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Publication numberUS2673614 A
Publication typeGrant
Publication dateMar 30, 1954
Filing dateOct 14, 1949
Priority dateOct 14, 1949
Publication numberUS 2673614 A, US 2673614A, US-A-2673614, US2673614 A, US2673614A
InventorsMiller Ira A
Original AssigneeOtis Eng Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Anchoring assembly for oil tools
US 2673614 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

March 30, 1954 L A M|| ER 2,673,614

ANCHORING .ASSEMBLY FOR OIL TOOLS Filed Oct. 14, 1949 IN VEN TOR.

A TTOR/VEYJ Patented Mar. 30, 1954 ANCHORING ASSEBIBLY FOR OIL TOOLS Ira A. Miller. Dallas, Tex., assigner to Otis Engineering Corporation, Dallas, Tex., a corporation of Texas Application October 14, 1949, Serial No. 121,434

(Cl. 16S- 12) 33 claims. 1

This invention relates to improvements in anchoring devices and assemblies used in the oil and gas industry and refers more particularly to such mechanism especially adapted for securing a plurality of tools within a string of well pipe at pre-selected levels therein and in such manner that the tools may be withdrawn from the well pipe.

In the drilling and production of oil and gas wells, it frequently becomes desirable to lodge one or more tools within a well string of pipe with each tool lodged at a selected level Within the pipe. The tools usually must be withdrawn from the well pipe from time to time for purposes of repair or replacement or in order to permit the performance of other operations. By way of example of this type of installation and not by way of limitation, it is frequently proposed to equip a producing gas Well with a plurality of pressure regulators or chokes whereby the pressure within the well tubing may be reduced successively across a plurality of chokes to prevent too great a pressure differential or reduction at any one level within the well.

Devices have heretofore been provided which have, with some degree of success, permitted installation of a plurality of tools within a well pipe but considerable difficulty has been encountered in their use due to the collection of sand and other debris in back of the locking mechanism or selector mechanism which has prevented ready withdrawal of the anchoring assembly and connected tools when the occasion arises. Also, in the prior art tools it has been necessary to employ reduced diameter landing sections within the well pipe with cach successively lower section of smaller diameter where provision has been made to positively arrest downward movement of the landing tool and. in small diameter well pipes, as for example flow tubing, such constrictions are frequently undesirable.

An object .of this invention is to provide improved anchoring devices and assemblies for securing tools in and releasing tools from a well pipe.

Another object is to provide anchoring devices and assembiies for securing tools at predetermined levels in a well pipe, constructed so that an accumulation of sand and other well debris will not prevent the withdrawal of the tool from the weil when desired.

A further object is to provide an anchoring assembly such that a Well tool may be positively landed at selected one of several stations within a well pipe.

Still another object is to provide an anchoring assembly having separate locking dogs and selector keys, the latter providing the means for selecting a predetermined station within a well pipe and preventing downward movement of a landing tool in the pipe past such station.

A still further object is to provide an anchoring assembly having separate locking dogs and selector keys, which in operation is first moved to a given level within a well pipe determined by the selector keys and then is secured in the well pipe in such manner that the selector keys are retracted whereby they will not interfere with removal of the tool from the well pipe even though debris does accumulate about such keys to such an extent as to freeze them in the position they occupy with the tool anchored within the well pipe.

Other and further objects of this invention will appear as the description proceeds.

In the accompanying drawings forming a part of the instant specication to be read in conjunction therewith and wherein like reference numerals are used to indicate like parts in the various views:

Fig. 1 is a schematic illustration of a well pipe having a plurality of landing sections made up therein in accordance with this invention,

Fig. 2 is a sectional view, upon an enlarged scale, of one of the landing sections of Fig. 1 showing in partial section an anchoring device or landing tool selecting the particular section, the device and entire anchoring assembly illustrating an embodiment of this invention,

Fig. 3 is a view taken along the line 3-3 in Fig. 2 in the direction of the arrows, and

Fig. 4 is a view similar to Fig. 2 but illustrates the anchoring device in locked position within the landing section.

` Referring to the drawings in detail, in Fig. 1 there ls shown a string of well pipe which may be a string of flow tubing for conducting petroleum products from the producing formation of a well to the ground surface. This string of pipe is made up of a plurality of tubing joints 5, only small portions of which have been shown, but which it is to be understood will constitute the major portion of the string of pipe. A plurality of landing sections 6 are made up in this string of pipe and constitute a part thereof. Preferably, but not necessarily, an equal number of iiow couplings 'i are made up in the pipe string, each of the fiow couplings residing above and adjacent the landing sections. These now couplings supply a thick walled conduit, comparedv to the thickness of the usual joint of ow tubing, which may be of relatively hard material to resist wear due to the turbulence usually encountered just above the constricted iiow passage provided by the anchoring device to be later described. These flow couplings may be provided with a pin on their lower end and a box upon their upper end to facilitate making up of the pipe string.

The landing section 6 may be provided with a box 8 at its upper end and a pin 9 at its lower end. Locking groove means are formed upon the interior wall of the section 6 and in the preferred embodiments includes two grooves I and II and an auxiliary groove I2 which may be considered as a part of the groove I I, even though it is not connected directly with the groove I I by reduced wall thickness for reasons which will hereinafter appear.

