NO20141001A1 - well tool - Google Patents

Description

The present invention relates to a valve system as stated in the introduction in claim 1. More specifically, the invention relates to a ball-activated downhole valve and its use.

The term "oil well" generally refers to wells for oil and/or gas extraction. "Oil well" includes wells in connection with the exploration of new prospects (fields), new production wells that are being tested or are being equipped for operation, production wells that have been put into operation, and wells that are being completed. As well as so-called shale gas wells for which this invention is particularly suitable.

An oil well usually consists of several pipes inside each other down a borehole, where the outer layer or layers are called "casing", and an inner production pipe, as well as control lines. The casing protects the inner production pipe and holds the formations surrounding the well in place so that they do not collapse into the well. They also protect against unwanted inflow of fluids from the external formations.

When completing and starting up shale gas and oil wells or other oil and gas wells, it is in some cases required to do a fracturing job. This means that a liquid is usually pumped into the reservoir under high pressure so that the shale or formation cracks open. This is done to get a large area down in the formation through the cracks so that the gas or oil can more easily flow in towards the production pipe.

When such a job is to be done, it is important to keep good control of the pressure in the various zones in the well, and it is also difficult to pump large enough amounts of liquid into the well to achieve the desired pressure simply because of the large volume the entire well constitutes.

It is therefore common to divide the well into zones. This is usually done today by using (lowering) a rubber element that swells in contact with hydrocarbons or water. These rubber elements are mounted on the outside of the production pipe which is led into the well in the reservoir. The rubber elements then swell up against the formation (well wall) and form a seal between the formation and the production pipe. If you then put on several such seals, you can divide the well into a number of closed zones between these seals.

In order to produce the well, in addition, a valve is usually installed that can be opened and closed between two such rubber elements that will form a zone, this to give the oil/gas an opening in the production pipe to flow in through this and to create an opening for the fracturing fluid and flow in through at the fracturing job. The division into zones means that you only need to pump a smaller amount of liquid into the well. Through the use of such rubber gaskets with valves in between, the fracturing jobs are simplified and you now do not need to pressurize the entire well, but only the area between two gaskets that make up a zone. This is done by the valve or valves being open in a zone between two gaskets, while the rest is closed. In this way, the well can be fractured or produced selectively and possibly shut off for water intrusion that occurs in another zone by closing the valves.

Another method of forming zones is to pump cement (concrete) down through the production pipe and up onto its outside so that the pipe is firmly cemented to the formation. This cement is pumped down into the production pipe from the surface and all the cement is forced out of the production pipe and onto its outside by dropping a cement arrow (what is this) on top of the cement which forces the cement down in front of it as it is pushed down into the production tube of fluid pressure applied behind it. The production pipe is open at the end and the cement will now flow out of this opening and into the cavity between the formation and the production pipe. This will leave the production pipe empty of cement inside and cemented firmly to the formation.

The production pipe can also now have a number of valves that can be opened, and the division into zones will now be made up of the cement that seals between each valve as the area between the production pipe and the formation is filled with cement.

When you then open one of the valves, the pressure applied from the surface will be large enough to crack open the cement in the immediate vicinity of the open valve, but not strong enough to crack open the cement up to the nearest second valve. This is also how the well can now be divided into zones.

The number of such zones and the number of valves in each zone varies with the well conditions, but it is very common to have many zones from 5 to up to 30 and each zone may contain up to 10 valves.

These valves can usually be opened/closed with a wireline intervention tool or they can be opened by dropping a ball or ball down the pipe in the well and which then stops in a seat in the valve. The pressure is then increased over the ball and a slide or sleeve is pushed down to open the valve. This is usually achieved by the valve at the top of the production pipe having a ball seat with a large diameter and then reducing the diameter of the ball seat successively down the well.

By first dropping a small ball into the pipe, one will then pass through all the upper valves and have the ball land on the seat in the valve located at the bottom of the well, which has a seat adapted to the diameter of the ball.

Thus, the right valve can be selected based on the diameter of the ball. This system then creates restrictions in the well as you are dependent on ball seats with a large diameter at the top which then become smaller and smaller successively down the well.

It is the purpose of the invention to produce a system where the same ball diameter can be used to open a number of valves in a well without creating restrictions in the well as all the zones can be opened with the large ball which is usually released last to open the last top zone . This is achieved by creating a construction according to the invention which means that the upper valves count the number of balls that pass, and only open when the correct number of balls have passed.

The method with different ball diameters which results in a restriction in the well, and this is undesirable in view of the operations that will later be carried out in the well. These operations can be, for example, well logging, setting plugs for and shutting off a section permanently, or simply that the restrictions in the pipe constitute a production bottleneck. For that reason, these ball seats must be drilled out from the pipe using an expensive operation with coiled tubing after the fracturing job is done so that the production pipe in the well gets a uniform large internal diameter without the restrictions posed by the ball seats.

