The present invention relates to a valve for use in a side pocket or sub in a well, comprising a housing with a first port and a second port, where the first port normally leads to the annulus and the second port normally leads to the production tubing, where there is at least one valve body mounted internally in the housing in order to open and close the valve for through-flow.
In some cases in a well, where a well fluid with a high specific gravity has been introduced into the well, it is desirable to be able to replace this well fluid with another well fluid with lower specific gravity. This may be the case, for example, when a displacement fluid has been introduced down in the well in order to conduct an operation. In order for this fluid to be circulated out, it is advantageous to be able to pressurise the tubing with the desired well fluid and circulate the well fluid with higher specific gravity out in the annulus and up to the surface. For this to be possible, it is necessary to have devices mounted in the tubing wall in order to open up access between the tubing and the annulus. Such devices in the tubing wall can be arranged in a so-called sub or in a side pocket mandrel. A known method of performing an operation of this kind is to provide a so-called “shear dump kill” valve in a sub or a side pocket in order to obtain this functionality for circulation from the tubing out into the annulus. A valve of this type is closed until a given pressure is applied in the annulus, whereupon a shear pin is broken and the valve is opened and remains open. The valve has no functions for closing the valve again and therefore has to be withdrawn and replaced by a plug or a new valve of the same type in order for the well to be operational again. This is a time-consuming and costly process.
U.S. 20040182437 A1describes a valve device for fluid connection between the annulus and the production tubing with a first valve body and a second valve body which open by pressurising the annulus.
AU 763592 B2 also describes a valve device for fluid connection between the annulus and the production tubing.
An object of the present invention is to simplify the procedure round the process where a well fluid requires to be circulated out by means of circulation from the production tubing to the annulus.
This is achieved by a valve as defined in the attached independent claim where further features of the invention are indicated in the dependent claims.
The invention relates to a valve device for use in a side pocket and/or sub in a well, comprising a housing with a first port and a second port, where during normal use the first port normally leads to the annulus and the second port normally leads to the production tubing, and a first valve body is movably mounted internally in the housing. Both a side pocket and a sub normally form a space arranged at the side of the main channel in tubing, generally in the material forming the main channel. The space normally has a port to the tubing's main channel and a port to the annulus formed outside the tubing, between it and a casing in the well. Devices mounted in a side pocket are normally capable of being pulled out, while devices in a sub are not capable of being pulled out.
According to the invention the valve device further comprises a second valve body mounted internally in the housing and movable relative to both the housing and the first valve body, a first locking device configured between the first valve body and the second valve body in order to lock the movement of the first valve body relative to the second valve body in one direction and in such a manner that when the first locking device is activated, to hold the first valve body in an open position as long as the second valve body is in an open position, thereby providing through-flow through the valve device and a third locking device configured between the second valve body and the housing, with the result that release of the third locking device will permit movement of the second valve body relative to the housing and thereby to a closed position of the valve device, thereby also permitting the first valve body to go to a closed position.
In an embodiment the first valve body may be designed in such a manner that together with a valve seat composed of a surface in the housing it shuts off the second port in the housing, forming a barrier for fluid flow from the tubing into the valve device and thereby also out into the annulus. In an embodiment the second valve body may be designed in such a manner that together with a valve seat formed in the housing it shuts off the first port in the housing, forming a barrier for fluid flow from the annulus into the valve device and thereby also into the tubing. The valve device housing is provided with external devices which enable it to be placed in a sub and/or side pocket, forming seals between the two ports in the sub or side pocket, so that all flow through the sub or side pocket runs through the valve device.
When the valve is in use it will normally be configured with the first valve body in a closed position and the second valve body in an open position. On this basis, when the first valve body is pressure-activated, the annulus will then be pressurised in order to move the first valve body from a closed position to an open position and by means of this movement thereby lock the first valve body relative to the second valve body in the first locking device. In such an open position of the valve device it will be possible to circulate fluids from the tubing to the annulus and in the opposite direction, depending on the requirement. When the desired fluid has been circulated in/out, either the annulus or the tubing is closed and the fluid in the well is pressurised until the third locking device is released. When it is released, the second valve body will move from an open position to a closed position and the first valve body will therefore also be moved to a closed position and the valve device closed. There will then be no fluid communication between the annulus and the tubing through the valve device.
