BR122013000176B1 - TOOL FOR USE IN AN UNDERGROUND WELL TO SEAL A GENERALLY CYLINDIC INTERNAL SURFACE OF A TUBULAR OR OTHER WELL BACKGROUND TOOL AND SEAL FORMATION METHOD - Google Patents

Description

Patent Descriptive Report for "TOOL FOR USE IN AN UNDERGROUND WELL FOR SEALING A GENERALLY CYLINDIC SURFACE OF A TUBULAR OR OTHER WELL BACKGROUND TOOL AND METHOD".

Divided from PI0209857-1, filed on May 15, 2002. BACKGROUND OF THE INVENTION

When drilling a well, a drillhole is typically drilled from the earth's surface to a selected depth and a row of casing pipes is suspended and then cemented into place within the drillhole. A drill is then passed through the initial covered drill hole and is used to drill a smaller diameter drill hole to an even greater depth. A smaller diameter casing tube is then suspended and cemented into place within the new probe bore. This is conventionally repeated until a plurality of concentric casing tubes are suspended and cemented into the well to a depth that causes the well to extend through one or more hydrocarbon production formations.

Instead of suspending a concentric liner tube from the bottom of the probe hole to the surface, a liner is often suspended adjacent to the lower end of the previously suspended liner tube, or from a previously suspended and cemented liner. extending the liner from the previously fitted liner or liner at the bottom of the new probe bore. A lining is defined as a lining pipe that does not extend to the surface. A liner hanger is used to suspend the liner within the lower end of the previously fitted liner or liner tube. Typically, the casing hanger may be provided with a joining tool for connecting the casing to a row of casing pipes extending from the casing hanger to the surface.

A slide and adjusting tool disposed at the lower end of a work tubing can be releasably attached to the liner hanger, which is attached to the top of the liner. The working tubing lowers the liner hanger and liner into the open probe hole so that the liner extends below the lower end of the previously fitted liner or liner tube. The borehole is filled with fluid, such as selected drilling mud, which flows around the liner and the liner hanger as the liner is moved to the borehole. The assembly is moved into the well until the casing hanger is adjacent to the lower end of the previously adjusted casing tube or casing, typically with the lower end of the casing slightly above the bottom of the open probe hole.

When the liner reaches the desired location with respect to the bottom of the open probe bore and the previously fitted liner or liner, an adjusting mechanism is conventionally actuated to move the sliding sleeves on the liner hanger from a retracted position to a expanded position and for engagement with the previously adjusted casing tube or casing. Then, when seated weight is applied to the hanger sliding sleeves, the sliding sleeves will be adjusted to support the liner. The typical casing hanger can be driven either hydraulically or mechanically. The liner hanger may have either a hydraulically operated adjusting mechanism for adjusting the slider sleeves or a mechanically operated adjusting mechanism for adjusting the sliding sleeves. A hydraulically operated adjusting mechanism typically employs a hydraulic cylinder that is driven by fluid pressure in the casing bore that communicates with the working tubing bore. When mechanically adjusting the liner hanger, it will generally be necessary to achieve relative drilling rotation of the parts between the adjusting tool and the liner hanger to disengage the slider sleeves from the liner. Suspension sliding sleeves are typically one-way acting where the suspender and liner may be raised or suspended upwardly, but a downward movement of the liner adjusts the sliding sleeves to support the support and liner within the well.

To disengage the adjusted casing hanger sliding tool, the adjusting tool can be lowered relative to the casing hanger and turned to disengage a sliding nut on the casing hanger adjusting tool. Cement is then pumped into the hole in the work tubing and casing and up to the annular crown formed by the casing and the open probe bore. Before the cement is laid, the adjusting tool and work tubing are removed from the drill hole. In the case of sloppy cement work, a liner plug and liner plug adjustment tool may need to be connected to the work piping and lowered back into the drill hole. The shutter is adjusted using a shutter adjustment tool. Coating shutters are often referred to as "coating insulation" shutters. A typical sheath insulation shutter system includes a shutter element mounted on a mandrel and a sealing nipple disposed below the shutter. The sealing nipple is crimped into the junction receptacle at the top or below the previously adjusted and cemented liner hanger. A liner insulation shutter may be used, as explained above, to seal the liner in case of sloppy cement work. The liner insulation plug is typically seated on top of the hanger after the hanger is secured to the outer tube, the plug being adjusted by the adjusting tool to seal the annular crown between the liner and the previously fitted liner or liner.

Generally speaking, the deeper a well is drilled, the higher the temperature and the higher the pressure that will be encountered. Accordingly, casing shutters that ensure quality cementation of the casing are desirable in order to provide a high safety factor to prevent formation gas from migrating to the annular crown between the casing and the outer casing pipe. .

During the cementing operation, fluid, such as drilling mud in the annular crown between the casing and the outer casing pipe, is displaced by the cement as the cement is pumped into the flow hole of the working tubing. First the drilling mud and then the cement flow around the bottom edge of the liner and up to the annular crown. If there is a significant flow restriction in the annular crown, the cement flow will be reduced, thus not achieving a good cementation work. Any decrease in cement in the annular crown gives time for the gas in the formation to migrate to the annular crown and through the cement, thus preventing good cementing work.

Sliding Tool Release Mechanism As a practical matter, the sling suspension tool has to include a slack mechanism so that once the sheath is reliably fitted to the lower end of the sheath tube, the sliding tool may be disengaged from the coating hanger and recovered on the surface. Conventional casing hanger sliding tool release mechanisms include hydraulically actuated mechanisms and release mechanisms that are manipulated by rotating the work tubing to the left. Rotation to the left of the work tubing is, however, generally considered undesirable as it may result in an unintentional disconnection of one of the work tubing joints, thereby causing the work tubing to separate, and a fishing to retrieve the slide tool, which may have been damaged by involuntary disconnection. For various reasons, hydraulically operated sliding tool release mechanisms may cease to operate, or may prematurely disengage the sliding tool from the liner hanger.

Accordingly, improvements in release mechanisms are desired which will reliably disengage the sliding tool from the adjusted liner only when desired, particularly when recovery is easily achieved and the unlikely disengagement of the sliding tool from the liner is highly unlikely.

