An improved packer cup

Abstract

A packer cup (102) is provided, comprising an annular base member (104) and a sleeve (200) having a proximal end fixed to an upper surface of the base member. The sleeve (200) has a plurality of first apertures (210) passing radially through the sleeve. A resilient cup body (122) is attached to an upper surface of the base member (104) such that it encapsulates the sleeve (200) and has a plurality of protuberances (127) which are located in the corresponding plurality of first apertures (210). Methods of forming such a packer cup and sealing an annulus within a wellbore with such a packer cup are also provided.

Description

[0001] P398409.W0.01

[0002] 1

[0003] AN IMPROVED PACKER CUP

[0004] Field of the Invention

[0005] The present invention is concerned with the field of oil well operations and in particular the apparatus and methods employed to perform remedial operations in live wells, or plug and abandon wells once they are no longer operational. More specifically, the present invention is an improved packer cup, also known as a swab cup, for use in such plug and abandon operations.

[0006] Background of the Invention

[0007] Packer or swab cups are widely used in the oil and gas industry as directional sealing devices which prevent fluid flow and retain pressure in one particular direction. One particular application for such cups is for them to be used in perforation, wash and cement (PWC) operations, which is a known way to abandon depleted wells in a cost-effective manner.

[0008] In a typical PWC operation a PWC tool assembly is run into the well to the desired depth. The PWC tool assembly includes a perforating gun and a wash tool, where the wash tool employs packer cups.

[0009] In the PWC operation the perforating gun is fired at the required location in the well, creating holes in the well casing right through to the rock behind the casing. A washing operation is then carried out to clean inside and behind the casing and create a suitable surface for the cement plug. The wash tool has one or more nozzles on the circumference thereof, and pairs of packer cups are located above and below these nozzles to prevent the wash fluids escaping up or down the well, thereby creating the cleaning pressure required for the operation. The cups may then subsequently be used to create high pressure inside the tool to manipulate a ball seat type of plug. A cementing operation is completed after washing, where cement is pumped through the or each nozzle into the casing, through the perforations and beyond the casing thus creating a rock-to-rock barrier and sealing the well. Again, the packer cups ensure that the cement slurry does not escape into other areas of the well.P398409.W0.01

[0010] 2

[0011] There are three basic types of packer cup: a standard cup, a garter spring cup and a finger spring cup. Standard cups have a flexible elastomeric (e.g. rubber) cup area and do not abrade against the internal casing wall. However, they are only suitable for low pressure operations. As with standard cups, garter spring cups have a flexible elastomeric cup which does not abrade against the internal casing wall. However, a garter spring embedded in the elastomer ensures that these cups can provide a very high pressure seal of up to 15000 PSI. Finger spring cups are similar to garter spring cups in that they have a number of finger springs embedded in the elastomeric cup area, which ensure positive contact against the internal casing wall. However, this means that these cups require a comparatively large force to move them and also may result in the elastomer of the cup area being damaged during running in or out. Consequently, finger spring cups are the least suitable to operations with limited space and / or restrictions in the well.

[0012] Whichever type of packer cup is to be used in a downhole operation (e.g. PWC, remedial, well intervention) they are usually unsuitable for operations where there are restrictions in the well casing (e.g. devices for installing safety valves). As explained in reference to prior art Figures 1-6 below these restrictions can damage the packer cups meaning that they cannot fulfil their sealing operations. The alternative is to have any such restrictions milled out of the casing before the operation can begin. However, whilst this may remove the possibility for the packer cups to get damaged milling out the restrictions inevitably increases the time and cost of the abandonment operation, not least because a larger downhole rig must be used.

[0013] Summary of the Invention

[0014] According to a first aspect of the present invention there is provided a packer cup comprising:

[0015] an annular base member;

[0016] a sleeve having a proximal end fixed to an upper surface of the base member, the sleeve having a plurality of first apertures passing radially through the sleeve; and

[0017] a resilient cup body attached to an upper surface of the base member such that it encapsulates the sleeve and has a plurality of protuberances which are located in the corresponding plurality of first apertures.P398409.W0.01

[0018] 3

[0019] Preferably, each first aperture has a first cross sectional area at an internal surface of the sleeve and a second cross sectional area at an external surface of the sleeve, and wherein the second cross sectional area is greater than the first cross sectional area.