The groove I!) preferably has tapered edges as shown in the ydrawings and constitutes the locking groove in which the locking mechanism of the anchoring device is to be secured, as will hereinafter more fully appear. This groove functions principally as a part of the means for securing a landing tool against upward movement within a well pipe. rThe groove I I constitutes the selector key groove and preferably has a stop therein which may be provided by an abrupt shoulder i Ia extending substantially normally to the longitudinal axis of the landing section. The other edge of the groove is tapered. The tapered edges of the grooves I il, II and I2 are for the purpose of facilitating withdrawal of the anchoring device from the landing section for these tapered surfaces will force inwardly any dog or key which might strike these shoulders as long as there is nothing behind the dog or key to prevent its inward collapse or retraction. The shoulder IIa, however, is purposely made to arrest downward travel of the anchoring device or landing tool when the selector key of the anchoring device falls into groove Il. Thus, groove II and shoulder IIa function to stop downward movement of an anchoring device both while it is being landed and at any time thereafter until the device is purposefully removed from the pipe.

By reference to the landing sections of Fig. 1, it will 'be seen that the grooves I I in the various sections are of different lengths but that the length of the shortest of these grooves is greater than the length of grooves normally found between tubing joints or other grooves in the landing section. It will be noted that the longest of the grooves is located at the lower station in the well string of pipe and that the grooves progressively shorten at progressively higher landing sections within the string. Thus, an anchoring device equipped with keys which will fit the W- ermost selector groove will pass up the selector grooves of the upper sections and, therefore, these grooves may be considered as key slots or key grooves. Preferably, the exterior of the landing sections carry some identifying indicia to indicate the size of their key grooves to facilitate making up of the pipe string with each landing section in its proper relative position in the pipe string. For instance, the lowermost section 6 has a single external groove in its periphery shown at I3, the intermediate section 6 has a Idouble groove shown at I4, and the uppermost section 6 has three grooves shown at I5. These grooves indicate the relative positions of each of these landing sections within the pipe string. It is to be understood, of course, that the number of total sections 6 may be less than or greater 4 than three and that this number was selected for purposes of illustration only.

With this selector groove arrangement of the landing sections, there is no necessity for each successively lower landing section to have a portion with a successively smaller internal diameter. The I. D. of the landing section may be the same as or greater or smaller than the nominal I. D. of the pipe sections with which it is to be used. The landing sections may be disposed at any desired position in the pipe string and even may *be formed as an integral portion of the well head equipment or Idirectly connected thereto.

Referring to the landing device or tool, reference is made to Figs. 2, 3 and 4. These devices maybe considered as comprising a multipart carrier indicated generally at I6 and made up of a shank or head piece II, a coupling I8 and a key holder I9. The carrier may have a iiow passage therethrough and has mounted thereon expansible locking dogs 20, a packing means 2I and at least one selector key 22.

Consi-dering the locking means, any arrangement may be employed which locks upon upward movement of the carrier or landing tool. The preferred arrangement includes locking dogs secured to shank or head piece Il by a collar 23 having a slide nt on the part I'I'. This collar` has an enlarged lower skirt portion having an internal counterbore with a shoulder 24 formed therein on which the key fingers or dogs ZI) are pivotally mounted by pivot lugs 25 carried at the upper ends of the fingers and resting on shoulder 24. Slight clearance preferably is provided between the fingers and the periphery of shank Il and the fingers and the internal wall of the enlarged portion of collar 23. Thus, these fingers are free to rock inwardly and outwardly upon their pivots.

Means is provided to radially expand locking dogs 26 when the carrier is shifted along its longitudinal axis in an upward direction relative to the dogs. This means includes a tapered surface 26 on the carrier and a corresponding taper 21 formed on the underside of the dogs 2i?. With this arrangement, the weight of collar 23 and of the dogs 20 causes the dogs and collar to tend to remain stationary or fall downwardly as the carrier is raised. This causes engagement between the tapered surfaces 26 and 21 to force the dogs 20 outwardly. The dogs have end parts which t in groove I0 to lock the device in one of the sections 6. Usually, at least two dogs are used and in the device shown in the drawings, four are shown and serve to substantially center the landing tool. Of course, two dogs held substantially diametrically opposed one to the other would accomplish the same purpose and indeed, the extra dogs of this embodiment serve principally as spacers and to give added ruggedness to the locking means.

In order that the carrier might be moved upwardly or downwardly within a well pipe, the shank or head piece I1 is provided with an enlarged portion I'Ia at its upper end which may be engaged by a socket or the like carried by a lowering medium as a wire line or rod string. Such devices are well known to those skilled in the art, and the drawings, in the interest of simplicity, do not include an illustration of such mechanism. However, it is to be understood that the head piece II is releasably engaged, as a rule, by such part or fishing tool so that a sharp upward pull upon the lowering medium releases the connection between it and the head IIa. When desired,

the socket may have parts which releasably engage the collar 23 to retain them in a raised position. In such devices, the part that engages the collar 23 has a lost motion connection with the part that engages head I'Ia and is released from the collar by a lesser upward pull than is required to release the device from the head I'Ia. The advantage of this type of lowering device is that the landing tool may be raised in the pipe string if desired for any reason and the dogs are not in position to engage the groove formed between adjacent pipe sections.

To withdraw the device from locked position in the well pipe, a fishing tool or the like is lowered by a suitable lowering medium such as a wireline and has a part which engages the head 23a of collar 23. These fishing tools have a part that first strikes the head I'Ia a hammer blow to drive the carrier down relativo to the dogs to drive the tapered section 26 out of engagement with the dogs. Thus, the dogs are free to retract inwardly when engaging the tapered edge of groove I0 for any sand or other debris that might have accumulated about the dogs is disloged by the positive shifting of collar 23 upon the shank I1.