Packing Bushing A casing hanger packing bushing is conventionally sealed between the casing hanger and the sliding tool, and consequently between the casing and the work tubing or work tubing, which can conventionally be a borehole. A packing sleeve is particularly required during cementing operations so that the fluid pumped through the borehole continues to the bottom of the well and then back to the annular crown between the well bore and the cementing liner. the flooring in place. During cementing operations, the packing bushing sealing body is fitted to the annular crown between the casing hanger and sliding tool, and includes outer diameter seals to seal the casing hanger and inner diameter seals to sealably engage the slide tool. The packing bushings are preferably recoverable with the slide tool so that the bushings do not have to be drilled after the cementing operation is completed. Also, a packing bush is preferably lockable on the casing hanger with the locking within a profile to prevent allow the bushing to move axially with respect to the casing hanger. If the stuffing bushing is not lockable in the casing hanger profile, the bushing may be "pulled out" through the top of the receptacle, thereby losing a cementing job.

A conventional recoverable and lockable packing gland includes clamps or lugs that are locked in engagement with the liner hanger to prevent the packing gland from moving axially during the cementing operation. The packing bushing is recoverable with the slide tool, thus eliminating the need to drill the bushing after the cementing operations are completed. Depending on the manufacturer, reclaimable packing bushings are also referred to as reclaimable sealing chucks or reclaimable cementing bushings. Regardless of terminology, the recoverable and lockable packing sleeve seals the annular crown between the work tubing and the top of the liner, and can be locked into a liner hanger profile by the smooth gasket to prevent the bushing from being extracted from the coating hanger.

Cooperating surfaces on the liner adapter, the smooth gasket on the slide tool, and the packing sleeve sealing body axially interconnect the bushing to the liner hanger while moving the liner hanger into the well. These cooperating surfaces can be unlocked to disengage the slide tool from the liner hanger and allow axial manipulation of the slide tool and smooth gasket with respect to the packing sleeve. The smooth gasket thus seals with the packing sleeve during axial movement of the slide tool. Since the cooperating surfaces are unlocked from each other, bosses on the packing sleeve and the slide tool engage after a predetermined degree of axial movement between the slide tool and the sealing body so that the packing sleeve can be recovered to the surface with the sliding tool after the cementing operations are completed. A conventional stuffing sleeve is described in U.S. Patent 4,281,711.

A significant limitation on prior art packing bushings relates to their desired recoverability with the slide tool when connected to the desire to retract the slide tool with respect to the packing bush prior to the cementing operation. An operator will typically wish to retract the slide tool after the hanger hanger has been released to ensure that these tools are disconnected. The length of the sliding tool's smooth joint determines the maximum length that the sliding tool must be retracted after the liner hanger disengages. When the packing bushing is removed from the casing hanger, the clamps or ears conventionally driven by the packing bushing may move radially inward, thereby preventing the reclaimable packing bushing from being reintroduced and locked into the casing hanger. Conventional casing hanger tools do not allow the packing bushing to be "reintroduced" into the casing hanger, thus restoring pressure integrity between the casing hanger and the sliding tool. In many applications, it is difficult for the operator to determine the exact amount of slide tool that has been collected, particularly when operating in highly deviated and deep wells. If the operator retracts the sliding tool at an axial distance that is not allowable for the length of a smooth joint, the packing sleeve will be pulled with the sliding tool and will be disengaged from the casing hanger, which may cause a cement failure. which will cost the operator millions of dollars in lost time and money. The consequences of unintentional disassembly of the packing sleeve from the liner hanger and possible non-reintroduction and braking on the liner hanger can be very serious. The smooth gasket used with the casing hanger sliding tool features a polished outside diameter surface that seals against the inside diameter seals on the packing sleeve seal body. The outer diameter surface of the smooth joint may be scratched or damaged during handling, thus causing a cement leak during the cementing operation. Since the slide tool is designed to move at axially substantial distances from the packing sleeve, the internal seals in the seal body may be worn during the cementing process due to alternating movement of the smooth slide tool joint. This problem will be aggravated when the quality of the smooth surface on the smooth joint has deteriorated. Axially long smooth joints are costly to manufacture and maintain.

Another problem with the prior art stuffing bushing concerns the limited load capacity of the ears locking the stuffing bushing in the casing hanger. Conventional packing bushings use multiple ears that protrude from the packing sealing body, which increases the complexity and cost of the packing bush. The limited size of these ears, however, restricts or limits the packing pressure of the packing sleeve.

Shutter Auster Assembly A conventional casing hanger sliding tool includes a shutter adjustment assembly, which enables activation and sealing of the casing top shutter. Conventional plug fitting assemblies incorporate multiple spring loaded clamps or ears that can be compressed into a reduced diameter position with insertion into the plug fitting sleeve when displacing the casing hanger in the well and casing cementation within. of the casing tube. When the shutter adjustment assembly is raised out of the shutter adjustment sleeve, the clamps or ears will expand to a diameter larger than the inside diameter at the upper end of the adjusting sleeve, which is also the liner hanger junction receptacle. . When the clamps engage the top of the adjusting sleeve, an adjusting force may be transferred from the work tubing through the clamps and to the plug fitting glove as the weight of the work tubing is loosened to adjust the plug element.

Some prior art plug fitting assemblies include an axial bearing to facilitate rotation of the work tubing while adjusting the plug element. Other shutter adjustment assemblies include both a bearing and a shear indicator to provide visual confirmation that proper adjustment load has been applied to the shutter, and / or an unlocking feature that allows the shutter adjustment assembly to be pulled. out of the shutter adjustment sleeve once without exposing the adjustment clamps. This tool allows you to reinsert the shutter adjustment assembly into the shutter adjustment sleeve once, thereby cocking the adjustment clamps so that they are ready to expand the second time they are pulled out of the adjustment sleeve. .

A major problem with prior art shutter adjustment mounts is poor reliability. In some well environments, the shutter adjustment clamps of the shutter adjustment assemblies rupture and are reintroduced into the adjusting sleeve without adjusting the shutter element. Manufacturers provided more clips or ears to alleviate this problem, and / or provided heavier springs to press the clips radially outward. These changes have had little, if any, effect on greater reliability. The present invention has sought to provide an improved downhole tool and corresponding method of forming a downhole seal.