[0020] Preferably, the sleeve further comprises a sleeve flange which projects radially outward from the sleeve, wherein the first apertures are located between the proximal end of the sleeve and the sleeve flange.

[0021] Preferably, the sleeve includes at least one niche located on the proximal end of the sleeve, and the base member has at least one fixing pin extending from the upper surface of the base member, and the at least one fixing pin is located in the at least one niche so as to fix the sleeve to the base member.

[0022] Preferably, the sleeve has at least one second aperture passing radially through the sleeve, wherein the at least one second aperture is threaded and the packer cup further comprises at least one threaded fixture located in the at least one second aperture and extending into a portion of the base member so as to fix the sleeve and base member to one another.

[0023] Preferably the packer cup further comprises a garter spring circumscribing the resilient cup body. The garter spring may be embedded in the resilient cup body. The garter spring may be located adjacent a join between the base member and the resilient cup body.

[0024] Preferably, the resilient cup body is bonded to the base member but is not bonded to the sleeve.

[0025] Preferably, the base member comprises a circumferential base flange which projects from the upper surface of the base member, the base flange has an internal surface with an internal flange groove, and a proximal end of the cup body has an external lip portion which is located in the flange groove. Preferably, the at least one threaded fixture extends into the internal flange groove.P398409.W0.01

[0026] 4

[0027] According to a second aspect of the present invention there is provided a downhole tool comprising at least one packer cup according to the first aspect.

[0028] According to a third aspect of the present invention there is provided a method of forming a packer cup, the method comprising:

[0029] providing an annular base member;

[0030] fixing a proximal end of a sleeve to an upper surface of the base member, the sleeve having a plurality of first apertures passing radially through the sleeve;

[0031] placing the base member and sleeve in a mould; and

[0032] pouring an elastomeric material into the mould so as to form a resilient cup body attached to an upper surface of the base member and encapsulating the sleeve such that a plurality of protuberances are formed in the corresponding plurality of first apertures.

[0033] Preferably, the step of fixing the proximal end of the sleeve to the upper surface of the base member comprises:

[0034] (a) providing at least one niche in the proximal end of the sleeve, and locating at least one fixing pin extending from the upper surface of the base member into the niche; and / or

[0035] (b) providing at least one threaded second aperture passing radially through the sleeve, and at least one threaded fixture located in the at least one second aperture and extending into a portion of the base member.

[0036] Preferably, prior to being placed in the mould an elastomer adhesive is applied to the base but not the sleeve, such that after moulding the resilient cup body is bonded to the base member but is not bonded to the sleeve.

[0037] According to a fourth aspect of the present invention there is provided a method of sealing an annulus within a wellbore, the method comprising:

[0038] providing at least one pair of packer cups according to the first aspect; loading the at least one pair of packer cups onto a downhole tool either side of a fluid nozzle in the downhole tool such that the cup bodies of the packer cups face one another;

[0039] running the downhole tool into the wellbore to a desired location, thereby forming the annulus between the downhole tool and a casing of the wellbore; andP398409.W0.01

[0040] 5

[0041] passing fluid from the downhole tool through the fluid nozzle into the annulus such that fluid pressure radially expands the cup bodies against an inner wall of the casing and fluid is prevented from flowing past the pair of packer cups.

[0042] Brief Description of the Drawings

[0043] A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0044] Figure 1 is a vertical section through a prior art packer cup;

[0045] Figure 2 is a vertical section showing the prior art packer cup within a well casing;

[0046] Figure 3 is a vertical section showing the prior art packer cup in use within the well casing;

[0047] Figure 4 is a detail view of the section view of Figure 3;

[0048] Figure 5 is a vertical section view of another prior art packer cup within the well casing;

[0049] Figure 6 is a detail view of the section view of Figure 5;

[0050] Figure 7 is a vertical section through an improved packer cup;

[0051] Figure 8 is a perspective view of a perforated ring used in the packer cup of Figure 7;

[0052] Figure 9 is a vertical section showing the packer cup within a well casing; Figure 10 is a vertical section showing the packer cup in use within the well casing;

[0053] Figure 11 is a detail view of the section view shown in Figure 10; and Figure 12 is a vertical section through an alternative improved packer cup.

