EP0787888B1 - Zirkulationsstück - Google Patents

Zirkulationsstück Download PDF

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Publication number
EP0787888B1
EP0787888B1 EP96306334A EP96306334A EP0787888B1 EP 0787888 B1 EP0787888 B1 EP 0787888B1 EP 96306334 A EP96306334 A EP 96306334A EP 96306334 A EP96306334 A EP 96306334A EP 0787888 B1 EP0787888 B1 EP 0787888B1
Authority
EP
European Patent Office
Prior art keywords
body member
outer body
circulating sub
fluid
circulating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP96306334A
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English (en)
French (fr)
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EP0787888A3 (de
EP0787888A2 (de
Inventor
Andrew Mcdonald
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
National Oilwell UK Ltd
Original Assignee
National Oilwell Varco UK Ltd
National Oilwell UK Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from GBGB9517841.4A external-priority patent/GB9517841D0/en
Priority claimed from GBGB9613894.6A external-priority patent/GB9613894D0/en
Application filed by National Oilwell Varco UK Ltd, National Oilwell UK Ltd filed Critical National Oilwell Varco UK Ltd
Publication of EP0787888A2 publication Critical patent/EP0787888A2/de
Publication of EP0787888A3 publication Critical patent/EP0787888A3/de
Application granted granted Critical
Publication of EP0787888B1 publication Critical patent/EP0787888B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B23/00—Apparatus for displacing, setting, locking, releasing or removing tools, packers or the like in boreholes or wells
    • E21B23/004—Indexing systems for guiding relative movement between telescoping parts of downhole tools
    • E21B23/006—"J-slot" systems, i.e. lug and slot indexing mechanisms
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
    • E21B21/10—Valve arrangements in drilling-fluid circulation systems
    • E21B21/103—Down-hole by-pass valve arrangements, i.e. between the inside of the drill string and the annulus