Referring now to the selector key arrangement, it will be seen that two diametrically opposed keys 22 are provided on the carrier and adapted to move radially inwardly and outwardly within slots 28 formed in the key holder I9. It is to be understood that a single key or three or more keys may be used. These slots 28 run longitudinally of the key holder and house resilient elements or spring 29 which urge the keys 22 radially outwardly within the slots. Elements 29 may be coil springs, as shown, leaf springs or the like. These keys have an elongate key surface it adapted to fit rather snugly within the groove I I and preferably have a guide portion 3I with tapered edges which resides in groove I 2 of the landing section. This guide portion is for the purpose of keeping the keys substantially aligned, as the carrier is lowered or lifted within the well pipe and landing section to insure even collapsing or retracting of the key 22 into the slot 28 when obstacles in the conduit are encountered. The keys have a stop part in the forni of an abrupt shoulder 32 adapted to engage the shoulder IIa of groove II, and the guides 3l reduce the likelihood of this stop accidentally engaging an obstacle in the conduit to arrest movement of the carrier.

The carrier has keeper washers at both ends of the keys 22 which prevent the keys from being lost from the slots 28. The Washer 33 may have a slide fit upon the upper end of holder I9 and is retained by the lower end of coupling I8 abutting thereagainst. An axially extending flange 34 overlaps the upper ends of keys 22 to prevent them from slipping out of the slots 28. The washer 35 actually may serve as a nut threaded directly to the lower end of holder I9 and also has an axially extending flange, designated at 36, for overlapping the lower ends of the keys 22. Nut 35 does not cover all of the threads on the lower end of the holder and, therefore, there may be secured to the holder I9 a regulator, choke or other tool to be secured within the well pipe.

The keys 22, to be used on a device to be anchored within any particular landing section, have their surfaces or portions 3U of substantially the same length as the slot I I within which they are to seat.

The coupling I8 may carry a peripheral packing means, as shown at 2 I. This packing may be of the V or chevron type and an expanding or spacer ring 3l may be employed in conjunction therewith Where this is desirable. If the packing is provided upon the anchoring device, a corresponding seal surface 38 is provided within the landing section positioned so that it registers with the packing 2i when the anchoring device is locked in place, as shown in Fig. e. Preferably this seal surface has a somewhat smaller I. D. than the nominal I. D. of the pipe string in order that the O. D. of the V packing may be somewhat less than the I. D. of the pipe string so as not to be worn as the landing tool is low ered into the well. Obviously, where the landing section is to be located near or adjacent the well head, this reduced I. D. of the section is not of as much advantage and may usually be dispensed with.

In operation, the landing sections 6 are made up in the pipe string at the desired levels in which the anchoring devices are to be landed. This is done as the pipe string is made up and lowered into the well. These landing sections actually constitute a part of the pipe string or conduit.

Where a plurality of tools are to be lodged within the pipe string, at least an equal number of landing sections are employed and the landing section having the longest slot II is placed at the lowermost position within the string. Thus, the anchoring device having the longest keys E2, or that is, the longest portion 3S of the keys 22, is first lowered within the well and when the keys 22 engage the annular groove Il, they are forced outwardly into the grooves by the springs 2? for the portions 36 of the keys are somewhat smaller than the length of the groove I I. Stop parts 32 and I Ia engage and arrest further downward movement of the device. In this position, as shown in Fig. 2, the locking dogs 2li rest in the locking slot or groove I0 but do not protrude to full locking position. In order to lock the device, itis necessary to shift the carrier upon its longitudinal axis in an upward direction, this being the only direction which the stop part Ila of groove il will permit. This causes engagement of the tapered surfaces 2l of the dogs and 2t of the coupling I8 to force the dogs outwardly into locking position shown in Fig. 4 wherein the dogs engage the upper tapered surface of groove Iii. The wire line or other lowering .medium may be broken loose from head Ila of the carrier by giving it a sharp upward pull. This leaves the device securely anchored against upward movement within the pipe string. The selector key or keys always are ready to go into operation to limit downward movement of the device. It will be appreciated that in normal circumstances the pressure differential across the anchoring device will be very great and will tend to drive the device upwardly out of the well pipe. Therefore, it is necessary to anchor the device against upward movement. However, not infrequently it is desired to pump fluid into a well and the selector keys will prevent unrestricted downward movement of the device at such time.

It will be noted that the selector keys, during the upward shifting of the carrier in order to lock the dogs 29 in the position shown in `E'ig. 4, have been retracted by engagement of the tapered upper edge of groove I I against the upper tapered ends of the keys 22. ln this collapsed position, even though sand, or other material, should accumulate below vthe packer in such quantities as to freeze the keys against radial inward or outward movement, nevertheless, the device may be withdrawn from the well pipe for the keys are locked in collapsed or retracted position within the landing section. The I. D. of the landing section at 38 is purposefully made at least as small as any I. D. to be encountered in the well string above the landing section. Thus, when the locking dogs are released by a suitable tool lowered to grab shoulder 23a of collar 23, the anchoring device, together with any tool that might be secured thereto, may be readily withdrawn from the well pipe.