SUMMARY OF THE INVENTION

According to one aspect of this invention, a tool for use in an underground well for sealing a generally cylindrical inner surface of a tubular or other wellbore tool is of the type comprising a wedge ring having a substantially tapered radially configured outer surface. expand an annular seal assembly with the axial movement of the annular seal assembly with respect to the wedge ring such that the seal assembly is expanded from its insertion position to its expanded seal position, where the sealing is in sealing engagement with the generally cylindrical inner surface.

According to the invention the tool is characterized in that the annular seal assembly has a reduced diameter insert position and an expanded seal position, the seal assembly including a metal frame having a radially inwardly annular base. and a plurality of metal ribs, each extending radially outwardly from the base, the metal frame including a downwardly angled upper main sealing metal rib to seal the pressure below the sealing assembly, a metal rib. bottom main sealing ring angled up to seal the pressure above the seal assembly, a main elastomeric seal in a radially outwardly hollow from the base and axially between the upper main sealing metal rib and the main sealing metal rib lower, one upper secondary seal metal rib angled down axia spaced above the upper main sealing metal rib, and an upwardly angled lower secondary sealing metal rib axially spaced below the lower main sealing metal rib.

Preferably, there is an upper biasing member between the upper main sealing metal rib and the upper secondary sealing metal rib to exert a downward pressing force on the upper sealing metal rib in response to high fluid pressure below. and a lower pressing member spaced between the lower main sealing metal rib and the second lower secondary sealing metal rib to exert an upward force on the lower main sealing metal rib in response to the high pressure of fluid above the seal assembly.

Conveniently, the upper biasing member is an upper secondary elastomeric seal between the upper main sealing metal rib and the upper secondary sealing metal rib, and the lower compression member is a lower secondary elastomeric seal spaced between the metal rib. lower main seal and the lower secondary seal metal rib.

Conveniently, an outer surface of each rib, the upper main sealing metal rib, the lower main sealing metal rib, the upper secondary sealing metal rib, and the lower secondary sealing metal rib is configured to form a metal to annular metal seal with a generally cylindrical inner surface.

Each rib, downwardly angled main sealing metal rib, upwardly angled main sealing metal rib, downwardly angled sealing metal rib and upwardly angled secondary sealing metal rib be inclined while in the insertion position at an angle of at least 15 ° with respect to a plane perpendicular to a central axis of the cylindrical inner surface.

Preferably, there is a guide tube for positioning the tool at a selected location below the well surface, the seal assembly creating a seal between the guide tube and a casing in the well. The guide tube may support the generally stationary wedge ring, while the seal assembly moves axially with respect to the stationary wedge ring.

Also, the conduit pipe may support the generally stationary seal assembly while the wedge ring moves axially with respect to the stationary seal assembly. The main elastomeric seal may include a void area when the main elastomeric seal is moved to the sealing engagement with the cylindrical surface, such that the main elastomeric seal may thermally expand to fill at least part of the void area. response to high drilling temperatures. It is advantageous to have one or more axially spaced protrusions on a radially inner surface of the annular base of the metal frame each for metal-to-metal sealing engagement with the conical outer surface of the wedge ring.

There may also be one or more annular elastomeric sealing members to seal between the base of the metal frame and the conical outer surface of the wedge ring. The tool may further comprise one or more annular metal protrusions on an outer surface of a guide tube or an inner surface of the wedge ring to form the metal-to-metal seal between the wedge ring and the guide tube.

There may be one or more annular elastomeric sealing members in the tool in one between the tapered wedge ring and a guide tube to form an elastic seal between the guide tube and the wedge ring. The tool may further comprise an elongate member having a tapered, outwardly facing surface adapted to be lowered and suspended within a wellbore, and a sliding sleeve comprising a circumferentially expandable and retractable C-ring having teeth sleeve sleeve around its outer side and a frusto-conical surface on its inner side arranged around the frusto-conical surface of the elongate member, so that the C-ring can be moved vertically between a contracted position in which the teeth are spaced apart. from the wellbore, and an expanded portion in which the teeth engage the wellbore. The elongate member may be recessed to receive one end of the C-ring to retain the contracted C-ring around the elongate member. as it is lowered whereby, by removing said end from the recess, the C-ring becomes free to expand in the direction From its fully expanded position to make its sliding sleeve teeth grasp the wellbore, so that the weight of the elongate member can be suspended from the casing tube with respect to the vertical movement of the tapered C-ring surfaces and of the elongated limb. The frusto-conical surface of the elongated limb may extend downward and inward, and the frusto-conical surface of the C-ring may be slidable upwardly over the elongated limb surface as it is lowered to cause its teeth to move outwards. to engage the wellbore. The tool may further comprise a workpiece driven by the elongate member for reciprocating guided movement thereon and engageable with the C-ring end or to remove the C-ring end from the undercut and thereby disengage it to expansion. Said C-sleeve sleeve comprises a tie rod that extends guidebly within the C-ring end when the C-ring end is in the recess, to allow removal of the C-ring from the recess by the tether. and then release it to allow the C-ring to expand into engagement with the casing bore.

Another aspect of this invention is a method of forming a downhole seal with a generally cylindrical inner surface of a pipe or other downhole tool, characterized in that it comprises: providing an annular seal assembly disposed around it. of a conduit pipe, the seal assembly having a reduced diameter insertion position and an expanded position, the seal assembly including a metal frame having a radially inwardly annular base and a plurality of metal ribs each extending radially outwardly from the base, the metal frame including a downwardly angled upper main seal metal rib to seal the pressure below the seal assembly, a lower downward angled main seal metal rib to seal the pressure above the seal assembly, a main elastomeric seal in a radius cavity outwardly from the base and axially between the upper main sealing metal rib and the lower main sealing metal rib, a downwardly angled axially spaced upper secondary sealing metal rib above the sealing metal rib upper main, and an upwardly angled lower secondary sealing metal rib axially spaced below the lower main sealing metal rib; providing a wedge ring having a substantially conical outer surface; and the axial movement of the annular seal assembly with respect to the wedge ring such that the seal assembly is expanded from its insertion position to its expanded position, where the seal assembly is in seal engagement with the generally cylindrical inner surface.

BRIEF DESCRIPTION OF THE DRAWINGS Figure D1 is a half section view of the sealing member according to the present invention positioned at the lower end of a junction receptacle for movement along a cone and for sealing with a casing pipe. . Figure D2 is an enlarged view of a sealing member shown in Figure 1 positioned when the sealing member initially engages the liner tube. Figure D3 is a cross-sectional view of the sealing member in its final adjusting position for the sealing engagement between the cone and the casing pipe.