Definitions

  • This invention relates to a circulating sub, and more particularly to a multi-opening circulating sub for use in energy exploration, milling and drilling.
  • Conventional oil and gas drilling techniques utilise drill-bits which are conveyed on individual lengths (usually 30 feet) of drill-pipe and rotated from the surface of the drilling rig floor to produce the necessary rotary cutting action required to drill well bores.
  • the rotary cutting action can be supplied by using a Positive Displacement Motor (PDM) located above the drill-bit and connected to the surface by either coil tubing that is provided in one continuous length, or by more conventional drill-pipe.
  • PDM produces the rotary action when drilling fluid is pumped through it from the surface.
  • the main advantage of using coil tubing in conjunction with a PDM is that of a decrease in the running-in time of the equipment into the well-bore.
  • BHA Bottom Hole Assembly
  • this first problem is overcome by using an additional tool in conjunction with the motor and drilling/milling assembly, known as a drop-ball circulating sub.
  • This tool is run above the motor and is operated by dropping a ball, from the surface, down the drill-pipe or coil tubing.
  • the ball seats on top of a piston within the tool and pressure is applied to the upper end of the piston and ball.
  • the pressure is increased until shear pins, which are located within the main body piston to move axially downwards within the main body thereby uncovering circulating holes in the main body drilled transverse to the centre-line of the drop-ball circulating sub.
  • These holes allow an increased flow rate to be pumped through the drill-pipe or coil tubing, thus giving a more effective hole cleaning capability.
  • this tool has the disadvantage that once the ball has been dropped to the circulating sub, no further milling or drilling can take place as the fluid path to the PDM has been blocked by the ball. If further milling or drilling is required then the tool must be removed from the well-bore so that the ball can be removed. Also, the length of time that the ball takes to drop down the drill-pipe or coil tubing can be considerable.
  • the second problem of pumping nitrogen is helped, but not solved, by using a drop-ball circulating sub as the drop-ball does not effect a complete seal on the piston allowing nitrogen to flow through the motor.
  • US 4,632,187 discloses a well safety and kill valve which is operated either by annulus/formation pressure or control lines.
  • US 4,298,077 discloses a circulation valve for an in-hole motor and GB 2,054,008A discloses a turbo-coring device equipped with a following pipe.
  • WO 96/30621 A has an effective filing date prior of the one of the present application, was published after said date and resulted in European Patent EP 0 815 343 B.
  • This document discloses a circulation valve comprising an inner and an outer body member which, in a given relative position, do not permit fluid flow in the throughbore of the valve.
  • a circulating sub apparatus having a throughbore for permitting circulation of fluid from within the throughbore out into a borehole annulus
  • fluid can pass from the inner bore of the outer body member to the inner bore of the inner body member and out of the bottom end of the inner body member.
  • the outer body member and the inner body member are positioned relative to one another in the aligned position, it is a bypass passage that is formed that allows fluid to flow from the internal bore of the circulating sub apparatus to the annulus between the outside diameter of the tool and the inside diameter of the well bore, in use.
  • the displacement mechanism is controlled by fluid pressure.
  • the displacement mechanism comprises a piston assembly and a restrictor nozzle in the fluid path.
  • the displacement mechanism typically includes a restraining device.
  • the restrictor nozzle is located on the uppermost portion of the inner body member such that fluid passing through the inner bore of the circulating sub apparatus passes through the restrictor nozzle.
  • the piston assembly is coupled to the inner body member.
  • an increase in the fluid pressure displaces the inner body member in a downwards direction.
  • the restraining device comprises at least one restraining member mounted on each of the inner and outer body members, the restraining member(s) mounted on the inner body member being selectively co-operable with the corresponding restraining member(s) mounted on the outer body member.
  • each of the inner and outer body members there are two restraining members mounted on each of the inner and outer body members.
  • the two restraining members mounted on one of the body members are spaced further apart than the two restraining members mounted on the other of the body members. More preferably, it is the two restraining members mounted on the inner body member that are spaced further apart than the two restraining members mounted on the outer body member.
  • the two restraining members mounted on the inner body member are mounted on the piston assembly.
  • one of the restraining members mounted on the inner body member and the corresponding restraining member mounted on the outer body member are adapted to rotate the inner body member with respect to the outer body member, following continued longitudinal movement of the inner body member with respect to the outer body member.
  • the restraining members in contact on the inner and outer body members are adapted to restrain the inner body member in a first position from further rotation.
  • longitudinal movement in the opposite direction moves the other of the restraining members mounted on the inner body member into contact with the corresponding restraining member mounted in the outer body member.
  • the other of the restraining members mounted on the inner body member and the corresponding restraining member mounted on the outer body member are adapted to rotate the inner body member with respect to the outer body member, following continued longitudinal movement of the inner body member in the opposite direction with respect to the outer body member.
  • a second restrained position is reached upon longitudinal movement in the opposite direction to the direction of longitudinal movement for which the first restrained position was reached.
  • the direction of rotation of the inner body member with respect to the outer body member for which the first restrained position is reached is the same direction of rotation for which the second restrained position is reached.
  • the first position is the aligned position and the second position is the obturated position.
  • the first position is the obturated position and the second position is the aligned position.
  • the sealing device deters the flow of fluid through the bottom end of the circulating sub, and more preferably deters the flow of fluid through the bottom end of the inner body member.
  • the sealing device seals the bottom end of the inner body member.
  • the invention has the advantage that nitrogen gas may be pumped through the circulating sub and through the circulating holes, when the circulating sub is in the aligned position, to clean the well bore without damaging any tools located below the circulating sub.
