Patent Grant
9683434
This application is a U.S. national stage filing under 35 U.S.C. §371 of PCT International Application No. PCT/GB2012/052928, filed Nov. 28, 2012, which claims the benefit of priority to Great Britain Application No. 1120448.4 filed Nov. 28, 2011. Each of the above-referenced applications is expressly incorporated by reference herein its entirety.
The present invention relates to a method and apparatus for controlling downhole devices.
It is necessary to control the actions of downhole valves and other tools from the surface. Valves or other downhole tools frequently need to be opened and closed at different stages of drilling, operating and maintaining a wellbore, so controllers to achieve the remote opening and closing of the valve in the well are needed.
Activation and de-activation of downhole devices often involve steps such as dropping activation or deactivation balls from the surface. One disadvantage of these methods is that time between dropping the ball from the surface and the ball landing on the designated tool seat is a variable factor in the method. For very long wells it can take e.g. up to 40 minutes to switch a tool on and another 40 minutes to drop a second ball to switch the tool off. These methods also limit the number of on/off cycles that are possible because the number of balls that can be dropped and retained in the ball catcher is limited, and once the ball catcher is full, the tool must be retrieved to the surface and the ball catcher must be emptied before the tool can be re-set.
It is also well known to control tools in the well using pressure changes transmitted via fluid in the wellbore, which shuttles a sleeve axially relative to a pin. Such arrangements are typically called J-slot devices, as the sleeve is slotted with a J-shaped slot in which the pin moves. The sleeve is caused to rotate relative to the stationary pin which is constrained to travel along the J-shaped slot. When the pressure is increased, the sleeve moves down, the pin is at one position in the slot, and the valve is open for example, and when the pressure is decreased, the sleeve moves up relative to the pin, which is guided into another relative position of the pin and the slot, in which the valve can be closed. The slot can be formed in a loop around the sleeve, with the two ends of the loop connected, so that the sleeve continually moves around its axis sequentially opening and closing the valve. The pressure acting on the sleeve can be wellbore pressure or can be control line pressure.
According to the present invention there is provided apparatus for controlling a downhole device in an oil, gas or water well, the apparatus having a body comprising a control slot engaging a pin, the control slot and the pin being provided on separate parts that are movable relative to one another, such that movement of the pin relative to the control slot switches the downhole device between active and inactive states, the slot having a first loop wherein the pin can move between different idling configurations of the pin and slot in which the device is inactive, and a separate second loop spaced around the body with respect to the first loop, and wherein the pin can move in the second loop between different configurations of the pin and slot which correspond to active and inactive configurations of the downhole device, and wherein the pin can be switched between the first and second loops, and wherein the pin can cycle between the different configurations within each of the first and second loops without switching between the first and second loops.
The invention also provides a method of controlling a downhole device in an oil, gas or water well, the apparatus having a body comprising providing a control slot and a pin on separate relatively movable components so that the slot engages the pin and the pin and slot are movable relative to one another, and moving the pin relative to the slot to switches the downhole device between active and inactive states, wherein the method comprises moving the pin in a first loop of the slot wherein the loop defines different idling configurations of the pin and slot in which the device is inactive, and moving the pin in a second separate loop of the slot spaced around the body with respect to the first loop, wherein the second loop defines different configurations of the pin and slot which correspond to active and inactive configurations of the downhole device, and wherein the method includes the step of switching the pin between the first and second loops and cycling the pin between the different configurations within each of the first and second loops without switching between the first and second loops.
Typically the pin can remain in one of the first and second loops without switching between them, moving between different configurations of the pin and slot within each loop. Typically the pin cycles repeatedly between the two different configurations of the pin and slot within each loop, moving repeatedly from one to the other until switched between the loops. Typically the pin cycles from the origin of each of the first and second loops to a second position in the loop and back to the origin of the same loop. The first and second loops can be connected to third or further loops or tracks that may have the same or different functions. Accordingly such third and further loops may optionally allow cycling in the same was as the first and second loops, but provided that the first and second loops allow cycling, it is not necessary for other loops or tracks to do so.
Typically the geometry of the slot restrains the movement of the pin within one of the loops until switched.
Typically each of the loops comprises a first track and a second track, wherein the second track returns the pin to the starting point of the first track. Typically the pin normally moves in opposite axial directions in the two tracks. Typically the pin can be switched between the first and second loops on the second return track. Typically the switching is achieved by reversing the relative axial direction of movement of the pin and slot, typically by reversing the axial direction of movement of a sleeve in which the slot is formed. Typically the switching is accomplished when the pin is in a transition portion of the second return track, typically having passed a junction (typically a Y-junction) leading to the next loop. Typically the y-junction is inverted, and the switching between loops is accomplished when the pin is in the combined trunk of the y, heading away from the junction between the connecting upper limbs of the y. Typically the two limbs of the y are parts of different respective loops. Typically one of the limbs (e.g. the limb connected to the second loop) is in axial alignment with the trunk of the y.
Typically the body comprises a piston responsive to pressure changes in the well, and axially movable in a bore in the apparatus in response to said pressure changes. Typically the axial movement of the piston in the bore drives the relative movement of the pin and the slot.
Typically the slot can be provided on a sleeve that moves relative to the body, and the pin can be provided on the body, but in other embodiments, the sleeve can have the pin and the slot can be provided on the body. The sleeve can typically be formed integrally with the piston. Thus the piston can optionally bear the slot, or it can be formed on a separate sleeve that is connected to the piston.
