US2237683A

US2237683A - Method and apparatus for suspending well casing

Info

Publication number: US2237683A
Application number: US269703A
Authority: US
Inventors: Burt S Minor
Original assignee: Regan Forge and Engineering Co
Current assignee: Regan Forge and Engineering Co
Priority date: 1939-04-24
Filing date: 1939-04-24
Publication date: 1941-04-08
Anticipated expiration: 1958-04-08

Description

API 8., 1941. B. s. MINOR f 2237533 METHOD AND APPARATUS FOR SUSTENDING WELL CASING Filed April 24, 1959 4 Sheets-Sheet l April 8 1941 asn/:moa 2,237,683

METHOD AND APPARATUS` FOR SUSPENDING WELL CASING Filed April 24, 1959 4 Sheeis-Sheet 2 am! g.

prix 8, 1941. B s, MINQR 2.237.683

METHOD AND APPARATUS FOR SUSPENDING WELL CASING Filed April 24, 1939 4 Sheets-Sheet 4 me/whom .Eu/Q7' J'. Mmmm,

etc. leaves a period of Fatented Apr. 8, 1941 AND APPARATUS FOR. SUSPE ING WELL CASI'NGl Calif., signor to nenn A ME'rnoD Burt S. Minor, Whittier,

Forge & Engineering Company,

of California a corporation Application April 24, 1939, Serial N0. 269,703

(Cl. 16S-F14) 19 Claims.

This invention Vrelates generally to casing head apparatus, particularly casing head apparatus used for suspending casing in oil wells and for controlling pressures in oil Wells.

It is the usual practice in drilling oil wells and the like to employ casing head structures for the support and suspension of the casings concentrically one within the other and for providing means for controlling pressures which may be encountered. With the ordinary type of casing head apparatus it is necessary to part the drilling tree, that is the drilling nipple, .blowout preventers, etc., which are mounted above the rst casing head member on the rst string of casing which has been set from the first casing head member, in order to insert slips in the casing head member head member to form a supporting means. It is also an object of this invention to provide an exlor the ysuspension of the next string of casing to be landed. The disadvantage of this is apparent when it is'considered that very high pressures are often encountered in drilling and the removal otlthe drilling tree with its blowout preventers. time when the weil is not under control.

It therefore is a primary object of this invention to provide a method and apparatus for landing casing through `the drilling tree and suspending the casing in the casing head so that control of the well may be maintained at all times and there willbe no possibility o! a blowout of the well and destruction of the equipment. In. this connection. it is a particular object of this invention to provide a method and apparatus for landing easing through a drilling tree where normal bore casing heads and normal bore drilling apparatus is used above the casing head so that the casing may be suspended within the casing head without removal of the drilling tree. It is also a particular object of this invention to provide for the landing and suspensionv of casing through the drilling tree where over-sized bore equipment is used.

In connection with the landing of casing through normal bore apparatus it is also an object of this invention to provide a method and ap paratus for providing a supporting means 'forming a ledge or shoulder in a normal bore casing head member, that is, one having a bore approximately equal to the inner bore of the last casing landed, after drilling has ybeen completed and prior to landing of another string of casing and without necessitating the removal of the drilling tree. In this connection it is a particular object of this invention to provide a supporting ring or ring insert member which is adapted to be expanded or deformed into a recess m the casing banding means for the ring and to provide means for positioning the expanding apparatus and the ring member in proper position opposite the re. cess into which it is to be deformed.

It is a further object oi this invention to pro vide a new and improved slip and spider apparatus for suspending casing. In this connection it is a particular object to provide a slip and spider apparatus that can be set or positioned on the casing prior :to suspending the casing ir the head and which will remain attached to the casing at the desired point.

It is a further object of this invention to provide a casing head member adaptable to accommodate either a slip apparatus or an abutment means such as an abutment coupling for suspend- It is a further object oi this invention to provide .a method o! and apparatus for landing casing through a drilling tree whereby it is possible to run the casing in the well, provide a slip assembly on the easing which may be run into the drilling tree to some point above the casing head which is to' support the casing, cement the casing, place the proper tension`on the casing after the cement has set, and subsequently force the slip assembly down in the drilling tree to its point o! support in the casing head by nuid pressure. To accomplish the last mentioned step it is a particular object of this invention to utilize an annular exible cup member on the casing above the slip assembly against which fluid pressure can be exerted to move the slip assembly.