  • the circulating sub is included in a drill string which also includes a fluid operated motor, such as a positive displacement motor, and/or a reamer.
  • a fluid operated motor such as a positive displacement motor, and/or a reamer.
  • the fluid may be a liquid or a gas and is preferably a drilling fluid.
  • the fluid may be nitrogen gas.
  • Fig. 1 shows a multi-opening circulating sub 100 which is not in accordance with the present invention, consisting of a main outer body 1, a bottom sub 2 which can stroke in and out of the main outer body 1, a hydraulic detent system 25 and an internal piston assembly 4 which will be detailed subsequently.
  • the multi-opening circulating sub 100 is required to be run into the borehole in a closed position such as that shown in Fig. 1.
  • Drilling fluid flows from a coil tubing through an inner passage 110 of the multi-opening circulating sub 100 and subsequently onwards to equipment located below the circulating sub 100 such as a PDM.
  • the circulation operation can be initiated, by observing the following procedure.
  • Fig. 4 shows that the bottom sub 2 is coupled to a drive-shaft 11, the drive-shaft 11 being slidably coupled to the main outer body 1.
  • Fig. 4 shows that lifting the tool string off the bottom of the borehole allows the bottom sub 2 to stroke out from within the main outer body 1 of the multi-opening circulating sub 100. This lifting action is necessary if for instance milling or drilling operation had been occurring just previously.
  • Fig. 5 shows that as the drilling fluid pump rate is increased, a back pressure of drilling fluid is created by a restricting nozzle 20 and from the bottom hole assembly. This back pressure forces the piston 4 to move downwards within the main outer body 1.
  • the piston 4 is not only deterred from downward movement by the spring 23 but also by a hydraulic detent system 25.
  • the hydraulic detent system 25 comprises a hydraulic fluid chamber 3 filled with viscous fluid, the piston 4 and a one-way flow restrictor 5.
  • the hydraulic detent system 25 restricts the downward movement of the piston by the action of the viscous fluid passing through the one-way flow restrictor 5. As seen in Fig. 5 the viscous fluid flows from one side of the one-way flow restrictor 5 to the other side of the flow restrictor 5 through a restrictor orifice causing the piston 4 to travel slowly.
  • Fig. 2 shows that when the piston 4 has travelled its full stroke the circulation holes 16 will be aligned with the bypass ports 8 and so the drilling fluid is able to flow therethrough. Further, with an exit path into the borehole annulus being provided for the drilling fluid above the PDM and under-reamer assembly, increased flow rates can be achieved thus increasing the borehole cleaning efficiency, without increasing the surface pressure.
  • the circulation holes 16 can be misaligned from the bypass ports 8 by reducing the flow rate of the drilling fluid to 50% or less of the maximum. This action decreases the backpressure caused by the restricting nozzle 20, thus relieving the load on the piston 4, which allows the spring 23 to return the piston 4 to its normal position.
  • the one-way flow restrictor 5 incorporates a one-way check valve located in parallel with the restrictor orifice, the check valve preventing fluid passing on the downstroke of the piston 4 but allowing fluid bypass on the return up stroke. Thus the check valve eliminates any waiting period while the piston 4 returns following a circulation operation.
  • the fluid path through the circulation holes 16 via the bypass ports 8 is discontinued, and fluid now flows down the inner passage 110 and onwards to the PDM and/or the under-reamer assembly below. This fluid flow path can be seen in Fig. 1.
  • the circulation holes 16 can be aligned with the bypass ports 8 so that drilling fluid can circulate therethrough.
  • the tool string and BHA is lifted off the bottom of the borehole and the drilling fluid pressure is sufficiently increased so that rotation of the PDM is initiated and if applicable under-reamer arms are opened if an under-reaming tool is being used.
  • increasing the pressure of the drilling fluid would initiate a circulation operation which will be detailed subsequently.
  • the hydraulic detent system 25 provides resistance to downwards movement of the piston 4 and effectively provides the operator with a period of time before the circulation operation starts.
  • This period of time is used to set down milling weight on the mill or drill bit. This weight pushes the bottom sub 2 upwards, and forces the drive-shaft 11 back into the main outer body 1 as shown in Fig. 7. This in turn prevents the piston 4 from moving downwards far enough for the circulation operation to occur, by a shoulder 10 located on the drive-shaft 11 butting against the piston 4, as shown in Fig. 8.
  • Fig. 9 shows a first example of a multi-opening circulating sub 50 in accordance with the present invention, consisting of an outer tubular body formed by a number of outer body sections 51, 53, 54, 55, 56 and 57, and an inner tubular body comprising an upper piston 52 and a lower piston 65.
  • the upper piston 52 is coupled at its lower end to the lower piston 65.
  • the upper end of the upper piston 52 is coupled to a restrictor nozzle 60.
  • drilling fluid flows from a coiled tubing that is connected to an upper outer body section 53, through the restrictor nozzle 60, through a bore 70 of the circulating sub 50, out of the lower outer body section 57 and subsequently onwards to equipment located below the circulating sub 50, such as a PDM.
  • the fluid flow rate through the circulation sub 50 is increased.
  • This increased fluid flow rate through the restrictor nozzle 60 creates a back pressure of drilling fluid across the restrictor nozzle 60, which forces the piston assembly 52, 65 longitudinally downwards within the outer body sections 51, 53, 54, 55, 56.
  • the upper clutch 58 is formed to have two restraint positions.
  • the first restraint position allows the piston assembly 52, 65 to only travel a short distance, so that the drilling fluid continues to flow through the circulating sub 50 and onto equipment located below.
  • the second restraint position allows the piston assembly 52, 65 to travel a greater distance, so that bypass ports 66 located on the lower piston 65 move into alignment with circulating holes 68 located on an outer body section 56. Drilling fluid will now flow down the bore 70 of the circulating sub 50 and out of the circulating holes 68 via the bypass ports 66.
  • a pack-off sealing element 69 prevents any drilling fluid from flowing through the lowest outer body section 57 and on towards equipment located below. The operation of the pack-off sealing element 69 will be described subsequently.
  • the drilling fluid flow rate is reduced. This action reduces the drilling fluid back pressure across the restrictor nozzle 60.
  • a return spring, 63 which acts between a shoulder 72 mounted on the outer body section 54 and a thrust bearing 62 mounted on the upper piston 52, biasses the upper piston 52 upwards, and when the drilling fluid flow rate is reduced the piston assembly 52 moves upward.
  • the thrust bearing 62 ensures that any residual torque retained in the return spring 63 is dissipated, and hence does not interfere with the rotation of the piston assembly 52, 65.