Typically the start and end of the first and second tracks, where the pin switches between the two tracks, are spaced apart axially along the sleeve/piston and/or they can optionally be spaced circumferentially, but in certain embodiments the start and end of the first and second tracks in each loop can be axially aligned along the axis of the body. The end point of each track, corresponding to the start point of the other track, is typically formed at a corner of the slot, which guides the change in the direction of movement of the pin relative to the slot, typically forming a stop that requires reversal of the axial direction of movement of the pin relative to the slot. For example, the first track can start at one end of the sleeve or piston, e.g. the lower end, and can extend axially up the sleeve/piston (typically with a lateral or circumferential component in addition to the axial component) to the end of the first track provided in the form of an inverted V at a position that is axially spaced apart on the sleeve/piston from the starting position of the first track, e.g. at or near to the top of the sleeve/piston. The inverted V marks the transition between the first and second tracks. From the apex of the inverted V, the pin is constrained to move down the second track.
Typically the first and second tracks have first portions that are typically linear (e.g. axial) and are typically arranged parallel to the axis (e.g. the axis of the body or sleeve and piston), and which do not drive relative rotation of the pin and slot components; and second portions, which typically also incorporate straight lengths but can also be deviated away from the first portion, and so typically extend axially and circumferentially, thereby driving rotation of the pin and slot components (typically driving the sleeve/piston relative to the stationary pin) in accordance with the angle of the deviation of the second track in relation to the axis. In some embodiments, both the first linear and second deviated portions can optionally be angled with respect to the main axis of the piston/sleeve. Such embodiments can optionally have deviated portions also, but typically the second deviated portions are set at a greater angle than the first linear portions to drive a greater rotation of the sleeve than the linear portions. Typically where the whole slot is angled (to a greater or lesser extent) then the movement of the pin through the slot will drive continued rotation of the piston around its axis, and the extent of rotation will typically vary in accordance with the angle of the linear and deviated portions of the slot with respect to the axis.
Typically the switching is accomplished when the pin is in a transition portion of the second return track. The transition portion of the second return track is typically an axial portion. Typically the switching is triggered by reversal of the direction of movement of the pin in the axial portion of the slot. Typically the axial transition portion is adjacent to the Y-junction in the slot, between the two loops, and typically the reversal of the movement of the pin in the transition portion of the slot causes the pin to move from one loop to the other.
Typically the slots comprise spaced apart end portions, each having blind ended tracks (typically extending axially) and deviated portions that typically deviate from the axis of the apparatus and axial transition portions. Typically at least part of the transition portion (typically the axial transition portion) of one second (return) track forms part of the first (outward) track of the adjacent loop.
Typically the apparatus comprises alternating loops spaced circumferentially around the sleeve/piston. Normally the loops are arranged in pairs. Simple embodiments of the invention can comprise merely one first and one second loop, and the pin can transition between the two loops, idling in the first loop, and switching between active and inactive in the other. However, in other embodiments of the invention, it is possible to have multiple pairs of first and second loops, optionally alternating in a sequence (e.g. first-second-first-second etc.) around the circumference of the sleeve or piston. Thus in such embodiments, the pin can idle in a first loop, switch to a second loop where it can move the device between active and inactive positions, and then move into another (optionally a different) first loop to idle once more before being switched into a (optionally different) second loop. 2, 3 4 or more pairs of first and second loops can optionally be provided in some embodiments. The different first loops can optionally have the same or different characteristics but typically they all have the same characteristics of idling between different positions of the sleeve/piston without activating the device. Likewise the different second loops can have the same or different characteristics, and optionally more variation in characteristics can be seen in different second loops, as these can, in some embodiments of the invention, be configured to switch between different active states of the device, for example, one second loop can switch between closed and 50% open, and another second loop can switch between closed and 75% open, etc.
In certain embodiments, instead of being arranged in pairs of first and second loops, the loops can be arranged in triplets, and the pin can cycle from first to second to third and optionally subsequent further loops before typically returning to the first loop and repeating the cycle. The third, fourth, fifth, and subsequent loops can optionally be chosen to correspond to the same or different configurations of the device, for example, the second loop can switch between e.g. closed and 50% open, and the third loop can switch between closed and 75% open, etc. or some different state of activation as compared with the second loop, after which the pin can optionally return to the first loop, or progress to another loop or series of loops that can optionally have different structural characteristic which set the tool in different configurations that provide different functional effects on the tool being controlled. Different embodiments can optionally have different configurations at the transitions of the slots.
Typically the speed of movement of the pin in the first track is different from the speed of the pin in the second return track, typically in each loop, or at least in the second loop. Typically the pin moves more slowly in the second track of the slot than in the first track. The movement of the pin through the first track is typically as quick as possible. However, the movement of the pin through the second (return) track is optionally deliberately slowed in order to provide a larger time window for triggering reversal of the direction of movement of the pin in the second track of the slot. This provides more time to trigger the transition between the two loops, which can then be accomplished more easily and more accurately, and typically using conventional surface apparatus, such as surface pumps. Typically the difference in speed between the two tracks can be controlled by hydraulic means, for example, by providing different fluid pathways for flow of fluid when moving the pin in the respective first and second tracks. For example, the pin can move more slowly in the second track than in the first because the fluid forcing movement of the pin in the second track can have a flow restrictor in the fluid pathway, whereas the fluid driving the pin through the first track can optionally typically move through higher capacity pathways with less resistance to fluid flow. Optionally the fluid flow pathways in each of the first and second tracks can be structurally the same, and the speed differential is controlled by functional steps, for example, applying different pressures during passage of the pin through each of the tracks, to move the pin more slowly through the second track than through the first.
