Field of the Invention

The present invention relates to a flowable material delivery system and, in particular, but not exclusively, to a system enabling the delivery of a flowable material such as grease or grout to a remote location.

Background of the Invention

In many mining and civil engineering activities it is necessary to deliver a material such as grout or grease for the purposes of sealing or stabilising fractured ground, or lubricating downhole equipment. For example, when core drilling in highly fractured ground, it may be desirable to deliver grout to a location in a bore hole to seal fractures through which drilling fluids may otherwise flow to avoid reduction of fluid pressure within the bore hole and unnecessary wastage of drilling fluids. Similarly, in civil construction, it may be necessary to stabilise fractured ground prior to a concrete pour to prevent ingress of water in to a pour site.

Summary of the Invention

According to one aspect of the invention there is provided a flowable material delivery system comprising: a working fluid valve; and, a pump in fluid communication with the working fluid valve, the pump configured to hold a supply of a flowable material; the valve being operable to provide fluid communication between a working fluid source and the pump wherein working fluid from the fluid source operates the pump to eject a flowable material held in the pump, and to selectively provide fluid communication between the working fluid source and a region outside the pump.

The working fluid valve may comprise a body configured to provide fluid communication between the working fluid source and the pump, and to provide fluid communication between the source and the region outside the pump; and, a mechanism for selectively opening and closing the fluid communication between the working fluid source and the region outside the pump.

The body may comprise at least one first fluid flow path providing fluid communication between the working fluid source and the pump, and at least one second fluid flow path providing working fluid communication between the fluid source and the region outside the pump.

The or each first fluid flow path may have a respective first inlet, and the or each second fluid flow path has a respective second inlet, and wherein the first and second inlets are circumferentially spaced from each other, and the mechanism selectively opens or closes the or each second inlet.

The mechanism may be moveable axially relative to the body between a closed position where the mechanism covers the or each second inlet, and an open position where the mechanism is spaced from the or each second inlet.

The or each first fluid flow channel may have a respective first outlet and the or each second fluid flow path may have a respective second outlet, and wherein the second outlet may be upstream of the first outlet.

The body may comprise a single first fluid flow path, and two second fluid flow paths and wherein the first fluid flow path comprises a channel that extends axially of the body.

The first outlet may be located axially of the body.

The or each second inlet may be located at an upstream end of the or each first inlet.

The or each second fluid flow paths may comprise a corresponding channel extending axially of the body and radially offset from a central axis of the body.

The body may comprise an inner body portion and an outer body portion, the inner body portion seated in a cavity formed in the outer body portion.

The or each of the first inlets may be formed in the outer body portion. The or each second inlets may be formed in the outer body portion.

The first fluid flow channel may be formed in the inner body portion.

The or each second fluid flow channel may be formed in the inner body portion.

The working fluid valve is configured to form a substantial fluid flow seal with an internal seat formed in a tubular member in which the flowable material delivery system can travel to deliver a flowable material to a remote location, wherein when the valve provides fluid communication between the fluid source and a region outside the pump, fluid from the source bypasses the substantial fluid flow seal.

The mechanism may comprise a sleeve which is axially moveable relative to the body.

The pump may comprise a pump body having opposite first and second ends, and defining a space for holding a flowable material, the first end being in fluid communication with the working fluid valve wherein when the working fluid valve provides fluid communication between the working fluid source and the pump, and wherein when a flowable material is held in the space, fluid pressure from the working fluid source is applied to the flowable material to directing the flowable material toward the second end of the pump body.

The pump may further comprise a piston slidably housed in the pump body upstream of the space in which the flowable material can be held, wherein fluid pressure from the fluid source is applied to the piston which in turn applies the fluid pressure to the flowable material.

The pump may comprise a pump valve in fluid communication with the second end of the pump body, the pump valve having a closed state where the pump valve prevents flow of flowable material held within the pump body from the pump, and an open state wherein flowable material held in the pump body can then be ejected from the pump through the pump valve.