  • an indexer 64 mounted on the lower piston 65 contacts a lower clutch 59 which is mounted to the outer body section 54.
  • the contact between the indexer 64 and the lower clutch rotates the piston assembly 52, 65 in the same direction as the rotation produced by the upper clutch 58 and the mating angles 61 on a downward movement. Through this rotation as the piston assembly travels upwards, it will have moved onto it's next restrained position and hence it's next mode of operation.
  • Figs. 10 (a) and (b), 11 (a) and (b), 12 (a) and (b) and 13 (a) and (b) shows the positional relationship between firstly the lower clutch 59 and the indexer 64, and secondly the upper clutch 58 and the mating angles 61, for a complete cycle of the circulating sub 50, with the components being shown laid out flat for clarity.
  • Fig. 10(a) shows the indexer 64 and the lower clutch 59 in an engaged position
  • Fig. 10 (a) shows the mating angles 61 longitudinally displaced from the upper clutch 58
  • Figs. 10 (a) and (b) show the piston assembly 52, 65 in the position as shown in Fig. 9.
  • Fig. 11 (b) shows that the indexer 64 and the lower clutch 59 have been longitudinally and rotationally displaced, due to downward movement of the piston assembly 52, 65. It can be seen in Fig. 11 (a) that the mating angles 61 are in contact with the upper clutch 58, and are restrained in the second, or furthest position possible by the upper clutch 58. This position corresponds to the drilling fluid circulation mode. It can also be seen that the piston assembly rotates in only one direction due to the combination of the profiles of firstly the upper clutch 58 and the mating angles, and secondly the lower clutch 59 and the indexer 64.
  • Figs. 12 (a) and (b) show that as the back pressure across the restrictor nozzle 60 is reduced, the indexer 64 and the lower clutch 59 come into contact and the piston assembly 52, 65 is further rotated in the same direction as previously.
  • the upper clutch 58 and the mating angles 61 are longitudinally and rotationally spaced once again, and await an increase in the drilling fluid flow rate to enter a drilling fluid flow through cycle.
  • Fig. 13 (b) shows that the lower clutch 59 and the indexer 64 are once again longitudinally and rotationally further displaced, although the longitudinal displacement is not as great as shown in Fig. 11 (b). This is due to the mating angles 61 being restrained in the first and least travel position by the upper clutch 58, as shown in Fig 13 (a). This is the drilling fluid flow through mode of operation of the circulating sub 50.
  • the circulating sub 50 has two modes of operation, drilling fluid flow through and circulation, for when the piston assembly 52, 65 is restrained in a first and a second position respectively.
  • the lower portion of the circulating sub 50 in the first restrained position is shown in detail in Fig. 14.
  • a seal 67 prevents any leakage of drilling fluid between the bypass port 66 and the circulating hole 68, whilst the circulating sub 50 is in the first position, and hence in drilling fluid flow through mode of operation.
  • the lower portion of the circulating sub 50 in the second restrained position is shown in detail in Fig. 15.
  • the lower piston 65 has moved downwards so that bypass ports 66 are now aligned with the circulating holes 68, thus allowing drilling fluid to exit from the bore 70 of the circulating sub 50 out through the circulating holes 68.
  • the bottom end of the lower piston 65 engages with the pack off sealing element 69 such that no drilling fluid can pass through an aperture 71 in a bottom plug 72 at the bottom end of the circulating sub 50 to the equipment below.
  • the seal between the pack off sealing element 69 and the lower piston 65 ensures that no nitrogen gas can pass through any of the tools below the circulating sub 50.
  • This invention relates to a circulating sub, and more particularly to a multi-opening circulating sub for use in energy exploration, milling and drilling.
  • Conventional oil and gas drilling techniques utilise drill-bits which are conveyed on individual lengths (usually 30 feet) of drill-pipe and rotated from the surface of the drilling rig floor to produce the necessary rotary cutting action required to drill well bores.
  • the rotary cutting action can be supplied by using a Positive Displacement Motor (PDM) located above the drill-bit and connected to the surface by either coil tubing that is provided in one continuous length, or by more conventional drill-pipe.
  • PDM produces the rotary action when drilling fluid is pumped through it from the surface.
  • the main advantage of using coil tubing in conjunction with a PDM is that of a decrease in the running-in time of the equipment into the well-bore.
  • BHA Bottom Hole Assembly
  • this first problem is overcome by using an additional tool in conjunction with the motor and drilling/milling assembly, known as a drop-ball circulating sub.
  • This tool is run above the motor and is operated by dropping a ball, from the surface, down the drill-pipe or coil tubing.
  • the ball seats on top of a piston within the tool and pressure is applied to the upper end of the piston and ball.
  • the pressure is increased until shear pins, which are located within the main body piston to move axially downwards within the main body thereby uncovering circulating holes in the main body drilled transverse to the centre-line of the drop-ball circulating sub.
  • These holes allow an increased flow rate to be pumped through the drill-pipe or coil tubing, thus giving a more effective hole cleaning capability.
  • this tool has the disadvantage that once the ball has been dropped to the circulating sub, no further milling or drilling can take place as the fluid path to the PDM has been blocked by the ball. If further milling or drilling is required then the tool must be removed from the well-bore so that the ball can be removed. Also, the length of time that the ball takes to drop down the drill-pipe or coil tubing can be considerable.
  • the second problem of pumping nitrogen is helped, but not solved, by using a drop-ball circulating sub as the drop-ball does not effect a complete seal on the piston allowing nitrogen to flow through the motor.
  • US 4,632,187 discloses a well safety and kill valve which is operated either by annulus/formation pressure or control lines.
  • US 4,298,077 discloses a circulation valve for an in-hole motor and GB 2,054,008A discloses a turbo-coring device equipped with a following pipe.
  • a circulating sub apparatus having a throughbore for permitting circulation of fluid from within the throughbore out into a borehole annulus
  • fluid can pass from the inner bore of the outer body member to the inner bore of the inner body member and out of the bottom end of the inner body member.
  • the outer body member and the inner body member are positioned relative to one another in the aligned position, it is a bypass passage that is formed that allows fluid to flow from the internal bore of the circulating sub apparatus to the annulus between the outside diameter of the tool and the inside diameter of the well bore, in use.
  • the displacement mechanism is controlled by fluid pressure.
  • the displacement mechanism comprises a piston assembly and a restrictor nozzle in the fluid path.