Discussion of prior art.

Norwegian patent application NO 20100211 mentions such a system with several ball sizes for each zone. It is based on two sleeves for actuation, an inner sleeve containing a loose ball seat which is fixed inside an outer sleeve with some shear pins. When the ball hits the seat, both sleeves will move down until a shear pin is broken and the ball is released and moved down to the next valve and the operation is repeated there, then continue down the well so that all the zones open. Although this system can activate multiple valves using the same ball diameter, it will leave all valves that the ball has passed activated and open. For that reason, the system cannot be used to produce a solution where all the zones in a well can be controlled independently with a ball size. It is not desirable to open all the zones for cracking in a single operation for the reason that this does not give a good result. This system, like other systems, must use a system where you start with a small ball to open the lower zone in the well and then continue to open the next zone with a somewhat larger ball. The system also cannot be reused for later operations as it is based on a cutting pin that cuts the inner sleeve. This cutting pin cannot be replaced down in the well so the system must be considered for single use.

On the other hand, it may be desirable to have several valves in the same zone, using the same ball diameter for activation, where this solution can be advantageously used in that each zone has its own ball diameter, i.e. at least at the bottom and then increase in diameter upwards in the well .

There are currently two solutions where you can use the same diameter ball on all zones.

One has an external indexing system that causes the sleeve to rotate, also known as a "jay slot system" as described in US Patent No. 2013/248201. This allows the balls to pass until the desired number of rotations/indexes on the sleeve is achieved. Typical of such systems is that there are the largest number of rotation points on the upper sleeves and the fewest on the lower ones.

The problem with this system is that you are dependent on a spring that pushes the sleeve back up to the starting point after the end of rotation. This is so that the seat for the ball that has passed will be activated again. These systems are also expensive and complicated to make and set up (assemble), in particular it is expensive to mill the external groove on the sleeve which will create rotation.

The system is also very sensitive to contaminants and impurities in the well fluid that enter the groove and the spring pocket and can cause it to lock up completely. It is also difficult to reset the system, whether a new cracking or acid stimulation job is to be done, or simply that you just want to close that zone. The system will also stop working if it is used in conjunction with cemented production pipe or if the spring should break.

Another known system is one which consists of several extended grooves in the tube of which the inner sleeve and ball seats are indexed m, as shown in British Patent No. GB-2,506,265. This system has a turned groove for each position the sleeve must have and entails an expensive and complicated internal turning to create, for example, 20-50 such internal accurate turns inside the valves. Another disadvantage is that, as described, all the tracks will be exposed to deposits and coatings that can settle in the tracks and prevent operation of the system.

The sleeve that performs the actual activation is here a separate part from the close/open sleeve and the function is based on the activation sleeve being moved downwards a desired number of times and finally landing on top of the close/open sleeve. This causes the opening sleeve to be moved down to the open position by means of the hydraulic pressure that occurs above the activation ball. It is important to note here that the activation sleeves with the ball seats have the same outer diameter as the closing sleeve and that they are two separate parts that cannot be easily moved to the open and closed position as a unit.

Common to all these solutions is the disadvantage that they are difficult to reset to their initial position after use. And they are therefore also to be considered a disposable system. Other disadvantages are that they require careful control of the number of balls released to get the indexing mechanism to work the entire round, or that the ball seats drop out of position on the last activation. The known systems are also exposed to deposits from previous cementing jobs, which mean that they are generally not suitable for use in wells with so-called cemented liners. When the production pipe "Liner" is cemented, cement will be pumped past all the valves, and parts of the cement will then penetrate the valves as it passes and harden there. This will then make it impossible to operate the valves after the cementing job has been carried out.

As mentioned, there are several systems that use balls of different sizes. When we talk about activation balls in this context, it is understood that this is not only about round balls, but that it can also be activation cementing arrows of various types known from the industry. Or other objects that can be hydraulically pumped down the well to land on a seat in the valve tool.

The systems that use balls of different sizes will not be relevant in this context as the purpose here is to produce a tool that does not have the disadvantages of several ball sizes as mentioned above.

Present invention.

The valve system according to the present invention is characterized by the fact that it is designed to be activated selectively using a spherical body (a ball) of a single size, where the body is designed to land on one or more seats inside the valve, where the seats can be activated for the landing of a spherical body either before driving in a well or when passing a previously released body or other adapted object of adapted diameter or shape. the valve housing comprises two separate sleeves in the form of an inner sleeve arranged inside an outer sleeve, where that inner sleeve can be moved in relation to the outer sleeve, the inner sleeve comprising one or more body/ball seats, one axially above the other, and which are activated to retain a body, successively in that the inner sleeve can be moved axially through the outer sleeve.