The pump valve may comprise a tube and a pump valve body of the pump valve, the pump valve body being coupled to an end of the tube distant the working fluid valve, wherein the pump valve compresses the pump valve body, and a collar mounted on the pump valve body, the pump valve body having one or more holes, the pump valve being in a closed state when the collar covers the one or more holes and in an open state when the collar is moved to a position where it uncovers the one or more holes in the pump valve body.

The pump valve may comprises a spring acting between the collar and the pump valve body, the spring acting to bias the collar to the position where it covers the holes in a pump valve body, thus biasing the pump valve toward the closed state.

The flowable material delivery system may comprise a one way valve between the second end of the tube and the pump valve, the one way valve enabling fluid communication therethrough in a direction from the second end of the tube to the pump valve and preventing fluid communication in a direction from the pump valve to the second end of the tube.

In an alternate embodiment the pump valve may comprise a compressible plug and a plug seat wherein the compressible plug sits in the plug seat and prevents a flow of flowable material held in the space through the pump valve, and wherein the compressible plug compresses in response to application of sufficient fluid pressure to force the compressible plug through the plug seat enabling the flowable material to be ejected from the pump through the pump valve.

According to a further aspect of the present invention there is provided a pump for delivery of a flowable substance to a remote location comprising: a pump body having first and second portions, a piston and a plug both being moveable within the pump body, the piston and plug being associated with the pump body wherein: in a first configuration the piston and plug are spaced apart in the first portion of the pump body and define a sealed region for holding a volume of a flowable substance; and, in a second configuration the plug is disposed in the second portion and the flowable substance can flow past or through the plug and out of the pump body in response to the application of a force on the piston which moves the piston toward the plug.

In one embodiment, the plug comprises a sealing member and the body and sealing member are relatively configured so that when the plug is in the first configuration the sealing member forms a seal against an inside surface of the first portion of the body, and when the plug is in the second configuration the flowable substance is able to flow between the sealing member and an inside surface of the second portion of the body.

In one embodiment, the second portion of the body is formed with an inner diameter greater than an outer diameter of the sealing member. However in an alternative configuration, the second portion of the body may be formed with a plurality of flutes or grooves extending in a generally longitudinal direction to form one or more gaps between the inside surface of the second portion of the body and the sealing member.

The plug may comprise a first cup portion on a side of the sealing member facing the piston, the first cup portion being provided with one or more holes wherein when the plug is in the second configuration, a flowable substance can flow through the one or more holes in the first cup portion and past the sealing member. The plug may also comprise a second cup portion on an opposite side of the sealing member to the first cup portion wherein the second cup portion is provided with one or more holes through which the flowable substance can flow subsequent to flowing past the sealing member.

The second portion of the body may be provided with a seat or stop against which the plug is held when the plug is in the second configuration.

In one embodiment the piston and body are relatively configured to maintain a seal between the piston and an inside surface of the body when the piston moves toward the plug.

However in an alternate embodiment wherein the piston and body are relatively configured to maintain a seal between the piston and an inside surface of the body when the piston moves toward the plug up to a location where motion of the piston is arrested by abutment with the plug wherein the working fluid exerting the force on the piston bypasses the piston and flows out of the body, wherein any remaining flowable substance is flushed form the body by the working fluid. The piston and plug may be further relatively configured so that motion of the piston toward the plug is arrested by abutment of the piston with the plug.

Brief Description of the Drawings

Embodiments of the present invention will now be described by way of reference only with reference to the accompanying drawings in which:

Figure 1 is a section view of an embodiment of the flowable material delivery system when used in a core drilling application;

Figure 2 is an enlarged view of a valve incorporated in the system, the valve being in a first state;

Figure 3 is a view of the valve shown in Figure 2 but when in a second state;

Figure 4 is an enlarged view of a body of a valve when in the first state;

Figure 5 is an enlarged view of the valve body shown when in the second state.