These and other objects will be apparent from the drawings and the following description thereof. Referring to the drawings which are for illustrative* purposes Ionly:

Fig. 1 is a sectional elevation of a part of the casing head structure of this invention as it appears prior to running of an inner string of cals- Fig. 2 is a sectional elevation of the apparatus of Fig. 1 showing associated therewith the supporting ring and the expander apparatus for deforming the ring;

Fig. 3 is a detail elevation o! the mandrel of the expander apparatus and the supporting ring and shows in section the positioning bolt extendlng therethrough;

Fig. 4 is 'a sectional elevation of the casina -head apparatus after casing has been landed and suspended within the head;

Fig. 5 is a fragmentary elevation partly in section of a portion of the inner casing of Fig. 4 and showing the slip mechanism mounted thereon;

Fig. 6 is a sectional rplan view on line 6-6 of i Fig.

Fig. 7 is a sectional plan view on line 1-1 of Fig. 5; and l Fig. k is an elevation, partly in section, of two casing head'members associated with parts of a having been set and cemented in the groundafter the first drilling operation. Welded to this is a landing base I2. '-Above the landing base and welded thereto is a casing head body member I3 which is provided with an enlarged bore I4 to accommodate the casing 1II and which has a smaller `bore I5 which is substantially the same as the inner bore of the casing II. ,The member I2 is welded to the casing I I and member I3 Welded to member I2-\at welds I6 and I1 respectively. Above the member I3'there is mounted by means of the usual `flange and bolt construction I8, a. drilling nipple I3.

It is to be understood of course that above the portion of the drilling nipple shown there is the usual drilling tree consisting of the drilling nipple I9 and suitable control means such as blowout preventers, :gates and the like, and above these the rotary table.

The body member I3 ofthe casing head is provided with a suitable threaded opening 2I to accommodate a .pipe 22. Opposite the opening 2 II is another threaded opening 23 which has been shown closed by aplug 24. The purpose of the opening 23 will subsequently be pointed out. The body member I3 is provided with an inner annular recess 25 which has a downwardly and outwardly sloping wall 26 terminating in a shoulder or shelf 21 which is recessed with respect to the bore I5.` The upper end of the bore I5 is threaded at 28 to accommodate a lock ring asrwill subsequently be described and is provided with a `flange 29 so that other elements may be bolted to it as shownin thedrawings and generally indicated by reference numeral I8. In the as` sembling of the units a ring 30 of deformable metal is utilized as a packing member 'and ex- 7 `tends into grooves 3 I in the flanges.

I I; With this type of apparatus normal size parts are used in the drilling tree above the casing head, that is, the borQcI the members above the casing head is substantially the same as the bore I5.

Fig. 1 shows the casing head\appar atus such as is used for drilling beyond the lower extremity of the casing II and, prior to setting of an inner casing. After drilling through this member and the casing II the drillingttools are removed from the hole and itbecomes desirable to land a casing in the newly bored hole. in order so dorms, piug 24 is removed and a bolt 34 (see Fig. 2) is threadably mounted in the opening 23. The bolt extends across and partially into\ the opening 2i.

This bolt is adapted to act as a stop or guide bolt for the positioning of the expanding apparatus generally indicated by reference numeral and the associated supporting ring 36 in position opposite the recess 25 so that the supporting ring may be expanded into the recess to form a shoulder or supporting ledge of less diameter than the bore I5.

The bolt 34 also'serves as a safety member to prevent the ring 36 or any portion of the expander 35 from dropping into the hole.

The expander apparatus 35 comprises a mandrel 38 having ya threaded shank 39, a cylindrical portion 40 and terminating in a head 4I. This head 4I is provided with a transversely extending slot 42 so ythat the expander may be lowered into position and fit over bolt 34. The shank 39 oi the mandrel is adapted to be threadably mounted in a collar 43 which is mounted on the lower end of a string of pipe 44. When the expander is assembled the ring 36 is iirst put on the expander in `the position in which it is shown in Figs. 2 and 3 and then a slip washer 45 is placed over it. Above the washer 45 and between it and the collar 43 is placed a suitable anti-friction thrust bearing 46, the mandrel being threadably mounted in the collar to bring the

parts

43, 36, 45 and 46 into contact as assembled and shown in Fig. 2.