Preferred embodiments are specified in the independent claims 2-18.

According to the invention, the valve system is used where it is inserted in a production string, to open a formation for the production of hydrocarbons, where a gasket is arranged between each unit 1 in the valve system which shuts off the axial fluid flow in the well (outside the production string), as the valve set is aligned for the successive opening of parts of the formation for production by pumping in fluid via the valve system and which cracks open the rock mass in the formation so that it starts producing hydrocarbons which can then flow into the well and up through the production pipe.

The present invention provides a solution to the problem of diameter restrictions in oil and gas wells as a result of ball-activated valves where the seats for the balls normally form a restriction, in that several valves in series can be opened with the same ball size at the desired time. This is done by arranging an outer sleeve 2 inside the production pipe which covers the outlet openings 14 in the production pipe when the outer sleeve 2 is in its starting position. Openings 29 are also formed through the wall of the outer sleeve 2, which are later to align radially with the openings 14, but which do not align in the initial position of the sleeve 2, and thus block the fluid outflow.

Inside the outer sleeve 2, a new inner sleeve 3 is arranged which comprises several ball seats (see perspective figure 13) of the same diameter. The uppermost ball seats in the valve's inner sleeve 3 are not activated when the system is run in the well, and will have a large enough diameter for the first ball to pass freely, but will stop in the lowermost seat 4a which is defined within the outer sleeve 2 since the constriction of the sleeve 2 presses the seat in the sleeve 3 radially inwards and prevents the ball 5 from passing.

The first, for example the bottom ball seat is thus activated (ie the seat is pressed in and the ball 5 cannot pass) and thus arranged to receive the first ball. When the first ball 5 lands on this activated seat, it will, as a result of the fluid pressure, displace the inner sleeve 3 one step downwards so that the next ball seat in the inner sleeve, which is located above the first ball, is activated as this seat enters in the outer sleeve 2 which has a smaller diameter and compresses the seat so that it is activated. When the next ball seat is activated, the first ball is released by this ball seat coming axially out of the outer sleeve 2 and down into a larger diameter so that the seat is no longer active as the increased diameter allows the seat to expand and release the ball.

The outer sleeve which seals the passage out to the formation is held in place by friction or some form of locking device such as splits, dowels or split fingers in a groove, this locking device being released by the inner sleeve when it reaches its final position. Until this, the inner sleeve is free to move axially through the outer sleeve. This prevents premature full opening and drifting of the radially directed channels 14 and 29 in the valve. It is only when the last seat in the inner sleeve 3 comes down to and moves downwards in the outer sleeve 2, that this is displaced and so that then all openings 14-29-50 align from outermost to innermost in the assembly.

The first ball will then continue down the fire pipe to the next valve where the same operation is repeated. Only when the correct number of balls have passed and the last seat in the valve is active, i.e. has entered the outer sleeve, will this open by simultaneous push down and thus both openings 14 and 29 will escape. A smaller proportion of liquid will also flow out into through the slits 190 which are formed between each finger 192, i.e. before the openings 50 align with 14 and 29. However, it is only when the three openings 50,14,29 align that a full outflow/inflow of liquid is obtained through the channels 14 and 29. Thus, an efficient counting mechanism can be produced where the top zone has, for example, 10 ball seats where the first 9 are used as a counting function through seat 1 activating seat 2 when ball 1 passes, seat 3 when ball 2 passes etc. When then seat 10 is activated the valve will be fully opened (all openings 50-29-14 escape) when ball 10 is dropped into the well. Through this, a system can be created where the very bottom valve has 1 seat that opens when ball 1 is released, that zone can then be cracked open by pumping hydraulic pressure.

As can be seen, for example, in Figure 4, the first ball has been passed through all previous sets of inner sleeves, and placed in the bottom 3. This has then meant that all inner sleeves 3 in each set have moved one step down so that the outer sleeve 2 now encloses and activates the second lowest inner sleeve in each set.

When ball 2 is released, it will land on the now active seat 2 in valve 2 from the bottom up and open this, at the same time the ball is now held firmly by the seat in valve 2 and is prevented from continuing down the well. Ball 2 now seals off fluid flow past the ball and zone 2, which is open above the ball seat, can be cracked open. This can be carried out without any of the overlying zones being open and without liquid flowing down to the underlying zone 1.

By ball is meant any object that is dropped into the well, and it can be a ball or a sphere of various optional varying materials, alternatively it can be an arrow specially designed for the purpose or another type of object that can be pumped down in the well using fluid pressure.

The present invention also provides a solution to the problem of resetting the valves to their initial position in a safe manner so that they can be used for subsequent maintenance cracking jobs. This is done by arranging a standardized profile for such operations at each end of the inner sleeve 1 which contains the seats, which can be connected to. Such a connection can be made in many ways, but a common method will be the use of coil pipes. You can then either forcibly open all the valves by running coil pipes or you can forcibly close them.