Optionally, different portions (e.g. the deviated and axial portions) of the second track have different characteristics concerning the maximum possible speed of movement of the pin in those portions, and in typical embodiments of the invention, the pin can optionally move more quickly through at least one of the deviated portions of the second track than through the axial portion. Therefore, these differential limits on speed of movement of the pin through the slot permit the quick movement of the pin to the point at which transition occurs between the two loops, and then a controlled, slower movement through the transition zone of the slot allowing more time (e.g. several minutes) to trigger changes from surface in order to switch the pin between adjacent loops, optionally followed by a quicker movement back to the starting point of the first track after the pin has passed the transition point at which switching between loops is possible.
Optionally the speed restrictors are fluid flow restrictors where the driving force moving the pin through the slot is hydraulic, but in other embodiments where the motive force for the movement of the pin through the slot is something else, then the speed restrictors can comprise other suitable components.
Optionally the apparatus is used to operate a valve, for example to move a sleeve/piston in order to open or close one or more ports to allow or restrict or choke fluid flow, for example in a circulation valve. Optionally the apparatus is used to operate a cutting tool, for example to move a sleeve/piston in order to cause a cutting element to extend from a body of the tool, for example in a reaming tool such as an under-reamer. The loops can be set up to allow the operator to circulate fluid though the tool without expanding cutters while in first loop. The second loop can be configured to move between unexpanded and partially expanded cutter positions i.e. 50% expanded, and the third loop can be configured to move between unexpanded and a different configuration e.g. 100% expanded. Embodiments of the apparatus can also be used to extend and recover the blades of stabilisers. Many other uses of the apparatus are possible.
It is particularly beneficial that the apparatus allows cycling between different idling configurations without necessarily activating the tool it is controlling. This allows operation of other pressure-activated tools in the string independently of the apparatus controlled by embodiments of the invention. Also, it permits a string incorporating apparatus of the invention to be broken and made up at the surface to add or remove stands of pipe to the string without affecting the configuration of the device, for example, without switching the device between inactive, partially or fully active configurations, until the pin is switched between the first and second loops at the desired time selected and controlled by the operator.
Typically the apparatus comprises a conduit passing through a body, allowing passage of fluid through the conduit past the apparatus. Optionally the body bore can be aligned with the bore of a string in which the apparatus is incorporated.
Typically the piston can be moved by fluid pressure in the bore of the body. Typically the bore allows transmission of the fluid pressure past the apparatus in the string in order to activate other tools in the string.
Optionally the sleeve/piston can be biased by a resilient device, such as a spring, e.g. a coiled spring, in one axial direction, and the fluid pressure (or other motive force driving the movement of the pin in the slot) can act in the opposite direction, against the force of the resilient device. Therefore, the sleeve/piston can typically be biased in one direction, e.g. upwardly, and the apparatus can optionally be activated by applying fluid pressure (or other motive force) to move the sleeve/piston down against the force of the resilient device.
The various aspects of the present invention can be practiced alone or in combination with one or more of the other aspects, as will be appreciated by those skilled in the relevant arts. The various aspects of the invention can optionally be provided in combination with one or more of the optional features of the other aspects of the invention. Also, optional features described in relation to one embodiment can typically be combined alone or together with other features in different embodiments of the invention.
Various embodiments and aspects of the invention will now be described in detail with reference to the accompanying figures. Still other aspects, features, and advantages of the present invention are readily apparent from the entire description thereof, including the figures, which illustrates a number of exemplary embodiments and aspects and implementations. The invention is also capable of other and different embodiments and aspects, and its several details can be modified in various respects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as “including”, “comprising”, “having”, “containing” or “involving”, and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term “comprising” is considered synonymous with the terms “including” or “containing” for applicable legal purposes.
Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention.
In this disclosure, whenever a composition, an element or a group of elements is preceded with the transitional phrase “comprising”, it is understood that we also contemplate the same composition, element or group of elements with transitional phrases “consisting essentially of”, “consisting”, “selected from the group of consisting of”, “including”, or is preceding the recitation of the composition, element or group of elements and vice versa.
All numerical values in this disclosure are understood as being modified by “about”. All singular forms of elements, or any other components described herein are understood to include plural forms thereof and vice versa.
In the accompanying drawings:
Referring now to the drawings,
The flow tube 10 defines an annulus between the outer surface of the flow tube 10 and the inner surface of the bore 5b within the body 5. Within the annulus, a spring 7 is provided in the lower part of the tool. The spring 7 bottoms out on the upwardly facing surface of the lower step 61. Typically, the spring 7 is held in compression by a piston 20 set within the annulus above the spring 7, and surrounding the upper part of the flow tube 10. The compression of the spring 7 between the upwardly facing surface of the lower step 6l and the downward facing surface of the piston 20 pushes the piston 20 upwards within the annular space, compressing it against the lower face of the collar 12. The force of the spring 7 is typically chosen to be relatively weak in its expanded configuration shown in
The body has a number of circumferentially spaced circulation ports 30, which are arranged at the same axial position, but at different circumferential positions around the body 5. These are aligned axially with ports 11 passing through the wall of the flow tube 10. The circulation ports 30 extend through the wall of the body 5, and allow fluid communication between the bore 5b of the body, and the outer surface of the body 5 in certain circumstances. However, in the position shown in
The piston 20 has a set of circumferentially spaced ports 25, which have the same circumferential spacing as the circulation ports 30 in the body 5. The flow tube 10 also has a number of ports 11 spaced around its circumference. In other examples, the circumferential spacing pattern of the ports 11 in the flow tube 10 can be the same or different to the spacing pattern of the ports 30 in the body 5. In this example, the ports 11 are aligned with the ports 30. However, the axial position of the ports 11 in the flow tube 10 is such that the ports 25 in the piston 20 only align axially with the ports 11 when the lower face of piston 20 bottoms out on the shoulder 6m. The ports 25 on the piston 20 are similarly arranged at a common axial location on the piston. Movement of the piston 20 to slide down the bore 5b to compress the springs therefore brings the ports 25 in the piston 20 into axial alignment with the ports 30 in the body 5, and with the ports 11 through the flow tube 10, which opens the flow path for communication of fluid between the bore 5b of the body 5, and the outside surface of the body.