  • the displacement mechanism typically includes a restraining device.
  • the restrictor nozzle is located on the uppermost portion of the inner body member such that fluid passing through the inner bore of the circulating sub apparatus passes through the restrictor nozzle.
  • the piston assembly is coupled to the inner body member.
  • an increase in the fluid pressure displaces the inner body member in a downwards direction.
  • the restraining device comprises at least one restraining member mounted on each of the inner and outer body members, the restraining member(s) mounted on the inner body member being selectively co-operable with the corresponding restraining member(s) mounted on the outer body member.
  • each of the inner and outer body members there are two restraining members mounted on each of the inner and outer body members.
  • the two restraining members mounted on one of the body members are spaced further apart than the two restraining members mounted on the other of the body members. More preferably, it is the two restraining members mounted on the inner body member that are spaced further apart than the two restraining members mounted on the outer body member.
  • the two restraining members mounted on the inner body member are mounted on the piston assembly.
  • one of the restraining members mounted on the inner body member and the corresponding restraining member mounted on the outer body member are adapted to rotate the inner body member with respect to the outer body member, following continued longitudinal movement of the inner body member with respect to the outer body member.
  • the restraining members in contact on the inner and outer body members are adapted to restrain the inner body member in a first position from further rotation.
  • longitudinal movement in the opposite direction moves the other of the restraining members mounted on the inner body member into contact with the corresponding restraining member mounted in the outer body member.
  • the other of the restraining members mounted on the inner body member and the corresponding restraining member mounted on the outer body member are adapted to rotate the inner body member with respect to the outer body member, following continued longitudinal movement of the inner body member in the opposite direction with respect to the outer body member.
  • a second restrained position is reached upon longitudinal movement in the opposite direction to the direction of longitudinal movement for which the first restrained position was reached.
  • the direction of rotation of the inner body member with respect to the outer body member for which the first restrained position is reached is the same direction of rotation for which the second restrained position is reached.
  • the first position is the aligned position and the second position is the obturated position.
  • the first position is the obturated position and the second position is the aligned position.
  • the sealing device deters the flow of fluid through the bottom end of the circulating sub, and more preferably deters the flow of fluid through the bottom end of the inner body member.
  • the sealing device seals the bottom end of the inner body member.
  • the invention has the advantage that nitrogen gas may be pumped through the circulating sub and through the circulating holes, when the circulating sub is in the aligned position, to clean the well bore without damaging any tools located below the circulating sub.
  • the circulating sub is included in a drill string which also includes a fluid operated motor, such as a positive displacement motor, and/or a reamer.
  • a fluid operated motor such as a positive displacement motor, and/or a reamer.
  • the fluid may be a liquid or a gas and is preferably a drilling fluid.
  • the fluid may be nitrogen gas.
  • Fig. 1 shows a multi-opening circulating sub 100 which is not in accordance with the present invention, consisting of a main outer body 1, a bottom sub 2 which can stroke in and out of the main outer body 1, a hydraulic detent system 25 and an internal piston assembly 4 which will be detailed subsequently.
  • the multi-opening circulating sub 100 is required to be run into the borehole in a closed position such as that shown in Fig. 1.
  • Drilling fluid flows from a coil tubing through an inner passage 110 of the multi-opening circulating sub 100 and subsequently onwards to equipment located below the circulating sub 100 such as a PDM.
  • the circulation operation can be initiated, by observing the following procedure.
  • Fig. 4 shows that the bottom sub 2 is coupled to a drive-shaft 11, the drive-shaft 11 being slidably coupled to the main outer body 1.
  • Fig. 4 shows that lifting the tool string off the bottom of the borehole allows the bottom sub 2 to stroke out from within the main outer body 1 of the multi-opening circulating sub 100. This lifting action is necessary if for instance milling or drilling operation had been occurring just previously.
  • Fig. 5 shows that as the drilling fluid pump rate is increased, a back pressure of drilling fluid is created by a restricting nozzle 20 and from the bottom hole assembly. This back pressure forces the piston 4 to move downwards within the main outer body 1.
  • the piston 4 is not only deterred from downward movement by the spring 23 but also by a hydraulic detent system 25.
  • the hydraulic detent system 25 comprises a hydraulic fluid chamber 3 filled with viscous fluid, the piston 4 and a one-way flow restrictor 5.
  • the hydraulic detent system 25 restricts the downward movement of the piston by the action of the viscous fluid passing through the one-way flow restrictor 5. As seen in Fig. 5 the viscous fluid flows from one side of the one-way flow restrictor 5 to the other side of the flow restrictor 5 through a restrictor orifice causing the piston 4 to travel slowly.
  • Fig. 2 shows that when the piston 4 has travelled its full stroke the circulation holes 16 will be aligned with the bypass ports 8 and so the drilling fluid is able to flow therethrough. Further, with an exit path into the borehole annulus being provided for the drilling fluid above the PDM and under-reamer assembly, increased flow rates can be achieved thus increasing the borehole cleaning efficiency, without increasing the surface pressure.
  • the circulation holes 16 can be misaligned from the bypass ports 8 by reducing the flow rate of the drilling fluid to 50% or less of the maximum. This action decreases the backpressure caused by the restricting nozzle 20, thus relieving the load on the piston 4, which allows the spring 23 to return the piston 4 to its normal position.
  • the one-way flow restrictor 5 incorporates a one-way check valve located in parallel with the restrictor orifice, the check valve preventing fluid passing on the downstroke of the piston 4 but allowing fluid bypass on the return up stroke. Thus the check valve eliminates any waiting period while the piston 4 returns following a circulation operation.
  • the fluid path through the circulation holes 16 via the bypass ports 8 is discontinued, and fluid now flows down the inner passage 110 and onwards to the PDM and/or the under-reamer assembly below. This fluid flow path can be seen in Fig. 1.
  • the circulation holes 16 can be aligned with the bypass ports 8 so that drilling fluid can circulate therethrough.