It is contemplated that the locking keys could be employed as a part of the landing section in which case the groove for receiving them would be provided in the anchoring device. While the locking means carried by the landing section have been shown as two separate grooves, it is to be understood that a single groove might be employed in which case the keys 22 would be located upon the carrier in such position that the locking dogs would extend below the keys when the keys have made contact with the selector groove. Then upward movement of the device to collapse the keys would cause the locking portion of the fingers 25 to engage and lock in the single groove of the landing assembly. Also, the selector keys may be mounted at the same position along the longitudinal axis of the carrier as the locking dogs.

From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed is:

l. In combination, a well pipe having a plu- Lty of spaced tubular landing sections cond therein at selected levels and each of said ng sections having an internal positioning and locking surface having an upwardly facing stop shoulder and a downwardly facing lock shoulder and each positioning and locking surface differing in configuration from the internal `positioning and locking surface of each of the other landing sections, and a device for releasably anchoring a well tool in a selected one of said landing sections and including: a carrier; selective locking means positioned on said carrier and expansible and retractable laterally of said carrier; said locking means having a downwardly facing stop shoulder engageable with the upwardly stop shoulder of the positioning and locking surface of only a selected landing section to limit wnward movement of said carrier, said selective locking means having an upwardly facing lock shoulder engageable with the downwardly facing lock shoulder of the positioning and locking surface of only said selected landing section; and means positioned on the carrier for expanding the stop and lock shoulders of said selective locking means to engage the positioning and locking surface of said selected landing sec- 8 tion to maintain said carrier locked in said seleeted landing section; said selective locking means being retractable to permit upward movement of the carrier from said landing section.

2. In combination, a tubular landing section for connection in a pipe string and having an internal positioning and locking surface having an annular groove formed therein, the lower limit of said groove being defined by a surface of the landing section providing an upwardly facing stop shoulder; a carrier; a selector member on said carrier expansible and retractable laterally of said carrier and having a downwardly facing stop shoulder and a longitudinal conguration corresponding to the longitudinal configuration of the groove of said landing section; means on the carrier for expanding said selector member to expanded position to engage said downwardly facing stop shoulder of said selector member with the upwardly facing stop shoulder of said landing section; locking means expansibly and retractably mounted on said carrier; and means on said carrier movable relative to said locking means to expand said locking means to locking engagement with the positioning and locking surface of said landing section.

3. In combination, a tubular landing section having an internal positioning and locking surface with an upwardly facing stop shoulder and a downwardly facing lock shoulder, and a device for releasably locking a well tool in said landing section including; a carrier; selective locking means on said carrier and expansible and retractable laterally of the longitudinal axis of said d ca Tier, said locking means having a downwardly facing stop shoulder and an upwardly facing lock shoulder; means on the carrier for expanding said downwardlyl facing stop shoulder and said upwardly facing lock shoulder of said locking means to expanded position to engage said downwardly facing stop shoulder with said upwardly facing stop shoulder of said landing section and said upwardly facing lock shoulder oi" said locking means to engage said downwardly facing shoulder of said landing section to maintain said carrier locked against displacement from said landing section, said locking means being retractable to a maximum diameter on the carrier less than the minimum diameter of the bore of the landing nipple and being expansible to engage the downwardly facing shoulder of said locking means with the upwardly facing shoulder of said landing section only when the configuration of said locking means correspends to the configuration of said positioning and locking surface of said landing section.

4. A device for releasably anchoring well tools at a selected level within a well pipe comprising a carrier, locking dogs mounted upon the carrier and radially expansible thereon, expander means on the carrier for expanding said dogs upon upward movement of the carrier relative to the dogs, a selector key expansibly mounted upon the carrier with resilient means urging it radially outwardly, said key having an upper surface inclined outwardly downwardly of the longitudinal axis of the carrier and a stop surface disposed below the upper surface and substantially normal tothe longitudinal axis of the carrier.

5. A device for releasably anchoring well tools at a selected level within a well pipe comprising a carrier, an assembly slidably mounted upon the carrier including a pluralityA of pivotally mounted dog fingers, headsuponboth thecarrier `aeraeml and assembly each adapted to be selectively engaged by a shing tool, cooperating tapered surfaces upon the dogs and carrier adapted to engage and radially expand the dogs upon lifting of the carrier relative to the assembly, a selector key expansibly mounted upon the carrier, and a resilient element urging the key outwardly, said key having an upper edge inclined outwardly downwardly of the longitudinal axis of the carrier, a lower stop surface disposed substantially normal to said axis and a guide portion spaced from said edge and said stop surface.

6. The device of claim with packing means mounted exteriorly of the carrier.

7. An assembly for releasably anchoring well tools at a selected level within a well pipe comn prising a landing section adapted to be made up in a pipe string to provide a part thereof and having two spaced apart annular internal locking grooves therein, the surface of the landing section defining one edge of one of the grooves being substantially normal to the longitudinal axis of the landing section to provide a stop, the surfaces of said landing section defining the other edges of the grooves being outwardly beveled; a tool carrier adapted to be lowered into said pipe string including said landing section and landed in the latter, two sets of radially expansible members mounted upon the carrier and spaced apart somewhat less than the spacing of the grooves of the landing section, one set of the members including a selector key with one abrupt edge for engaging the one of the landing section grooves having the stop and of substantially the same length as the length of the groove having the stop, this length being greater than the length of any groove to be encountered in the pipe string above the landing section, resilient means urging the selector key radially outwardly, the other of the members being lock dogs mounted. for radial expansion upon shifting of the carrier along its longitudinal axis in a direction permitted by the stop of the one landing section groove, the dogs adapted upon expansion to seat in the other groove of the landing section to anchor the carrier, this shifting of the carrier to expand the dogs unseating and retracting the selector key.

