SELECTIVE PLUG AND METHOD
A selective plug including a body; and a rotator configuration in operable communication with the body capable of causing the plug to selectively pass a number of borehole restrictions to reach and engage a target restriction and method.
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In the Drilling and completion industries it is often desirable to affect tools or formations at a great distance from a surface located facility such as a rig. One example of an operation intended to affect a formation is a fracturing operation. In order to perform such an operation, hydraulic pressure is built within a tubing string until the pressure exceeds formation capability for holding that pressure and fractures form in the formation. This type of operation is most effective if done in small incremental sections of a borehole for reasons related to control and distribution of fractures to serve the ultimate purpose of the borehole. Such purposes include hydrocarbon production, CO2 sequestration, etc.
In the art, fracturing discrete locations of the borehole tends to require a number of tools that increase expense initially and generally create other issues to be overcome after the fracturing process is complete such as removal of the tools that enabled the pressuring of a discrete location. Where multiple fracturing locations are contemplated, generally a staged system must be built and administered correctly for it to work. One such system uses progressively larger seat diameters from the toe back to surface and then progressively increasing diameter balls. While the system works well, it is limited by the number of different size balls that can be used. Tolerance is required in any system and therefore limits the number of diameters that will be functional even further.
Since fracturing and other operations where discrete locations are desired to be isolated or accessed continue to become more prevalent and ubiquitous, alternate systems for accessing and manipulating the downhole environment is always well received.
SUMMARYA selective plug including a body; and a rotator configuration in operable communication with the body capable of causing the plug to selectively pass a number of borehole restrictions to reach and engage a target restriction.
A method for conducting borehole operations including determining where in a borehole an operation is desired; setting a selective plug; and deploying the selective plug into the borehole.
Referring now to the drawings wherein like elements are numbered alike in the Figures:
Referring to
The body 16 further includes openings 22 (two shown but more may be disposed about the periphery of the body 16). The openings 22 allow for the through passage of rotationally secured keys 24. The keys are interactive with the restrictions(s) 12 as a rotational axis 26 of each key comes into proximity with the restriction 12. As can be viewed in
Finally, the ratchet housing 28 includes a dampener 32 comprising in one embodiment, a fluid chamber 34 and a piston 36 bifurcating the fluid chamber 34. The piston includes a flow passage 38 having a relatively restricted dimension through which fluid may pass from one end of the piston to the other end of the piston thereby moving the fluid in the fluid chamber 34 from one side of the piston to the other during operation of the plug 10. The function of the dampener 32 is to slow the reaction of the keys 24 when they rotate due to contact with a restriction 12. This causes a pressure spike uphole of the plug 10 that can be detected to verify that the plug 10 has encountered a restriction. Counting the verification events then provides confidence that when the plug does land without passing a restriction, it is the correct target restriction. It is to be appreciated that although the dampener provides for desirable functionality, it is not required for the plug to operate with respect to its primary objective, which is to selectively pass a number of restrictions and to not pass a target restriction. The plug 10 will do so whether or not a pressure spike is produced or received at a remote location.
In embodiments that do include the dampener 32 a variation of its structure allows for easier setting of the plug 10 by including a check valve 40, which provides a much greater flow area for movement of the piston 36 in a setting direction than it does for piston movement during operation of the plug 10.
Finally the plug 10 includes a selection indicator 42. An operator uses the indicator to set the plug 10 to bypass a number of restrictions that will cause the plug to set in the target restriction.
Operation of the plug illustrated in
As noted above, the ratchet housing 28 is moved such that end 44 moves away from surface 46 during setting of the plug 10. In embodiments where dampener 32 is employed a specific embodiment of the dampener 32 includes the check valve 40 noted above. Due to the increased flow area that is gained through the check valve 40, an operator moving the ratchet housing 28 for setting purposes will not have to work as hard as he or she would if the check valve were not present (which is certainly contemplated in some embodiments).
In another embodiment of a selective plug 110, referring to
The teeth 130 are positioned upon a ratchet housing 128. The ratchet housing further includes a one or more dog supports 156 thereon that at a particular position of the ratchet housing 128 will support the dogs 154 in a radially outwardly extended position. This position is achieved when the ratchet housing 128 is fully stroked within the body 116 by having passed through the selected number of restrictions 12. To ensure that the ratchet housing 128 moves by only one tooth increment per restriction passed, a biasing arrangement 158 is included such as a compression spring that bears against one end of the body 116 and one end of the ratchet housing 128 as illustrated. These components make up an incrementing configuration for this embodiment.
Finally, at an uphole end of the ratchet housing, a wiper 160 is disposed to enable the plug 110 to be moved through the borehole using fluid pressure applied from uphole and a selection indicator 142 to assist the operator in setting the plug 110 to bypass a denied number of restrictions.
In operation, the plug 110 is initially manually set at a surface location by an operator. The ratchet housing 128 is positioned relative to the body 116 such that a selected number of teeth 130 are required to be ratcheted through before the dog support 156 moves to support the dogs 154. The number of teeth is the same as the number of restrictions through which the plug is being set to pass before it is to hold its position to support another operation such as a fluid pressure build up uphole of the plug 110 for tool actuation or fracturing, etc. Because the biasing arrangement 158 applies a force on the ratchet housing 128 in a direction to the left in the drawing
In yet another embodiment, referring to
Upon the body 216 is mounted a key 224 that is interactive with a rotator 276 in operation of the plug 210. The key 224 further provides a seat 274 for a biasing arrangement 258. The biasing arrangement will in one embodiment comprise a compression spring such as a coil spring as shown. The biasing arrangement 258 acts between the seat 274 and the collet 270, urging the two apart from one another.
The rotator 276 is disposed between the collet 270 and the body 216 and provides, in one embodiment, the selectivity in target restriction in cooperation with key 224. A selection indicator 242 is also provided for purposes identical to those described above.
Before making reference to
Referring now to
Finally it is to be understood while one or more embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.
Claims
1. A selective plug comprising:
- a body;
- a rotator configuration in operable communication with the body capable of causing the plug to selectively pass a number of borehole restrictions to reach and engage a target restriction.
2. The selective plug as claimed in claim 1 wherein the rotator configuration is in operable communication with a collet.
3. The selective plug as claimed in claim 2 wherein the collet includes a lug that extends into the rotator.
4. The selective plug as claimed in claim 2 wherein the rotator includes a J-Slot configuration thereon responsive to movement of the collet.
5. The selective plug as claimed in claim 1 wherein the rotator configuration further includes a key interactive with the rotator configuration to prevent rotation thereof after a selected number of increments.
6. The selective plug as claimed in claim 5 wherein the key interacts with one of a plurality of step profile teeth.
7. The selective plug as claimed in claim 1 wherein the body includes a flared end.
8. The selective plug as claimed in claim 7 wherein the flared end supports one or more collet fingers of a collet mounted at the body.
9. The selective plug as claimed in claim 1 wherein the rotator configuration includes a biasing arrangement.
10. The selective plug as claimed in claim 9 wherein biasing arrangement is a spring.
11. A method for conducting borehole operations comprising:
- determining where in a borehole an operation is desired;
- setting a selective plug; and
- deploying the selective plug into the borehole.
Type: Application
Filed: May 22, 2009
Publication Date: Nov 25, 2010
Applicant: BAKER HUGHES INCORPORATED (HOUSTON, TX)
Inventor: Richard Y. Xu (Tomball, TX)
Application Number: 12/470,931
International Classification: E21B 33/12 (20060101);