Figures B1A and B1B are, respectively, a partially broken elevation view and an end view of the C-ring along its fully contracted position, where its side edges are engaged with one another; the outer side of the C-ring has vertical slits to facilitate fluid passage between the casing and the outer well casing tube when the slide sleeve is expanded.

Figures B2A and B2B are similar views of the C-ring in the fully expanded position.

Figures B3A and B3B are vertical sectional views of the slide sleeve assembly, where the ruptured C-ring is shown in Figure B3A disposed around the liner with its lower end received within the recess of the liner, and in Figure B3B, elevated from the recessed and expanded to a position where the casing can be raised to move its outer side upwardly over the tapered surface of the casing so that its teeth engage the well casing tube. Figure B3C is an enlarged detailed view of a portion of Figure 3B to illustrate the controlled friction teeth on the inner C-ring slide.

Figures B4, B5, and B6 are an enlarged vertical section view of the assembly showing the C-ring as it is moved by the liner from the retracted to the expanded position, the C-ring being shown in the retracted position on the Figure 4, raised outside the recess by the tie rod in Figure 5 to disengage it to expand outward to engage the liner pipe, and in Figure 6, the tie rod has a raised frusto-conical surface of the liner over the surface. inside of the C-ring to cause the C-slide sleeve to be moved outward to engage the well casing tube.

Figures B3AA and B3BB are detailed section views as shown in Figures B3A and B3B.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially to Figure D1, an annular plug member D10, in accordance with a preferred embodiment of the present invention, is positioned at the lower end of a drive sleeve D12 at the lower end of a junction receptacle prior to sealing engagement with a pipe. Coating C. Conventional D28 slots or threads or similar connectors may be used for interconnecting the plug element to the junction receptacle. The axial movement of the plug sleeve D12 and, consequently, of the plug element D10 in response to the plug adjustment operation, pushes the plug element down relative to the tapered cone D14 to expand the sealing element into the sealing engagement with the plug. casing tube. Cone D14 is in turn supported on a D16 casing hanger body. In an environment where the obturator element is not the top liner hanger seal, the obturator element D10 may be supported at the end of a seal driver replacing the drive sleeve D12, and the liner hanger body D16 may be a shutter chuck or other conduit tube to position the shutter element in the well. In the embodiment of Figure D1, body D16 is thus part of the conduit tube which positions the plug element in a selected position within the wellbore. The junction receptacle drive sleeve, shown in Figure D1, represents a lower portion of a drive sleeve that presses the plug member from a reduced diameter insertion position to a expanded diameter sealed or activated position. The drive sleeve can thus apply a selected axial force to the plug element to adjust the plug. The actuator may be selectively driven by various mechanisms, including seated weight or other handling of the conduit tube, and may include axial movement of a piston in response to fluid pressure, either with the plungers or falling balls to increase the pressure of the piston. fluid, be without them. Further details regarding the use of the plug element in a coating hanger application are described in US Serial Provisional Application No. 60 / 292,049 filed May 18, 2001. The plug element as shown in Figure D1 is in original configuration in which the outside diameter is reduced before being sealed with the casing pipe. The plug element D10 is expandable so that it is moved downwardly over stationary cone D14 to seal against the liner pipe as discussed below and as shown in Figure D3. It is a feature of the invention that the obturator element D10 is moved into reliable sealing engagement with the casing pipe by an adjusting operation, which includes movement of the obturator element D10 axially with respect to the obturator cone D14 at instead of the movement of the cone with respect to the stationary shutter element. This adjusting operation forms a more reliable seal with the liner tube, allowing ribs D20 during the tuning operation to be bent or deformed into the liner tube shape.

Referring to Figures D1 and D2, obturator member D10 comprises an inner metal body or base D18 for sliding over the tapered wedge ring or cone D14 and annular flanges or ribs D20 extending radially outwardly from the base. D18 to engage the casing tube. Base D18 is relatively thin to facilitate radial expansion. The base D18 and the ribs D20 form a metal frame to support the rubber or other resilient, preferably elastomeric sealing bodies. Resilient seal body rings D22, D24 and D26 are provided between ribs D20, with the upper and lower sides of each seal body preferably engaging with a respective rib. The body D18 and the ribs D20 are formed of material having sufficient ductility to expand into the annular crown between the casing tube and the casing hanger. The metal portion of the plug element, i.e. base D18 and radially projecting ribs D20, is thus formed of material that is relatively soft compared to the metals commonly associated with drilling tools. This allows the plug element to reliably expand into the sealing engagement with the liner pipe at a reduced adjustment load.