The movement of the piston 20 within the bore 5b is regulated by a pin and slot arrangement, constraining the extent of axial movement of the piston 20 within the bore 5b, and guiding rotation of the piston around its axis. The piston 20 is in the form of sleeve having an axial bore, and in this example, the control slot is formed on the outer surface of the piston. The pin and slot arrangement is shown in
The slot 50 in the sub 1 has at least two loops i.e., the slot has a first loop allowing the pin 40 to move between different configurations that define two different closed configurations of the piston 20, where the ports 25 through the piston are not aligned with the ports 30 through the body 5 and the ports 11 through the flow tube 10, and fluid communication does not take place, and a second loop, in which the pin 40 cycles between two different positions in the slot 50 corresponding to different configurations of the piston 20 in which fluid flow through the ports 30 is either allowed or disallowed. The pin 40 can be switched between the two loops at a time of the operator's choosing as will now be described, but also allows repeated cycling between the two configurations on each loop without necessarily switching between the two loops until the operator chooses to do so. Therefore, the device can be cycled between different inactive configurations where, in both configurations, the outer ports 30 are closed and no fluid communication takes place through them; but at a time of the operator's choosing, the pin and slot arrangement can be switched to track the pin through the second loop, and allow opening and closing of the outer ports 30.
Fluid pressure in the bore 5b is communicated to the piston 20 by means of an axial port 12p passing in an axial direction through the collar 12, thereby providing a fluid communication pathway between the bore 5b and the annulus between the flow tube 10 and the inner surface of the bore 513. The inner and outer surfaces of the piston 20 are sealed above and below the ports 25. Therefore, pressure changes in the bore 5b are transmitted to the upper face of the piston 20 through the port 12p, thereby causing axial sliding movement of the piston 20 in response to pressure changes, e.g. to compress the spring 7 when the pressure is sufficiently high to overcome the spring force. Rotation of the piston around the flow tube 10 is governed by the constraint of the pin 40 within the slot 50, which cams the piston.
As is best seen with reference to
In the position shown in
The first and second tracks described above make up the first loop, and allow the pin 40 to cycle through the first loop as many times as is needed for making up various connections or breaking them at the surface, without activating or de-activating the downhole tool controlled by the sub 1.
When the sub 1 is ready to open the circulation ports 30, the pin 40 is cycled though the first track from position P1 to P2 as shown in the transition between
When circulation operations have been completed, and the circulation is to be ceased, the pumps are switched off (or otherwise adjusted) at the surface, and the force of the spring returns the piston 20 to the
The flow tube has a set of circumferentially arranged small ports 116 arranged in a ring passing through the wall of the flow tube 110 near to the upper end of the flow tube 110. The precise axial distance of the ring of small ports 116 is typically selected in accordance with passage of the pin 140 past the junction between the first and second loops of the slot 50, at the start of the axial section of the second track of the slot 50, as will be explained further below, but this distance can be varied if desired without departing from the scope of the invention. The piston seals above and below the ring of small ports 116 in the
The modified collar 112 still has a port 112p to admit fluid under pressure from the bore 105b, but this is provided with a one way check valve 113, allowing fluid to pass into the annulus from the bore 105b, but preventing fluid egress from the annulus back through the valve 113 into the bore 105b. Typically three ports 112p are provided each having a respective one-way valve 113. The valves typically allow high pressures and high flow rates of fluid in the direction permitted, allowing rapid flooding of the annulus and rapid transmission of pressure to the piston 120, leading to relatively few transmission losses. The collar also has, typically spaced equidistantly between adjacent ports 112p, at least one, and optionally more than one bleed valve 114 allowing fluid flow from the annulus back into the bore 105b. The bleed valve 114 can optionally be adjustable. The bleed valve typically has a very small bore, or can be adjustable to allow only very small flow rates through the bleed valve 114, typically much less than the port 112p and check valve 113. As the piston 120 is sealed in the annulus on its inside and outside surfaces, fluid can only escape from the annulus above the piston through the bleed valve 114. Therefore, the speed at which fluid can escape through the bleed valve determines the speed at which the piston can move back up the annulus after pressure has been reduced. This speed of movement can therefore be adjusted by the setting of the bleed valve.
