US2207469A

US2207469A - Casing hanger

Info

Publication number: US2207469A
Application number: US249301A
Authority: US
Inventors: Richard T Roye
Original assignee: Gray Tool Co
Current assignee: Vetco Gray LLC
Priority date: 1939-01-04
Filing date: 1939-01-04
Publication date: 1940-07-09
Anticipated expiration: 1957-07-09

Description

R. T. ROYE CASING HANGER July 9, 1940.

3 Sheets-Sheet 1 Filed Jan. 4, 1939 lllll llllll I. ill'llllll H R WWMRA R. T. ROYE GAS ING HANGER July 9, 1940.

Filed Jan. 4, 1939 3 Sheets-Sheet 2 fobhdra ffl a R. T. ROYE CASING HANGER Jufiy 9, 1940.

Filed Jan. 4, 1939 5 Sheets-Sheet 3 Patented July 9,

Richard T. Roye, Houston, Tex, assignmto Gray Tool Company, Houston, Tea, a corporation of a Texas Application January 4, 1939, Serial No. 249,361

4 Claims.

The present invention relates to a novel form of casing hanger and methods of using the same in completing a well.

An object of the invention is to provide for disposing the lower end of a well casing at any desired point, on the bottom of the hole, or spaced as far as desired above the bottom thereof, to

, facilitate cementing, or for other reasons. The

accomplishment of the above objectives is somewhat difiicult when using ordinary hangers which are threaded to the end of a casing, for when the lower end of the casing .is at the desired position, the point of hanging may be intermediate the ends' of the top joint of easing, where an ordinary hanger cannot be conveniently attached. Spacing nipples of various lengths have been previously employed to solve this problem, but their use requires backing oil the .top joint of casing for which they are substituted, and this is not desirable.

The hanger of the present invention may be disposed at any desired pointon a joint of casing, intermediate the ends thereof.

The application discloses a hanger construc- 2 tion which permits casing to be pulled upwardly therethrough to remove the slack from, or put a strain on the casing, which hanger is adapted to support the casing by slip means or the like, and has provision above the 'point of support for welding the hanger to the casing to form a seal about the latter. Y

An important feature of the invention is to provide a hanger adapted to be welded to a casing, and having slip means to support the casing below the welding point, which hanger is adapted to be lowered through such control equipment as a drilling master valve and blowout preventers, and is provided with means for forming a seal in the casing head. Ancillary to this feature, it is also important that the hanger should have means for sealing with a second casing head above the same, which second casing head is to support an inner string of casing or tubing.

One of the principal objects of the invention is to provide a hanger of the above type having means for retaining the slip means in inoperative position after the hanger is placed on the casing, until it is desired to suspend the casing by the hanger.

Another important feature of the invention is the provision of a novel form of slip segments which facilitates their insertioninto the hanger and permits reduction -of'the space required between the segments.

The departure of the present invention from the prior art is illustrated by the different ways in which the hanger may be used. The disclosure of these procedures is believed to be necessary to teach those skilled in the art the use of the invention.

In the drawings, which are illustrative of several forms of the invention, and which show the hanger associated with now well known combinations of control devices in practicing the in- 1vention, which drawings are in no sense restric- 10 Figure 1 is a vertical sectional view through acasing and hanger, with the casing supporting slips in inoperative position.

Figure 2 is a view similar to Figure 1, with 15 the slips supporting the casing and the hanger welded thereto.

Figure 3 is a horizontal cross sectional view along the line 3-3 of Figure 1.

Figure 4 is a similar sectional view along the 20 line 4-4 of Figure 1.

Figure 5 is a view similar to Figure 2, of a modified form of the hanger.

Figure 6 is a vertical sectional view through now well-known control equipment, showing cas- 25 ing being run in accordance with the present invention.

Figure 7 is a vertical sectional view through a casing head, with a hanger seated therein.

Figure 8 is a view similar to Figure '7, show- 30 ing the hanger welded to the casing.

Figure 9 is a vertical sectional view through the equipment at the top of a well, showing a manner in which several casing heads of the present invention are nested, and 35 Figures 10, 11 and 12 are vertical sectional views through the casing head, somewhat diagrammatical, showing a manner of completing a well with control equipment not large enough to pass the hanger of this invention.

The present invention is intended to provide a system of completing wells wherein the various casings used will be surmounted by a low nest of casing heads at thesurface of the well. The casing hanger disclosed herein, and the method of using the same, may be employed in connection with the broad method of building a well disclosed in Patent No. 2,117,444 to Mueller and Yancey, which issued on May 17, 1938.