Figure 6 is a cut away perspective view of a portion of the valve body;

Figure 7 is a view of Section A-A of the valve body shown in Figures 6;

Figure 8 is a view of the valve body attached to a head assembly;

Figure 9 is a cross section view of an adapter incorporated in the system 10;

Figure 10 is a cross section view of a pump valve incorporated in a second embodiment of the system,

Figure 11 is a cross section of a pump incorporated in a third embodiment of the system; and,

Figure 12 is an enlarged cross section view of a portion of an alternate pump incorporated in a fourth embodiment of the system. Detailed Description of Preferred Embodiments

Figure 1 illustrates an embodiment of the flowable material delivery system 10 coupled to a head assembly 12 and disposed in a drill string 14. The construction and operation of the head assembly 12 is immaterial to the present invention. A description of the head assembly 12 can be found in Applicant's corresponding Australian application no. 2009900823. The drill string 14 functions as a conduit or tube through which the system 10 travels in order to eject the flowable material to a remote delivery point. While the embodiments of the system 10 are described in connection with the head assembly 12 and drill string 14, application of the system 10 is not limited to use in a drilling environment. Embodiments of the system 10 may be used in any applications where it is required to deliver a flowable material to a remote location through a tube, conduit or similar structure.

In broad terms, the system 10 comprises two main interacting components or subsystems, a valve 16, and a pump 18.

In one example of use, the system 10 may be coupled to the head assembly 12 for delivering say grout to a remote location for example to a region in a bore hole one kilometre from the surface of the earth. The system 10 being coupled to the head assembly 12 is lowered via a wire line down the drill string 14 until a seat 20 of the system 10 engages a landing ring 22 inside the drill string 14. Engagement of the seat 20 with the landing ring 22 forms a substantial fluid seal 23. In order to eject a flowable material such as grout loaded in to the pump 18, a fluid such as water is pumped down the drill string 14. With reference to Figure 2, where the dark broken lines with arrows depict a first fluid path 24, it can be seen that the valve 16 directs water to flow into the pump 18. As described in greater detail below, this communicates the pressure of the water (and thus the water source) to the pump 18 forcing the flowable material from the pump 18.

Once the flowable material has been delivered, the system 10 can be retrieved by lowering an overshot on a wire line through the drill string 14 to engage the head assembly 12 and then reeling in the wire line. However the head of water acting on the system 10 above the seal 23 may exceed the breaking strain of the wire line or may exceed the pulling capacity of a winch for the wireline. In order to relieve the water pressure acting on the system 10, the valve 16 can be selectively opened as shown in Figure 3 to provide fluid communication along a second fluid flow path 30 between a region 25 above (upstream of) the seal 23 and a region 27 below (downstream of) the seal 23. The region 27 is outside of the pump 18. This has the effect of equalising water pressure or at least reducing pressure differential on opposite sides of the seal 23 thus reducing strain on the wire line and/or winch used for retrieving the system 10.

The construction and operation of the system 10 and in particular the valve 16 and pump 18 will now be described in greater detail.

The valve 16 comprises a valve body 26 and a mechanism in the form of a sleeve 28 for selectively opening and closing the fluid flow path(s) 30 of the valve 10. In order to open this fluid communication path, the sleeve 28 is moved from a first position shown in Figures 2 and 4 to a second position shown in Figures 3 and 5.

With particular reference to Figures 4 - 7, the valve body 26 comprises an inner body portion 34 and an outer body portion 36. The inner body portion 34 may be made for a single component in which is formed various passages that constitute parts of the fluid flow paths 24 and 30. The inner body portion 34 is formed with a conical head 38, a central axially passage 40 and two axially extending but radially offset passages 42. The passage 40 does not extend axially through the entire inner body 34 but has an inlet 44 that extends radially opening onto an outer circumferential surface 46 formed in a surrounding recess 47 of the body 34. An outlet 48 of the passage 40 is located axially of the body 34 at a downstream end 50.

Each of the passages 42 have respective inlets 52 which open onto the conical head 38 and respective outlets 54 formed in a reduced diameter portion 56 of the body 34 adjacent and inboard of the downstream end 50. The outlets 54 direct fluid in a radial direction of the body 34.

The outer body portion 36 comprises a cylindrical portion 60 at an upstream end, and downstream thereof a frustoconical portion 62. There is a stepped transition between the cylindrical portion 60 and the frustoconical portion 62 forming a shoulder 64. Downstream of the frustoconical portion 62 is a tail portion 66 formed of a reduced but constant diameter. An axial cavity 68 is formed in the outer body portion 36 for seating the inner body portion 34. A void 70 is formed between the conical head 38 and an upstream end of the cavity 68.

