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
• • 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
• • 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
• • 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
  • E21B34/00—Valve arrangements for boreholes or wells
  • E21B34/06—Valve arrangements for boreholes or wells in wells
  • E21B34/12—Valve arrangements for boreholes or wells in wells operated by movement of casings or tubings
• • 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
  • E21B34/00—Valve arrangements for boreholes or wells
  • E21B34/06—Valve arrangements for boreholes or wells in wells
  • E21B34/14—Valve arrangements for boreholes or wells in wells operated by movement of tools, e.g. sleeve valves operated by pistons or wire line tools
  • E21B34/142—Valve arrangements for boreholes or wells in wells operated by movement of tools, e.g. sleeve valves operated by pistons or wire line tools unsupported or free-falling elements, e.g. balls, plugs, darts or pistons
• • 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
  • E21B41/00—Equipment or details not covered by groups E21B15/00 - E21B40/00
  • E21B41/0007—Equipment or details not covered by groups E21B15/00 - E21B40/00 for underwater installations

Definitions

• the current invention can be applied in many different types of tools and devices. For instance it may be incorporated in under reamers, casing cutters, ball valves and other type of valves, packers and tools for deep mineral air drilling.
• the invention would also be useful in flushing devices used in drilling strings in oil and gas explorations and extraction.
• One of these challenges is in respect of maintaining suitable conditions for the operation of the drill head or bit to cut through the medium.
• a build up of cuttings may result in a reduction in the flow of slurry to and from the drill head, it may place unnecessary loads on the drill head and stem assembly and may also cause the drill head to be wedged or jammed in the bore. Furthermore, with the increase in use of horizontal bores in well networks, a build up of cuttings on the lowermost or bottom surface of the bore may cause side displacement of the drill head which will result in the bore taking on a new and incorrect direction.
• US patent 6,161 ,632 Several of these flushing devices are referred to in US patent 6,161 ,632.
• the invention disclosed in US patent 6,161 ,632 provides a flushing device which remains in a closed state by the weight of the drill stem which acts downwardly. Relieving this weight by applying a relative pull upon the drill stem results in the flushing device moving to an open state, causing a predetermined percentage of the slurry to be diverted from the main passage into the annular space for as long as the weight of the drill stem assembly has been relieved.
• a compressive force must be maintained upon the flushing device.
• a tractive force must be maintained upon the flushing device. If the compressive or tractive force is not constantly applied to the flushing device during the required condition, the flushing device may automatically and uncontrollably move to the alternate condition.
• a further deficiency in this device is in relation to the bleed holes located on the outer wall of the tool. These bleed holes allow cuttings to get into the flushing device, contaminating the various parts within the flushing device and resulting in tool failure.
• This device relies on hydraulic pressure to achieve the required tensile loading. Owing to the configuration of the device, hydraulic lock can occur resulting in a build up of pressure. When the pressure builds beyond a predetermined value, a relieve disc bursts causing the device to default to an open state, requiring the drill stem assembly to be brought back to the surface so that the flushing device can be repaired or replaced.
• the present invention provides an actuating mechanism comprising: an inner member and an outer member axially slidable relative to each other, the inner and outer members cooperating to define an internal passage for the flow of a fluid therethrough; the inner member being configured such that upon a predetermined change in pressure between a first region and a second region the actuating mechanism is caused to move between a first condition and a second condition.
• the first region is in the internal passage of the actuating mechanism.
• At least a section of the inner member is exposed to both the first and third regions.
• an inner surface of the inner member is exposed to the first region and an outer surface of the inner member is exposed to the third region.
• unequal forces are exerted across the inner member.
• this inequality reaches the predetermined value the actuating mechanism is caused to move between its first and second conditions.
• the inner member and outer members are in the form of pipes.
• the inner member may comprise a wash pipe which is configured to have a first end with an outer diameter larger than the outer diameter at the second end.
• the wash pipe has a portion having a tapered outer diameter. The portion may have a constant inner diameter.