The radially projecting ribs D20 of the obturator element are each substantially angled with respect to a plane perpendicular to a central axis of the obturator element. More specifically, the center line of each rib is angled beyond 15 °, and preferably about 30 °, with respect to the plane D38 perpendicular to the central axis of the obturator element. Although the ribs may be slightly tapered to become thinner with radially outward movement, the ribs preferably have a substantially uniform axial thickness. The rib D32 is shown in Figure D2 at an angle D33 between the rib centerline and the plane D38. This feature allows each rib D20 to expand substantially as the diameter of the casing varies or "develops", either in response to internal pressure and / or thermal expansion. Because the D20 angled ribs can be flexed, reliable metal-to-metal contact is maintained between the rib ends and the casing as shown in Figure D3. The obturator element D10 inherently forms both a main seal with the liner pipe and a secondary seal with the liner pipe, with the secondary seal depending on the pressure direction. Also, the sealing member may include both a main elastomeric seal and a spare elastomeric seal as well as a main metal seal and a spare metal seal. Referring to Figure D3, it should be understood that the downward inclination of ribs D30 and D32 is such that the relatively high fluid pressure above the obturator member can pass through these ribs and the elastomeric upper sealing body D22 such that the body D24 inner seal, which forms a major part of the elastomeric sealing area, forms the main elastomeric seal against fluid flow. The term "fluid" as used herein includes gas, liquids, and gas and liquid combinations. The sealing body D24 preferably engages ribs D32, D34 and base D18, and substantially fills the annular void between these surfaces. When the fluid pressure is above the sealing member D10, the lower sealing body D26 positioned between ribs D34 and D36 will form a spare secondary elastomeric seal in the event of leakage of the main elastomeric seal. Similarly, when the high fluid pressure is below the plugging element, the high pressure fluid is likely to flow beyond the ribs D36 and D34, so that the sealing body D24 is the main sealing element. The sealing body D22 between ribs D30 and D32 thus becomes the secondary elastomeric sealing member. The main elastomeric sealing member is thus pressed in an axial direction (usually along the central axis of the conducting tubular body or casing tube) in response to pressurized fluid against a sloping rib that is angled in the upward direction. pressure, the secondary elastomeric sealing member being captured between two ribs, each angled toward the high pressure side, so that the secondary sealing member is also pressed in an axial direction against an angled upward direction rib. pressure. Most importantly, the spare seal, either that of the seal body D22 or D26, is captured between two ribs, thus minimizing the likelihood of external bending of the axially innermost rib D32 or D34 to be aligned with the rib. plane D38, i.e. perpendicular to the wall of the casing tube. The sealing body material D22 or D26 thus acts as a biasing force that tends to hold the D32 or D34 rib at a desired angle, which then holds the main sealing body D24 and prevents the D32 or D34 rib from becoming perpendicular. to the casing wall C. In the event that the ribs are flexed beyond the point where they are perpendicular to the casing wall, the sealing member will likely lose its sealing integrity with the casing. The radial ribs D20 are thus vertically spaced from each other and act independently with respect to the upward and downward pressure forces. The plug element D10 also includes multiple metal sealing surfaces, i.e. ends of each rib D20, to form metal-to-metal annular seals with the casing tube. More particularly, these angled ribs are configured to maintain a constant metal-to-metal seal with the liner pipe, even though the sealing member may be subjected to varying temperature and fluid pressure cycles. Under high pressure, the two ribs adjacent to the high pressure may be flexed towards the base D18, thus not maintaining the sealing integrity. A main metal seal is, however, formed by one of the axially inner ribs D32 or D34 on the downstream side of the elastomeric plug body D24, and a spare metal-to-metal seal is formed by the axially outer rib D30 or D36 axially further away from high pressure. High fluid pressure forces both spare main and secondary ribs to reduce angle D33, thereby forming a tight sealed engagement with the liner tube. The spare or redundant elastomeric seal D22 or D26 exerts a biasing force that tends to prevent the main metal seal D32 or D34 from becoming new beyond its position perpendicular to the wall of the liner tube.

Referring again to Figure D2, each of the elastomeric sealing bodies D22 or D24 and D26 is provided with a substantial void area D23, D25 and D27 to allow elastomeric body compression and thermal expansion, so that, During both the final adjustment operation and during drilling use, the rubber-like material is not squeezed outward beyond the rib ends, or squeezed to exert substantial rib forces that will alter the flexing of the ribs. Preferably, the void area between the rib ends and the base of the sealing member is such that at least about 5% to 10% of the thermal expansion of the elastomeric material may occur. This 5% to 10% void area thus allows the thermal expansion of each resilient elastomeric seal, thus preventing the creation of additional forces on the D20 ribs. Each of the elastomeric seal bodies thus preferably includes voids which allow each resilient seal body to be compressed between the metal ribs without overvoltage or rib deformation. These voids will thus be substantially filled due to compression of the resilient sealing material, and will become full as shown in Figure 3 due to compression of the sealing bodies and thermal expansion of the resilient sealing bodies. The stress level on each of the elastomeric seals can therefore remain substantially constant with the various thermal cycles in the wellbore.

As shown in Figure D3, the elastomeric seal bodies were compressed to reduce the void area, leaving only a small void volume for further thermal expansion. The void area is preferably designated to be from 5 to 10% of the volume of resilient seal bodies, since each seal body is in its compressed position with the ends of the ribs engaging the liner pipe, although prior to expansion. thermal Figure D3 depicts plug element D10 according to the present invention in sealed engagement with casing tube C at a temperature at which the elastomeric material has already been expanded to fill most of the void area discussed above. Figure D3 also shows the flexing or bending of these ribs from the insertion position as shown in dashed lines with respect to the sealing position as shown in solid lines. The inclination of the ribs, that is, the angle D33, as shown in Figure D2, is thus increased during the shutter adjustment operation. The ribs D30 and D32 at the upper end of the obturator element D10 are angled downward, and the ribs D34 and D36 at the lower end of the obturator element are angled upwards. As explained above, the centerline of each rib is angled at least 15 ° with respect to the plane D38 perpendicular to the central axis of member 10 prior to adjustment, i.e. when of a reduced diameter, as shown in Figure D1. Shutter seal base D18 includes a plurality of inwardly projecting protrusions D40. These annular protrusions or crimps on the plug element provide a reliable metal-to-metal sealing engagement with the D14 plug cone. These bulges provide high stress points to form a reliable metal to metal seal. Similar protrusions D42 on the shutter mandrel D16 provide a metal-to-metal sealing engagement between the shutter mandrel D16 and the shutter cone D14. Accordingly, the seal of the present invention operates in conjunction with the plug cone to obtain a complete metal-to-metal seal between the plug mandrel and the plug cone, between the plug cone and the sealing member, and between the plug member. sealing tube and casing tube. The multiple sealing bosses or crimps D40 form axially spaced metal-to-metal seals between the sealing member D10 base D18 and the tapered cone D14, while the D42 bosses seal between the D14 cone and the plug body or other conduit pipe D16. These metal to metal seals are energized as the shutter seal is adjusted, and preferably include multiple redundant metal to metal annular seals. Alternatively, one or both of the radially internal and intermediate metal to metal seals could be formed by annular protuberances on the plug cone to seal with either or both, i.e. the plug element base D18 and plug spindle D16.

Resilient elastomeric seals D48 in the inner diameter of sealing hole D18 may be spare seals, as spaced apart metal protrusions D40 form the metal-to-metal seal between the obturator element and the cone, as the obturator element is fully adjusted. Another elastomeric seal, such as a V15 seal, provides a spare elastomeric seal between cone D14 and body D16. These metal protrusions D40 on the inner diameter of element D10 are axially aligned (substantially laterally opposed) with the area where ribs D20 seal against the casing tube. The interface between the casing tube and the metal ribs D20 of the sealing element D10 thus forces the metal sealing bosses D40 into the metal-to-metal sealing contact with the D14 cone. The protrusions D42 in body D16 are similarly axially aligned with element D10. Metal-to-metal seals between the plug element and the cone are preferably provided in the plug element, as its axial position relative to the cone may vary with well conditions when in the set position.