With reference to Figure 5, the cylindrical portion 60 is formed with two radially extending ports 72. The ports 72 lead into the void 70. The void 70 in turn is in fluid communication with the inlets 52 of the passages 42.

As shown in Figure 4, the frustoconical portion 62 of the outer body portion 36 is provided with two diagonal ports 74 which provide fluid communication via the recess 47 with the inlet 44 of the passage 40 formed in the inner body portion 34.

With reference to Figures 2 and 4, the first fluid flow path 24 comprises the port 74, recess 47, inlet 44, channel 40, and outlet 48. The flow path 24, is always open. Thus fluid is always able to flow through the first fluid flow path 24 to the pump 18. However, the second fluid flow path 30 is selectively opened and closed by a sliding motion of the sleeve 28 relative to the valve body 26. With particular reference to Figures 3 and 5, when the sleeve 28 is in a first position where it sits on the shoulder 64, the sleeve closes or blocks the ports 72 thereby shutting the second fluid flow paths 30. When the sleeve 28 is moved in an axial direction relative to and away from the body 26, it is moved to a position uncovering the ports 72 where fluid can now flow through the second fluid flow paths. Each path 30 comprises a port 72, void 70, inlet 52, channel 42 and outlet 54. As shown in Figures 3, when the sleeve 28 opens the second fluid flow paths 30, fluid is able to flow from above to below the seal 23 and outside of the pump 18. The opening of the second fluid flow paths 30 provides pressure equalisation on opposite sides of the seal 23.

With reference to Figure 8, in this particular embodiment, the sleeve 28 is formed as part of a latch body of the head assembly 12, and the valve body 26 is attached to or formed as part of a latch carrier 76 of the head assembly 12. The sleeve 28 and latch carrier 76 are slidably coupled together by a bolt 78. The bolt 78 passes through an annular internal land 80 formed inside the sleeve 28 and a washer 82 which is retained by a head of the bolt 78. A spring 84 extends about the bolt 78 and is retained between the land 80 and the washer 82. The washer 82 is configured so that it cannot pass through the land 80. As the bolt 78 is threadingly coupled to the latch carrier 76 and the washer 82 is unable to pass through the land 80, the valve body 26 is effectively slidably coupled to the sleeve 28.

With reference to Figures 2 and 3, the valve body 26 is coupled to a first adapter body 86. Indeed the adapter body 86 may equally be considered to be a portion of the valve body 26. The adapter body 86 is formed with an axial passage 92 and threadingly engages at an upstream end with a thread formed on the outer circumference of tail portion 66 of the outer body 36. The seat 20 which is in the form of a ring is sandwiched between a downstream end of the frustoconical portion 62 and a shoulder 88 formed circumferentially about the adapter 86. The adapter 86 is also formed with a circumferential groove 90 for seating a rubber O-ring (not shown). The O-ring provides a fluid seal between the adapter 86 and an inner surface of the landing ring 22.

The axial passage 92 is in fluid communication with the outlet 48 of the passage 40. Two radial passages 94 are also formed in the adapter 86 which communicate with the outlets 54 of the passages 42.

The pump 18 is coupled to the valve 16 by a further adapter 96 (see Figures 2, 3 and 9) which comprises a threaded stem 98 and a downstream increased outer diameter stub 100. The stem 98 is formed with an axial passage 102 and threadingly engages with a downstream portion of the passage 92 in the adapter 86. The passage 102 leads to an increased inner diameter void 101 formed in the stub 100. Lock nut 103 (Figures 2 and 3) locks the adapter 96 to the adapter 86.

The pump 18 is threadingly coupled at an upstream end with a thread 105 formed on an outer surface of the stub 100. Thus fluid flowing through the first fluid flow path 24 subsequently flows through the passage 92 in the adapter 86, the passage 102 in the adapter 96, into the stub 100 and into the pump 18 to provide fluid pressure which operates the pump 18.