In operation, the application of pressure to the bore 105b drives the piston 120 down the annulus, moving the pin 140 up the slot from position P1 to P2. The device can cycle between settings P1 and P2 as previously described. The annulus floods quickly due to the large bore ports 112p and the one way valves 113 do not substantially restrict flooding of the annulus so the piston moves down (and the pin moves up through the first track of the first loop) relatively quickly to the position shown in
However, the movement of the piston back up the annulus (and the downward movement of the pin back down the second (return) track of the first loop requires the fluid in the annulus above the piston to escape from the annulus before the piston 120 moves up. The fluid in the annulus cannot pass through the check valves 113. When the piston is in the position shown in
Switching between the loops typically only takes place when the operator decides. For switching loops, the operator typically increases flow rates, causing the pin to travel to position P2, and the operator then reduces (or cuts off completely) the pressure from surface pumps for approximately 15 seconds-2 minutes to allow the pin to travel to the transition zone P3, and then while the pin is still in the transition zone P3, the operator again increases the flow rate to move the pin to position P4. The annulus floods by wellbore fluid passing through the large bore check valves 113 and ports 112p to drive the piston 120 down the annulus (and the pin 140 up the slot 50) to position P4, which can be done quickly as a result of the higher flow areas of the ports 112p and check valves 113. Therefore, the second example allows the operator to manipulate the timing of the transition phase with more control. The other operations of this example are similar to the operations previously described for the last example. Any drill string activity while the pumps are switched off typically takes longer than the 15 s-2 minutes transition time for the pin to return through the transition zone P3 to position P1. This allows drill string changes to add or remove stands of pipe to be performed while the pin continues cycling within the two tracks of the first loop. Usually adding a stand of drill pipe to the drill string will take more than 2 minutes.
The flow tube 210 has the same arrangement of small ports 216 with piston seals above and below the ring of small ports 216.
The modified collar 212 has a port 212p to admit fluid under pressure from the bore 205b, with a one way check valve 213 similar to the valve 113, allowing fluid to pass into the annulus from the bore 205b, but preventing fluid egress from the annulus back through the valve 213 into the bore 205b. Typically three ports 212p are provided each having a respective one-way valve 213. The collar 212 also has, typically spaced equidistantly between adjacent ports 212p, at least one, and optionally more than one bleed valve 214 allowing fluid flow from the annulus back into the bore 205b. The bleed valve 214 is typically adjustable as previously described for the second example and allows control over the speed at which fluid can escape through the bleed valve and thus the speed at which the piston can move back up the annulus after pressure has been reduced, which can be adjusted by the setting of the bleed valve, as previously described for the last example.
The third example illustrates how certain devices embodying the invention can typically be used to close the bore below the circulation port, and divert more of the fluid through the circulation port. The present example differs from the second example in that the lower end of the spring 207 is stopped by a collet that shoulders on an upwardly facing shoulder surrounding a narrowed throat of the bore 205b. The lower end of the flow tube carries a valve tube 215, held against rotation in the bore 205b by a guide pin. The valve tube 215 passes through the throat at the shoulder, and on its lower end, the valve tube 215 carries a closure device such as a flap 219 which is typically hinged to one side of the valve tube 215. The upper face of the flap 219 is adapted to seal off the lower end of the valve tube 215, thereby closing the bore through the sub 201. The lower face of the flap 219 is formed to interact with the arcuate upper face of a funnel 218 that gradually curves to guide the closure of the flap around the axis of the hinge as the flap and valve tube move axially down the bore 205b of the sub 201. When the valve tube has moved down the bore of the sub 205b, the arcuate upper surface of the funnel 218 has guided the closure of the flap 219 over the lower end of the valve tube 215. Accordingly all fluids passing through the upper end of the flow tube 210 are diverted through the ports 225, 230 when they are aligned, and it is thereby possible to create more turbulent circulation conditions in the annulus outside the body 205b.
The operation of this example is otherwise similar to the previous version; the application of pressure to the bore 205 drives the piston 220 down the annulus, moving the pin 240 up the slot from position P1 to P2. The device can cycle repeatedly between settings P1 and P2 as previously described, without switching loops until the operator is ready. The annulus floods quickly due to the large bore ports 212p and the one way valves 213 do not substantially restrict flooding of the annulus so the piston moves down (and the pin moves up through the first track of the first loop) relatively quickly to the position shown in
The movement of the piston back up the annulus (and the downward movement of the pin back down the second (return) track of the first loop as shown in
The fourth example differs from previous versions in that it in addition to a circulation sub, it comprises a cutting tool which in this example is in the form of an under-reamer. The lower end of the spring 307 is landed on an upwardly facing shoulder of an actuator sleeve 315 pushing a cutter 319 radially outward from the body. When the actuator sleeve 315 moves down the bore of the sub 305b, the cutter 319 is moved up a ramp against the force of a retaining spring 317 to extend radially out of the body 305 and initiate cutting operations.
In operation, the application of pressure to the bore 305b drives the piston 320 down the annulus, moving the pin 340 up the slot from position P1 to P2. The device can cycle between settings P1 and P2 as previously described. The annulus floods quickly due to the large bore ports 312p and the one way valves 313 do not substantially restrict flooding of the annulus so the piston moves down (and the pin moves up through the first track of the first loop to position P2) relatively quickly to the piston position shown in
The repeated cycling movement of the piston back up the annulus (and the downward movement of the pin back down the second (return) track of the first loop is controlled via the small ports 316 and bleed valve 314 as previously described. When the uppermost piston seals pass the small ports 316, the pin has just moved past the Y-junction between the first and second loops and is in the transition zone at P3, ready to transition from the first loop into the second loop. At this point the seals on the piston cover the small ports 316 denying fluid passage through the small ports 316, so that the fluid in the annulus can only escape through the small bore bleed valve 314 in the collar 312. The flow rate through the small bore bleed valve is much slower than the flow through the small bores 316 and the ports 312p, so the piston 320 moves slowly, and the pin remains in the transition zone P3 for a longer period, which can be adjusted by manipulating the pressure differential, and the setting of the bleed valve. The typical settings can allow the pin to remain in the transition zone of the second (return) track at position P3 for 15 seconds-2 minutes or longer. The pumps at surface can be stopped if desired, and changes to the string can be made as previously described, at a time of the operator's choosing. The annulus can be flooded through the check valves 313 and ports 312p to drive the piston 320 down the annulus (and the pin 340 up the slot 50 to position P4) which can be done quickly as a result of the higher flow areas of the ports 312p and check valves 313. The sub 305 is then in the configuration shown in
The fifth example differs from the fourth example in that the cutter 419 is hingedly attached to the body and moves radially outward from the body 405 by pivoting around the hinge axis when the actuator sleeve 415 moves down the bore of the sub 405b. The cutter 419 is urged by a retaining spring 417 as before, to return it to its starting position when cutting operations have concluded.