  • the tool string and BHA is lifted off the bottom of the borehole and the drilling fluid pressure is sufficiently increased so that rotation of the PDM is initiated and if applicable under-reamer arms are opened if an under-reaming tool is being used.
  • increasing the pressure of the drilling fluid would initiate a circulation operation which will be detailed subsequently.
  • the hydraulic detent system 25 provides resistance to downwards movement of the piston 4 and effectively provides the operator with a period of time before the circulation operation starts.
  • This period of time is used to set down milling weight on the mill or drill bit. This weight pushes the bottom sub 2 upwards, and forces the drive-shaft 11 back into the main outer body 1 as shown in Fig. 7. This in turn prevents the piston 4 from moving downwards far enough for the circulation operation to occur, by a shoulder 10 located on the drive-shaft 11 butting against the piston 4, as shown in Fig. 8.
  • Fig. 9 shows a first example of a multi-opening circulating sub 50 in accordance with the present invention, consisting of an outer tubular body formed by a number of outer body sections 51, 53, 54, 55, 56 and 57, and an inner tubular body comprising an upper piston 52 and a lower piston 65.
  • the upper piston 52 is coupled at its lower end to the lower piston 65.
  • the upper end of the upper piston 52 is coupled to a restrictor nozzle 60.
  • drilling fluid flows from a coiled tubing that is connected to an upper outer body section 53, through the restrictor nozzle 60, through a bore 70 of the circulating sub 50, out of the lower outer body section 57 and subsequently onwards to equipment located below the circulating sub 50, such as a PDM.
  • the fluid flow rate through the circulation sub 50 is increased.
  • This increased fluid flow rate through the restrictor nozzle 60 creates a back pressure of drilling fluid across the restrictor nozzle 60, which forces the piston assembly 52, 65 longitudinally downwards within the outer body sections 51, 53, 54, 55, 56.
  • the upper clutch 58 is formed to have two restraint positions.
  • the first restraint position allows the piston assembly 52, 65 to only travel a short distance, so that the drilling fluid continues to flow through the circulating sub 50 and onto equipment located below.
  • the second restraint position allows the piston assembly 52, 65 to travel a greater distance, so that bypass ports 66 located on the lower piston 65 move into alignment with circulating holes 68 located on an outer body section 56. Drilling fluid will now flow down the bore 70 of the circulating sub 50 and out of the circulating holes 68 via the bypass ports 66.
  • a pack-off sealing element 69 prevents any drilling fluid from flowing through the lowest outer body section 57 and on towards equipment located below. The operation of the pack-off sealing element 69 will be described subsequently.
  • the drilling fluid flow rate is reduced. This action reduces the drilling fluid back pressure across the restrictor nozzle 60.
  • a return spring, 63 which acts between a shoulder 72 mounted on the outer body section 54 and a thrust bearing 62 mounted on the upper piston 52, biasses the upper piston 52 upwards, and when the drilling fluid flow rate is reduced the piston assembly 52 moves upward.
  • the thrust bearing 62 ensures that any residual torque retained in the return spring 63 is dissipated, and hence does not interfere with the rotation of the piston assembly 52, 65.
  • an indexer 64 mounted on the lower piston 65 contacts a lower clutch 59 which is mounted to the outer body section 54.
  • the contact between the indexer 64 and the lower clutch rotates the piston assembly 52, 65 in the same direction as the rotation produced by the upper clutch 58 and the mating angles 61 on a downward movement. Through this rotation as the piston assembly travels upwards, it will have moved onto it's next restrained position and hence it's next mode of operation.
  • Figs. 10 (a) and (b), 11 (a) and (b), 12 (a) and (b) and 13 (a) and (b) shows the positional relationship between firstly the lower clutch 59 and the indexer 64, and secondly the upper clutch 58 and the mating angles 61, for a complete cycle of the circulating sub 50, with the components being shown laid out flat for clarity.
  • Fig. 10(a) shows the indexer 64 and the lower clutch 59 in an engaged position
  • Fig. 10 (a) shows the mating angles 61 longitudinally displaced from the upper clutch 58
  • Figs. 10 (a) and (b) show the piston assembly 52, 65 in the position as shown in Fig. 9.
  • Fig. 11 (b) shows that the indexer 64 and the lower clutch 59 have been longitudinally and rotationally displaced, due to downward movement of the piston assembly 52, 65. It can be seen in Fig. 11 (a) that the mating angles 61 are in contact with the upper clutch 58, and are restrained in the second, or furthest position possible by the upper clutch 58. This position corresponds to the drilling fluid circulation mode. It can also be seen that the piston assembly rotates in only one direction due to the combination of the profiles of firstly the upper clutch 58 and the mating angles, and secondly the lower clutch 59 and the indexer 64.
  • Figs. 12 (a) and (b) show that as the back pressure across the restrictor nozzle 60 is reduced, the indexer 64 and the lower clutch 59 come into contact and the piston assembly 52, 65 is further rotated in the same direction as previously.
  • the upper clutch 58 and the mating angles 61 are longitudinally and rotationally spaced once again, and await an increase in the drilling fluid flow rate to enter a drilling fluid flow through cycle.
  • Fig. 13 (b) shows that the lower clutch 59 and the indexer 64 are once again longitudinally and rotationally further displaced, although the longitudinal displacement is not as great as shown in Fig. 11 (b). This is due to the mating angles 61 being restrained in the first and least travel position by the upper clutch 58, as shown in Fig 13 (a). This is the drilling fluid flow through mode of operation of the circulating sub 50.
  • the circulating sub 50 has two modes of operation, drilling fluid flow through and circulation, for when the piston assembly 52, 65 is restrained in a first and a second position respectively.
  • the lower portion of the circulating sub 50 in the first restrained position is shown in detail in Fig. 14.
  • a seal 67 prevents any leakage of drilling fluid between the bypass port 66 and the circulating hole 68, whilst the circulating sub 50 is in the first position, and hence in drilling fluid flow through mode of operation.
  • the lower portion of the circulating sub 50 in the second restrained position is shown in detail in Fig. 15.
  • the lower piston 65 has moved downwards so that bypass ports 66 are now aligned with the circulating holes 68, thus allowing drilling fluid to exit from the bore 70 of the circulating sub 50 out through the circulating holes 68.
  • the bottom end of the lower piston 65 engages with the pack off sealing element 69 such that no drilling fluid can pass through an aperture 71 in a bottom plug 72 at the bottom end of the circulating sub 50 to the equipment below.
  • the seal between the pack off sealing element 69 and the lower piston 65 ensures that no nitrogen gas can pass through any of the tools below the circulating sub 50.