8. An assembly for releasably anchoring Vwell tools at a selected level within a well pipe coml prising a landing section adapted to be interposed in a well pipe string as a part thereof and having spaced apart annular grooves formed internally of the section, the surface of the landing section forming the lower limit of one of the grooves providing an upturned stop shoulder in said one of the grooves; a carrier having locking dogs supported thereby for radial expansion to engage the one of the grooves not having said upturned shoulder upon upward movement of the carrier, a selector key expansibly secured to the carrier with resilient means urging it radially outwardly, said key corresponding in length to the groove of said landing section having the stop shoulder and including a part engageable with said stop shoulder to arrest downward movement of the carrier and to position the dogs in alignment with the second groove; means on the carrier for expanding the dogs to locking engagement in said second groove; the landing section grooves being spaced apart a distance different than the spacing apart of said carrier dogs and key in such manner that upon engagement of the key with `said stop .and subsequent lifting of thecar- 10 rier to expand vthe dogs, the dogs will engage the second groove and the key will be retracted.

9. The assembly of claim 8 wherein pivotally mounted lock fingers constitute the carrier dogs and cooperating tapered surfaces upon the carrier and ngers provide the means for radially expanding the dogs upon upward movement of the carrier.

10. The assembly of claim 8 wherein a seal surface and packing means are carried one by the landing section and the other by the carrier in such relative positions as to register to seal therebetween with the locking dogs expanded in locking position relative to the landing section.

11. In combination, a landing section adapted to be made up in a string of well pipe as a part thereof and having an internal annular locking groove therein, a carrier adapted to be lowered into a string of pipe and secured in the landing section, locking dogs mounted upon the carrier engageable when expanded with said internal annular locking groove in the landing section to secure the carrier therein, means between the carrier and dogs to expand the latter when the carrier is moved upwardly relative to the dogs, a selector key and a matching groove, one carried by the landing section and the other by the carrier, a pair of opposed surfaces forming stop parts on said landing section and carrier, one on the key and the other forming a part of said matching groove and engageable with each other for arresting downward movement of the carrier through said landing section when engaged, resilient means urging the key to groove engaging position, the locking dogs and selector key being spaced apart a distance different than the spacing apart of said grooves so that upon engagement of said stop parts the carrier can be moved upwardly to expand the locking dogs to engage the locking groove and to retract the selector key.

12. In combination a landing section adapted to be made up in a string of well pipe as a part thereof, a carrier adapted to be lowered into a pipe string and secured in the landing section, locking dogs and a selector key mounted upon the carrier, means for expanding the locking dogs radially upon upward movement of the carrier, resilient means urging the selector key radially outwardly, said landing section having groove means adapted to receive the locking dogs and selector key, cooperable lstop parts carried by the key and groove means adapted to engage to arrest downward movement of the carrier, at least one of said groove means and selector key having a surface inclined upwardly inwardly so that upward movement of the carrier will cause the groove means and key to engage to retract the latter from engagement with the groove means, the relative positions of the groove means and the key and dogs being such that after the key has become engaged with the groove means, upward movement of the carrier expands the dogs to engage the groove means, and retracts the key.

13. In combination a landing section adapted to be included in a pipe string, a landing tool, locking means parts on the landing section and landing tool engageable upon upward movement of the latter to secure the latter against upward movement in the landing section, a spring pressed selector key and a groove of corresponding size, one carried by the landing section and the other by the landing tool, said key and groove having engageable stop parts for arresting downward movement of the landing tool, and said key and `grpove also having cooperating beveled surfaces 1l engageable upon upward movement of the landing tool with respect to the landing section to retract the key from the groove.

14. The combination of claim 13 where the locking means parts and key and groove are arranged on the landing section and tool so that the key and groove are engaged when the landing tool is in one position within the landing section and the locking means parts are engaged with the landing tool in a higher position within the landing section in which position the selector key is retracted against the spring.

15. As a subcombination, a landing section comprising a hollow cylindrical member with fastening means at its ends adapting it to be made up in a pipe string and having spaced apart internal grooves encircling vthe interior of the member, the surface of the member defining the lower limit of one groove providing an upwardly facing stop shoulder substantially normal to the longitudinal axis of the member, and the surfaces of the member defining the other upper and lower limits of each of the grooves being beveled divergently inwardly of the bore of said member.

16. As a subcombination, a landing section comprising a hollow cylindrical member with fastening means at its ends adapting it to be made up in a pipe string and having spaced apart internal grooves encircling the interior of the member, the surface of the member defining the lower limit of one groove providing a shoulder disposed substantially normal to the longitudinal axis of the member to provide a stop, and the surfaces of the member providing the other shoulders of each of the grooves being divergent inwardly of said member, said member having formed in its interior a third spaced groove relatively small and adjacent and beneath the groove with the stop.

17. A device for releasably anchoring a well tool at a selected level within a well pipe comprising: a carrier, selective locking means expansibly and retractably mounted on the carrier and having a downwardly facing stop shoulder, an upwardly facing lock shoulder and a surface below said lock shoulder inclined upwardly and outwardly of the longitudinal axis of the carrier, said selective locking means also having a selector key portion thereon; means for expanding said locking means to expanded position, said selective locking means being retractable to a diameter on the carrier not greater than the maximum diameter of the carrier.