This is done by connecting to the profile at either the bottom or top of the inner sleeve and pulling or pushing this to its end stop where the connection is released.

When the sleeve is pulled back to the starting position, the outer sleeve will follow up to the closed position. Likewise, the outer sleeve will follow to the lower position if the adjustment tool that fits in the profile is pressed down and thereby the inner sleeve, which takes the outer one with it to the open position.

It is understood that other standard profiles can also be used for such conversion tools, and that a profile at one end of the tool may be sufficient. It is also important to note here that the system does not depend on shear pins which can be regarded as a one-off solution. The system can of course be made with shear pins as a replacement for the preferred solution with split rings, but then you will get a disposable system which is not a preferred solution, but which may be acceptable in some cases.

The present invention also solves the problem of pumping cement/concrete mixture past the valves in that all cavities and surfaces in the valve are filled/covered with a suitable grease which contains a sugar level high enough to prevent hardening of the cement pumped past the valve. The sugar mixed with the lubrication will prevent the cement from hardening in the area where the lubrication is, but will not prevent the hardening of the cement/concrete that passes the lubrication.

The present invention solves at least one of the stated problems.

The present invention provides a device according to the characteristic part of the following independent claim. Alternative and advantageous embodiments are indicated in the independent claims.

In what follows, a detailed, non-limiting description of possible embodiments of the invention is given with reference to the attached figures, where: Figure 1a shows a borehole 100 for a well that runs down through an oil/gas-bearing formation 102 and where a production string 104 runs down into the well. It appears that the well first runs vertically and then deviates to a horizontal direction. The figure shows an example where nine valve units 1 have been installed in the well in order to be able to pump fluid into the formation 100 in sections to make it ready for the production of oil/gas. Figure 1 b shows an enlarged section from the horizontal part of the well, and shows that gaskets 10 are placed around the pipe 104 between each valve unit 1 in order to be able to isolate the sections from which it is to be sprayed to crack open the formations. In this case, three such zones have been created, and three valve units have been arranged as according to the invention. Figure 2 shows a model of a well with several valves 1a, 1b and 1c installed. The figure shows a section of a preferred embodiment of a valve device 1a, 1b and 1c according to the present invention with a varying number of ball seats. The valve device 1a has one seat 4a, valve device 1b has two seats 4a and 4b, valve device 1c has three seats 4a, 4b, 4c, all three valve systems comprising an outer sleeve 2 which encloses an inner sleeve 3. The valve 1a is shown after it the first ball 5 has been dropped into the well pipe and shows that the valve device 1a is about to open with the ball 5 placed on the seat 4a. Figure 3 shows a sectional detail of valve 1a from Figure 2 with the first ball 5 lying on the seat 4a. The following details are also shown here: An outer sleeve 2, a first sleeve 19 which together with several units will constitute an inner sleeve 3, a split 6, splits 8, locking grooves for splits 11 and 12, gaskets 17 and 18, an opening channel 14 in the wall of the valve 1a, an opening channel 29 in through the wall of the outer sleeve 2 as well as the top reset profile 20. Figure 4 shows in section details of figure 2 after two balls have been dropped into the well. Here it is shown that zone number two marked with the number 23 in well 15 is ready for fracturing by pumping in fluid under pressure, as ball 5 number two (5b) is located on seat 4b in valve 1b and the outer sleeve 2 has been moved axially to open position from the inside to the outside of valve 1b through the channels 29/14, first through the slots between each finger in the inner sleeve, and then through the openings 50 and further out through 29 and 14. We also see that the well 15 is divided into zones with gaskets 21. Zone 22 is all cracked open by cracks 25 with the aid of fluid pressure. We also see that ball 1 (5a) is on the seat in valve 1a. Figure 5 shows a sectional detail of ball no. two 5b on seat 4b in an embodiment where ball 5b is retained in valve 1b after the outer sleeve 2 has been displaced so that the channels/openings 29/14 align with each other and the liquid can flow out outside the tube . Figure 6 shows a section of valve 1c with the third ball 5c on the seat 4c which has been moved to this position actively by ball no. two 5b (see figure 5) which has previously passed. Ball 5c is now ready to open channel 29/14 by displacing outer sleeve 2 axially (downwards). We also see a (schematic) threaded connection 16 at each end of the valve unit 1c for connection. Such connections are found on all the valves 1 with the purpose of attaching them to the production pipe 26. Figure 7 shows a section of the valve unit 1c where the inner sleeve 3 and outer sleeve 2 are mutually moved to the open position when creating fluid pressure over ball 5c. The ball is "stuck" as a result of the fingers 4a being pressed inwards by the constriction formed by the outer sleeve 2, and all the channels 50, 29 and 14 escape. It is thus the last seat structure in the sleeve 1 that pushes the outer sleeve 2 with it axially (downwards) so that the channels align. Figure 8 shows a section of the valve unit 1c when the first ball 5a passes through it and lands on the seat 4a. The arrows 27 show the direction the ball moves from top to bottom. The number 16 shows threaded connection in the valve structure 1c for attachment (as an insert) to the production pipe 26

Figure 9 shows a longitudinal section of valve 1c with ball no. two - 5b - on the seat 4b.

