardly relative to the middle body 14. The sleeves 44a,b are also pressed outwardly toward the inner surface of the drill string due to the angled surface of the middle body 14, thereby forming a seal against the drill string and preventing any backflow of cementitious material around the tool 10 and upwards within the drill string.
As the sleeves 44a,b push the upper sleeve 18 upwardly relative to the middle body 14, the upper sleeve 18 moves from the first position shown in
Cementitious material is then injected into the hollow stem, downwardly toward the tool 10. The cementitious material passes into the chamber 24 and thence into the cavity 26, ultimately passing out the apertures 56 and downwardly toward the bit, where it will pass through the bit and into the annulus between the drill string and borehole walls.
Once a volume of cementitious material has been injected that the user has determined will be adequate for the desired cementing activity, the plug 64 is sent down the hollow stem to the tool 10. Once the plug 64 reaches the tool 10, it presses into the chamber 24, where the lower rubber member 70 terminates travel in the chamber 24 and the O-rings 74 seal against the upper end of the cavity 26. The upper rubber member 66 helps to centralize and stabilize the plug 64. Once in position, the plug 64 prevents any material from passing through the tool 10 to the bit. In addition, the ball 54 presses upwardly against the hardened seat ring 52 to prevent backflow into the cavity 26, while the sleeves 44a,b prevent backflow around the outside of the tool 10. The hollow stem can then be disengaged from the threaded section 22 and tripped out of the hole, leaving the tool 10 in position adjacent the bit.
As can be readily seen, then, there are numerous advantages provided by the present invention. First, the tool can be deployed and allowed to engage the inner surface of a drill string without rotation of the tool. Also, the tool can be deployed in an in-place drill string, so no tripping out is required. The use of the ball valve and plug help prevent undesired flow of cementitious material in either direction, and the plug itself can be used to clean out the hollow stem as it travels downwardly toward the tool.
The foregoing is considered as illustrative only of the principles of the invention. Thus, while certain aspects and embodiments of the invention have been described, these have been presented by way of example only and are not intended to limit the scope of the invention. The scope of the claims should not be limited by the exemplary embodiments set forth in the foregoing, but should be given the broadest interpretation consistent with the specification as a whole.
Claims
1. A sealable wellbore tool comprising:
- an inner body;
- at least one deformable member disposed adjacent an external surface of the inner body and configured for sealing engagement with an inner surface of the wellbore; and
- an outer sleeve slidably disposed adjacent the external surface of the inner body, the outer sleeve below and in operable communication with the at least one deformable member;
- wherein the outer sleeve is movable from a first downwardly disposed position relative to the inner body to a second upwardly disposed position relative to the inner body when the tool is lowered into the wellbore and the outer sleeve contacts a downhole obstacle;
- wherein when the outer sleeve is in the first position, the at least one deformable member is disengaged from the inner surface of the wellbore; and
- wherein when the outer sleeve is in the second position, the outer sleeve presses upwardly against the at least one deformable member causing the at least one deformable member to deform and engage the inner surface of the wellbore.
2. The tool of claim 1 wherein the at least one deformable member is at least one deformable sleeve disposed around the inner body.
3. The tool of claim 1 wherein the downhole obstacle is a drill bit and the at least one deformable member is configured to engage inner surfaces of a drill string within the wellbore.
4. The tool of claim 1 further comprising a bushing disposed between the outer sleeve and the at least one deformable member, the bushing configured to receive upward force from the outer sleeve and to transmit the upward force to the at least one deformable sleeve.
5. The tool of claim 4 wherein the bushing is secured to the inner body by a shear pin to hold the outer sleeve in the first position, the shear pin configured to rupture upon application of downward force to the tool.
6. The tool of claim 1 wherein the at least one deformable member is held in place by a rupturable retention member positioned above the at least one deformable member, the retention member configured to rupture upon application of upward force when the at least one deformable member is pressed upwardly by the outer sleeve moving into the second position.
7. The tool of claim 1 wherein the inner body comprises an angled outer surface configured for the at least one deformable member to move against when the outer sleeve presses upwardly against the at least one deformable member, thus causing the at least one deformable member to move outwardly and engage the inner surface of the wellbore.
8. The tool of claim 2 wherein the inner body comprises an angled outer surface configured for the at least one deformable sleeve to move against when the outer sleeve presses upwardly against the at least one deformable sleeve, thus causing the at least one deformable sleeve to move outwardly and engage the inner surface of the wellbore.
9. The tool of claim 1 wherein the outer sleeve extends downwardly past a lowest extent of the inner body.
10. The tool of claim 1 wherein the outer sleeve comprises an upper sleeve and a lower sleeve separated by a shear pin, the shear pin configured to rupture when the lower sleeve contacts the downhole obstacle and thereby allow upward movement of the upper sleeve into the second position.
11. A method for sealing a tool in a wellbore, wherein the method comprises the steps of:
- a. providing a tool comprising an inner body, an outer sleeve slidable relative to the inner body between first and second positions, and at least one deformable member configured for sealing engagement with the wellbore;
- b. lowering the tool with the outer sleeve in the first position into the wellbore until the outer sleeve contacts a downhole obstacle;
- c. forcing the inner body of the tool downward relative to the outer sleeve;
- d. allowing the outer sleeve to move to the second position, thereby pressing upwardly on the at least one deformable member;
- e. allowing the at least one deformable member to deform and press outwardly toward walls of the wellbore; and
- f. allowing the at least one deformable member to sealingly engage the walls of the wellbore.
12. The method of claim 11 wherein the outer sleeve is retained in the first position by a shear pin, the method further comprising the step of allowing the shear pin to rupture in response to the forcing of the inner body of the tool downward relative to the outer sleeve.
13. The method of claim 11 wherein the inner body comprises an angled outer surface configured for the at least one deformable member to move against when the outer sleeve presses upwardly against the at least one deformable sleeve, thus causing the at least one deformable sleeve to press outwardly toward the walls of the wellbore and to sealingly engage the walls of the wellbore.
14. The method of claim 11 wherein the tool is lowered into a drill string in the wellbore and the downhole obstacle is a drill bit, such that:
- the at least one deformable member deforms and presses outwardly toward inner walls of the drill string; and
- the at least one deformable member sealingly engages the inner walls of the drill string.
Type: Application
Filed: Jun 25, 2014
Publication Date: Nov 20, 2014
Inventor: Robert Grainger (Regina)
Application Number: 14/314,852
International Classification: E21B 33/128 (20060101);