[0054] Detailed Description of the Drawings

[0055] A prior art packer cup is shown in Figures 1-6, which in this case is a garter spring cup. Figure 1 is a vertical section through the cup 2. The cup 2 has an annular metal base component 4, which can be manufactured from steel or another suitable metal. An internal bore 6 of the base 4 is provided with a circumferential groove 8 in which an O-ring seal 10 sits. An upper surface 12 of the base 4 has a flange 14 which extends away from the upper surface 12 and around the circumference of the upper surface 12. The flange 14 shares the same external surface diameter as the remainder of the base 4 but has an inner flange surface 16 whose diameter is greater than that of the internal bore 6. As a result, a step or recess 18 is definedP398409.W0.01

[0056] 6

[0057] between the internal bore 6 and the inner flange surface 16. The inner flange surface 16 is also provided with a flange groove 20 which extends circumferentially along the inner flange surface.

[0058] An elastomeric cup body 22 is moulded onto the base 4 such that the two components are bonded to one another along and about the flange 14. During moulding the elastomer material is allowed to enter the recess 18 and flange groove 20 such that a male / female interface is created between the two bonded components. The cup body 22 has an internal bore 23 which is slightly larger in diameter than the internal bore 6 of the base 4.

[0059] This process would result in the creation of a standard packer cup, but as the illustrated cup is a garter spring cup there is an annular garter spring 24 inserted in the mould adjacent where the elastomeric cup body 22 and metal base 4 will bond to one another. The garter spring 24 is located towards the internal surface of the mould such that once the moulding is complete the spring is encased in the cup body 22 adjacent the outer surface of the cup body. The garter spring 24 is an extension spring. In other words, the spring 24 is configured to exert inward radial forces such that it will contract and reduce the outer diameter of the cup body when not under pressure.

[0060] Figure 2 shows the prior art packer cup loaded on a downhole tool 30 in a well casing 36. Typically, one or more pairs of cups are mounted on the tool 30 so as to provide a seal that prevents fluid in the casing annulus leaving a designated region downhole. In the PWC operations referred to earlier in this specification the cups ensure that first cleaning fluid and then cement slurry remain in the targeted area downhole. To do this at least one cup is placed below an injection nozzle on the downhole tool and at least one cup is placed above the nozzle. Two pairs of cups below and above the nozzle are preferred.

[0061] The cups are mounted on the tool 30 so that their open ends face towards the nozzle or other fluid inlet. So in Figure 2 although the nozzle is not shown it is located above the illustrated cup on the tool. A spacer sleeve 32 formed from aluminium or steel is located in the internal bore 23 of the cup body 22, so as to rest upon the upper surface 12 of the base 4, and between the tool 30 and the cup body 22. AnP398409.W0.01

[0062] 7

[0063] example of a restriction 34 which can be encountered in the casing 36 can also be seen in Figure 2. The outer diameter of the base 4 of the cup 2 is narrow enough to pass by the restriction 34. The outermost diameter of the cup body 22 is wider than the restriction but is flexible enough to allow the cup body 22 to pass through the restriction.

[0064] Figures 3 and 4 illustrate what happens to the known packer cup when under pressure from fluid within the sealed area. For example, in the washing step of a PWC operation the open end of each cup body 22 may be pressurised up to around 1800 PSI, for example. The tool and cups are then reciprocated up and down the casing along axis R over a length of 200-300 ft, for example, in order to clean the perforated casing area(s).

[0065] As best seen in Figure 4, the pressure P in the downward direction on the cup body 22 presses the body radially outwards to the casing 36. The pressure also overcomes the inward bias of the garter spring 24, forcing the spring radially outwards along with the remainder of the cup body 22. In doing so, the bond between the base 4 and cup body 22 along a top surface 15 of the flange 14 is broken.

[0066] Figures 5 and 6 shown what happens to a prior art cup once the fluid pressure has been reduced. The garter spring 24 will revert to its inward position, bringing the remainder of the cup body back inwards as well. As the tool 30 is pulled upwards in the well the cups which have their open ends facing downwards (i.e. those cups positioned above the fluid nozzle or inlet) are vulnerable to damage on any of the restrictions 34 in the casing 36. As the cup body 22 comes into contact with a restriction 34 the elastomeric material can be torn away from base 4, particularly as the bond between the cup body 22 and base 4 has already been broken on the top surface 15 of the flange 14. The tearing typically takes place at the weakest point of the cup body 22, which is a thin bottom section 25 of the cup body 22. The bottom section 25 of the cup body 22 is defined between the cup body internal bore 23 and the flange inner surface 16 of the base 4, immediately above (or below in the case of downward facing cups like that shown in Figures 5 and 6) the male / female interface provided by the flange groove 20 in the flange inner surface. In Figures 5 and 6 the bottom section 25 has completely torn, separating the majority of the cup body fromP398409.W0.01

[0067] 8

[0068] the male / female interface where a small portion of the cup body and the base 4 remain bonded to one another.