In operation, the application of pressure to the bore 405b drives the piston 420 down the annulus, moving the pin 440 up the slot from position P1 to P2. The device can cycle repeatedly between settings P1 and P2 as previously described, without switching loops. The annulus floods quickly due to the large bore ports 412 and the one way valves 413 do not substantially restrict flooding of the annulus so the piston moves down (and the pin moves up through the first track of the first loop to position P2) relatively quickly to the piston position shown in
The movement of the piston back up the annulus (and the downward movement of the pin back down the second (return) track of the first loop is controlled via the small ports 416 and bleed valve 414 as previously described. When the uppermost piston seals pass the small ports 416, the pin has just moved past the Y-junction between the first and second loops and is in the transition zone at P3, ready to transition from the first loop into the second loop. At this point the seals on the piston cover the small ports 416 denying fluid passage through the small ports 416, so that the fluid in the annulus can only escape through the small bore bleed valve 414 in the collar 412. The flow rate through the small bore bleed valve is much slower than the flow through the small bores 416 and the ports 412p, so the piston 420 moves slowly, and the pin remains in the transition zone P3 for a longer period, which can be adjusted by manipulating the pressure differential, and the setting of the bleed valve. The typical settings can allow the pin to remain in the transition zone of the second (return) track at position P3 for 15 seconds-2 minutes or longer. The pumps at surface can be stopped if desired, and changes to the string can be made as previously described. The annulus can be flooded through the check valves 413 and ports 412p to drive the piston 420 down the annulus (and the pin 440 up the slot 50 to position P4) which can be done quickly as a result of the higher flow areas of the ports 412p and check valves 413. The sub 405 is then in the configuration shown in
Referring now to
Referring now to
Although the pin is allowed to travel in increasingly large ranges of axial movement through the different loops L1, L2 and L3, this does not necessarily correspond to increasing levels of activation possible in the tool being controlled, and for example, L3 might allow a lower level of activation than L1 or L2.
In a possible second example of operation of the
In another possible application of the
The slot 650 can be arranged to cycle through the sequence of loops L1, L2, L3 in either direction, in accordance with the opposing directions of the slots 550 and 50, as previously described. More than 3 loops can be provided.
Referring now to
Optionally the slot 750 can be arranged to cycle through the sequence of loops in either direction, in accordance with the opposing directions of the slots 550 and 50, as previously described. More than 2 loops can be provided in the slot 750.
In a typical example, apparatus according to the invention that is incorporated into a control sub in a circulating string typically according to the first example can be operated as follows:
1. Prepare to run tool string into the hole, pumps at surface can be idle, pumping 0 GPM/0 PSI. Pin is typically held in position P1.
2. Run tools into the predrilled hole, while operating surface pumps at around 100 GPM, which typically corresponds to around 24 PSI at bit. Pin moves to position P2.
3. Add subsequent sets of drill pipe at surface, while pumps idle pumping 0 GPM/0 PSI at bit. Pin moves from position P2 back to position P1 (passing through transition zone P3). Adding a set of drill pipe to the string can take approximately 2-5 minutes.
4. Continue steps 2 and 3 until tool string reaches required depth.
5. Drill with higher pressure from pumps at surface, typically around 300+GPM, corresponding to around 225 PSI at bit. Travel pin is moved into position P2, with circulation valve closed.
6. Add another set of drill pipe at surface, while pumps are idle, at 0 GPM, 0 PSI at bit. Travel pin moves from position P2 back to position P1 (passing transition zone 3) again adding set of drill pipe.
7. Continue steps 5 and 6 until required to activate presented tool e.g. circulation sub, under-reamer, stabiliser etc.
8. To activate tool by switching between first and second loops, increase flow rate at surface pumps to 100+GPM, moving the pin into position P2, corresponding to around 24+PSI at the bit, then reduce the flow rate to less than 60 GPM at surface, or around 9 PSI at the bit, or shut down surface pumps completely for approximately 20-50 seconds. Pin moves to transition zone (position P3). While the travel pin is crossing transition zone P3 start pumps again with 100+GPM, 24+PSI at the bit. This causes the pin to switch between loops and move to position P4. In this position, the pin has entered the second loop, allowing entry to the long travel slot and accordingly the tool is activated. The circulation sub typically increases TFA, the under-reamer can typically extend the cutter face, and/or the stabiliser can typically extend stabilising pads.
9. If tool is required to stay in the ON position, continue drilling as per steps 5 & 6 until required to deactivate presented tool. Pin will travel between position P4 and P5 corresponding to the flow. If there is a small mount of pressure on the piston, the travel pin will move to position P4. If there is no pressure on the piston, the travel pin will return to position P5 (passing through the transition zone P6).