In that patent, a method of building wells by running successive strings of casing while maintaining control is disclosed. The method of that patent is such that complete mechanical control is maintained at all times, and yet a low nest of casing heads results. The present ap 55 plication employs the system of the above-mentioned patent, and particularly provides for the disposition of the hanger at intermediate points on a length of casing, as well as permitting exact adjustment of the casing with respect to the hanger after the latter is seated in the casing head. The hanger of the present application also provides for welding the casing to the hanger while the casing is supported by slip means below the welding point.

Referring to Figures 1 through 4, the hanger H is shown embracing a casing C. Said hanger comprises a lower downwardly and inwardly converging conical portion it, a substantially cylindrical collar portion l2 below the same, and an upwardly and inwardly converging conical portion ll above the portion 10. The surface so is adapted to seat in the conical bowl of a casing head, and when seated therein, a seal is formed between the hanger and the casing head by the circular strips of hydraulic packing it which are carried in grooves in the surface I of the hanger. The packing i6 extends throughout the entire circumference of the hanger.

The upper surface H is likewise provided with packing rings l8, which form a seal with an upper casing head as shown in Figure 9, the upper casing head being used to support an inner string of easing or tubing, as shown in said Patent. 2,117,444.

The hanger is provided with a central longitudinal bore 20. This bore is smooth, and is of such diameter that the hanger may slide freely over the casing which it is designed to fit. It will be understood that said hangers are provided of size to fit over and support the various sizes of easing used in building a well. The bore 20 extends downwardly through the interior of the hanger to a point just below the shoulder 22 between the upper and lower sealing surfaces II and ill of the hanger. At this point, the bore merges into an enlarged slip chamber defined by an upwardly diverging conical wall 24 which terminates in a shoulder 26 defining the top of the chamber. This chamber serves to retain any number of slip segments S. The general construction and manner of operation of these slips is well known in the art. They are shaped to fit within the slip chamber, having outer smooth conical walls 21 and inner walls 28 provided with upwardly directed teeth which are adapted under certain circumstances to engage the casing C and support the same. Adjacent the upper ends of the slips, they have an inside groove in which is carried a spring wire 3|, said wire serving to hold the slip segments in proper relation to each other,

Each slip section is provided with a threaded opening 29 adapted to be aligned with a corresponding opening 30 through the wall of the lower collar portion i2 of the hanger. Screws 32 are passed through the openings II and are threaded into the openings 2! in the slip sections. to retain the slips in their upper or inoperative position as shown in Figure 1.

' The hanger described above is adapted to be slipped over a string of well casing as the same is being run into a well, or to be slipped over the upper end of a string of casing after the same has been run into the well and cemented. At the present time, strings of well casing are supplied by the manufacturer to the field with the attaching collars more or less rigidly secured to the upper end of a particular section of easing. While this collar can-be removed, it is desirable not to do so unless necessary. as it is sometim a difilcult tong job to unscrew it, and there is, of course, the possibility of gelling the threads when the collar is removed. Consequently, it is desirable to slip the hanger H upwardly over the lower end of a particular Joint. of easing, said end not being equipped with a collar, as supplied to the field. As this upward movement of the hanger with respect to the casing is one which would ordinarily tend to move the slip sections s downwardly in their chamber causing them to grip the casing, it is necessary to have the releasable screws 22 to lock the slip sections in their inoperative position as shown in Figure 1, during this movement.

In using the above-described hanger. it is slipped over the string of casing being inserted and positioned at the desired point thereon, either during the lowering of the casing into the well or after the casing has been run in and cemented. After the cement has set, the hanger is moved downwardly over the casing into the bowl of the casing head, and the casing is then pulled up wardly by the conventional means in the derrick to remove the slack therefrom, or to take a strain on the casing, as desired. It will be understood that before the hanger is disposed in the bowl of the casing head, the screws 32 will have been removed, to release the slip sections S. When the strain taken by the derrick draw works is released, the resulting downward movement of the casing moves the slip sections S downwardly in the chamber on the interior of the hanger, and the outside conical surfaces 26 on the slip sections move downwardly along the inside conical surface 24 of the hanger, causing the slips to be forced against the casing so that the teeth 28 thereof rigidly grip the casing to support the same.