• the wash pipe has a first seal assembly located along the outer diameter adjacent the first end and a second seal assembly located along the outer diameter adjacent the second end.
• first seal assembly and the second seal assembly each have at least one seal.
• the at least one seal of the second seal assembly has a smaller cross section than the at least one seal of the first seal assembly.
• the degree of change in pressure required between the first region and the second region to operate the actuating mechanism may be varied by changing the cross sectional diameter of the at least one seal of the second seal assembly.
• an internal portion of the outer member against which the second seal assembly slidingly engages can be varied according to changes in cross sectional diameter of the at least one seal in the second seal assembly.
• a cavity is defined between the inner member and outer member.
• the cavity is filled with a lubricant such as oil.
• the cavity may have an opening which opens into a chamber of an equalising device.
• the equalising device may be in the form of a floating sleeve which is slidingly retained on an outer portion of the outer member and which surrounds the chamber.
• volumetric changes in the cavity result in the floating sleeve moving with respect to the opening.
• the floating sleeve is in communication with the second region such that pressure in the second region is transmitted to the cavity.
• the cavity provides the third region.
• the cavity is sealed from the internal passage such that the cavity may not be contaminated.
• the cavity is also sealed from the area external the actuating mechanism to again ensure the cavity remains free from contamination. This ensures that the moving parts of the actuating mechanism are retained in an environment where contaminants cannot affect the operation of the actuating mechanism, increasing its reliability.
• the equalising device may also balance and cushion the movement between the inner and outer sleeve.
• the actuating mechanism comprises an indexing mechanism which indexes between a first position, wherein the actuating mechanism is in the first condition and a second position wherein the actuating mechanism is in the second condition.
• the indexing mechanism is located between the first and second members.
• the indexing mechanism operates within the cavity.
• the indexing mechanism engages the inner member.
• the indexing mechanism may comprise an indexing sleeve, a travel stop and a positioning sleeve.
• the indexing sleeve may be fixed rotationally to the inner member, this may be by way of a key way arrangement.
• the indexing sleeve is axially movable relative to the inner member.
• the travel stop may be mounted on the inner member such that it may rotate about the longitudinal axis thereof.
• the travel stop is substantially constrained against axial movement relative to the inner member.
• the positioning sleeve may be fixed rotationally to the inner member, this may be by way of a key way arrangement.
• the positioning sleeve is axially movable relative to the inner member.
• the indexing sleeve and travel stop may be biased away from each other.
• the biasing force may be provided by a first spring.
• the travel stop and positioning sleeve may also be biased away from each other.
• the biasing force may be provided by a second spring.
• the travel stop is adapted to co-operate with the indexing sleeve during the indexing sequence.
• the indexing sleeve may have a first end which provides a bottom face and a second end having a projection, defining a pawl, extending in an axial direction from the periphery of said second end.
• the travel stop may have a first end adapted to engage and mesh with the projection on the indexing sleeve and a second end adapted to engage and mesh with the positioning sleeve.
• a first end of the positioning sleeve is shaped to engage and mesh with the second end of the travel stop.
• the second end of the travel stop is configured to provide a plurality of fingers and corresponding slots, which co-act with corresponding fingers and slots integral with the positioning sleeve.
• Each finger and slot of the travel stop may terminate in at least one depression or trough.
• Each finger and slot of the positioning sleeve may terminate in at least one peak.
• Each peak may be complimentary in shape to each trough so that upon engagement each finger on the travel stop aligns with a finger and/or slot on the positioning sleeve depending on whether the indexing mechanism is in its first position or second position.
• the slots on the travel stop align and mate with the fingers on the positioning sleeve, whilst the fingers on the travel stop align and mate with the slots on the positioning sleeve. In this condition the fingers are interlaced.
• each finger and each slot on the travel stop each have one trough, and each finger and each slot on the positioning sleeve each have one peak.
• the actuating mechanism actuates, or cycles, between the first and second conditions in alternating fashion.