Landscapes

  • Engineering & Computer Science (AREA)
  • Geology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • Physics & Mathematics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Mechanical Engineering (AREA)
  • Earth Drilling (AREA)
  • External Artificial Organs (AREA)
  • Media Introduction/Drainage Providing Device (AREA)
  • Bearings For Parts Moving Linearly (AREA)

Claims (12)

  1. Ein Zirkulationsübergangsapparat (50), der eine Durchgangsbohrung (70) aufweist, um die Zirkulation von Fluid aus dem Inneren der Durchgangsbohrung (70) in einen Bohrlochringraum hinaus zu erlauben, wobei der Apparat (50) Folgendes beinhaltet: ein röhrenförmiges äußeres Körperteil (51, 53, 54, 55, 56, 57) und ein röhrenförmiges inneres Körperteil (52, 65), wobei sowohl das äußere Körperteil (51, 53, 54, 55, 56, 57) als auch das innere Körperteil (52, 65) ein Loch oder mehrere Löcher (66, 68) aufweisen und die Löcher (66, 68) im Wesentlichen quer zur Längsachse des äußeren Körperteils (51, 53, 54, 55, 56, 57) und des inneren Körperteils (52, 65) stehen, sowie einen Verdrängungsmechanismus zum Erzeugen einer relativen Bewegung zwischen dem äußeren Körperteil (51, 53, 54, 55, 56, 57) und dem inneren Körperteil (52, 65), so dass das innere Körperteil (52, 65) und das äußere Körperteil (51, 53, 54, 55, 56, 57) wiederholt zwischen einer ausgerichteten Position, in der ein Loch oder mehrere Löcher (66, 68) auf dem inneren Körperteil (52, 65) auf das Loch oder die mehreren Löcher (66, 68) auf dem äußeren Körperteil (51, 53, 54, 55, 56, 57) ausgerichtet ist/sind, so dass es einem innerhalb der Durchgangsbohrung (70) enthaltenen Fluid erlaubt ist, aus der Durchgangsbohrung (70) durch die Löcher (66, 68) und in den Bohrlochringraum hinaus zu fließen, und einer abgedichteten Position, in der das eine Loch oder die mehreren Löcher (66, 68) auf dem inneren Körperteil (52, 65) durch das äußere Körperteil (51, 53, 54, 55, 56, 57) abgedichtet sind, so dass ein innerhalb der Durchgangsbohrung (70) enthaltenes Fluid davon abgehalten wird, durch die Löcher (66, 68) zu fließen, bewegt werden können, und eine Dichtungsvorrichtung (65, 69), welche die Durchgangsbohrung (70) unterhalb der Löcher (66, 68) abdichtet, wenn sich das innere (52, 65) und äußere Körperteil (51, 53, 54, 55, 56, 57) in der ausgerichteten Position befinden, aber es dem Fluid erlaubt, von dem Durchgangsbohrungsdurchlass (70) weiter zu einem Gerät zu fließen, das sich unterhalb des Zirkulationsübergangs (50) befindet, wenn sich das innere (52, 65) und äußere (51, 53, 54, 55, 56, 57) Körperteil in der abgedichteten Position befinden, wobei der Zirkulationsübergangsapparat (50), ungeachtet der Position des inneren (52, 65) und äußeren (51, 53, 54, 55, 56, 57) Körperteils relativ zu einander, eine Fluidströmung in der Durchgangsbohrung (70) erlauben kann und wobei der Verdrängungsmechanismus durch das Variieren der Fluidströmungsgeschwindigkeit von der Oberfläche des Bohrlochs durch die Durchgangsbohrung (70) betrieben wird.
  2. Zirkulationsübergangsapparat (50) gemäß Anspruch 1, wobei Fluid aus der inneren Bohrung (70) des äußeren Körperteils (51, 53, 54, 55, 56, 57) zur inneren Bohrung (70) des inneren Körperteils (52, 65) und aus dem unteren Ende des inneren Körperteils (52, 65) hinaus passieren kann, wenn das äußere Körperteil (51, 53, 54, 55, 56, 57) und das innere Körperteil (52, 65) relativ zu einander in der abgedichteten Position positioniert sind.
  3. Zirkulationsübergangsapparat (50) gemäß Anspruch 1 oder Anspruch 2, wobei ein Umgehungsdurchlass (66, 68) gebildet wird, der es dem Fluid bei Gebrauch ermöglicht, von der internen Bohrung (70) des Zirkulationsübergangsapparats (50) zum Ringraum zwischen dem Außendurchmesser des Zirkulationsübergangsapparats (50) und dem Innendurchmesser des Bohrlochs zu fließen, wenn das äußere Körperteil (51, 53, 54, 55, 56, 57) und das innere Körperteil (52, 65) relativ zu einander in der ausgerichteten Position positioniert sind.
  4. Zirkulationsübergangsapparat (50) gemäß einem der vorhergehenden Ansprüche, wobei der Verdrängungsmechanismus durch Veränderungen des Fluiddrucks, die durch das Variieren der Fluidströmungsgeschwindigkeit erzeugt werden, gesteuert wird.
  5. Zirkulationsübergangsapparat (50) gemäß einem der vorhergehenden Ansprüche, wobei der Verdrängungsmechanismus eine Kolbenanordnung (52, 65) und eine Drosseldüse (60) im Fluidweg beinhaltet.
  6. Zirkulationsübergangsapparat (50) gemäß Anspruch 5, wobei der Verdrängungsmechanismus ferner eine Rückhaltevorrichtung (58, 59, 61, 64) beinhaltet.
  7. Zirkulationsübergangsapparat (50) gemäß Anspruch 6, wobei die Rückhaltevorrichtung (58, 59, 61, 64) montiert auf dem inneren (52, 65) und dem äußeren (51, 53, 54, 55, 56, 57) Körperteil je mindestens ein Rückhalteteil (58, 59, 61, 64) beinhaltet, wobei das/die auf dem inneren Körperteil (52, 65) montierte(n) Rückhalteteil(e) (58, 59, 61, 64) selektiv mit dem/den auf dem äußeren Körperteil (51, 53, 54, 55, 56, 57) montierten entsprechenden Rückhalteteil(en) (58, 59, 61, 64) zusammenarbeiten kann/können.
  8. Zirkulationsübergangsapparat (50) gemäß Anspruch 7, wobei es montiert auf dem inneren (52, 65) und äußeren Körperteil (51, 53, 54, 55, 56, 57) je zwei Rückhalteteile (58, 59, 61, 64) gibt.
  9. Zirkulationsübergangsapparat (50) gemäß Anspruch 8, wobei die zwei auf dem inneren Körperteil (52, 65) montierten Rückhalteteile (61, 64) mit größerem Abstand voneinander angeordnet sind als die zwei auf dem äußeren Körperteil (51, 53, 54, 55, 56, 57) montierten Rückhalteteile (58, 59).
  10. Zirkulationsübergangsapparat (50) gemäß Anspruch 9, wobei eines der auf dem inneren Körperteil (52, 65) montierten Rückhalteteile (61, 64) und das entsprechende auf dem äußeren Körperteil (51, 53, 54, 55, 56, 57) montierte Rückhalteteil (58, 59) angepasst sind, um das innere Körperteil (52, 65) in Hinsicht auf das äußere Körperteil (51, 53, 54, 55, 56, 57) im Anschluss an eine fortgesetzte Längsbewegung des inneren Körperteils (52, 65) in Hinsicht auf das äußere Körperteil (51, 53, 54, 55, 56, 57) zu drehen.
EP96306334A 1995-09-01 1996-09-02 Zirkulationsstück Expired - Lifetime EP0787888B1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
GB9517841 1995-09-01
GBGB9517841.4A GB9517841D0 (en) 1995-09-01 1995-09-01 A circulating sub apparatus
GBGB9613894.6A GB9613894D0 (en) 1996-07-03 1996-07-03 A circulating sub apparatus
GB9613894 1996-07-03