Figure 10 shows a section of valve 1c with ball no. three - 5c - on seat 4c.

Figure 11 shows a section of valve 1c with ball no. three - 5c - on the seat, now in the open position and channel 14 open flush with channels 29 and 50, as well as the narrowing 9 for the split 6. Ball 5c is retained in the narrowed channel ( the inside of the outer sleeve 2 keeps the fingers 194 pressed inward to a constriction that the ball cannot pass), and fluid can be pumped out through the channels 50,29,14. Figure 12 shows a longitudinal section of valve 1c which releases ball no. three 5c further after opening the valve. Figure 13 shows a 3d isometric perspective drawing of an assembled inner sleeve 3 which in this case consists of three ball seat sections 19a + 19a + 19b, as well as upper and lower sections 20 and 21 respectively for connection.

The lower of the two identical seat sections 19 a has a ball seat 4, i.e. as the first (lower) unit. No. 4b shown is the second seat in the row and the third unit is No. 4c. etc. The top unit 4c/19b in this example has openings 50 in the wall around the entire pipe circumference, and these are arranged to flush/correspond with the channel 14 of the valve pipe 1 and the holes 29 in the outer sleeve 2 for and provide full and free opening in open position for pumping out liquid/fluid. The number 28 shows parts of the sleeve unit which are not split longitudinally so that several sleeve sections 19 together with end profiles 20 can be screwed together to form the inner sleeve 3.

More specifically, figure 13 shows an example of a multi-part inner sleeve 3, comprising lower and upper connecting parts 20 between which are inserted a number of ball seat sections 19a and an upper section 19b, for example in the case of screw connections. Each of the sections 19 comprises a pipe socket where a number of axially designed U-shaped slots 190 are cut in the annular wall, each defining a flap 4/192 which can be bent outwards or inwards. At the bottom, each tab includes a wall thickening, outgrowth or bead 194 which normally projects outside the outer side of the outer side of the sleeve 3. Figure 13 shows two such separate sections 19a (joined together with a screw connection as indicated by the number 193), plus a third section 19b which, in addition to tabs 109, comprises a number of through holes/recesses 50 through the sleeve wall 19b around its circumference. In an annular recess around the outer circumference of the sleeve 3 in its upper part, a split ring is laid designed to be compressed by the fact that, when pushed down, it hits a narrowing 9 (figure 11) in the inner side of the valve 1.

The sleeve 19 is mounted internally in the cut-in valve sleeve 1, where the bottom section is then mounted inside the enclosing outer sleeve 2. During said pushing down, the sleeve 3 is released for further axial travel independent of the sleeve 2. This release preferably takes place after the sleeve 2 has been moved to the open position in the valve sleeve 1.

When the sleeve 3 is moved inside the outer sleeve 2, the radial inward-facing narrowing rings in the sleeve 2 will press against each of the beads 194 so that the tabs 192 are pressed radially inward, thereby forming a stop seat for the balls/balls 5 which are moved axially inside the sleeve 3.

Furthermore, when the outer sleeve 2 is pushed downwards and the openings 29 and 14 align to form a radial flow channel, fluid can flow out through the slits

The invention in the preferred version solves the problem of different ball sizes and reducing the diameter of the production pipe by all the ball seats having the same diameter and at the same time can be activated in the desired sequence, typically from the bottom upwards.

In the present invention, the object/ball/ball 5 that is dropped or pumped down into the well will be able to move freely past all the seats in a valve 1 except those that are engaged in the outer sleeve 2 which creates a constriction that presses the fingers 4 inward and thereby preventing the ball 5 from continuing downwards. When the first activation object (ball) 5 is dropped into the well, this will hit the lowest seat in the inner sleeve 3 which is in the active position through the constriction created by the outer sleeve's 2 narrower inner opening.

When you then drop a first ball or other activation object 5 into the well, in a valve with three seats it will first hit the seat 4c at the top of the upper valve 1c. This seat 4c is now not activated (squeezed together) by the outer sleeve 2 and will drop the ball 5 freely through and past. The same applies to subsequent seat 4b in this first valve 1c (see figure 8). The ball "races" past the seats 4c and 4b until it hits the bottom seat 4a which is now activated in engagement (squeezed together) by the outer sleeve 2 and thereby activated. When the ball hits the activated seat 4a which is activated in the outer sleeve 2, it will pull the inner sleeve 3 downwards due to the pressure above.