• each finger and each slot on the travel stop each have one trough, and each finger on the positioning sleeve has one peak, whilst each slot on the positioning sleeve has two peaks.
• the actuating mechanism actuates, or cycles, from first condition to second condition to second condition before returning to the first condition.
• indexing mechanism will obviously allow for a variety of different cycles depending on the number of troughs each finger and/or slot on the travel stop has, and/or the number of peaks each finger and/or slot on the positioning sleeve has.
• the peaks may be on the fingers and slots of the travel stop whilst the troughs may be on the fingers and slots on the positioning sleeve.
• the actuating mechanism may comprise at least one retention mechanism to releasably retain the actuating mechanism in one condition until the predetermined pressure differential between the first and third regions is reached whereupon the actuating mechanism is able to move from one condition to the other.
• the retention mechanism may comprise a ball fixed relative to the inner member but biased radially outward from the inner member.
• the outer member may have a first groove and a second groove on its inner surface spaced a distance from each other. Preferably this distance is substantially equal in length to the axial distance the inner member moves relative to the outer member as the actuating mechanism moves between its first and second conditions.
• Each groove may be annular with a cross section complimentary to the ball so that the ball can be received therein and hold the inner member relative to the outer member.
• the ball may be fixed relative to the outer member and biased radially inward from the outer member
• the inner member may have the first groove and the second groove on its outer surface spaced a distance from each other substantially equal in length to the axial distance the inner member moves relative to the outer member as the actuating mechanism moves between its first and second conditions.
• the actuating mechanism is capable of flexing whilst still capable of effective operation.
• the actuating mechanism may incorporate a joint capable of allowing pivotal movement relative to the longitudinal axis.
• the joint is in the form of a knuckle joint and allows the inner member to pivot. The joint allows the actuating mechanism to operate effectively even when loads applied to the outer member cause it to deflect between its ends.
• the actuating mechanism is incorporated in an apparatus, such as a tool, for actuating the apparatus between first and second operational condition.
• the apparatus is a flushing device, whereby the actuating mechanism causes the flushing device to move between the first operable condition, wherein the flushing device is closed and the second operable condition wherein the flushing device is open.
• an inner sleeve of the flushing device comprises the inner member of the actuating mechanism
• an outer sleeve of the flushing device comprises the outer member of the actuating mechanism.
• the flushing device also has an internal passage which incorporates the internal passage of the actuating mechanism.
• the outer sleeve may incorporate openings. These openings may be blocked from the internal passage when the flushing device is in the closed operable condition, and register with the internal passage when the flushing device is in the open operable condition.
• the flushing device is configured such that the flushing device remains in the selected open or closed operable condition regardless of any expansive or compressive force.
• the openings provide a flushing outlet, whereby when the flushing device is in an open operable condition a predetermined percentage of the fluid is diverted from the passage.
• the flushing outlet preferably comprises a plurality of apertures in the inner sleeve, an annular chamber in the outer sleeve and a plurality of nozzles.
• the flushing outlet may form a passage between the annular chamber and the outside of the flushing device when the flushing device is in its open operable condition.
• Each nozzle may be shaped so as to direct diverted fluid backwards, away from the drill head.
• a fluid tight seal is provided between the inner and outer sleeve as the flushing device moves from a closed operable condition to an open operable condition.
• the flushing device may comprise an intermediate sleeve located between the inner and outer sleeve and located between the flushing outlet and the inlet of the flushing device to provide the fluid tight seal.
• the apparatus is an under reamer or casing cutter whereby the actuating mechanism causes the under reamer or casing cutter to move between a first operable condition, wherein a cutting device is contained within the under reamer or casing cutter, and a second operable condition wherein the cutting device, protrudes from the under reamer or casing cutter to cut as required.
• the actuating mechanism may cause the cutting device to move between a first operable condition, wherein the cutting device is off, and a second operable condition wherein the cutting device is on.
