| WO/1998/054439 | DOWNHOLE PRESSURE ACTIVATED DEVICE AND A METHOD |
| WO/2009/073391 | MULTI-POSITION VALVES FOR FRACTURING AND SAND CONTROL ASSOCIATED COMPLETION METHODS |
| WO/2009/151684 | TEMPERATURE TRIGGERED ACTUATOR |
KLEPPA, Erling (Klovsteinsveien 17, Jørpeland, N-4100, NO)
STOKKA, Øyvind (Veslefrikkvegen 11, Sandnes, N-4315, NO)
TVEITEN, Magnar (Bauneveien 7a, Sandnes, N-4328, NO)
KLEPPA, Erling (Klovsteinsveien 17, Jørpeland, N-4100, NO)
STOKKA, Øyvind (Veslefrikkvegen 11, Sandnes, N-4315, NO)
| A valve device (1) for use in a well bore, where the valve device (1) comprises an outer hollow housing (2) with at least one inlet (3) and one outlet, the at least one inlet and one outlet being connected with an internal passage, forming a flow passage, an orifice (12) being arranged in connection with the flow passage, characterized in that the valve device ( 1 ) further comprises a pressure sensitive device comprising a bellows (6) and being connected to a regulating element (15), where the bellows (6) being exposed to an external pressure from a fluid will control a movement of the regulating element (15) relative the orifice (12), in order to vary a cross section of flow of the orifice (12). A valve device according to claim 1, characterized in that the valve device comprises a pressure controlled valve within the flow passage and downstream of the orifice. A valve device according to claim 1, characterized in that the regulating element (15) is a hollow structure. A valve according to any one of the claims 1 to 3, characterized in that the regulating element (15) is provided with a variable cross sectional area over a part of its length, when seen in a longitudinal direction of the flow passage. A valve device according to any one of the previous claims, characterized in that the regulating element (15) comprises a tapered end (19), arranged on an opposite end of the connection with the bellows (6). A valve device according to claim 3, characterized in that the regulating element (15) is provided with an internal bore over at least a part of its length and a plurality of through holes (21) over its periphery and length, the internal bore and through holes (21) forming a flow passage through the regulating element (15). A valve device according to claim 1, characterized in that the orifice (12) is provided with a variable cross sectional area, when seen in the longitudinal direction of the flow passage. A valve device according to any one of the previous claims, characterized in that the pressure sensitive device further comprises a pair of spaced end stoppers (18) arranged inside the outer hollow housing (2), the pair of end stoppers (18) defining a predetermined movement of the regulating element (15) in the longitudinal direction of the flow passage. A valve device according to claim 8, characterized in that the pressure sensitive device further comprises a plate element (17) arranged between the pair of spaced end stoppers (18), the plate element (17) being connected to the bellows (6) and the regulating element (15) through an anchorage point (16). 10. A valve device according to claim 2, characterized in that the pressure controlled valve comprises an internal movable body (8) provided with an internal bore (13), at least one outlet (14), where one end of the internal movable body (8) is closed, the internal bore and at least one outlet (14) forming a flow passage through the internal movable body (8), and forming part of the flow passage through the device. 11. A valve device according to claim 10, characterized in that a valve seat (4) is arranged inside the housing (2), the valve seat (4) being adapted to cooperate with an annular valve element sealing surface (7) formed on the internal movable body (8). 12. A valve according to any one of the previous claims 1-9, characterized in that the orifice (12) is provided with a cross section area larger than the cross section area of the regulating element (15). |
The present invention relates to a device which is typically used in connection with oil and gas wells with the object to enhance the production, and more particularly the present invention concerns a pressure operated valve which is capable of vary- ing a fluid flow through the valve.
With gas injection a gas under high pressure is injected into the annular space between the casing and the tubing. For this purpose a pressure-controlled valve, a so- called gas lift valve, is usually employed in openings between the annulus and the production tubing in order to be able to supply and control or check the amount of gas flowing into the actual tubing.
Pressure-controlled valves of this kind can also be used during a well start-up phase, where completion fluid can be found in both the well's annulus and in the tubing. In order to start production in such a well, completion fluid must be displaced from the annulus, through one or more of these pressure-controlled valves, and up to the surface through the tubing.
Another similar area of application will be after a well shut-in, where production fluid has filled up at least parts of the annulus or where production fluid has been present for some time in the annulus whereby the gas has migrated to the surface and where the pressure in the well due to this is too low for the well to begin pro- ducing without receiving pressure support from gas injection.