[0069] This separation of the cup body 22 from the base 4 presents several possible operational issues. Firstly, the detached cup body 22 may be lost within the casing, presenting possible impediments to later operations. Secondly, a later operation such as the cementing step of a PWC job may be compromised as the sealing element may be absent, or unable to maintain a seal as before. In either of these situations it will not be possible for the damaged packer cup to maintain a high pressure (e.g. 3200 PSI) seal sufficient to unseat a ball valve and allow the cementing operation to take place.

[0070] An improved packer, or swab, cup which addresses these issues with prior art cups is shown in Figures 7-11. Referring to Figures 7 and 8 initially, an improved packer cup 102 is shown. In this preferred embodiment the packer cup 102 is a garter spring cup. The cup 102 has an annular metal base component 104, which can be manufactured from steel or another suitable metal. An internal bore 106 of the base 104 is provided with a circumferential groove 108 in which an O-ring seal 110 sits. An upper surface 112 of the base 104 has a flange 114 which extends away from the upper surface 112 and around the circumference of the upper surface 112. The flange 114 shares the same external surface diameter as the remainder of the base 104 but has an inner flange surface 116 whose diameter is greater than that of the internal bore 106. As a result, a step or recess 118 is defined between the internal bore 106 and the inner flange surface 116. The inner flange surface 116 is also provided with a flange groove 120 which extends circumferentially along the inner flange surface.

[0071] Prior to moulding, a perforated sleeve or ring 200 is attached to the upper surface 112 of the base 104, where an inner diameter of the perforated sleeve 200 is substantially identical to that of the bore 106 in the base 104. As a result the sleeve 200 and bore 106 are substantially co-axial. At least one pair of fixing pins 202 are provided at opposing locations around the bore 106. These pins 202 extend axially so that they project a small distance from the base 104. A proximal end of the sleeve 200 has at least one corresponding pair of fixing grooves or niches 204 into which the pins 202 locate. These cooperating pins 202 and niches 204 preventP398409.W0.01

[0072] 9

[0073] relative rotation between the base 104 and the sleeve 200. The proximal end of the sleeve 200 also has a plurality of threaded apertures 206 into which grub screws 208 or equivalent threaded fixtures are threaded. These grub screws 208 extend from the sleeve apertures 206 into the flange groove 120 in the base so as to fix the sleeve 200 to the base 104. The grub screws 208 prevent axial separation between the base 104 and the sleeve 200.

[0074] The sleeve 200 has a plurality of apertures or perforations 210 which extend between inner and outer surfaces of the sleeve. The apertures may be circular holes or elongate slots, or a mixture of the two. Each aperture 210 preferably tapers outwardly from the centre of the sleeve 200. In other words, the diameter of each aperture 210 on the inner surface of the sleeve 200 is less than the diameter of the same aperture on the outer surface of the sleeve.

[0075] To fabricate the cup 102 the base 104 has an elastomer adhesive applied to selected areas where a cup body 122 is to be bonded to the base 104. The connected base 104 and sleeve 200 are then positioned in a mould and an elastomer such as rubber is poured in to form the cup body 122. This not only bonds the base 104 and cup body 122 but also allows the elastomer to enter and fill the apertures 210 in the sleeve 200, forming elastomeric nodules or protuberances 127 within the apertures 210. The elastomer also enters the recess 118 and flange groove 120 such that a male / female interface is created between the two components. As elastomer adhesive is applied to the base 104 but not the sleeve 200 the base is bonded to the cup body 122 but the sleeve is not bonded to the cup body.