Publications (3)

Publication Number Publication Date
EP0787888A2 EP0787888A2 (de) 1997-08-06
EP0787888A3 EP0787888A3 (de) 1998-05-20
EP0787888B1 true EP0787888B1 (de) 2005-03-02

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Application Number Title Priority Date Filing Date
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EP (1) EP0787888B1 (de)
DE (1) DE69634399T2 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8844634B2 (en) 2007-11-20 2014-09-30 National Oilwell Varco, L.P. Circulation sub with indexing mechanism

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Publication number Priority date Publication date Assignee Title
GB9913370D0 (en) * 1999-06-10 1999-08-11 Nat Oilwell Uk Ltd A circulating sub apparatus and method
US6349763B1 (en) * 1999-08-20 2002-02-26 Halliburton Energy Services, Inc. Electrical surface activated downhole circulating sub
CA2473372C (en) 2002-01-22 2012-11-20 Presssol Ltd. Two string drilling system using coil tubing
US6834726B2 (en) 2002-05-29 2004-12-28 Weatherford/Lamb, Inc. Method and apparatus to reduce downhole surge pressure using hydrostatic valve
GB0312180D0 (en) 2003-05-28 2003-07-02 Specialised Petroleum Serv Ltd Drilling sub
EP3475520B1 (de) 2016-06-22 2021-08-04 Qtt A/S Bohrlochwerkzeug mit richtungsdüse und bohrstrang dafür

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Publication number Priority date Publication date Assignee Title
US4632187A (en) * 1984-05-24 1986-12-30 Otis Engineering Corporation Well safety and kill valve

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US4298077A (en) * 1979-06-11 1981-11-03 Smith International, Inc. Circulation valve for in-hole motors
FR2458670A1 (fr) * 1979-06-13 1981-01-02 Foraflex Dispositif de carottage a la turbine avec tube suiveur
US5443129A (en) * 1994-07-22 1995-08-22 Smith International, Inc. Apparatus and method for orienting and setting a hydraulically-actuatable tool in a borehole
GB9505998D0 (en) * 1995-03-24 1995-05-10 Uwg Ltd Flow control tool

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US4632187A (en) * 1984-05-24 1986-12-30 Otis Engineering Corporation Well safety and kill valve

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8844634B2 (en) 2007-11-20 2014-09-30 National Oilwell Varco, L.P. Circulation sub with indexing mechanism
US8863852B2 (en) 2007-11-20 2014-10-21 National Oilwell Varco, L.P. Wired multi-opening circulating sub

Also Published As

Publication number Publication date
EP0787888A3 (de) 1998-05-20
DE69634399D1 (de) 2005-04-07
EP0787888A2 (de) 1997-08-06
DE69634399T2 (de) 2005-12-29

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