The gas lift valve(s) can be controlled or checked according to several different principles, for example by a pressure, where it is the pressure differential round and/or across the valve which permits a controlled opening or closing of the valve.
The above mentioned gas lift valves are normally designed with fixed diameter ori- fices, whereby only a "constant" volume and velocity of gas will be allowed to flow through the valve when the valve is in an open position.
However, as the conditions in a well will change during the lifetime of the well, it may be required that a larger (or smaller) volume of gas per time unit must be injected into the well. As a result of this, the installed gas lift valves must be replaced with other gas lift valves having different diameter orifices, or the installed gas lift valves must be retrieved and adjusted to have the required diameter orifice. This will result in that the well may not produce optimally all the time and/or that well must be stopped in order to carry out the replacement of the installed gas lift valves.
There are developed some valves where one may have an opening which varies over time. One such solution is described in US 3,888,273, where there is described a gas lift valve for use in oil wells utilizing a variable flow orifice with the amount of flow area being inversely proportional to the different in pressure between casing and the tubing. Other examples of valves with variable orifice is described in US 6,200,645, US 5,618,022, GB 2 354 270 and US 4,869,100.
The object of the present invention is therefore to provide a device for controlling the injection of a fluid into a tubing in a gas and/or oil well. Where this device is adjustable dependent on the surroundings in the well, i.e. having a variable orifice, and which is easily and possibly self adjustable.
Another object of the present invention is to provide a device which is capable of operating within a predefined pressure area.
These objects are achieved with a device as indicated in the following independent claim, where further features of the invention will become evident from the dependent claims and the description below.
The present invention relates to a valve device, where the valve device comprises an outer hollow housing with at least one inlet and at least one outlet, where the inlet and outlet being connected with an internal passage, forming a flow passage. An orifice is being arranged in connection with the flow passage. There may be more than one inlet and more than one outlet. The orifice will be the element regulating the amount of flow through the flow passage and therefore through the device, when there is a flow through the device. Furthermore, according to the invention the valve device comprises a pressure sensitive device comprising a bellows, where the pressure sensitive device is connected to a regulating element. By being connected one should understand that they are linked to each other physically, and movement of the pressure sensitive device will influence the regulating device directly. When the bellows is exposed to an external pressure from a fluid flowing into the valve device through the at least one inlet, the bellows will extend or retract and thereby control a movement of the regulating element relative the orifice, in order to vary a cross section of flow of the orifice. By this there is provided a system where the flow passage in the device is regulated automatically. The pressure sensitive device, the regulating element and the orifice may be configured such that with an increase in pressure in the fluid acting on the pressure sensitive device the orifice becomes larger when there is a flow through the device. Alternatively they may be configured to give an opposite effect.
As the valve device according to the present invention is to be used in a well in or- der to inject a gas into a production tubing, the valve device may also comprises a pressure controlled valve being arranged within the flow passage and downstream of the orifice. In one possible embodiment the pressure controlled valve is formed by a section of the outer housing of the valve device and comprises further an internal movable body provided with an internal bore, one end of the internal movable body being closed and an opposite end being open, forming an inlet. At least one outlet is provided over a periphery of the internal movable body, such that the inlet, the at least one outlet and the internal bore form a flow passage through the internal movable body, thereby also forming a part of the flow passage through the valve device according to the invention. The internal movable body is arranged movable within the outer housing. The valve device according to the present invention also comprise a valve seat arranged inside the housing, where the valve seat is adapted to cooperate with an annular valve element sealing surface formed on the internal movable body, thereby forming the sealing elements of the pressure controlled valve. A pressure in the fluid at the inlet of the valve device according to the invention will flow into the valve device and through the orifice and act on the internal movable body. When there is a given pressure difference from the inlet to the outlet of the internal movable body this will move to open or close the pressure controlled valve within the valve device. When this pressure controlled valve device is in an open state there will be a flow of fluid through the valve device, where the amount of this flow of fluid is regulated by the variable opening of the orifice.
In an aspect of the invention the orifice in the valve device is the inlet of the internal movable body. As the internal movable body is movable in relation to the outer housing, the orifice of the valve device is also movable relative the outer housing. The internal movable body will normally have two positions, open or closed position of the pressure controlled valve.
According to one aspect the regulating element may be provided as a solid structure or as a hollow structure. In one embodiment of the present invention the regulating forms a stem like portion. This stem like portion may be hollow or solid. The stem like portion will in such an embodiment interact with the orifice to regulate the opening of this. The regulating element may be provided with a tapered end, where this end may be arranged on the opposite end of the connection with the bellows.