[0076] This process would result in the creation of an improved standard packer cup, but as the illustrated cup is a garter spring cup there is an annular garter spring 124 inserted in the mould adjacent where the elastomeric cup body 122 and metal base 104 will bond to one another. The garter spring 124 is located towards the internal surface of the mould such that once the moulding is complete the spring is encased in the cup body 122 adjacent the outer surface of the cup body. The garter spring 124 is an extension spring. In other words, the spring 124 is configured to exert inward radial forces such that it will contract and reduce the outer diameter of the cup body 122 when not under pressure.P398409.W0.01

[0077] 10

[0078] Figure 9 shows the improved packer cup 102 loaded on a downhole tool 30 in a well casing 36. As described above in respect of the prior art, one or more pairs of cups are mounted on the tool 30 so as to provide a seal that prevents fluid in the casing annulus leaving a designated region downhole in a PWC operation or similar.

[0079] The cups 102 are mounted on the tool 30 so that their open ends face towards a nozzle or other fluid inlet. A spacer sleeve 32 formed from aluminium or steel is located in the internal bore 123 of the cup body 122, so as to rest upon an upper surface 201 of the perforated sleeve 200, and between the tool 30 and the cup body 122. The outer diameter of the base 104 of the cup 102 is narrow enough to pass by the restriction 34 in the casing 36. The outermost diameter of the cup body 122 is wider than the restriction but is flexible enough to allow the cup body 122 to pass through the restriction 34.

[0080] Figures 10 and 11 illustrate what happens to the improved packer cup 102 when subjected to fluid pressure within the sealed area defined between upper and lower packer cups on the tool 30. After being pressurised due to fluid flow from a nozzle or fluid inlet on the tool 30 the tool and cups 102 may be reciprocated up and down the casing along axis R.

[0081] As best seen in Figure 11, pressure in the downward direction on the cup body 122 presses the body radially outwards to the casing 36. The pressure also overcomes the inward bias of the garter spring 124, forcing the spring radially outwards along with the remainder of the cup body 122. In doing so, the bond between the base 104 and cup body 122 along a top surface 115 of the flange 114 is broken. As the cup body 122 is forced radially outwards the nodules 127 within the sleeve apertures 210 are drawn at least partially out of the apertures 210 in the radial direction, as the cup body 122 is not bonded to the sleeve 200.

[0082] When the fluid pressure is backed off the garter spring 124 moves inwardly to its original position, forcing the cup body 122 inwards at the same time. As this happens, the nodules 127 of the cup body 122 return fully into the apertures 210 in the perforated sleeve 200. The nodules 127 act as anchors between the cup body 122 and the perforated sleeve 200, which is attached to the base 104.P398409.W0.01

[0083] 11

[0084] Consequently, as the tool 30 is pulled upwards or downwards in the well the cup bodies 122 of the cups 102 comes into contact with a restriction 34 as in the prior art, but thanks to the nodules 127 anchoring the cup body 122 this prevents the tearing of the cup body 122 from the base 104. The cup body 122 is not left in the casing 36 and is still fully integrated with the base 104 so that the cup 102 it can perform subsequent sealing functions without any reduction in sealing performance.

[0085] An alternative improved packer, or swab, cup is shown in Figure 12. Unless otherwise stated it should be understood that the alternative packer cup 102’ shares the vast majority of its features with the example shown in Figures 7-11, including a sleeve 200’, cup base 104’, cup body 122’ and a garter spring, although the latter is not shown in Figure 12 and may be omitted if desired. The features shared between the two examples of packer cup will not be described again in detail here in the interests of brevity.

[0086] Where the alternative packer cup 102’ differs from the first example is that the sleeve 200’ further comprises a sleeve flange 203 which extends circumferentially about the exterior of the sleeve 200’ and projects radially outward therefrom. The sleeve flange 203 is positioned on the sleeve 200’ such that the first apertures 210’ are located between the proximal end of the sleeve and the sleeve flange. Most preferably, and as illustrated, the sleeve flange 203 is located at a distal end of the sleeve 200’, adjacent or at the upper surface 20T. As can be seen in Figure 12 the cup body 122’ encapsulates the sleeve flange 203 along with the rest of the sleeve 200’, such that the sleeve flange projects outwardly into, and is at least partially embedded in, the cup body.

[0087] In the event that pressure forces the nodules of the cup body out of the first apertures during use, the sleeve flange ensures that the cup body does not become detached from the sleeve and base. If the cup body is pulled away from the sleeve the nodules will come into contact with the sleeve flange, limiting the extent to which the cup body and sleeve can be pulled apart in the axial direction.