• An under reamer is a tool used to smooth the wall of a well, enlarge the hole, help stabilize the bit, straighten the well bore and/or to drill directionally.
• the present invention also provides a flushing device comprising: an inner sleeve and an outer sleeve, moveable relative to each other between an open operable condition, wherein a percentage of the fluid passing through a central passage of the flushing device can be diverted through a plurality of flushing outlets, and a closed operable condition, wherein the fluid outlets are blocked from the passage, an actuating mechanism operable between the inner and outer sleeves, and having first and second conditions which correspond to the open and closed operable conditions, the actuating mechanism being responsive to a fluid pressure differential between a cavity defined between the inner and outer sleeves, and the pressure in the internal passage, for movement between its first and second conditions, whereby the actuating mechanism, when in the first or second condition couples the inner sleeve to the outer sleeve to prevent movement of the inner sleeve relative to the outer sleeve until predetermined value of pressure differential is reached.
• the present invention also provides a flushing device comprising: an inner sleeve, slidingly received in an outer sleeve, the inner and outer sleeves cooperating to define an internal passage for the flow of a fluid, and are permanently coupled such that there is no rotational movement between the two sleeves; the outer sleeve having a plurality of flushing outlets an actuating mechanism comprising an inner and outer member, incorporated within the inner and outer sleeves, an internal passage which is common with the internal passage of the flushing device, the actuating mechanism being caused to cycle between open and closed conditions with change in the pressure differential acting upon the inner member; an indexing mechanism which indexes as a result of the operation of the actuating mechanism, the indexing mechanism indexes between first and second positions such that the flushing device moves between an open operable condition, whereby the plurality of flushing outlets are open for discharging a quantity of the fluid from the internal passage, and a closed operable condition, whereby the plurality of flushing outlets are closed, the operable condition depending on the position of the
• Figure 1 is a sectional view of the invention used in a flushing device
• Figure 2 is a sectional view of the invention in a closed condition during operation;
• Figure 3 is a view similar to figure 2 but in an open condition;
• Figure 4 is a sectional view of the inlet end of the flushing device depicted in figure 1 ;
• Figure 7 is a sectional view of the outlet end of the flushing device depicted in figure 1 ;
• Figure 8 is a sectional view of the outlet end of the flushing device depicted in figure 2
• Figure 9 is a sectional view of the outlet end of the flushing device depicted in figure 3
• Figure 10 is a view of an indexing mechanism in an opposed relation
• Figure 11 is a view similar to figure 4 but in an interlaced relation
• Figure 12 is a view of the indexing mechanism according to the sequence of positions as it moves between an opposed to interlaced relation.
• the invention is in the form of an actuating mechanism 111 comprising an indexing mechanism 80, an inner member 113 and an outer member 115, which cooperates with the inner member 113 to provide an internal passage 117 through which fluid passes.
• the internal passage 117 also provides a first region 119, whilst a second region 120 is defined by an area external to the outer member 115.
• the actuating mechanism 111 is incorporated in a flushing device 20.
• the flushing device 20 comprises an inner sleeve 21 and an outer sleeve 23, which cooperate to provide a fluid passage 32 having an inlet 22b and an outlet 22a.
• the fluid passage 32 incorporates the internal passage 117 of the actuating mechanism 111.
• the inner sleeve 21 comprises the inner member 113 of the actuating mechanism 111 and provides a plurality of apertures 38 spaced annually therearound, as shown in figures 1 to 6.
• the outer sleeve 23 of the flushing device 20 comprises the outer member 115 of the actuating mechanism 111 and defines the inlet 22b and the outlet 22a of the flushing device 20.
• the outer sleeve 23 is adapted to be releasably incorporated in the drill stem assembly and provides a plurality of flushing outlets 33.
• the flushing outlets 33 allow fluid to pass from passage 32 to the annular space between the flushing device 20 and the bore wall (not shown) when the flushing device 20 is in an open condition, as represented in figure 6.