The supporting ring 36 is an annular member having cut-out portions 48 formirg an interrupted lower end and forming teeth 49. The interruptions in the lower end of the ring serve t0 facilitate the expansion of the ring as will subsequently be described. Preferably the ring member is composed of deformable metal.

The expander 35 with ring mounted thereon is lowered into the position in which it is shown in Fig. 2 so that the expander rests on the bolt 34. In this position the ring member is so positioned as to permit of its expansion into the recess 25. Rotation of the string of pipe 44 with its attached collar 43 serves to draw the mandrel 38 through the ring and deform it into the recess so that it assumes the position in which it is shown in Fig. 4. The expander apparatus 35 is then removed from the casing head member and associated drilling tree. Expansion of the supporting ring 36 into the recess 25 provides a supporting shoulder or ledge within the bore I5 of the body member I3 upon which the inner casing may be suspended by means of means ptotruding therefrom.

Referring to Figs. 4 to 7 inclusive, there is shown a preferred form of means for suspendin an inner casing 52 in the casing head. This means comprises a slip and spider assembly generally indicated by reference numeral 53 and comprising a singleslip member 54, a spider member and a retaining ring 56. The slip member 54 is a single piece element provided with a longitudinal slot 58. Internally the slip is provided with the ordinary serrations 59. Externally the slip is provided with longitudinal grooves 5I which are provided for the purpose of making the slip member yieldable to a certain'degree. In this connection it should be pointed out that the slip member is designed to have an inner diam'- eter slightly less than the outer diameter of the casing to be supported by it. With this construction it is possible to place the slip member aboutthe casing, then place the spider 55 over the slip member and subsequently secure the two members together by means of the split ring 56 abutting against the upper end oi' the slip member and fitting into a groove 62 in the spider.

When the slip assembly 53 is thus mounted on a casing as is shown in Fig. the assembly will remain in place on the casing at the desired point. In Fig. 5 there is also shown a flexible cup 84 which will be described subsequently and may be disregarded for the present. Therefore, it is pos-l sible with the apparatus shown to land the casing through the drilling tree and casing head and then raise it to the desired amount, fasten the slip assembly to the casing as-in Fig. 5 and then Above the drilling nipple 8| is mounted a blowlower the casing down into the casing head until the slip assembly rests upon and is supported by the supporting ring 38. Preferably the spider 55 is provided with a shoulder 55', which is adaptedV to seat upon the upper end of the supporting ring 38. After the casing 52 has been lowered into place as shown in Fig. 4 and supported in the casing head by means of the slip assembly 53, the drilling tree including the drilling nipple I9 may be removed from the casing head member I3 and a lock ring 64 threadably mounted in the upper end of the body member I3. This lock ring has an annular recess v85 which is adapted to accommodate packing 66. The packing is compressed into sealing engagement with the inner casing 52 by means of a packing compression ring 61 which is mounted in the lock ring by means of bolts t8. The casing 52 may then be cut oiI at the proper height and another casing head member mounted on the ange 29 of the casing head member I3. This casing head member has been partially shown in Fig. 4 and is indicated generally by reference numeral 15. It is also shown in Fig. 8. It is to b`e understood `of course, that the operation may be repeatedv for as many strings of easing as it is desiredjto set so that when the well is completed there will be a series of casing head members mounted one upon the other supporting a series of casings onewithin the other.

`It is to be understood of course that in place oi the slip assembly 53 an abutment collar of any type may be mounted or secured to the inner casing 52 for supporting the casing uponthe supporting ring 35.