10. To switch OFF the tool the same method is followed as per step 8. This time when pressure reduces, pin moves from position P4 to transition zone P6 and after increasing flow in the system the pin will move to position P2′ which corresponds to position P2 above.
11. Tool can be activated and deactivated as many times as required using the method described in steps 8 and 10.
As mentioned in step 8, in order to activate the tool the pumps can be switched off for 20-50 seconds, but this can be adjusted for different periods of time. Also 60 GPM with 9 PSI can be adjusted if required. Pump rates and pressure values can be varied within the scope of the invention.
Embodiments permit the construction of tools that switch between high and low pressure (or on and off) where the pressure can be reduced (optionally to zero) for a particular time, after which the pressure can be increased or applied again with the tool in the active configuration. Other embodiments allow switching between high and low pressure where the pressure is reduced to a particular value that allows switching between the in-active (first) and active (second) loops.
The invention also provides a control slot for a pin and slot arrangement for a downhole controller, wherein the slot comprises a first loop and a second loop, the first loop being configured to cycle the tool between different inactive configurations, and the second loop being configured to cycle the tool between inactive and active configurations.
Thus embodiments of the slot provide loops in both ON and OFF configurations, and permit switching between the loops.
Radial spacing of the P1, P2 and other positions in the profile can typically be varied within the scope of the invention. One profile might have positions P1 and P2 that are spaced circumferentially from positions P5 and P4 by e.g. 180 degrees, but other examples might have different spacing and/or more or less pairs of loops. For example, there might be three pairs of loops with equivalent positions spaced 60 degrees around the circumference of the piston. There might be a different numbers of profiles spaced with different angles.
In the examples disclosed, the positions P1 and P2 are typically functionally equivalent to positions P5 and P4, but these pairs of loops do not need to have structural equivalence, and P1 and P2, for example, do not need to be in axial alignment with one another as shown in the examples. Position P1 can optionally be displaced around the circumference with respect to position P2, which will change the shape of the profile but need not change functionality of the tool.
The body 805 is divided into a valve sub 805v secured by a pin and box arrangement below a piston sub 805p. The valve sub 805v carries a closure member in the form of a flap 819 that closes the bore 805b in a similar manner to the flap 219. The flap 819 is secured to the end of a valve tube 815, and moves with the valve tube 815. The valve tube 815 is mounted on the lower end of a valve piston 816, which is co-axially mounted on the outer surface of the flow tube 810, and can slide relative to the flow tube 810, which is fixed to the body, typically by means of the collar 812. Optionally the collar 812 can comprise an upper collar 812u and a lower collar 812l, spaced along the flow tube, and typically immovably connected to the body e.g. by welding, screw attachment, etc. The collars 812u,l typically centre the flow tube 810 in the bore 805b as well as fixed it axially to the body. The lower collar 812l typically acts as an end stop for the spring 807, which is compressed between the lower collar 812l and the lower end of the piston 810.
The ports 830 through the body are typically spaced away from the piston 850, and in this embodiment are provided on the valve sub 805v. The valve piston 816 typically carries the ports 825, and the ports 811 on the flow tube are also carried in the valve sub 805v. The valve piston 816 slides axially over the flow tube 810 to expose and cover the ports 811 and allow and deny communication through the ports 830. The valve piston 816 has a piston area having different sealed diameters so that when subjected to a pressure differential it moves down the bore 805b towards the flap 819. Also, the valve piston is pushed in the same direction by a very thin valve actuator sleeve 817 (best seen in
The present example also contains an optional mechanism to limit the travel of the spring when the piston has moved down the annulus, so that the pin essentially functions as a rotation controller, and bears less axial load when it approaches the ends of the slots, allowing the present example to be used in high pressure scenarios without overloading the pin.
The travel limiting mechanism comprises a pair of intercalating upper and lower sleeves 860u and 860l mounted on the piston 850 and the lower collar 812l respectively, which have opposed intercalating formations permit different extents of axial travel dependent on the relative rotations positions of the formations 860u,l. In the present example, the intercalating formations are provided by generally parallel sided fingers 861u and 861l, although the precise shape can vary in different embodiments. Because the lower sleeve 860l is fixed to the lower collar, which is fixed to the body, the lower fingers 861l do not rotate and do not translate axially. However, the upper sleeve 860u is fixed to the axially movable and rotatable piston 850, and so rotates and translates with the piston 850, relative to the static lower sleeve.
Thus the upper fingers can be circumferentially aligned with the lower fingers and spaced apart therefrom as shown in
The operation of this example is otherwise similar to the
Optionally the piston can be formed with all upper slots having the same dimensions, and the limit of travel within the slot can be defined by the sleeves 860 alone.