• the inner member 113 of the actuating mechanism 111 incorporates a portion called a wash pipe 121.
• the wash pipe 121 has a constant internal diameter whilst a portion of the outer diameter tapers inwardly from a first end to a second end, the first end being closer to the inlet 22b of the flushing device 20.
• the inner member 113 has a second seal assembly 93 comprising a pair of seals 96 located along an outer diameter and adjacent its second end.
• the inner member 113 also incorporates a further set of seals 35b comprising a pair of seals 95 adjacent the annular chamber 35.
• the seals 96 of the second seal assembly 93 have a smaller cross section than the seals 95 of the set of seals 35b.
• An internal portion 165 of the outer member 115 provides a surface 167 against which the second seal assembly 93 of the inner member slidingly engages.
• the pressure differential required between the first region 119 and the third region 122 in order for the actuating mechanism 111 to alternate between first and second conditions can be varied by changing the cross sectional diameter of th e seals 96 in the second seal assembly 93. Changes in cross sectional diameter of the seals 96 are accommodated by changes in the diameter of the internal portion 167 of the outer member 115, against which the second seal assembly 93 slidably engages varies according to
• the inner sleeve 29 provides a pawl 68 projecting from an end thereof.
• the indexing sleeve 29 is rotationally fixed relative to the inner member 113 by a key way arrangement 131.
• the indexing sleeve 29 also comprises a projection 29a extending inwardly from a first end of the indexing sleeve 29, as best shown in figure 10.
• the portion 29a of the indexing sleeve 29 provides a face upon which first spring 67 acts to bias the indexing sleeve 29 towards a shoulder 171 on the internal surface of the outer member 115.
• the positioning sleeve 129 comprises a plurality of fingers 28a and slots 28b which are configured to provide a peak at their periphery.
• the positioning sleeve 129 is rotationally fixed relative to the inner member 113 by a key way arrangement 133, as shown in figure 1.
• the outer member 115 provides a shoulder 163 against which the positioning sleeve 129 abuts.
• the fingers 27a do not entirely align with slots 28a.
• continued upward movement of the inner member 113 results in the fingers 27a sliding over the fingers 28a causing further rotation of the travel stop 62 until the fingers 27a align with slots 28a of the positioning sleeve 129, such that the fingers are interlaced.
• Continued upward movement of the inner member 113 will result in the engagement of the fingers 27a with the slots 28b.
• the actuating mechanism 111 is in its second condition, and the flushing device 20 is in its open operable condition, as shown in figure 1.
• a similar process will in turn cause the rotating travel stop 62 to be indexed to a second position whereby the fingers 27a align with fingers 28a such that they are in an opposed relation.
• the actuating mechanism 11 is in its first position, and the axial movement of the inner member 113 is sufficient only for the pawl 68 to disengage the ratchet 69.
• the axial movement of the rotating travel stop 62 is restricted to the movements of the inner member 113. Downward movement of the travel stop 62 relative to inner member 113 is prevented by shoulder 139.
• the biasing force exerted by second spring 127 prevents upward movement of the travel stop 62 relative to the inner member 113.
• the rotational movement of the travel stop 62 is governed by the flushing device 20 and the travel stops 62 position with respect to indexing sleeve 29, and fingers 28a and slots 28b.
• the actuating mechanism 111 also comprises a retention mechanism 141 to releasably retain the actuating mechanism 111 in one condition until the predetermined pressure differential between the first region 119 and third region 122 is reached, whereupon the actuating mechanism 111 is permitted to move from one condition to the other.
• the retention mechanism 141 is provided by a plurality of detents comprising a ball 143 fixed axially relative to the inner member 113 but biased radially outwardly from the inner member by detent spring 145.
• the outer member 115 has a first groove 147 and a second groove 149 on the inner surface, each being spaced a distance from each other substantially equal in length to the axial distance the inner member 113 moves relative to the outer member 115 when the actuating mechanism 111 moves between its first and second conditions.