In general terms the pump 18 comprises a tube 104, a movable seal in the form of a piston 106 and a pump discharge valve 108. The tube 104 screws onto the thread 105 at one end to couple the pump 18 to the valve 26 (via the adapters 86 and 98), with the pump valve 108 being coupled to an opposite (downstream) end of the tube 104. The tube 104 accommodates the piston 106 and defines a space 109 for holding the flowable material such as grout to be discharged. Fluid pressure through the path 24 is communicated to the pump 18 as described above and acts to push the piston 106 in a downstream direction which in turn forces the flowable material out through the valve 108 into a region outside of the pump 18.

The tube 104 is composed of: an upstream section 104i which threadingly engages the thread 105 on stub 100 and houses the piston 106 prior to the application of fluid pressure; and, a tubular extension 104 ₂ which is threadingly coupled to an opposite end of the section W ₁ and defines the space or volume 109 for containing the flowable material to be delivered by the system 10.

A one way valve 124 is coupled between a downstream end of the section 104 ₂ and the valve 108. The one way valve 124 allows fluid flow in a direction from the piston 106 toward the valve 108, but prevent fluid flow in a reverse direction.

The piston 106 comprises a piston head 110 and an integrally formed trailing rod 112. An end of the rod 112 is formed with a flared tail 114 having an outer diameter substantially equal to the inner diameter of the tube 104. The tail 114 is formed with a plurality of longitudinal grooves or slots to allow water or other working fluid to flow between the rod 112 and the inside of the tube 104. The head 110 is formed with a circumferential groove 116 which seats an O-ring 111 forming a seal against the inner surface of the tube 104.

The valve 108 is in fluid communication with a downhole end of the tube 104 via the intermediate one way valve 124. The valve 108 comprises a valve body 126 formed at one end with a constant diameter nozzle 128 in which is formed a plurality of radially extending holes 130 _. A collar 132 is mounted on the body 126 and in particular the nozzle 128. The collar 132 is able to slide axially of the nozzle 128 between an open position (shown in Figure 1) where the collar 132 is spaced from the holes 130, and a closed position (not shown) where the collar 132 covers the holes 130. The collar 132 is prevented from falling from the nozzle 128 by a stop 134 comprising in combination a washer 136 having an outer diameter greater than the outer diameter of the nozzle 128, and a nut 138 which fastens a washer 136 to the nozzle 128.

The collar 132 is biased toward the closed position by action of a spring 140 which is disposed about the body 126 and bears at opposite ends against the collar 132 and an outer surface of the body 126. Channels 142 are formed in a generally axial direction through the collar 132 and provide fluid communication between the inside of the drill string 14 and a region outside of the drill string 14. As the present embodiment of the system 10 is illustrated as operating within a core drilling environment, the collar 132 is configured to seat on an inside surface of a core drill bit 144 coupled to a down hole end of the drill string 14. The core bit 144 in effect operates as a stop which engages the collar 132 and enables operation of the pump valve 108.. In particular, with the collar 132 engaging the drill bit 144, the body 126 is able to slide axially relative to the collar 132 to move the valve 108 to the open position allowing flowable material to flow through the holes 130 into the surrounding bore hole being drilled by the core drill.

Naturally, if the system 10 is being used in a different environment, where the system 10 is delivered through a tube or conduit that is not provided at an end with a core drill bit 144, a stop is required at the end of the tube to engage the collar 132 to enable operation of the valve 108 in the manner described above.

Looking at the valve body 126 more closely it will be seen that it has an upstream portion 127 followed by a contiguous conical portion 129 and finally the nozzle 128. An inner surface 131 of the upstream portion 127 progressively reduces in inner diameter in a direction toward the conical portion 129, with a stepped reduction of inner diameter at a junction with the conical portion 129 to form an internal ledge or seat 133. This configuration is exploited in further embodiments of the system descried later in the specification and shown in Figures 11 and 12.

