Patent Application
20130020089
Tubular systems often employ valves that allow fluid to flow through a tubular or to block fluid flow through the tubular. After closing a valve to block flow it is sometimes desirable to reopen the valve to reestablish flow therethrough. Doing so can be difficult in systems wherein the blockage is via a plug run within the tubular to a seat. Removal of the plug to reopen the tubular may require reversing flow to pump the plug back out through the pathway that it entered. Other options include milling or machining the plug out. Many methods, including the two foregoing require time (during reverse flow or running of a milling tool) to remove the blockage. This time could be spent more productively. Tubular valving systems and methods that overcome these drawbacks are well received in the art.
Disclosed herein is a tubular valving system. The system includes a tubular, a seat movably engaged with the tubular, a sleeve movably engaged with the seat between at least a first position, a second position and a third position, a release member in operable communication with the sleeve and the seat that maintains the sleeve relative to the seat in the first position until release thereof, a biasing member configured to urge the sleeve from the second position toward the third position, and a flapper sealingly engagable with the seat. Pressure greater than a first threshold level against the flapper when seated causes release of the release member allowing the sleeve and the seat to attain the second position. Subsequently, a drop in pressure against the seated flapper below a second threshold level allows the biasing member to move the sleeve relative to the seat to the third position thereby unseating the flapper from the seat and preventing the flapper from again seating with the seat.
Further disclosed herein is a method of actuating valves in a tubular system. The method includes, pressuring up against a flapper seated with a seat within a tubular to pressure greater than a first threshold pressure, releasing a release member fixedly attaching the seat to a sleeve, decreasing pressure below a second threshold pressure and moving the sleeve relative to the seat thereby opening the flapper.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
Referring to
The foregoing structure allows pressure within the tubular 14, upstream of the flapper 22 when seated on the seat 18 (leftward in the Figures), to increase thereby generating a force on the seat 18 relative to the sleeve 26. The release members 36 support this force until a threshold pressure causes them to release. After release the seat 18 is moved by a dimension 44 relative to the tubular 14. It should be noted that in both the first position and the second position the flapper 22 is seated against the seat 18 and thus pressure upstream thereof can be employed to do work such as actuating an actuator, or fracturing or treating a formation, for example, in a case where the invention is employed in a downhole hydrocarbon recovery system, for example. It should be further noted that pressure subsequent release of the release member 36 could be increased to pressures greater than the first threshold pressure.
A subsequent reduction in pressure below another threshold pressure allows the biasing member 40 to move the sleeve 26 and the seat 18 until the shoulder 28 again contacts the shoulder 32 thereby stopping the seat 18 from moving further. Continued movement of the sleeve 26 relative to the seat 18 causes the system 10 to move from the second position to the third position. As the sleeve 26 moves it causes the flapper 22 to pivotally open relative to the seat 18. A shoulder 48 on the sleeve 26, in this embodiment, contacts the shoulder 33 on the seat 18 to limit travel therebetween. The sleeve 26 holds the flapper 22 open and defines the third position.
Any practical number of the tubular valving systems 10 can be employed within the tubular 14. Actuation of each of the systems 10 along the tubular 14 would then be actuatable, with nothing more than changes in pressure, in sequence starting with the most upstream one and moving downward toward the most downstream one of the systems 10. Actuation as used herein means; pressuring up against the flapper 22, releasing the release members 36, pressuring up if desired to another pressure, and finally reducing pressure and allowing the sleeve 26 to move to the third position.
Referring to
The system 110 therefore allows for an altered operational sequencing relative to that of the system 10. By employing a plurality of the systems 110 along the tubular 14, for example, the sequence can be such that all the flappers 22 are initially open and then are made to actuate one at a time in order from the furthest downstream first to the furthest upstream last. Actuation of the systems 110 means moving the hold-open element 112A, 112B, closing the flapper 22, pressuring up against the flapper 22, releasing the release members 36, pressuring up if desired to another pressure, and finally reducing pressure and allowing the sleeve 26 to move to the third position
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