The movement of the piston 820 back up the annulus (and the downward movement of the pin back down the second (return) track of the first loop requires the fluid in the annulus above the piston to escape from the annulus before the piston 820 moves up. The fluid in the annulus cannot pass back through the check valves 813, and as before, the fluid in the annulus is routed into the bore 805b via the small ports 816. The combined flow area of the small ports is relatively large and the initial upward movement of the piston 820 is rapid as the fluid exhausts through the small ports 816. When the uppermost piston seals pass the small ports 816, the pin has just moved past the Y-junction between the first and second loops and is in the transition zone, ready to transition (if desired) from the first loop into the second loop. At this point the seals on the piston cover the small ports 816 denying fluid passage through the small ports 816, so that the fluid in the annulus can only escape through the small bore bleed valve 814 in the collar 812. The flow rate through the small bore bleed valve is much slower than the flow through the small ports 816 and the ports 812p, so the piston 820 moves very slowly, and the pin remains in the transition zone for a longer period, which can be adjusted by manipulating the pressure differential, and the setting of the bleed valve. The typical settings can allow the pin to remain in the transition zone of the second (return) track for 15 seconds-2 minutes (for example) or longer. The pumps at surface can be stopped if desired, and changes to the string can be made as previously described. While the pin 840 is cycling in the first (inactive) loop, the fingers are aligned as shown in
When the operator decides to switch tracks and activate the device, when the pin is in the transition zone, the annulus can be flooded once again through the check valves 813 and ports 812p to drive the piston 820 down the annulus (and the pin 840 up the slot 850) to the position shown in
Thus, in the active position when pressure is applied, piston 820 moves the attached upper sleeve 860u down the outer surface of the flow tube. When the intercalating fingers on the upper sleeve slide in between the fingers on the lower sleeve 860l, they engage the upper end of the thin valve actuator sleeve 817 (underlying the lower sleeve 860l). The valve actuator sleeve is attached to the valve piston 816, and as it is pushed down the flow tube, this pushes the valve piston down the outer surface of the flow tube until a seal on the inner surface of the valve piston passes below the ports 811 on the flow tube, which admits the high fluid pressure pumped from the surface through the bore of the flow tube through the ports 811 and behind the sealed area of the valve piston 816. The outer surface of the valve piston 816 is also sealed against the inner surface of the valve sub 805v, and the opening of the ports 811 through the flow tube creates a differential across the different diameters of sealed inner and outer areas of the valve piston 816, which is thereby urged down the bore 805b against the force of a spring which is held in compression between a step on the valve piston 816 and a collar that is fixed to the valve body 805v. Under the force generated by the pressure differential the valve piston 816 moves down relative to and independently from the upper control piston 820, and has a stroke that is not limited to the stroke of the piston 820. When the force generated by the pressure differential reduces below the force of the compressed spring, the spring force returns the valve piston 816 to the initial position, with the ports 811 sealed. Optionally the upper control piston 820 could stop moving in the bore, and the valve piston 816 could travel alone to close the flap and align ports 830 and 825, although in some embodiments, both pistons will typically travel together providing more force to close the flap. The annulus (which is typically sealed) below the sealed area of the valve piston 816 is typically at ambient pressure, and typically has a small port through the wall of the valve sub 816 to connect the annular area to the exterior of the tool, which reduces the risk of hydraulic locking of the valve piston. When there is no pressure in the system, the valve piston 816 is typically in the closed position shown in
Once the valve piston 816 has moved down enough to align the ports 825 on the valve piston 816 and the ports 811 on the flow tube, the force from the fluid pressure in the bore 805b is then transferred to the valve piston 816, and it is urged downwards in the valve sub 805v by the large force of the hydraulic pressure. Hence the initial motive force transferred by the actuator sleeve 817 to allow the fluid pressure to bear on the valve piston 816 can be relatively small and the associated components can be lighter and less complex. Also, the forces closing the valve can thereby be arranged to act directly on the valve piston allowing efficient force transfer and high closure forces. Typically a small port through the wall of the valve sub into the piston area reduces the risk of hydraulic locking of the valve piston 816.
The jetting ports 830 permit re-circulation of fluid from the bore 805b at high pressures, while the bore is closed below by means of the flap, thereby directing all of the bore fluid through the jetting ports. Spacing the jetting ports from the piston 820 means that the slot 850 can be sealed off from the high pressure fluids passing through the bore 805b and out of the jetting ports 830, and so there is less risk of debris entering the slot and restricting movement of the piston.
When the circulation operations are finished, the pumps are switched off at surface, and the valve piston 816 returns to the closed position shown in
As before, the flap 819 only engages the funnel 818 when the pin moves into the second loop and into position P4. Therefore, this example also allows the operator to manipulate the timing of the transition phase with more control, and can apply more of the wellbore pressure to the circulation ports 830 as a result of the closure of the bore 805b by the flap 819. Also, the piston 820 and slot 850 can be engineered to a lower level as their function can be focussed on controlling the operation rather than providing the motive force for operating the tool, but the device as a whole can be used in higher pressure applications as the high force aspects can be engineered into the valve piston which can be separated from the control piston 820.
The present arrangement also allows less engineering focus on the slot, which can typically have both first and second loops having physically identical shapes, but the behaviour of the pin in the different loops can be governed by other factors such as the intercalating fingers below the piston.
It should be noted that the present example can operate tools other than valves (e.g. cutters, under-reamers etc. as shown in other examples herein), and different kinds of valves other than flap valves as shown, and the present embodiments are shown for example only.
One advantage of certain embodiments over J-slot and dropped ball alternative, is that the device can be reversibly activated and de-activated within a short period of time, e.g. within 1 minute. The device can be arranged to cycle between inactive configurations, without changing the cycle until the unique procedure of changing loops is initiated by choice of the operator. Therefore, when the operator stops the surface pumps to add another set of drill pipe, the device will typically stay in same (typically inactive) loop. When the operator increases the flow rate again, the device will typically cycle back within the same loop, without changing the configuration of the device being controlled.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1120448.4 | Nov 2011 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2012/052928 | 11/28/2012 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2013/079929 | 6/6/2013 | WO | A |
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| Number | Date | Country | |
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| 20140318806 A1 | Oct 2014 | US |
