Patent Application
20110278016
Tubular systems include various valves for controlling fluid flow. A wide variety of mechanisms are employed to actuate these valves; electric motors, hydraulic systems, and longitudinal movements of complete tubular strings, are a few. Although, these various mechanisms function adequately, all have their advantages and disadvantages, which strongly influence the applications for which they are well suited. Operators of tubular systems are, therefore, always receptive to new valving devices and methods to add to their list of available tools.
Disclosed herein is a valving device including a tubular with a port and a sleeve slidably sealingly engaged with the tubular between a first position and a second position. The sleeve is configured to occlude the port when in the first position and uncover the port when in the second position. The valving device is configured such that pressure inside the tubular does not urge the sleeve toward the second position while pressure applied radially outwardly of the tubular and the sleeve urge the sleeve toward the second position.
Further disclosed is a valving method that includes slidably engaging a sleeve with a tubular having a port between a first position that occludes flow through the port and a second position that allows flow through the port. The valving method also includes failing to urge the sleeve toward the second position with pressure inside of the tubular, pressuring up an outside of the tubular and the sleeve, and urging the sleeve toward the second position with the pressuring up and moving the sleeve with the urging from the pressuring up to the second position.
Further disclosed is a valve including a tubular with at least one port, a sleeve slidably engaged with the tubular and is movable between a first position and a second position. The valve also includes, a first seal, a second seal and a third seal that are each sealable to both the tubular and the sleeve. The first seal and the second seal straddle the port thereby occluding flow through the at least one port when the sleeve is in the first position, and the first seal is nonsealingly engaged with one of the tubular and the sleeve when the sleeve is in the second position thereby permitting flow through the at least one port. The valve is configured to increase urging of the sleeve toward the second position in response to increases in pressure radially outwardly of the sleeve and the tubular and to not increase urging forces on the sleeve toward the second position in response to increases in pressure within the tubular.
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 first seal 30 defines a first area 40, the second seal 34 defines a second area 44 and the third seal 38 defines a third area 48. The first area 40 and the second area 44 are equal such that pressure from an inside 52 of the tubular acting on the first and second areas 40, 44 through the first ports 18 does not generate a longitudinal urging force on the sleeve 26. The third area 48, however, is larger than the second area 44 such that pressure acting across these two areas 44, 48 does generate a longitudinal urging force on the sleeve 26. For example, increases in pressure radially outwardly of the tubular 14 and the sleeve 26, such as in an annular space 56 defined as radially outwardly of the tubular 14 and the sleeve 26 and radially inwardly of a structure 60 (such as a casing when the valving device 10 is employed in a downhole completion application for example) that is radially outwardly of the sleeve 26, causes an increase in an urging force on the sleeve 26. This increase in urging force is in a direction toward the second position.
Additionally, an optional biasing member 64, illustrated in this embodiment as a compression spring, is positioned between a ring 68 attached to the tubular 14, and a shoulder 72 of the sleeve 28 attached to the sleeve 26. The biasing member 64 thus biases the sleeve 26 toward the first position.
Also optional, is a second port 76 in the tubular 14 located between the second seal 34 and the third seal 38 that fluidically connects a chamber 80 defined between the second seal 34, the third seal 38, the sleeve 26 and an outer surface 84 of the tubular 14 with the inside 52. Since the second port 76 is optional, forces generated on the sleeve 26 from pressure within the chamber 80 varies depending upon whether the second port 76 is present or not. When the second port 76 is present, pressure from the inside 52 of the tubular 14 acts upon the difference in area of the second area 44 and the third area 48 in a direction that urges the sleeve 26 toward the first position. Alternately, when the second port 76 is not present, selected pressure within the chamber 80, such as ambient surface pressure when the device 10 is assembled at surface while at ambient pressure, act upon the difference in area to urge the sleeve 26 toward the first position.
The foregoing valving device 10 then permits an operator to move the sleeve 26 from the first position to the second position, and thereby open the first ports 18, by simply pressuring up the annular space 56. This increase in pressure acts across the difference between the third area 48 and the second area 44 thereby generating a force toward the second position, while the common values of the first area 40 and the second area 44 result in no net force on the sleeve 26 therefrom. As such, the operator can accurately predict the pressure required in the annular space 56 to open the valving device 10 since it must simply overcome friction, the biasing by the biasing member 64 if present and the pressure in the chamber 80 (be it the selected pressure or pressure from the inside 52, depending upon whether the second port 76 is present). Further, the operator can accurately predict at what pressure in the annular space 56 will result in closure of the valving device 10.
The valving device 10 can be employed as a gas lift valve, for example, when employed in a downhole completion wellbore. The operator can pressure up the annular space 56 with air (or other gas), from surface to cause the sleeve 26 to move to the second position, to thereby open the first ports 18 to a flow of air therethrough for mixing with fluids within the tubular 14 aiding in lifting of the fluids toward the surface. Injection of air into the tubular 14 can be halted by decreasing pressure of the air in the annular space 56 until the urging forces on the sleeve 26 return it to the first (or closed) 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.