The valve 124 comprises a cup like structure 146 having a mouth 148 which faces the valve 108, and an opposite planar wall 150. The wall 150 is provided with a central hole through which a bolt 152 extends. A sealing washer 154 is held on the bolt 152 adjacent a downstream side of the wall 150. Adjacent the sealing washer 154 is a retaining washer 156. A spring 158 is retained on the shank of the bolt 152 between the washer 156 and a nut 160. A plurality of axially extending holes 162 are formed in the wall 150. The bias of the spring 158 pushes the sealing washer 154 against the holes 162. When sufficient pressure is applied in a direction from the tube 104 to the valve 108a, this pressure is communicated to the washers 154 and 156 compressing the spring 158 to space the washer 154 from the wall 150 thereby allowing material to flow from the tube 104 through the holes 162. Fluid pressure applied in an opposite direction enhances the bias provided by the spring 158 and further pushes the sealing washer 154 against the holes 162 preventing a flow in the reverse direction.

A second form of pump 18b which may be used in a second embodiment of the system 10 in place of the pump 18 is depicted in Figure 10. The pump 18b may be used when the flowable material to be dispensed contains particulate material that is either too large to pass through the holes 130 in the valve 108, or may otherwise pack and clog the interior of the nozzle 128 and/or the holes 130. The pump 18b differs from the pump18 by virtue of the (a) replacement of valve 108 with valve 108b; (b) omission of the one way valve 124; and, (c) integration of the tube sections 104i and 104 ₂ into a single tube 104b which houses the piston 106 and defines the space 109.

In the valve 108b the stepped internal ledge or seat 133 of the valve 108 is replaced with seat 133b which has a progressively reducing internal diameter in the downstream direction and leads directly to an elongated nozzle 128b, omitting the conical portion 129 of valve 108. The valve 108b also comprises a compressible plug 166 which initially resides in the upstream portion 127b of the valve body 126b. The plug 166 is of a diameter that can freely sit within, or is relatively lightly compressed radially, in the portion 127b but cannot, without application of additional pressure, pass through the seat 133b into the nozzle 128b. Thus when the plug 166 is seated on the seat 133b it effectively closes the valve 108b.

In order to open the valve 108b, fluid pressure is transmitted through the tube 104, via piston 106b and the grout, which compresses or otherwise distorts the plug 166 pushing it through the seat 133b and the nozzle 128b. With the plug 166 now ejected, the flowable material held within the tube 104 can be freely ejected. The nozzle 128b is of a length so that its distal end extends from the drill bit 144.

Typical operational scenarios of the system 10 to dispense a flowable material through a core drill will now be described.

For the system 10 incorporating pumps 18 or 18b initially, the valve 108 and valve 124; or, 108b, as the case may be, is removed from the pump 18 and the space 109 is filled with the flowable material to be dispensed. In this configuration, the piston 106 is near an upstream end of the tube 104. The respective valves 108 and 124, or 108b are reconnected to the downstream end of the tube 104. The pump is then attached via the adapter 96 to the valve 16 which in turn is attached to the head assembly 12. The head assembly is lowered through the drill string 14 to a point where the seat 20 engages the landing ring 22 (see Figures 3 and 4). A substantial fluid seal 23 is now formed between the seat 20 and the landing ring 22. In order to dispense the flowable material held within a space 109, fluid such as water is pumped through the drill string 14. The sleeve 28 is biased to sit on the shoulder 64 (shown in Figures 2 and 4) closing the ports 72 and thereby shutting the second fluid flow paths 30. Water however is able to flow through the first fluid flow paths 24 and in particular through the ports 74, inlet 44, channel 40, outlet 48, through the adapters 86 and 96 and into the tube 104. The pressure of the fluid acts on the piston 106 causing it to travel in the downstream direction through the tube 104 thereby forcing the flowable material in the space 109 in a downstream direction. In the event that pump 18, is used, the fluid pressure of the grout opens the one way valve 124. Either the weight of the system 10 by itself, or with the addition of fluid pressure causes the body 126 of valve 108 to move in a downstream direction relative to the collar 132 thereby uncovering the holes 130 and opening the valve 108. Thus the flowable material is now ejected through the holes 130 into the surrounding bore hole.