With the desired adjusting force applied to the plugging element D10, the plugging element will be pushed down to the ramp of a cone D14 so that ribs D20 engage metal against metal with the liner tube. The metal sealing bosses D40 and D42 between sealing member D10 and cone D14, and between body D16 and cone D14 are in contact, but have not been energized. When the set pressure is increased, the ribs on the sealing member may be bent inward to a solid line position in Figure D3. This high adjusting force will compress the sealing bodies between the ribs and cause the outer diameter of each sealing body to seal tightly with the liner pipe. This high adjusting force will also cause the D40 metal bulges along the inside diameter of the D10 sealing member and the D42 metal bulges along the outside diameter of the D16 mandrel to form a reliable metal to metal seal with the cone. D14. Under this load, these metal bulges form a high stress located at the point where the bulges engage the cone to achieve a reliable metal-to-metal seal. Metal protrusions which provide the desired metal-to-metal seals between body or mandrel D16 and cone D14 could be provided on each of these surfaces, the generally cylindrical outer surface of body D16 or the generally cylindrical inner surface of cone D14. A reliable fluid-tight barrier, which can be either a liquid barrier or a gas barrier, is thus formed with high reliability under various temperatures, pressures and sealing longevity conditions due to the combination of metal and elastomeric seals. After the sealing member contacts the liner pipe, water hammer preventers can be closed around the drill pipe (or other conduction pipe) and fluid pressure can be applied to the annular crown to assist by pressure in shutter element adjustment. The sealing member of the present invention is well suited for use in a liner hanger for sealing between the liner hanger shutter mandrel and the liner pipe. The initial seated weight on sealing member D10 will thus force the sealing member into cone D14 and into contact with casing tube C. Initially, sealing material radially outwardly from rib ends D20 will be compressed. to occupy much of the void area in the sealing bodies. Once the elastomeric bodies have been deformed so that the rib ends engage the liner pipe, the remaining void area may be 5% to 10% of the volume of each sealing body, assuming no want significant expansion of sealing bodies due to thermal expansion. If the sealing bodies experience high thermal expansion prior to an adjustment operation, the void area will be reduced by compressing the sealing bodies.

During well operations, pressure may cause the casing pipe to expand in diameter, and this expansion will cause the ribs to expand with the casing pipe, so that the position of the ribs relative to the casing pipe. expanded liner may resume for configuration as shown in dashed lines in Figure D3. The ability of ribs to "develop" in diameter with the expanded casing keeps the rib ends in reliable metal-to-metal contact with the casing as the well goes through pressure and temperature cycles. When pressure is released and the casing tube shrinks, the ribs may return to the solid line configuration as shown in Figure 3. The sealing member D10 of the present invention is thus ideally suited for applications where high pressure can be applied. applied from each direction to the sealing member, as the sealing member inertially has both a main seal and a secondary seal, with each elastomeric seal being supported in one direction to resist axial movement in response to high pressure by a rib that is angled in the direction of high pressure and which allows bending to conform to the casing pipe. The rib on each side of the main seal body is supported by the secondary seal body, which pushes the rib in the direction of high pressure.

In the case of a casing hanger, the casing hanger sliding tool conventionally includes the actuator that provides compressive force to the plug element D10 to adjust the plug. In other applications where the sealing member is used, an actuator may be used to apply compressive force to move the seal from an insertion position or radially reduced to a seal position or radially expanded. The actuator may be hydraulically powered or may use mechanical adjustment operations. Thereafter, a retainer maintains the sealing member in sealing contact with the liner pipe after the slide tool is returned to the surface, preventing or limiting the axial movement of the sealing member when fluid pressure is applied. The sealing member of the present invention may be used in various applications in a wellbore having a tube disposed therein, where a plug mandrel or other conduit tube is positioned within the wellbore to position the plugging member in a selected location. The plug element is disposed around the conduit pipe and includes a plurality of elastomeric sealing bodies for sealing engagement with the borehole pipe, and a plurality of metal ribs separating the elastomeric sealing bodies, with the rib ends for metal-to-metal sealing engagement with the pipe. The plugging element may be collided with the well in a configuration similar to that shown in Figure D1, in which the sealing element is of reduced diameter, and the plugging element is radially deformed outwardly to the sealing engagement with the bore tube. well as it moves relative to a tapered wedge ring until the obturator member reaches the final adjustment position as shown in Figure D3. The radial adjustment sealing member of the present invention can thus be used for various types of drilling tools. Additional spare secondary metal ribs could be provided, as well as additional spare elastomeric bodies engaging these additional ribs. Various types of conduit pipes may be used to position the plug element at a selected location below the well surface. The substantially tapered cone or wedge ring may have various constructions with a generally outer conical surface configured to radially expand the annular seal assembly or plug with the axial movement of the plug element relative to the wedge ring due to or axial movement of the plug element with respect to the stationary wedge ring or axial movement of the wedge ring with respect to the stationary plug element. In a preferred embodiment, the seal assembly includes an upper elastomeric seal body, a main elastomeric seal body and a lower elastomeric seal body. While each of the upper and lower sealing bodies ideally gives the spare elastomeric seal, in case of leakage of the main elastomeric seal, it is an important function of the upper sealing body D22 and the lower sealing body D26 to provide a pressing force. against the respective rib D32 or D34. These elastomeric sealing bodies thus function as biasing members between the axially outermost rib and the adjacent inner rib to exert a force that prevents the inner rib from flexing beyond a predetermined stage. For example, the lower sealing body D26 engages both the inner rib D34 and the outer rib D36 and exerts an upward pressing force to prevent the rib D34 from moving downward beyond a position where it is perpendicular to the pipe wall. coating. At the same time, the lower sealing body D26 exerts a downward biasing force which will tend to increase downward flexing to the outer rib D36 when the inner rib D34 is bent downwardly in response to the high pressure above the obturator member.