In one other embodiment the above discussed solid structure may be provided with an internal bore over at least a part of its length, where a plurality of through holes are provided over the structures periphery and length. The internal bore and the through holes such arranged that the form a flow passage through the regulating element. In an alternative embodiment the regulating element may be more sleeve- formed. This sleeve may be arranged outside or possibly within the outer housing. The sleeve may be formed with a plurality of through going holes. By moving the sleeve relative the outer housing, the amount of holes in the sleeve aligned with an inlet in the housing, which in this embodiment forms the orifice in the valve device, is regulated and thereby regulating the opening of the orifice of the valve device. The sleeve will be connected to the pressure sensitive device, with the bellows, as in the other embodiment of the invention to regulate the movement of the sleeve in accordance with a pressure in a fluid acting on the bellows. According to another embodiment of the present invention the regulating element is a hollow device, where the regulating element is comprised of several parts. A first part is formed as an annular hollow cylinder, where a number of holes are arranged over the length and periphery of the annular hollow cylinder. The annular hollow cylinder has a tapered end such that the tapered end can be connected to a smaller diameter annular hollow cylinder, where also this annular cylinder is provided with a tapered end.
The regulating element has preferably a circular cross section, but may also have other polygonal cross sections.
Furthermore, the regulating element may be provided with a variable cross sectional area over a part of its length, when seen in an axial direction of the regulating element. The axial direction of the regulating element will in most cases coincide with a main flow passage direction through the valve device.
In a similar way, the orifice may also be provided with a variable cross sectional area, when seen in the longitudinal direction of the flow passage through the orifice. Furthermore, the orifice is formed with a cross sectional area that is larger than the cross sectional area of the regulating element. With such a configuration the orifice will always allow some fluid through the orifice, and downstream to the possible pressure operated valve within the valve device.
According to one embodiment of the present invention, the pressure sensitive device is connected to the regulating element through an anchorage point. To the anchorage point is also attached an annular plate, where the cross section of the annular plate is substantially the same as the internal passage in the outer housing. The annular plate is further arranged between a pair of end stoppers, where the end stop- pers also are arranged in the internal passage of the outer hollow housing. The end stoppers are arranged spaced from each other, thereby only allowing the annular plate to travel between them. This arrangement will provide a predetermined travel for the regulating element, thereby providing a movement of the regulating element relative to the orifice. The bellows will, due to exposure to the external pressure from the fluid influence the movement of the regulating element.
Other advantages and special features of the present invention will become apparent from the following detailed description, the attached figures and the following claims.
The invention will now be described in greater detail with reference to the follow- ing figures, in which:
Figure 1 is a longitudinal cross section of a first embodiment of the valve device according to the present invention, Figure 2 is a longitudinal cross section of a second embodiment of the valve device according to the present invention, and
Figure 3 is a longitudinal cross section of another embodiment of the valve device according to figure 2.
The figures illustrate different embodiments of the valve device according to the present invention, where the valve device is intended to be installed in a tubing. A person skilled in the art will understand how this is done and it is therefore not covered in the description.
As the three different embodiments of the present invention are based on the same principles, only the differences between the different embodiments will be described and explained. If one or more of the different elements of the valve device is/are formed or constructed in the same way, this or these elements will not be explained further.
In figure 1 is shown a first embodiment of a valve device 1 according to the present invention. The valve device 1 comprises an outer hollow housing 2, which outer hollow housing 2, for the sake of simplicity, is shown as a single element. However, is should be understood that the outer hollow housing 2 also could be comprised of several elements. The outer hollow housing 2 is provided with one inlet 3 and outlet (not shown). At one of its end the outer hollow housing 2 is closed by an end plate 5. Inside the outer hollow housing 2, and towards the end plate 5 is arranged a pressure sensitive device 6 in form of a bellows element. At an opposite end of the end plate 5, inside the outer hollow housing 2, is arranged an internal valve seat 4. The valve seat 4 is adapted to cooperate with an annular valve element sealing surface 7 formed on an internal movable body 8 that is arranged inside the outer hollow hous- ing 2. In a closed state of the valve device 1 the annular valve element sealing surface 7 will therefore abut against the valve seat 4. However, since the internal movable body 8 can be moved axially in the outer hollow housing 1, the internal movable body's 8 position can be changed to a position where the annular valve element sealing surface 7 is brought out of abutment with the valve seat 4, thereby forming a fluid connection between the at least one inlet 3 and outlet (not shown) of the valve device 1. In this embodiment the inlet 3 is composed of one or more through holes arranged over the valve device's 1 periphery. Similarly, the outlet (not shown) is composed of one or more through holes, where the one or more through holes are arranged to have an angled flow out of the valve device 1. As can be seen on the figures, the inlet 3 and the outlet (not shown) are arranged on opposite sides of the valve seat 4 in all shown embodiments of the valve device 1.