18. A device for releasably anchoring a well tool at a selected level in a well pipe including: a carrier; selective locking means on said carrier expansible and retractable laterally of said carrier; means for expanding said locking means to expanded position, said selective locking means having a downwardly facing stop shoulder formed thereon, said selective locking means having a selector key portion and also having a guide portion disposed below said stop shoulder, said guide portion having outwardly convergent surfaces, said selective locking means having an upwardly facing lock surface maintained in expanded position by said expander means and retractable from such expanded position.

19. A device for releasably anchoring a well tool at a selected level Withinva well pipe comprising: a carrier, locking means on said carrier expansible and retractable laterally thereof, means on said carrier movable to expand said locking means; a selectormember on said carrier movable laterally -of said-carrier; meansA biasing Cil l2 said selector member outwardly of said carrier, said selector member having outwardly convergent surfaces at its upper and lower ends and an outwardly extending abrupt stop shoulder intermediate said convergent surfaces.

20. A device of the character set forth in claim 19 wherein the distance between said stop shoulder and one of said convergent surfaces of said selector member is greater than the distance between said stop shoulder and the other convergent surface.

21. In combination, a Well pipe having a plurality of spaced tubular landing sections connected therein at selected levels and each of said landing sections having an internal positioning and locking surface having a plurality of spaced annular grooves formed therein, the lower limit of one of said grooves being defined by an upwardly facing stop shoulder, one of said grooves having upper and lower limits defined by divergently inwardly extending shoulders, said positioning and locking surface or" each lan-:ling section having at least one of the grooves formed therein or" different configuration than the corresponding groove of the other landing sections and a device for releasably anchoring a well 'tool in a selected one of said landing sections, including: a carrier; locking dogs mounted on said carrier; expander means on said carrier for lateral expansion of said dogs upon longitudinal movement of the expander means relative to said dogs; and a selector kcy mounted on said carrier for limited lateral expansion and retraction; means biasing said `key outwardly, said selector key having an elongated key section having a downwardly facing stop shoulder engageable with the one of said grooves of a selected one of said landing sections having said upwardly facing stop shoulder to stop downward movement of the carrier at said selected landing section and to position the dogs in alignment with one of said grooves in said landing section whereby upward movement of the carrier will expand the dogs to locking engagement in said groove, said selector key section having a length greater than that of the corresponding grooves of non-selected landing sections connected above said selected landing section in the pipe whereby said selector key section will not enter the grooves of such non-selected landing sections.

22. A device for releasably anchoring a well tool at a selected level in a well pipe having a plurality of spaced tubular landing sections connected therein at selected levels and each of said landing sections having an internal positioning and locking surface having a plurality of spaced annular grooves formed therein, the lower limit of one of said grooves being defined by an upwardly facing stop shoulder, one of said grooves having upper and lower limits dened by divergently inwardly extending shoulders, said positioning and locking surface of each landing section having at least one of the grooves formed therein of different configuration than the corresponding groove of the other landing sections, and including: a carrier; locking dogs mounted on said carrier; expander means on said carrier for lateral expansion of said dogs upon longitudinal movement of the expander means relative t0 said dogs; and a selector key mounted on said carrier for limited lateraly expansion and retraction; means biasing said key outwardly, said selector key having an elongate key section having a downwardlyfacing stop shoulder engageable with the one of said grooves'ofa selected 'one of said 13 landing sections having said upwardly facing stop shoulder to stop downward movement of the carrier at said selected landing section and to position the dogs in alignment with one of said grooves in said landing section whereby upward movement of the carrier will expand the dogs to locking engagement in said groove, said selector key section having a length greater than that of the corresponding grooves of non-selected landing sections connected above said selected landing section in the pipe whereby said selector key section will not enter the grooves of such nonselected landing sections.

23. A device for releasably anchoring a well tool at a selected level in a Well pipe having a plurality of spaced tubular landing sections connected therein at selected levels and each of said landing sections having an internal positioning and locking surface having a plurality of spaced annular grooves formed therein, the lower limit of one of said grooves being defined by an upwardly facing stop shoulder, one of said grooves having upper and lower limits defined by divergently inwardly extending shoulders, said positioning and locking surface of each landing section having at least one of the grooves formed therein of different conguration than the corresponding groove of the other landing sections, and includng: a carrier; locking dogs mounted on said carrier; expander means on said carrier for lateral expansion of said dogs upon longitudinal movement of the expander means relative to said dogs; and a selector key mounted on said carrier for limited lateral expansion and retraction;

means biasing said key outwardly, said selector n key having an elongate key section having a downwardly-facing stop shoulder engageable with the one of said grooves of a selected one of said landing sections having said upwardly facing stop shoulder to stop downward movement of the carrier at said selected landing section and to position the dogs in alignment with one of said grooves in said landing section whereby upward movement of the carrier will expand the dogs to locking engagement in said groove, said selector key section having a length greater than that of the corresponding grooves of non-selected landing sections connected above said selected landing section in the pipe whereby said selector key section will not enter the grooves of such non-selected landing sections; said selector key having a guide portion disposed below the downwardly facing stop shoulder of said selector key section and having a downwardly and inwardly beveled lower surface engageable with the well pipe and landing sections to prevent the downwardly facing stop shoulder of said selector key section from moving into engagement with the upwardly facing stop shoulders of non-selected landing sections.