• Each groove 147, 149 is annular and has a cross section complimentary to that of the ball 143 such that the ball 143 is snugly received therein so as to hold the inner member 113 relative to the outer member 115.
• the ball 143 is received in the first groove 147, as shown in figure 1.
• the ball 143 is forced inwardly by the action of the axial force on the inner member 113 caused by the pressure of the fluid flowing through the passage.
• the inner member 113 moves rapidly to either an intermediate position between the first groove 147 and second groove 149, as shown in figure 2, or until the actuating mechanism 111 is in its second condition, as shown in figure 3, wherein the ball 143 aligns and engages with the second groove 149, whereby the actuating mechanism 111 is held in its second condition.
• the fingers of the travel stop 62 are interlaced with the fingers on the positioning sleeve 129. This allows for greater axial movement of the inner member 113 with respect to the outer member 115 so that the actuating mechanism 111 is able to move to its second condition, as shown in figure 3.
• the actuating mechanism 111 incorporates a knuckle joint 151 capable of allowing pivotal movement of the inner member 113 relative to its longitudinal axis.
• the knuckle joint 151 allows the actuating mechanism 111 to operate effectively even when loads applied to the outer member 115 cause it to deflect between its ends.
• the cavity 153 defined between the inner member 113 and the outer member 115, filled with a lubricant such as oil.
• the cavity 153 which is sealed to prevent the ingress of any contaminants, houses the indexing mechanism 80 and the retention mechanism 141 , and ensures reliable conditions for the functioning of these components.
• the actuating mechanism 111 incorporates an equalising device 155.
• the equalising device comprises a floating sleeve 157 which is slidingly retained on an outer portion 159 of the outer member 115, and provides a chamber 161 which is in fluid communication with the cavity 153 through an opening 154. As the inner member 113 moves, the volume of the cavity 153 changes accordingly.
• the lubricant exits the cavity 153 through opening 154 and into the chamber 161 , causing the floating sleeve 157 to move accordingly to allow for the increase in volume in the chamber 161.
• the floating sleeve 157 moves relative to the opening 154 to accommodate volumetric changes within the cavity 153.
• the floating sleeve 157 is in communication with the second region 120.
• the pressure in the second region 120 is transmitted to the chamber 161 and the cavity 153.
• the pressure, and volume, of the third region 122 provided by the cavity 153 is representative of the pressure in the second region 120.
• the pressure in the second region 120 affects the operation of the actuating mechanism 111.
• the equalising device 155 balances and cushions the movement between the inner and outer members.
• the outer member 115 also provides a port 37 which is in communication with the cavity 153 allowing it to be filled with lubricant if so required.
• the intermediate sleeve 42 comprises a outwardly extending shoulder 46 at its first end, and terminates at its other end with a sloping face 42a.
• the sloping face 42a mates with upwardly sloping face 42b located on the inner sleeve 21 to provide a seat.
• the intermediate sleeve 42 also contains a plurality of holes 43 which receives a plurality of balls 44.
• Each ball 44 has a diameter greater than the radial thickness of the intermediate sleeve 42 such that when the intermediate sleeve 42 is at its lower most position each ball 44 protrudes beyond the interface between the intermediate sleeve and the inner sleeve 21 and rests against the downwardly sloping face 45 of the inner sleeve 21.
• the mating of seat portion 42a of the intermediate sleeve 42 with the upwardly sloping face 42b of the inner sleeve 21 is at a predetermined distance from the plurality of holes 43 such that the balls 44 are not permitted to enter aperture 38.
• the intermediate sleeve 42 is rotationally fixed to the outer sleeve 23 by key way arrangement 142. This arrangement assists in ensuring the interface between the intermediate sleeve 42 and outer sleeve 23 does not become clogged with fluid (slurry) passing through the flushing device 20.
• the annular chamber 35 has a set of seals 35a, 35b adjacent each side thereof. These seals render the interface between the inner sleeve 21 and outer sleeve 23 fluid tight, preventing slurry passing from the passage 32 and into the interface and the cavity 153 when the flushing device 20 is in an open operable condition.