In addition to the metal to main metal seal, the metal to secondary metal seal, the main elastomeric seal and the secondary elastomeric seal, additional sets of metal to metal and elastomeric seals could be provided in the plug element. Elastomeric bodies that are configured in addition to those shown here may thus be used for this purpose. Various types of plastic materials in various configurations can provide the desired pressing force, and ideally also a secondary resilient seal. Alternatively, a bent spring or other metal material biasing member may be used in place of or in cooperation with elastomeric bodies D22 and D26.

Preferably each of the metal ribs of the obturator member as described herein are annular members with the extreme surface of each rib when in the insertion position having substantially the same radial spacing from a central axis of the engaging tool. reliable seal with the surface to be sealed. In other embodiments, one or more ribs could include radial notches such that the rib did not form a complete metal to metal annular seal, which could then be provided by the elastomeric seal, although the complete annular metal seal would not be provided. obtained. Preferably, a plurality of axially spaced protuberances are provided for metal-to-metal sealing engagement between the obturator member and the cone, and between the cone and the conduit tube. In other applications, a single annular protuberance may be sufficient to form the desired metal to metal sealing function.

Referring now to Figures B3A and B3B, a liner B20 has a downwardly and inwardly extending frusto-conical surface B22 above an upwardly facing annular recess B23. The liner has been lowered into a suitable slide tool (not shown) to a position in the outer well casing tube into which the liner is to be lowered.

As described in more detail below, the C-ring is initially expanded to allow it to be arranged around the conical wedge surface of the liner. It can then be contracted and forced downward to cause its lower end B26 to move to recess B23. When so installed, the C-ring casing hanger will be held in the stowed position in a shape somewhat larger than its fully contracted form of Figures B1A and B1B.

When the C-ring has been pulled upward to remove its lower end from recess B23, it will expand toward its fully expanded position of Figures B2A and B2B, whereby the downward facing teeth B22 around outside will engage the outer well casing pipe as shown in Figure B3B in a position somewhat lower than the fully expanded position. Then, when the C-shaped slide sleeve is raised, the inner surface of the C-ring will slide over the wedge surface B22 to press it outward to make its teeth snap into the outer well casing tube, thus allowing the weight of the liner and its associated parts to be lowered into the liner tube.

As shown in Figures B3A and B3B and in detail in Figures B3AA and B3BB, the inner frusto-conical surface of the C-ring slide sleeve has blind teeth CF in it, which, as is well known in the art, controls frictional engagement with the lining and therefore the external force applied to the lining tube. Thus, as the teeth initially snap into the liner tube, the blind teeth on the inner side of the slide sleeve will begin to skin the wedge surface of the liner to control the extent to which the teeth snap into the liner tube. The force thus applied to the liner pipe and liner can be controlled by the mutual relationship of the inner and outer teeth. Although CF teeth are preferred, the inner surface of the C-ring can be smooth.

Referring to Figures B4 to B6, one or more connecting rods B30 extend downwardly through a slot B40 in the sheath for guided alternating movement thereon. The lower end of each tie rod is attached to the upper end of the slide sleeve to raise its lower end off the undercut. Thus, as shown in Figures B4 - B6, the lower end of each tie rod B30 has a flange 50 which is received in a groove B36 around the inside diameter of the C-ring as the C-ring is initially mounted on the recess. As the tie rod is raised to lift the C-ring out of recess B23, flange B50 at its lower end moves out of groove B36 to disengage the C-ring from there, as shown in Figure B5 . At this time, of course, the weight of the liner may be loosened on the outer tapered surface of the C-ring to force the C-ring teeth outward to engage with the outer casing tube as shown in Figure B6.

As an alternative to slide sleeve assemblies, as described above, another apparatus for this purpose - that is, by suspending an inner liner tube within an outer liner tube, has locking elements adapted to expand into the corresponding locking grooves formed. in the outer casing tube. In some cases, the locking elements are adapted to be spring-loaded into the corresponding grooves formed in the outer casing tube. However, these springs are susceptible to rupture or other defects. This is especially true since the hanger generally comprises a large number of complex parts that are expensive to replace and which cause a delay in full well operations. In still other cases, the suspenders having only a single coupling piece to fit within a single slot thus limit their load carrying ability.

In one embodiment of this invention, a casing hanger system comprising a casing tube joint is adapted to be connected as part of an outer casing tube installed within a borehole, and a casing adapted to be lowered and supported. inside the outer casing tube. The casing pipe bore has a polished bore and vertically spaced upwardly facing bearing surfaces formed therein, and the casing includes a tubular body having a recess formed around its body, and a suspension member which comprises a circumferentially expandable and contractile C-ring disposed within the recess. The ring has teeth in its outer diameter for bearing on the supporting surfaces of the liner pipe joint, when in its expanded portion, and with relative vertical movement relative to the liner, it is expanded outwardly against the polished hole. With the continued relative movement of the liner and ring, the teeth will move to a position in which they further expand outward to the positions supported on the bearing surfaces to allow the liner to be suspended thereafter.

Claims (19)