When the activated seat 4b and the ball 5 on it have moved to the end of the outer sleeve 2, the ball 5 will be released again (the constriction ceases), as the seat 4a on which it rests is no longer active when it comes out of the outer sleeve 2 At the same time, the axial movement of the sleeve 3 caused by the first passing ball 5 will activate the seat 4b which has now entered and engaged the outer sleeve 2.

When ball 5 number two is released, it will again move the inner sleeve 3 axially downwards and release ball 5 so that it can continue its journey down the well to the zone below. The valve 1c in the preferred embodiment has now counted two balls 5 without being activated / opened (without the channels 29,14 escaping). When ball 5 number three is ground down into the well, it will land on the now activated seat 4c in valve 1c and again move the inner sleeve 3 axially downwards due to the fluid pressure that builds up behind ball 5.

During this last movement, the inner sleeve 3 hits a split ring 6 mounted on the sleeve 3 (see e.g. Figure 3) on top of the outer sleeve 2 and the pressure builds up behind the ball 5 so that the friction applied to the outer sleeve 2 by the split rings 8 are overcome, the split rings 8 lie in grooves in grooves 11 and 12. When the friction created by the split rings 8 is overcome, the outer sleeve 2 and the inner sleeve 3 move together axially/downwards with the help of the pressure that builds up behind the ball 5 which lies on seat 4c. The axial movement of the outer sleeve 2 causes the channels 29 and 14 to align, and opens for fluid connection out through valve 1c so that pressure communication with external well 15 is achieved through the now open channels 29/14. The now open channels 14 were previously closed using the gaskets 17 and 18 as well as the outer sleeve 2. In a preferred embodiment, the splitting ring 6 is compressed when it hits a constriction 9 (figure 11) on the inside of the valve 1. This will in turn release the sleeve 3 for further axial travel independent of the sleeve 2. This release preferably takes place after the sleeve

2 has been moved to the open position in valve 1.

When the sleeve 3 is released for further travel downwards, it will grind free the ball 5 again to be able to further operate one or more valves further down the well, preferably with the same number of seats 4. Now the ball then hits the last valve 1 in the well with the same number of seats 4 will it can now be retained by either the narrowing 9 being removed and thereby the compression function it has on split ring 6 i, or by, for example, introducing another physical form of end stop which prevents the split 6 from being compressed. Both of these solutions will prevent the last valve 1 and release the ball 5 further into the well if they are placed correctly.

A third solution is that the inner sleeve 3 gets a separate end stop which prevents it from traveling so far axially that it takes the seat out of the outer sleeve 2 with it. This can be in the form of a simple end stop which is not compressible, but only pulls the outer sleeve open with it.

This will also leave the last valve in this zone open with the ball on the seat which will thus constitute a seal so that the well can be pressed up above the ball.

Between the ball 5 and the seat 4 there will always be some leakage, but this is marginal compared to if the ball was not present on the seat and in practice has proved to be of little importance. The point is not to provide a 100% tight connection between ball 5 and seat 4, but to create a sufficiently large flow restriction that enables the build-up of fluid pressure over ball 5.

It is understood that ball 5 number one (5a) opened the bottom valve 1a and that the subsequent next ball 5 opened the second bottom valve 1 b.

It is also understood that the valve 1a 1b and 1c can have any number of ball seats such as 4a 4b and 4c to achieve activation after the correct number of balls dropped into the well. Typically, there could be up to twenty zones in a well, then the top valve 1 would like to have twenty such ball seats 4 in front and be able to drop down nineteen balls 5 past before activation.

Another preferred embodiment is to use five ball sizes to obtain a maximum of five seats 4 in each valve. This can be done for production reasons. Then you will be able to get twenty zones in a well with relatively little restriction compared to and use twenty ball sizes.

In the preferred embodiment, the ball seats 4 are designed through a partial splitting of a sleeve 19. A number of sleeves 19 are assembled into the sleeve 3 and the number of sections determines how many seats there are in the valve and thereby how many balls 5 can pass before activation. The use of such split sleeves is a well-known solution for creating a radial diametral movement on a sleeve. Other known methods for this can also be used such as lugs which are activated when the inner sleeve 3 slides into the outer sleeve 2, or a split such as ring 6. Or other forms of execution where the seats in the sleeve 3 will be inactive when they are not is compressed inside sleeve 2.