• a first section 49a of the inner sleeve 21 co-acts with seals 35a to provide a seal.
• the intermediate sleeve 42 moves upwardly to co-act with the seals 35a and provide a seal below the annular chamber 35, preventing fluid passing through the apertures 38 and ingressing between the inner sleeve 21 and outer sleeve 23.
• the inner member 113 moves downwardly relative to the outer member 115, providing a barrier between the inner passage 32 and the annular chamber 35 of the flushing outlet 33.
• the inner member 113 will result in the sloping face 42b abutting mating conical face 42a of the intermediate sleeve 42 whilst simultaneously the downwardly facing slope 45 passes groove 48.
• the plurality of balls 44 will then be forced to move in an inward direction resulting in the intermediate sleeve engaging the inner sleeve 21 to move downwardly with further downward movement of the inner sleeve 21.
• Sloping face 42b and conical face 42a remain in intimate contact until they have passed seals 35a.
• the travel stop 62 is free to move in the same axial direction, being biased to do so as the second spring 127 forces the travel stop 62 to disengage from the positioning sleeve 129.
• the retention mechanism 141 prevents the closure of the flushing outlet 33 until the force exerted by spring 127 is able to overcome both the force of the retention mechanism 141 holding the inner member 113 relative to the outer member 115, and the pressure differential between the first region 119 and the third region 122.
• the pressure differential between the first region 119 and third region 122 is reduced so that the force of spring 127 is greater than the force exerted by the retention mechanism 141 , at which point the ball 143 disengages the second groove 149, allowing the inner member 113 to rapidly move with respect to the outer member 115 towards the inlet 22b.
• the travel stop 62 disengages from the positioning sleeve 129 and moves towards the indexing sleeve 29, ready to cycle to a new position.
• the switching between the two conditions of the flushing device 20 may be controlled remotely by the operator on the surface.
• the operator will know to activate and deactivate the flushing device 20 according to the behaviour of the drilling stem assembly, the drilling head, and the slurry which is being returned to the surface.
• the flushing device 20 may be placed anywhere along the drilling stem assembly, its position depending on the application. Indeed the drilling of a well may require the inclusion of one or more flushing devices 20 to be used to maintain the required conditions in the bore.
• the required pressure differential between the first region 119 and third region 122 can be varied by varying the force exerted by detent spring 145 on ball 143.
• pressure differential required to operate the actuating mechanism may be varied by varying the diameter of the seals 96 of the second seal assembly 93, as previously discussed. This does not however affect the ratio between opening and closing pressures.
• the flushing device 20 does not include the intermediate sleeve 42.
• the inner sleeve 21 is configured to ensure a fluid tight seal exists between the inner sleeve and the outer sleeve.
• the invention can be used in relation to many other applications. For instance, it may be used in operating or actuating a ball valve or any type of valve, an under reamer or casing cutter, it can be easily converted to a single shot operation for a permanent installation, and it may be used for deep mineral air drilling.

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• Engineering & Computer Science (AREA)
• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Physics & Mathematics (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Mechanical Engineering (AREA)
• Earth Drilling (AREA)
• Quick-Acting Or Multi-Walled Pipe Joints (AREA)
• Multiple-Way Valves (AREA)

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Cited By (2)

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• 2004
  • 2004-11-01 US US11/666,674 patent/US20090126936A1/en not_active Abandoned
  • 2004-11-01 WO PCT/AU2004/001512 patent/WO2005045180A1/en active Application Filing
  • 2004-11-01 AU AU2004287892A patent/AU2004287892A1/en not_active Abandoned
  • 2004-11-01 EP EP04796962A patent/EP1815104A4/de not_active Withdrawn
• 2007
  • 2007-05-16 NO NO20072534A patent/NO20072534L/no not_active Application Discontinuation

Patent Citations (4)

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