According to an embodiment the first locking device may comprise a detent latch, where the first valve body has a detent device facing in one direction and the second valve body has a detent device facing in the opposite direction. When these two detent devices engage with each other, they permit further movement in one direction, but prevent movement in the opposite direction. Alternatively, the first valve body may comprise a locking ring which, when the valve body has moved to an open position, engages with a groove in the second valve body, locking them relative to each other.
According to an embodiment the valve device may also comprise a second locking device configured between the second valve body, the housing and the first valve body, in such a manner that the second valve body is permanently locked relative to the housing in an open position until the first valve body is locked in the first locking device and thereby in an open position of the valve device. A locking device of this kind may also prevent the third locking device from being released before the first valve body is locked by the first locking device of the second valve body. The introduction of this second locking device therefore provides a greater guarantee that the operation of the valve device will follow the desired procedure.
According to yet another embodiment the valve device may also comprise a fourth locking device configured between the housing and the first valve body in such a manner that it locks the first valve body to the housing in a closed position and is further arranged so that it has to be released before the first valve body can be moved and locked by the first locking device. Such a locking device may be arranged to be broken by a higher pressure differential between the annulus and the tubing than the pressure differential which without this fourth locking device will move the first valve body from a closed position to an open position if the valve body is pressure-activated. This fourth locking device may be a shear pin mounted between the first valve body and the housing, or alternatively a rupture disc which admits fluid in order to influence the first valve body or another type of rupture element which after rupture enables the first valve body to be moved to an open position. As an alternative to a fourth locking device, choking of the fluid supply may be employed instead, causing the first valve body to go to an open position on account of the pressure differential across the valve body. This ensures that the valve body does not open on account of sudden and brief pressure variations in the fluids round the valve device. In a further alternative embodiment this choking process may furthermore be provided by a ball, which enables the rate of flow through the valve to be regulated/choked in order to open the first valve body relative to the housing, but also to arrange the ball and the flow rate so as to be able to have a larger flow diameter in the opposite direction, for example reduced flow rate in the direction from the annulus to the tubing and greater flow rate in the direction from the tubing to the annulus.
According to an embodiment the first locking device may be activated from a neutral position to a locked position by the first valve body being moved relative to the housing from a closed position to a locked open position when there is a given pressure differential between a pressure in the annulus and a pressure in the tubing. This is achieved by having pressure faces on the first valve body which, when influenced by fluids in the annulus and in the tubing, will exert forces on the first valve body, causing it to be moved between a closed and an open position. The valve body may also be prestressed in a closed position by means of an elastic element mounted between the housing and the valve body.
According to an embodiment of the invention a chamber provided with a given pressure before installation of the valve device in the well may be provided between the second valve body and the housing. This pressure may be a vacuum or other pressure set before installation of the valve device in the well. Furthermore, an embodiment of the housing and the second valve body may be such that this chamber is opened and/or punctured, thereby no longer forming a closed chamber when the second valve body is moved, with the result that no “fluid cushion” is formed for movement of the second valve body as a consequence of this chamber.
According to an embodiment the third locking device may be configured in such a manner that when the valve device is in an open position, the third locking device can be released when there is a given pressure differential between the chamber and a pressure applied in the well, with the result that the second valve body goes to a closed position. In an embodiment where there is also a second locking device in the valve device, release of the third locking device requires that the second locking device should already be released. The third locking device may be a shear pin or also a rupture disc, locking ring or other device.
According to an embodiment a second locking device may be configured with at least one recess internally in the housing, a through-going groove in the second valve body and a recess in the first valve body, with a locking ring or dog/claw mounted in the groove in the second valve body. When it is aligned with the recess in the housing, this locking ring will be engaged with it and will only permit relative movement between these parts when a force is overcome and the recess of the first valve body is aligned with the groove and the recess in the housing so that the locking ring has room to be moved out of the recess in the housing. When the recess of the first valve body is not aligned with the groove in the second valve body and the recess in the housing, the locking ring will have no room to be moved out of the recess in the housing, with the result that the second valve body is permanently locked to the housing.