Another preferred embodiment is that the seats 4 before entering the sleeve 2 are in the activated position but that they do not have radial support from the overlying outer sleeve 3 or from the material in the valve 1 so that they can freely expand and let the ball 5 pass. When the seats 4 then move into the sleeve 2, this will constitute the radial support for the seats 4 and thereby activate them so that the ball will push/move the sleeve 3 axially to the point where the inner sleeve 3 with the ball seats 4 again comes out of the outer the sleeve 2. thus identical function of the invention can be achieved without compressing the seats when they enter the outer sleeve 2. It must be understood that also for such a solution, alternatives to the seat 4 which is made up of the split fingers in the sleeve 19 which together form the inner sleeve 3, could be used. Such as splits, dogger pins or other solutions where the outer sleeve 2 constitutes a radial support for the seats 4 and thereby prevents the ball 5 from passing.

According to a preferred embodiment of the invention, there will be the most ball seats 4a 4b 4c etc. in the upper valve and the least in the lower one. For example, the uppermost valve can have ten seats and the lower one one seat, the second lowest two, etc. Then you will be able to drop a ball 5 that goes through all the valves and lands in the lowermost valve 1a. When it then lands in the bottom valve 1a, this will immediately move axially as it all rests on split 6 which forms the end stop for the inner sleeve 3 relative to the outer sleeve 2.

According to a preferred embodiment of the invention, all internal cavities are filled with a viscous lubrication such as petroleum-based gease, heavy paraffin wax or a natural grease containing sufficient sugar which will prevent cement that may penetrate into the cavities from starting to harden. This lubrication can also include beeswax, or pure honey which will also prevent the cement (concrete) from hardening while providing a lubricating effect. The point is that this lubrication contains some type of chemical such as sugar or something else that prevents hardening of the cement. The hardening of the cement can also be stopped by mixing in other chemicals known in the field, such chemicals are considered to be covered by the invention and are not dealt with further herein.

In its simplest form, the valve can consist of a sleeve 2 mounted inside the production pipe, this sleeve is then arranged to seal off outflow or inflow through openings in the valve pipe 1 in its one position. In its second position, this sleeve 2 allows free flow of liquid or gas either from the valve pipe 1 out into the formation or from the formation into the valve pipe. Inside this sleeve 2 is placed as described an inner sleeve 3 which has one or more ball seats which have the same diameter in the preferred embodiment. This inner sleeve is free to move axially inside the outer sleeve between two end stops which will prevent the inner sleeve 3 from slipping out of the outer sleeve 2.

One can also imagine solutions where the ball seats in the inner sleeve 3 have several diameters to further increase the flexibility of the valve.

In cases where one of the sleeves is stuck or you have to return the valve to the initial position, the inner sleeve can also have built-in profiles for well tools so that it can be displaced axially also when using typical coiled pipe or wireline tools or other used well intervention tools.

The counting mechanism's main purpose is to open the valve at the correct time, but it can of course also be used to activate other well equipment via the same timing or counting function. As a non-exhaustive example can be mentioned: activation of well perforation guns, activation of other types of well inflow valves, injection valves for chemicals, gas lift valves and so-called "sliding sleeves".

The valve sleeve 1 can preferably be produced in any material suitable for installation in a well, and as a non-exhaustive example some used steel types such as ASI 4140, 420 mod 13%Cr, super duplex or high-quality steel such as Inconel 718 without and material can be mentioned the types of valve 1 to these. It is also conceivable that ceramic materials and other composite materials can be used.

The material types for the other parts of the valve can typically be the same as for valve 1, but for the inner sleeve, a flexible material will preferably be chosen which can also be a spring steel that enables movement of the seats in the sleeve 3.

While the invention is described with reference to a preferred embodiment, it should be understood that a number of modifications can be made without going beyond the scope of the appended patent claims.

Claims (19)