In the event that valve 108b is used, the fluid pressure transmitted by the flowable material in the tube 104 forces the plug 166 through and out of the nozzle 170 again enabling the flowable material to be ejected from the pump.

Once the flowable material has been dispensed and it is required to retrieve the system 10 an overshot (not shown) is lowered into the drill string and engages the head assembly 12. A wireline is reeled in which operates to disengage the head assembly 12 from the drill string. The upward force applied to the head assembly 12 during this action also axially slides the sleeve 28 in an uphole direction relative to the valve body 26 to uncover or open the ports 72 (shown in Figures 3 and 5). Now, the second fluid flow paths 30 are open allowing fluid communication between the regions 25 and 27 which are separated by the seal 23. The provision of this fluid communication effectively equalises pressure on opposite sides of the system 10 and provides a fluid flow path for the water from above the seal 23 to below the seal 23 between the pump (i.e. tube 104) and the inside of the drill string. During this time, the first fluid communication path 24 remains open.

Figure 11 depicts a third form of pump 18c. The pump 18c differs from the pump 18 by way of substitution of the one way valve 124 with a plug 200, the provision of a cup portion 180 at the end of head 110 of piston 106c, and the integration of the tube sections 104i and 104 ₂ to form a single one piece tube 104c. The pump 18c includes the valve 108.

Together the tube 104c and the valve body 126 may be considered to constitute a pump body 201 of the pump 18c, with the tube 104c forming a first portion of the pump body and the valve body 126 forming a second portion of the pump body. The piston 106c and plug 200 have a first configuration or juxtaposition where they are space apart in the first portion of the pump body (i.e. the tube 104c) to define the sealed region 109 to hold the flowable substance. The region 109 is sealed by virtue of sealing contact between the interior surface of the tube 104c and the piston 106c, and, the plug 200. The piston 106c and plug 200 have a second configuration or juxtaposition where the plug 200 is seated in the second portion of the pump body (i.e. in the valve body 126) and in which the flowable substance can flow past or through the plug 200 and thus to the pump valve 108 from which it can be injected into a region outside of the pump body 201. This arises due to the provision of the reduced inner diameter of the upstream portion 127 of the valve body 126 and is described in greater detail below.

The cup portion 180 has an open mouth 182 which faces the valve 108 (which is of identical configuration and operation to the valve 108 shown in Figure 1). The cup portion 180 is formed with a circumferential groove 184 about its outer diameter located between the seal 111 and the mouth 182. This groove 184 creates an annular space 186 between the inside surface of the tube 104 and the outside surface of the cup portion 180. A plurality of radially extending holes 188 is formed in the cup portion 180 providing fluid communication between the inside of the cup portion 180 and the annular space 186. The space 186 moves with the piston 106c.

The plug 200 is formed with first and second cup portions 220 and 222 which are separated by an integral radially extending internal wall 224. The cup portion 220 is on a side of the wall 224 facing the piston 106c and has a mouth 226 also facing the piston 106c. A circumferential groove 228 is formed about the cut portion 220 intermediate the mouth 226 and the wall 224. A plurality of radially extending holes 230 provide fluid communication between the circumferential groove 228 and an interior of the first cut portion 220. The cup portion 222 is of an identical configuration but of opposite orientation to the cup portion 220 and thus has a mouth 232 which faces the valve 108, a circumferential groove 234 intermediate the mouth 232 and the wall 224, and a plurality of radially extending holes 236 which provide fluid communication between the groove 236 and the interior of the cup portion 222.

Plug 200 is also formed with a central circumferential groove 238 which seats an O-ring seal 240. Initially, the plug 200 is located at an upstream of and inside the tube 104c so that it's seal 240 is in contact with an internal surface of the tube 104c, while the plug 200 is near a downstream end and inside the tube 104c (i.e. the first portion of the pump body 201). The flowable substance is in the region 109 between the plug 106c and the plug 200