1. A tool for use in an underground well to seal a generally cylindrical inner surface of a tubular or other wellbore tool, the tool comprising: a wedge ring (D14) having a substantially tapered outer surface configured to radially expand a annular seal assembly with the axial movement of the annular seal assembly with respect to the wedge ring (D14) such that the seal assembly is expanded from its insertion position to its expanded seal position, where the assembly sealing is in sealing engagement with the generally cylindrical inner surface; characterized in that the annular seal assembly has a small diameter insert position and an expanded seal position, the seal assembly including a metal frame having a radially inward annular base (D18) and a plurality of ribs (D20), each extending radially outwardly from the base (D18), the metal frame including a downwardly angled upper main sealing metal rib (D32) to seal the pressure below the seal assembly, an upwardly angled lower main seal metal rib (D34) to seal the pressure above the seal assembly, a main elastomeric seal (D24) in a radially outwardly hollow from the base (D18) and axially between the upper main sealing metal (D32) and lower main sealing metal rib (D34), an angled upper secondary sealing metal rib for the lower (D30) axially spaced above the upper main sealing metal rib (D32), and an upwardly angled lower secondary sealing metal rib (D36) axially spaced below the lower main sealing metal rib (D34). A tool according to claim 1, further comprising: an upper biasing member (D22) between the upper main sealing metal rib (D32) and the upper secondary sealing metal rib (D22). D30) to exert a downward pressing force on the upper sealing metal rib (D32) in response to high fluid pressure below the sealing assembly, and a lower pressing member (26) spaced between the sealing metal rib lower main (D34) and second lower secondary sealing metal rib (D36) to exert an upward force on the lower main sealing metal rib (D34) in response to high fluid pressure above the seal assembly. Tool according to claim 2, characterized in that the upper pressing member is an upper secondary elastomeric seal (D22) between the upper main sealing metal rib (D32) and the upper metal sealing rib. upper secondary seal (D30), and lower depressing member is a lower secondary elastomeric seal (D26) spaced between the lower main seal metal rib (D34) and the lower secondary seal metal rib (D36). Tool according to claim 1,2 or 3, characterized in that an outer surface of each rib, the upper main sealing metal rib (D32), the lower main sealing metal rib (D34) , the upper secondary seal metal rib (D30) and lower secondary seal metal rib (D36) is configured to form an annular metal to metal seal with a generally cylindrical inner surface. A tool according to claim 4, characterized in that each rib, downwardly angled main sealing metal rib (D32), upwardly angled main sealing metal rib (D34), downwardly angled secondary seal metal rib (D30) and upwardly angled secondary seal metal rib (D36) is angled while in the insertion position at an angle of at least 15 ° with respect to a plane perpendicular to a central axis of the cylindrical inner surface. Tool according to any one of claims 1 to 5, characterized in that it further comprises a guide tube (D 16) for positioning the tool at a selected location below the well surface, the seal assembly creating a seal. between the conduit tube (D16) and a casing in the well. Tool according to claim 6, characterized in that the guide tube (D16) holds the generally stationary wedge ring (D14) while the seal assembly moves axially with respect to the wedge ring stationary (D14). Tool according to claim 6, characterized in that the conduit pipe (D16) supports the generally stationary seal assembly while the wedge ring (D14) moves axially with respect to the stationary seal assembly. . Tool according to any one of claims 1 to 8, characterized in that the main elastomeric seal (D24) will include a void area (D25) when the main elastomeric seal (D24) is moved to the locking engagement. sealing with the cylindrical surface such that the main elastomeric seal (D24) can thermally expand to fill at least part of the void area (D25) in response to high drilling temperatures. Tool according to any one of claims 1 to 9, characterized in that it further comprises one or more axially spaced protuberances (D40) on a radially internal surface of the annular base (D18) of the metal frame, each for metal to metal sealing engagement with the conical outer surface of the wedge ring (D14). A tool according to claim 10, further comprising one or more annular elastomeric sealing members (D48) for sealing between the base (D18) of the metal frame and the conical outer surface of the ring. wedge (D14). A tool according to claim 10 or 11, further comprising one or more annular metal protrusions (D42) on an outer surface of a guide tube (D16) or an inner surface of the wedge ring ( D14) to form the metal to metal seal between the wedge ring (D14) and the conduit pipe (D16). A tool according to claim 12, characterized in that it further comprises one or more annular elastomeric sealing members (D48) in one between the tapered wedge ring (D14) and a guide tube (D16) for form an elastic seal between the conduit pipe (D16) and the wedge ring (D14). A tool as claimed in any one of claims 1 to 13, further comprising an elongate member (B20) having an outwardly facing frusto-conical surface (B22) adapted to be lowered and suspended within a borehole; and a red-colored sleeve comprising a circumferentially expandable and retractable C (C) ring having sliding sleeve teeth around its outer side and a frusto-conical surface (B22) on its inner side disposed around the frusto-conical surface of the limb. B20 so that the C-ring can be moved vertically between a contracted position in which the teeth are spaced from the wellbore and an expanded portion in which the teeth engage the borehole. well, Tool according to claim 14, characterized in that the elongate member (B20) is formed with a recess (B23) to receive one end of the C-ring (C) to retain the contracted C-ring around it. of the elongate member (B20) as it is lowered, whereby, by removing said end from recess (B23), the C-ring is free to expand toward its fully expanded position to make with its sliding sleeve teeth grasp the wellbore so that the weight of the elongate member (B20) can be suspended from the casing tube with respect to the vertical movement of the conical surfaces of the C-ring (C) and member elongated (B20). Tool according to claim 14 or 15, characterized in that the frusto-conical surface (B22) of the elongate member (Β20) extends downward and inward and the frusto-conical surface of the C-ring (C) is slidable upwards. on the surface of the elongate member (B20) as it is lowered to cause its teeth to move outward to engage the wellbore. A tool according to any one of claims 14 to 16, characterized in that it further comprises a part (B30) driven by the elongate member (B20) for reciprocating guided movement thereon and engageable with the end of the ring in C (C) or in order to remove the end of the C-ring from the recess (B23) and thereby disengage it for expansion. A tool according to claim 17, characterized in that said part (B30) for disengaging the C-slide sleeve (C) comprises a connecting rod (B30) which extends guidebly within the end of the C-ring (C) when the end of the C-ring is in the recess (B23) to allow removal of the C-ring from the recess by the tie rod and then release thereof to allow the C-ring to snap off. expand into engagement with the liner pipe bore. A method of forming a downhole seal with a generally cylindrical inner surface of a pipe or other downhole tool, characterized in that it comprises: providing an annular seal assembly arranged around a downhole pipe. (D16), the seal assembly having a small diameter insertion position and an expanded position, the seal assembly including a metal frame having a radially inwardly annular base (D18) and a plurality of metal ribs ( D20), each extending radially outwardly from the base (D18), the metal frame including a downwardly angled upper main sealing metal rib (D32) to seal the pressure below the sealing assembly, a sealing rib. bottom-angled lower main seal metal (D34) to seal the pressure above the seal assembly, a main elastomeric seal (D24) in a cavity radially outwardly from the base (D18) and axially between the upper main sealing metal rib (D32) and the lower main sealing metal rib (D34), a downwardly angled upper secondary sealing metal rib ( D30) axially spaced above the upper main sealing metal rib (D32), and an upwardly angled lower secondary sealing metal rib (D36) axially spaced below the lower main sealing metal rib (D34); providing a wedge ring (D14) having a substantially conical outer surface; and the axial movement of the annular seal assembly with respect to the wedge ring (D14) such that the seal assembly is expanded from its insertion position to its expanded position, where the seal assembly is in engagement with each other. sealing with the generally cylindrical inner surface.