2e. A device for releasably anchoring a well tool at a selected level in a well pipe having a plurality of spaced tubular landing sections connected therein at selected levels and each of said landing sections having an internal positioning and locking surface having a plurality of spaced annular grooves formed therein, the lower limit of one of said grooves being defined by an upwardly facing stop shoulder, one of said grooves having upper and lower limits dened by divergently inwardly extending shoulders, said positioning and locking surface of each landing section having at least one ofvtheugroovesiformed. therein of different configuration than the corresponding groove of the other landing sections, and including: a

V14 carrier, looking dogs mounted on said carrier; expander means on said carrier for lateral expansion of said dogs upon upward movement of said carrier relative to said dogs; and a selector key mounted on said carrier for limited lateral expansion and retraction; means biasing said key outwardly, said selector key having an elongate key section having a downwardly facing stop shoulder engageable with the one of said grooves of a selected one of said landing sections having said upwardly facing stop shoulder to stop downward movement of the Carrier at said selected landing section and to position the dogs in alignment with one of said grooves in said landing section whereby upward movement of the carrier will expand the dogs to locking engagement in said groove, said selector key section having a length greater than that of the corresponding grooves of non-selected landing sections connected above said selected landing section in the pipe whereby said selector key section will not enter the grooves of such non-selected landing sections.

25. A device for releasably anchoring a well tool at a selected level in a well pipe having a plurality of space-d tubular landing sections connected therein at selected levels and each of said landing sections having an internal positioning and locking surface having a plurality of spaced annular grooves formed therein, the lower limit of one of said grooves being dened by an upwardly facing stop shoulder, one of said grooves having upper and lower limits defined by divergently inwardly extending shoulders, said positioning and locking surface of each landing section having at least one of the grooves formed therein of different configuration than the corresponding groove of the other landing sections, and including: a carrier; locking dogs mounted on said carrier; expander means on lsaid carrier for lateral expansion of said dogs upon upward movement of said carrier relative to said dogs; and a selector key mounted on said carrier for limited lateral expansion and retraction; means biasing said key outwardly, said selector key having an elongate key section having a downwardly facing stop shoulder engageable with the one of said grooves of a selected one of said landing sections having said upwardly facing stop shoulders to stop downward movement of the carrier at said selected landing section and to position the dogs in alignment with one of said grooves in said landing section whereby upward movement of the carrier will expand the dogs to locking engagement in said groove, said selector key section having a length greater than that of the corresponding grooves of non-selected landing sections connected above said selected landing section in the pipe whereby said selector key section will not enter the grooves of such non-selected landing sections; said selector key having a guide portion disposed below the downwardly facing stop shoulder of said selector key section and having a downwardly and inwardly beveled lower surface engageable with the well pipe and landing sections to prevent the downwardly facing stop shoulder of said selector key section from moving into engagement with the upwardly facing stop shoulders of non-selected landing sections.

26. A device for releasably anchoring a well tool at a selected level in a well pipe having a plurality of spaced tubular landing sections connected therein at selected levels and each of said landing sections having an internal positioning and locking surface having a plurality of spaced annular grooves formed therein, the lower limit of one of said grooves being dened by an upwardly facing stop shoulder, one of said grooves having upper and lower limits defined by divergently inwardly extending shoulders, said positioning and locking surface of each landing section having at least one of the grooves formed therein of different conguration than the corresponding groove of the other` landing sections, and including: a carrier; locking dogs mounted on said carrier; expander means on said carrier for lateral expansion of said dogs upon upward movement of said carrier relative to said dogs; and a selector key mounted on said carrier for limited lateral expansion and retraction; means biasing said key outwardly, said selector key having an elongate key section having a downwardly facing stop shoulder engageable with the one of said grooves of a selected one of said landing sections having said upwardly facing stop shoulder to stop downward movement of the carrier at said selected landing section and to position the dogs in alignment-l with one of said grooves in said landing section whereby upward movement of the carrier will expand the dogs to looking engagement in said groove, said selector key section having a length greater than that of the corresponding grooves of non-selected landing sections connected above said selected landing section in the pipe whereby said selector key section will not enter the grooves of such non-selected landing sections; said selector key having a guide portion disposed below the downwardly facing stop shoulder of said selector key section and having a downwardly and inwardly beveled lower surface engageable with the well pipe and landing sections to prevent the downwardly facing stop shoulder of said selector key section from moving into engagement with the upwardly facing stop shoulders of non-selected landing sections; said selector key and said locking dogs each having an inwardly upwardly beveled surface at their upper ends.

27. In combination, a well pipe having a plurality of spaced tubular landing sections connected therein at selected levels and each of said landing sections having an internal positioning and locking surface having a plurality of spaced annular grooves formed therein, the lower limit of one of said grooves being defined by an upwardly facing Stop shoulder, one of said grooves having upper and lower limits defined by divergently inwardly extending shoulders, the positioning and locking surface of each of said landing sections having at least one of the grooves formed therein of different configuration than the corresponding groove of each of the other landing sections, and a device for releasably anchoring a well tool in a selected one of said landing sections including: a carrier; selective locking means on said carrier expansible and retractable laterally of said carrier; means for expanding said selective locking means to expanded position; said selective locking means having a guide portion extending outwardly of said carrier and engageable with the well pipe and landing sections, said guide portion having outwardly convergent shoulders whereby said guide portion may project into said one of said grooves having the divergently inwardly extending shoulders; said selective locking means having a selector key portion, said selector key portion having a downwardly facing stop shoulder engageable with said one of said grooves of a selected one of said landing sections having said upwardly facing stop shoulder to stop downward movement of the carrier at said selected landing section, said selector key portion having a dimension greater than that of the corresponding grooves of non-selected landing sections connected thereabove in the well pipe whereby said selector key portion will not enter the grooves of such non-selected landing sections; said guide portion preventing the selector key portion of the selective locking means from moving the downwardly facing stop shoulder of said selector key portion into engagement with the upwardly facing stop shoulders of nonselected landing sections.