[0088] As stated above although the preferred embodiment of the invention described herein is a garter spring packer cup the perforated sleeve arrangement may equallyP398409.W0.01

[0089] 12

[0090] be applied to “standard” packer cups, i.e. those without any form of spring reinforcement.

[0091] Modifications and improvements may be incorporated without departing from the scope of the invention as defined by the appended claims.

Claims

P398409.W0.0113CLAIMS:

1. A packer cup comprising:an annular base member;a sleeve having a proximal end fixed to an upper surface of the base member, the sleeve having a plurality of first apertures passing radially through the sleeve; anda resilient cup body attached to an upper surface of the base member such that it encapsulates the sleeve and has a plurality of protuberances which are located in the corresponding plurality of first apertures.

2. The packer cup of claim 1, wherein each first aperture has a first cross sectional area at an internal surface of the sleeve and a second cross sectional area at an external surface of the sleeve, and wherein the second cross sectional area is greater than the first cross sectional area.

3. The packer cup of either preceding claim, wherein the sleeve further comprises a sleeve flange which projects radially outward from the sleeve, wherein the first apertures are located between the proximal end of the sleeve and the sleeve flange.

4. The packer cup of any preceding claim, wherein the sleeve includes at least one niche located on the proximal end of the sleeve, and the base member has at least one fixing pin extending from the upper surface of the base member, and the at least one fixing pin is located in the at least one niche so as to fix the sleeve to the base member.

5. The packer cup of any preceding claim, wherein the sleeve has at least one second aperture passing radially through the sleeve, wherein the at least one second aperture is threaded and the packer cup further comprises at least one threaded fixture located in the at least one second aperture and extending into a portion of the base member so as to fix the sleeve and base member to one another.P398409.W0.01146. The packer cup of any preceding claim, further comprising a garter spring circumscribing the resilient cup body.

7. The packer cup of claim 6, wherein the garter spring is embedded in the resilient cup body.

8. The packer cup of claim 4 or claim 5, wherein the garter spring is located adjacent a join between the base member and the resilient cup body.

9. The packer cup of any preceding claim, wherein the resilient cup body is bonded to the base member but is not bonded to the sleeve.

10. The packer cup of any preceding claim, wherein the base member comprises a circumferential base flange which projects from the upper surface of the base member, the base flange has an internal surface with an internal flange groove, and a proximal end of the cup body has an external lip portion which is located in the flange groove.

11. The packer cup of claim 10 when dependent upon claim 5, wherein the at least one threaded fixture extends into the internal flange groove.

12. A downhole tool comprising at least one packer cup according to any preceding claim.

13. A method of forming a packer cup, the method comprising:providing an annular base member;fixing a proximal end of a sleeve to an upper surface of the base member, the sleeve having a plurality of first apertures passing radially through the sleeve;placing the base member and sleeve in a mould; andpouring an elastomeric material into the mould so as to form a resilient cup body attached to an upper surface of the base member and encapsulating the sleeve such that a plurality of protuberances are formed in the corresponding plurality of first apertures.P398409.W0.011514. The method of claim 13, wherein the step of fixing the proximal end of the sleeve to the upper surface of the base member comprises:(a) providing at least one niche in the proximal end of the sleeve, and locating at least one fixing pin extending from the upper surface of the base member into the niche; and / or(b) providing at least one threaded second aperture passing radially through the sleeve, and at least one threaded fixture located in the at least one second aperture and extending into a portion of the base member.

15. The method of claim 13 or claim 14, wherein prior to being placed in the mould an elastomer adhesive is applied to the base but not the sleeve, such that after moulding the resilient cup body is bonded to the base member but is not bonded to the sleeve.

16. A method of sealing an annulus within a wellbore, the method comprising:providing at least one pair of packer cups according to any of claims 1 to 11;loading the at least one pair of packer cups onto a downhole tool either side of a fluid nozzle in the downhole tool such that the cup bodies of the packer cups face one another;running the downhole tool into the wellbore to a desired location, thereby forming the annulus between the downhole tool and a casing of the wellbore; andpassing fluid from the downhole tool through the fluid nozzle into the annulus such that fluid pressure radially expands the cup bodies against an inner wall of the casing and fluid is prevented from flowing past the pair of packer cups.

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