The operation of the system 10 incorporating the pump 18c will now be described. In substance, the operation of the system 10 with the pump 18c is similar to that described in relation to the system 10 with the pump 18. The pump 18c is loaded with grout with the piston 106c in its initial position where the tail 114 is near an upstream end of the tube 104c, and the plug 200 is located in the initial position described above. The system 10 is lowered or pushed through the drill string until engagement of the valve 26 with the landing ring 20. Water is now pumped down the drill string and eventually reaches the valve 26. Initially the water flows through the path 24 and into the pump 18c causing the piston 106c to travel in the downstream direction. This in turn causes the plug 200 to slide in a downstream direction into the second portion of the pump body (i.e. the valve body 126) until it abuts the seat 133. When the plug 200 is in this position, grout located between the piston 106c and the plug 200 can now flow through and past the plug 200. This flow is possible by creation of a fluid flow path which comprises the holes 230, an annular space or gap 241 between the seal 240 and the reduced diameter portion 127 of the valve body 126, the holes 236 and the mouth 232. The flowable substance can then flow through the holes 130 in the valve 108. The piston 106c reaches the end of its travel when it abuts the plug 200, signifying that substantially all of the grout/flowable substance has been forced through the valve 108.

Retrieval of the system 10 with the pump 18c and operation of the valve 26 during this operation is identical to that described above in relation to the earlier embodiments.

Figure 12 shows a pump 18d which may be incorporated in another embodiment of the system 10. The pump 18d allows the water that flows through the path 24 and pushes the piston 106 to force out the flowable substance; to also flow thought the valve 108 and thus flush the system 10. The pump 18d is the same as the pump 18c except for the provision of a hollowed portion 270 at a downstream end of the tube 104d. The hollowed portion has an inner diameter which, moving in the downstream direction, initially reduces from, then progressively increases back to, the internal diameter of the remainder of the tube 104d. This variation in internal diameter in the hollow portion 270 results in the creation of an annular gap 272 between the O-ring 111 and the internal surface of the tube 104 when the piston 106c is moved by the fluid pressure in a down hole direction as far as possible as shown in Figure 12. This position is characterised by the plug 200 being pushed hard up against the seat 133. As a consequence of the creation of this gap 272, the water flowing through the flow path 24 is now also able to bypass the piston 106c by flowing through the gap 272, past the O-ring 111 , through the holes 188, and out from the mouth 182 and into mouth 226 of the plug 200, though holes 230, past o-ring 240, through holes 236, out of mouth 232 and subsequently through valve 108. This flow path is shown by arrowed line 274 in Figure 12. Accordingly the water can now flow through the valve 108 to flush the system 10. When it is desired to retrieve the system 10 incorporating the pump 18d, the valve 26 operates in the same manner as described above, so that the fluid flow path 24 is shut and the second fluid flow path 30 is opened to relieve the pressure of the head of water above the system 10.

Now that various embodiments of the invention have been described in detail it will be apparent to those of ordinary skill in the art that numerous variations and modifications can be made without departing from the basic inventive concepts. For example with reference to system 10 shown in Figure 1 which incorporates the pump 18, the tube sections 104i and 104 ₂ may be integrated to form a single tube as shown in the embodiment in figure 11. Also with reference to the pump 18d shown in figure 12 which allows for water flushing of the system 10, the hollowed portion 270 can be formed in the valve body 126 instead of the end of the tube 104d, or alternately a short adaptor tube having a hollowed portion identical to hollowed portion 270 can be screwed between the tube 104 and the valve body 126. This enables the tube 104d to be made a simple tube of uniform internal diameter for the entirety of its length. Further, with reference to the pumps 18c and 18d either one of or both the cup portions 220 and 222 can be replaced with other structures that allow a flow of the grout past the plug 200 when the plug 200 abuts the seat 133. For example one or both of the cup portions 220 and 222 may be replaced with solid cylindrical bodies having longitudinal flutes or grooves on their outer circumferential surface through which the flowable substance can flow once the plug 200 is in the valve body 126 and seated on the seat 133. Further, the gap or space between the O ring 240 and the inner surface of portion 127 of the valve body 126 may be in the form of a plurality of flutes or grooves formed on the inner surface of the portion 127. All such modifications and variations, together with others that would be apparent to those of ordinary skill in the art are deemed to be within the scope of the present invention the nature of which is to be determined from the above description and the appended claims.