An elastic element 9 is arranged between a shoulder 10 of the outer hollow housing 2 and a shoulder 11 of the internal movable body 8. This arrangement will bias the annular valve element sealing surface 7 towards the valve seat 4 thereby closing the valve device 1. However, when the pressure differential across the internal movable body 8 reaches a set limit, the internal movable body 8 will be moved against the elastic element 9 thereby opening the valve device 1.
The internal movable body 8 is formed with an internal bore 13, where an orifice 12 arranged on one end of the internal movable 8 forms part of the internal bore 13.
Opposite end of the internal movable body 8 is closed by a plate (not shown), where this plate form an internal bottom of the internal movable body 8. Further, the internal movable body 8 is provided with at least one outlet 14, where the outlet 14 is arranged in vicinity of the closed end of the internal movable body 8.
The pressure sensitive device 6 is attached by means of an attachment means to the end plate 5. A regulating element 15 is connected to the pressure sensitive device 6 through an anchorage point 16. To the anchorage point 16 is also attached an annular plate 17, where the diameter of the annular plate 17 is substantially the same as the inner diameter of the outer hollow housing 1. The annular plate 17 is arranged between a pair of end stoppers on the inside of the outer hollow housing 1. The pair of end stoppers is arranged with a distance between each other, thereby only allowing the annular plate 17 to travel between the pair of end stoppers 18.
The pressure sensitive device 6 is comprised of a number of composite sections or discs, where the sections or discs are arranged to an accordion-shaped and closed unit. The pressure sensitive device is furthermore filled with an incompressible fluid. Due to its form, the pressure sensitive device 6 can be extended or retracted in its axial direction when influenced by a force.
The regulating element 15 is provided with a tapered end 19. Furthermore, the regulating element 15 will, with exception for the tapered end 19, have a diameter that is smaller than the diameter of the orifice 12, thereby letting a fluid to flow between the orifice 12, and the regulating element 15 when the valve device 1 is in a closed position. The tapered end 19 of the regulating element 15 will then be situated inside the internal movable body 8.
In the outer hollow housing 2 there is also provided at least one through hole 20, which through hole 20 connects the exterior and interior of the outer hollow housing 2. The through hole 20 forms a connecting point for a hydraulic supply line (not shown), which supply line is used for supplying a fluid to the inside of the outer hollow housing 2. The fluid may also be under pressure.
Figure 2 illustrates a second embodiment of the valve device 1 according to the pre- sent invention. As mentioned above, only the constructional differences between the different embodiments will be explained. In this embodiment the regulating element 15 is not a solid regulating element, but a hollow regulating element provided with a number of through holes over the length and periphery of the regulating element 15. The tapered end 19 of the regulating element 15 is provided with an outlet 22, such that fluid, when entering the outer hollow housing 1 through the inlet 3, can flow into the regulating element 15 and through the regulating element 15 and out through the outlet 22.
Furthermore, the orifice 12 is provided with a cross section area that is substantially larger than a cross section area of the regulating element, whereby this will provide a constant open communication over the orifice.
Figure 3 shows a third embodiment of the valve device 1 according to the present invention, where the regulating element 15 is comprised of several parts. A first part is formed as an annular hollow cylinder 151, where a number of through holes 22 is arranged over the length and periphery of the annular hollow cylinder 151. The annular hollow cylinder 151 is formed with a tapered end 152. The annular hollow cylinder 151 has a diameter the substantially corresponds to the inner diameter of the outer hollow housing 2.
The tapered end 152 is further connected to a smaller diameter annular hollow cylinder 153, where the annular hollow cylinder 153 is provided with the tapered end 19.
Only elements relating to the invention are explained and described above and a person skilled in the art will understand that the outer hollow housing may be designed as one unit or it may be composed of several connected elements. The valve device should furthermore have suitable devices for connection or mounting in a process fluid flow. A skilled person will furthermore appreciate that several versions and modifications of the described and illustrated embodiment may be provided within the scope of the invention as defined in the attached claims.