It has been pointed out as an object of this invention to provide a method of landing casing through the drilling tree whereby it is possible to run the casing in the well and provide a slip assembly on the casing which may be run into a drilling tree to some indeterminate point ab`ove the casing head after which the casing may be cemented in place. After the cement has set the casing may be elevated to give it the proper tension and subsequently the slip assembly may be moved downwardly in the drilling tree into the casing head where it will be supported. Referring,

to Fig. 8 to illustrate this method and the apparatus for carrying it out, there is illustrated a lower casing head which is generally indicated by reference numeral which is in all respects similar to the casing head heretofore described and most clearly illustrated in Fig. 4 and the parts of the head therefore bear the same reference numerals. Above this is mounted a second casing head 18'which is of less diameter than the first casing and is adapted to support a third string of casing 11. This casing head 16 is provided with a supporting ring .36 in the manner previously described and the third string of casing 11 is run through the drilling tree into the hole. This drilling tree has been generally indicated by reference numeral 18 and has been shown as comprising a drilling nipple 19, a ram gate valve 80 and another drilling nipple 8|.

tubing 83 which may extend up to any desirable height to some point below the rotary table. It is to be understood that the drilling tree shown is merely for illustrative purposes and that the Y makeup of drilling trees varies greatly. In run- ,ning the casing 11, after sufiicient casing has been run to determine the approximate point at which it is desired to` mount the slip assembly 53, the casing is raised and slip assembly mounted thereon. So that the slip assembly may be moved on the casing after the casing has been run into the hole to proper position for cementing and the slip assembly is at some point in the drilling tree above the ring 36 in head 16, an annular flexible seal or cup 84 is p-laced over the casing above the slip assembly. This cup is shown in Figures 5 and 8. The casing is then run into the hole into position for cementing and cemented into place by pumping cement down casing in the ordinary manner. After the cementhas set and it is desired to place the casing 11 under tension and suspend it from the casing head 16, this may be done by pumping fluid under pressure down inside of the

members

82, 18, 8|, 80, 1 9, thereby forcing the slip assembly down until it rests upon the supporting ring 36 in head 18. In this connectionthe cup 84 under the action of the pressure fluid seals off against the various members of the drilling tree and against the casing 11 and thereby acts as a piston under the action of pressure uid forcing the slip assembly down into the casing head 16.

It is to be understood that the member 82 may be provided with suitable closure means such as a cementing head or the like provided with suitable ports so that pressure iiuid maygxbe introduced and maintained under pressure within member 82 and the other elements of the drilling tree.

After the slip assembly 53 has been forced p down into the casing head 1B, the drilling tree may be parted from that head and a lock ring, packing and compressionspring secured in place as shown in Fig. 4 in connection with head 15. The casing 11 may then be cut off at the desired point. Subsequently other strings of casing may be landed in a similar manner by utilizing successively smaller size casing heads on top of casing head 18.

Referring to Fig. 9 there is shown a type of casing head construction for use where it is desired to use over-size equipment, that is, equipment having a bore larger than the bore of the outer casing or in the case of casing head .members above the lowermost casing head member. a bore larger than the last casing landed. Welded to the outer casing by means of welding 85 is a landing base 81. Welded, above the landing base and mounted on the upper end of casing 85 is a casing head member y88. Member 88 has a bore 89 adapted to accommodate the upper end of the casing 85. Above the bore 88 is an intermediate bore 90 or less diameter and above this bore is an enlarged bore or over-size bore 9| which is of greater diameter than the bore of the casing 85. In the region of the bore 9|) are provided suitable threaded

ports

92 and 93 which are shown as having a plug 94 and a pipe 95 mounted therein respectively. The upper end of the member 88 ls provided with a ange 96 to accommodate another easing head member generally indicated by reference numeral 98 which may be bolted to member 88 by means of the bolt assembly 88. l

'I'he lower end of the bore 9| of member 88 terminates in a downwardly and inwardly sloping shoulder while the upper end of the bore terminates in a threaded portion I0 I. At the upper end o! the threaded portion l0! there is another and larger bore |02. An annular lip |03 is located between portions |0| and |02.