According to a further embodiment the valve device according to the invention may comprise a fifth locking device which locks the second valve body securely relative to the housing in a closed position. In an embodiment this fifth locking device may be composed of detents mounted on the second valve body and in the housing, which when engaged do not permit movement in the opposite direction.
According to a possible embodiment of the invention the first valve body may be mounted relatively inside the second valve body, where the first valve body in a closed position shuts off the port to the tubing and the second valve body in a closed position shuts off the port to the annulus. In a possible embodiment the second valve body may be substantially sleeve-shaped and comprise an admission port through the sleeve wall for fluid through-flow. The first valve body may comprise a substantially cylindrical main part with a central through-flow passage with a port at one end of the cylinder facing the first port of the valve device and a closed opposite end of the cylinder with ports arranged in a side wall of the cylinder facing the second port of the valve device. The closed end of the cylinder gives an area which enables opening/closing of the valve to be controlled so that it is pressure-controlled. According to another embodiment the first valve body may be of another shape than cylindrical, for example polygonal, octagonal, hexagonal, triangular, etc. The second valve body will then have a complementary shape to the shape of the first valve body. These alternative embodiments may also have a central through-flow passage through the first valve body which is open at one end and closed at the opposite end with ports in the side wall near this closed end. In these cases too this internal end surface may be employed for pressure control of the movement of the first valve body between an open and a closed position. A device of this kind also provides a large flow area and only a small number of deflections on the flow path through the valve.
The present invention also relates to a method for operation of a valve device between the production tubing and annulus in a well, where the valve device comprises a first port and a second port. According to the method fluid in the annulus is pressurised and permitted to flow into the valve device until a pressure differential is achieved between annulus pressure and tubing pressure, thereby causing the second port of the valve to be opened and the valve locked in this position and fluid is permitted to flow through the valve, whereupon the fluid in the well is pressurised so that a locking device internally in the valve is broken and both the second and the first port are shut off.
The invention will now be explained by a non-limiting embodiment with reference to the attached figures, in which;
In an embodiment the first valve body 11 is secured to the housing 1 by a fourth locking device D. The first valve body 11 is then in a closed position so that sealing surfaces 12 on the first valve body 11 are in contact with a valve surface 6 in the housing 1, as illustrated in
When the first valve body 11 has moved to an open position, see
As indicated in
As illustrated in
The pressure required for releasing the third locking device is a pressure differential between the fluid in the well and a pressure in an atmospheric chamber. In the illustrated embodiment, this chamber 31 is formed between the second valve body 20 and the housing 1. The chamber 31 is defined by a sealing surface 7 round the first port 2 and an additional gasket 32 between the second valve body 20 and the housing 1. In an alternative embodiment, the chamber is comprised by the open end 31′ on the second valve body and against the housing 1, limited in the rear by the tool behind (see e.g.
Furthermore, when the second valve body 20 has moved relative to the housing to a closed position, as illustrated in
In a first locked position of the second locking device, the locking segment 28, which may be one or more segments arranged round a circumference, will interact with a first groove 8a provided in the housing 1. When the third locking device is released and the fifth locking device has gone into engagement, the locking segment 28 will be located in connection with a second groove 8b provided in the housing 1. A seal in connection with the chamber 31 is also located in this position in connection with the groove 8b, with the result that the chamber in this position is also opened on this side of the chamber 31. In a variant the valve may be designed so that the locking segment 28 in this position is not located in connection with any groove in the housing.
In
The invention has now been explained with reference to an embodiment. A person skilled in the art will appreciate that several modifications and changes to this embodiment will be possible within the scope of the invention as indicated in the following claims. For example both the second, fourth and fifth locking devices may be omitted while still having a valve which fulfils the object of the invention. The valve may also be realized with other types of locking devices than those illustrated.
Number | Date | Country | Kind |
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20100228 | Feb 2010 | NO | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2011/052211 | 2/15/2011 | WO | 00 | 11/13/2012 |