1. Valve system, characterized in that it is arranged to be activated selectively using a spherical body (5) (a ball) of a single size, where the body is arranged to land on one or more seats inside the valve, where the seats (4 ) can be activated for the landing of a spherical body (5) either before driving in a well or when passing a previously released body (5) or other adapted object (5) of adapted diameter or shape. the valve housing (1) comprises two separate sleeves (2 or 3) in the form of an inner sleeve (3) arranged inside an outer sleeve (2), where the inner sleeve (3) can be moved in relation to the outer sleeve (2), since the inner sleeve (3) comprises one or more body/ball seats (4) one axially above the other, and which are activated to retain a body (5), successively by allowing the inner sleeve (3) to be moved axially through the outer sleeve (2). 2. Valve system in accordance with claim 1, characterized in that the inner sleeve (3) pulls the outer sleeve (2) with it to the open position when the ball (5) lands on the last seat 4 in the row in the inner sleeve 3. 3. Valve system in accordance with claims 1-2, characterized in that the last seat (4c fig. 13) of the inner sleeve (3) forms an indentation in order not to release the ball (5) when it lands on this last seat 4. 4. Valve system in accordance with one of the preceding claims, characterized in that the last seat (4c) in the inner sleeve (3) can release the ball (5) after opening the outer sleeve (2) which makes up the valve, for example so that several valves (1 ) is installed in the same zone of use where the bottom valve (1) will then hold back the ball (5) in accordance with claim 3, thereby enabling several openings for fluid flow out to and in from the same zone. 5. Valve system in accordance with one of the preceding requirements, characterized in that the first ball seats (4) in the inner sleeve (3) release the ball (5) past the valve (1) and axially downward until a next valve (1) in a row reaches the inner sleeve (3 ) its actuated (narrowed) seat (4) comes out of engagement with the outer sleeve (2) and into the now increased internal diameter (ID) of the valve (1). 6. Valve system in accordance with one of the preceding requirements, characterized in that the first ball seats (4) with the help of the pressure behind an activation object, displace/move the inner sleeve (3) axially down a position for each activation object (ball (5)) as with fluid pressure from above is pumped down into the well, thus activating a final seat (4c - fig. 13) for final opening of the valve (1) by an axial displacement of the outer sleeve (2) parallel to the inner sleeve (3). 7. Valve system in accordance with one of the preceding claims, characterized in that the inner sleeve (3) comprises one or more end pieces - profiles (20) for connecting a conversion tool. 8. Valve system in accordance with one of the preceding claims, characterized in that the outer sleeve (2) in the valve (1) is physically locked in the valve via at least one splitting ring (8) until the inner sleeve (3) has been moved to a position where a final seat (4c - fig. 13) is activated and is only then released for opening when the friction in at least one split (8) is overcome by the pressure that builds up behind the ball (5), thereby overcoming the friction created by the locking. 9. Valve system in accordance with one of the preceding claims, characterized in that the outer sleeve (2) can be locked for movement by the use of locking means, for example a shear ring, shear pin, split fingers, which locking means immobilize the outer sleeve in position for fluid flow upon said movement of the inner sleeve (3) . 10. Valve system in accordance with one of the preceding claims, characterized in that the locking device of the outer sleeve (5) is held in lock via a pressure applied from the inner sleeve (3), in that the pressure from the adapted inner sleeve (3) affects one or more pins which is pushed through the outer sleeve (2) by the inner sleeve (3) and out into a notched groove in the valve (1) on its way, when the inner sleeve (3) reaches its activation position, this then has a smaller diameter in an area that enables the pins to collapse inwards and release the outer sleeve (2) for movement so that the openings (14,29) align for fluid flow. 11. Valve system in accordance with one of the preceding claims, characterized in that the inner sleeve (3) comprises ball seats (4) for placing balls (5) of different diameters in order to further increase the flexibility of the system. 12. Valve system in accordance with one of the preceding claims, characterized in that the outer sleeve (2) is held in place by, for example, a split sleeve which exerts friction against the outer wall of the valve. 13. Valve system in accordance with one of the preceding requirements, characterized in that All internal cavities and all exposed surfaces are filled with a lubrication that contains a chemical that prevents hardening of cement such as, for example, sugar. 14. Valve system in accordance with one of the preceding requirements, characterized in that the outer sleeve 2 is provided with internal protrusions that will enable expansion of the ball seats 4 and release the ball before the ball seat is out of the outer sleeve 2. 15. Valve system in accordance with one of the preceding claims, characterized in that the valve 1 has a further number of ball seats than the described 4a, 4b, 4c to allow even more valves and to be operated by a ball 5 size. 16. Valve system in accordance with one of the preceding claims, characterized in that the valve (1) comprises a ball seat as described (4a- figure 2) to allow even greater flexibility. 17. Valve system in accordance with one of the preceding claims, characterized in that the inner sleeve (3) or outer sleeve (2) is designed with one or more, for example, splits for increased friction in the inner sleeve (3) or outer sleeve (2), or by other known constructions for increased friction such as, rougher surface on the material, different material than the other parts, coating with a different material, grooves in the material, c-clip rings, shear rings or shear pins with the purpose of preventing accidental movement of the outer sleeve (2). 18. Valve system in accordance with one of the preceding claims, characterized in that the valve (1) comprises ball seats which are designed to first open the valve and then close it if further balls (5) are dropped into the pipe/well (1/3). 19. Application of a valve system according to the preceding claims, where the valve system is inserted in a production string, to open a formation for the production of hydrocarbons, where between each unit 1 in the valve system a gasket is arranged which shuts off the axial fluid flow in the well (outside the production string) , as the valve set is designed to successively open parts of the formation for production by pumping in fluid via the valve system and which cracks open the rock mass in the formation so that it starts producing hydrocarbons which can then flow into the well and up through the production pipe.