28. A device for releasably anchoring a well tool at a selected level in a well pipe having a plurality of spaced tubular landing sections connected therein at selected levels and each of said landing sections having an internal positioning and locking surface having a plurality of spaced annular grooves formed therein, the lower limit of one of said grooves being defined by an upwardly facing stop shoulder, one of said grooves having upper and lower limits defined by divergently inwardly extending shoulders, the positioning and locking surface of each of said landing sections having at least one of the grooves formed therein of different configuration than the corresponding groove of each of the other landing sections, and including: a carrier; selective locking means on said carrier expansible and retractable laterally of said carrier; means for expanding said selective locking means to expanded position; said selective locking means having a guide portion extending outwardly of said carrier and engageable with the well pipe and landing sections; said guide portion having outwardly convergent shoulders whereby said guide portion may project into said one of said grooves having the divergently inwardly extending shoulders; said selective locking means having a selector key portion, said selector key portion having a downwardly facing stop shoulder engageable with said one of said grooves of a selected one of said landing sections having said upwardly facing stop shoulder to stop downward movement of the carrier at said selected landing section, said selector key portion having a dimension greater than that of the corresponding grooves of non-selected landing sections connected thereabove in the well pipe whereby said selector key portion will not enter the grooves of such non-selected landing sections; said guide portion preventing the selector key portion of the selective locking means from moving the downwardly facing stop shoulder of said selector key portion into engagement with the upwardly facing stop shoulders of non-selected landing sections.

29. In combination, a tubular landing means provided with an annular upwardly facing stop shoulder lying in a plane substantially perpendicular to the longitudinal axis of said landing means, a downwardly facing lock shoulder and an annular guide groove having a pair of opposed annular beveled outwardly and convergently disposed surfaces, and an anchoring device comprising: a carrier, selective locking means mounted on said carrier and expansible laterally of said carrier, means on said carrier for moving said locking means into expanded position, said locking means having a downwardly facing shoulder adapted to abut said upwardly facing shoulder of said landing means to limit downward movement of said carrier when said locking means is in expanded position. said locking means having a guide portion receivable in said guide groove and having outwardly convergent beveled upper and lower surfaces engageable with said beveled surfaces of said guide groove, said locking means having a locking shoulder engageable with said downwardly facing lock shoulder of said landing means for preventing upward movement of said carrier when said locking means is in expanded position, said locking means being retractable to permit said carrier to be removed upwardly from said landing means.

30. An assembly for releasably anchoring well tools at a selected level within a well pipe comprising: a landing section adapted to be interposed in a well pipe string as a part thereof and having spaced apart annular grooves formed internally of the section, the surface forming the lower limit of one of the grooves providing an upturned stop shoulder in said one of the grooves; a carrier having locking means supported thereby for expansion laterally thereof, a selector key expansibly secured to the carrier with resilient means urging it laterally outwardly, said key corresponding in length to the groove of said landing section having the stop shoulder and including a part engageable with said stop shoulder to arrest downward movement of the carrier and to position the locking means in alignment with the second groove, means on the carrier for expanding the locking means to locking engagement in said second groove upon upward movement of said carrier relative to said locking means, the landing section grooves being spaced apart a distance different than the spacing apart of said locking means and selector key when said locking means is in locked position in such manner that upon engagement of the key part with said stop shoulder and subsequent lifting o the carrier to expand the locking means, the locking means will engage the upper limit of the second groove and the key will be retracted.

31. In combination, a landing section means adapted to be connected in a pipe string, a landing tool means, one of said landing section means l and landing tool means having a spring pressed selector key, the other of said landing section means and said landing tool means having a groove of corresponding longitudinal size and conguration to said selector key, said key and groove having engageable stop parts for arresting downward movement of the landing tool means through said landing section means, locking means parts on the landing section means and landing tool means engageable to secure the landing tool means against upward movement out of said landing section means and retractable from engagement to permit said landing tool means to be removed upwardly from said landing section means, said selector key having a. beveled surface cooperating with a beveled surface dening one corresponding limit of said groove and engageable upon upward movement of said landing tool means to retract the key from said groove.

32. As a subcombination, a landing section comprising a hollow cylindrical member with fastening means at its ends adapting it to be made up in a pipe string and having spaced apart internal grooves encircling the interior of thc member, the surface of the member defining the lower limit of one groove providing an upwardly faced inwardly extending stop shoulder, and the surfaces of the member dening the other upper and lower limits of the grooves being divergently inclined inwardly of the section.

33. As a subcombination, a tubular landing section adapted to be connected in a well string and having an internal recess formed therein, the surfaces of said section dening the upper and lower limit of said recess being divergent inwardly of said section, said section having an abrupt upwardly facing stop shoulder formed in said recess intermediate said divergent surfaces.

IRA A. MILLER.

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Classifications
U.S. Classification166/214, 166/115, 166/216, 166/136, 166/134
International ClassificationE21B23/00, E21B23/02
Cooperative ClassificationE21B23/02
European ClassificationE21B23/02