.After the first string of casing 85 has been landed and the

casing head members

81 and 88 mounted thereon, the ordinary drilling tree is mounted upon the flange 86 of the member 88 and the hole is drilled deeper. Subsequently the casing 52a is landed through the drilling tree. A

. slip mechanism generally indicated by reference nular double flange |08 which is adapted to extend into -the recess |03 in the flange 96 and is adaptedto extend into a groove |01 in the lower end of the casing head member 98 when the same is mounted on flange 86. Suitable packing |08 and a packing compression ring |08' are then mounted in connection with the lock ring |05 and secured thereto by the bolts |08. The casing may then be cut off at. the proper height `and the casing head member 98 mounted thereon.

The casing head member 98 is provided at its lower end with a flange ||0 so that it may be mounted upon the member 88. From the iiange H0 the walls oi member 88 extend inwardly at to an inner bore H2. Upwardly oi the bore ||2 is an enlarged bore ||3 which bears the same relation to the casing 52a as bore 9| bears to casing 85. The upper end of the member 88 is the same as the upper end of member 18 except that it is of smaller size and therefore need not be described in detail. The slip assembly, lock ring and packing means for suspending an inner casing ||4 is the same as the slip assembly, lock ring and packing means described in connection with the member 88 except that it is smaller in diameter and therefore need not be described in detail.

It is of course apparent that after member 88 has been mounted on the member 08 that the drilling tree may be mounted -on the member 98 and drilling conducted in the ordinary manner prior to the setting of the casing ||4. Other members 08 of reduced size maybe mounted upon the member 98 for suspending successive inner casings as is the usual practice.

Although the invention has been particularly shown and described it is contemplated that various changes and modifications may be made without departing from the invention and it -is intended to cover such changes and modifications as come within the scope of the claims.

I claim as my invention:

1. The method of providing supporting means in a casing head member having lan inner-annular recess therein which comprises providing an expander, placing a supporting ring on said expander, lowering said expander and ring into said casing head member to position said ring opposite said recess, and operating said expander to position the lower part of said ring in said recess.

2. The method of providing supporting means in a casing head member having an inner annular recess therein which comprises providing an expander, placing a supporting ring on said expander, said ring being wider than said recess, lowering said expander and ring into said casing head member to position the lower end of said ring opposite the lower end of said recess, and operating said expander to deform the lower part of said ring into said recess.

3. 'Ihe method of providing supporting means in a casing head member having an inner annular recess therein which comprises providing an expander, placing a supporting ring on said expander, said ring being wider than said recess, the annularity of said ring being interrupted at its lower end by cut-out portions thereby forming teeth, lowering said expander and ring into said casing head member to position the lower end of said ring opposite the lower end of said recess, and operating said expanderto position said teeth and adjacent portions of said ring in said recess.

4. The method of providing supporting means in a casing head member having an annular recess therein and having means for the reception of a cross bolt in the region of said recess which comprises inserting a cross bolt in said casing head in lthe region of said recess, providing an expander, placing a supporting ring on said expander, lowering said expander and ring into said casing head to seat said expander on said cross bolt, said cross bolt being positioned so as to bring the lower end of said ring opposite the lower end of said recess when said expander is seated thereon, and operating said expander to position the lower part of said ring in said recess.

5. The method of suspending an inner casing within an outer casing which comprises mounting a casing head member on the upper end of said outer casing, said casing head member having an inner annular recess with a shouldery 'at its lower end, lowering a one-piece supporting ring in said head and deforming said ringy into said recess whereby the lower end of said ring is free to seat on said shoulder and the upper end of said ring forms an inwardly extending annular ledge in said casing head member, mounting a supporting means on said inner casing, and lowering said inner casing in said casing head member until said supporting means rests on said ring.

6. The method of suspending an inner casing within an outer casing which comprises mounting a casing head member on the upper end oi said outer casing, said casing head member having an inner annular recess terminating in a shelf` at its lower end, lowering a one-piece supporting ring in'said head and deforming said ring into said recess whereby the lower end of said ring is seated on said shelf and the' upper end of said ring forms a supporting ledge in said casing head member, placing a split slip member on said inner casing, mounting a spider on said slip, saidfs'pider serving to hold said slip in placeA on said inner casing, and lowering said inner casing in said casing head member until said spider rests on said ring.

7, The method of suspending an inner casing within an outer casing which comprises mount-f jing a casing head member having an internal iannular recess terminating in a shelf at its lower