With the slip sections supportingthe casing in the hanger, the latter in turn being supported in the bowl of the casing head, the upper end of the hanger is welded to the casing as shownv at 34, the hanger being provided with a countersunk portion 3 at the upper end of the bore 20 to receive the welding metal. It will be understood that the welding is performed after the derrick equipment has pulled the casing upwardly through the hanger, so that when the strain of the draw works is released, the casing is supported by the slip sections 8. Consequently, during the welding operation, there is no strain on the casing, and thus no tendency for the same to elongate during the time the welding heat is applied,

After the performance of the above operations, the casing is supported by the hanger in the casing head through the slips, at a point below the weld 24. The weld serves principally to form a seal between the hanger and the casing at the upper end of the bore 20, it being obvious that the outside surface III of the hanger will already have formed a seal between the outside of the hanger and the bowl of the casing head when the hanger is seated therein. While the principal function of the weld 34 is to form a seal as described above, it also acts as an auxiliary supporting means for the casing in the event that the slip. sections should not function to retain the load of the casing and serves to prevent any upward movement of the casing. 1

In Figure 5, a modification of the hanger is disclosed wherein the lower collar i2 of the embodiment of Figures 1 and 2 is eliminated, and the sealing surface Ill continues to converge spouse receive screws 44 which are adapted to engage beneath the lower ends of the slip sections 8 and hold them in their upper inoperative position, similar to that disclosed in Figure 1, when the hanger is being slipped over the casing.

When the screws N are removed, the weight of the casing'will move the'slips downwardly to [their engagin position as shown in Figure 5, at

which time they support the casing, and the weld may beperformed at 84 as described in connection with the principal embodiment of the invention.

In Figure 6, a now well known arrangement of control equipment is disclosed for use in running casing under control as described in the abovementioned patent to Mueller and Yancey, No. 2,117,444. This control equipment is shown mounted on a casing head 48, which is secured to the upper end of the outer string of casing 60. This casing head need not be described in detail, other than to perhaps say that it is provided with the usual side outlets 52 and with a conical bowl seat 54 to receive the surface III of the hanger. I

Secured to the upper end of the casing head 48 by fittings of like size, and forming a seal therewith, is a well-known master drilling valve 5i, and mounted above said valve and sealed thereto by fittings of like size are a pair of

blowout preventers

56 and 58. These blowout preventers are well-known in the art, and they include retractible semi-cylindrical shoes which engage and form a seal with the casing being inserted or withdrawn. These blowout preventers may be manually or fluid operated.

The bore 59 through the master drilling valve and blowout preventers is larger than the interior diameter of *the casing 50 on which this control equipment is mounted, and said bore is of sufficient diameter to permit the passage of the hanger H therethrough to its seat 54. A pair of blowout-preventers are provided, so that one may be in engagement with the casing C while the hanger H is being passed through the other of said blowout preventers. The function of the master drilling valve is of course to close off the I upper end of the well during the period when changes of equipment are being made.

The above-described hanger may be used in various ways in association with the control equipment illustrated in Figure 6.

In a preferred method of running casing, the same is passed throughthe control equipment while maintaining complete mechanical control as described in the above-mentioned patent to Mueller and Yancey, No. 2,117,444; Before the last string of casing is attached to the collar 60, the hanger H may be passed upwardly over the lower end of the said section of casing to any desired point throughout the length thereof, preferably to a point as shown in Figure 6 wherein it is above the control equipment during the cementing operation. Obviously, the hanger is then above the point of hanging of the casing. With the control equipment still in place, the cementing is performed in the usual manner, by pumping cement downwardly through the casing while a seal is maintained by the blowout preventers, circulation being effected by discharge of the upwardly moving fluid in the casing 50 through the outlets 52. After the cement has removed.

set, and the blockade is thus formed, the hanger, H is moved downwardly over the casing through the controlequipment until it is seated in the bowl ll. With the hanger seated in the bowl of the casing head, the control equipment is th It will be understood that the slip retaining screws 32' may have been removed after the hanger was first disposed on the casing above the control equipment, although such procedure is not Preferred, or they may be removed just before the hanger is lowered through the control equipment into its seat. If necessary, any wellknown form of strap 82 may have'been used to support the hanger in the desired position during the cementing operation. However, the preferred procedure is to remove the retaining screws 32 just before the hanger is finally seated, after the control equipment is removed.

When the hanger has been disposed in its seat as shown in Figure '1, the casing will of course extend upwardly beyond the hanger, and by attaching the derrick draw works thereto, the slack in the casing may be removed, or a strain may be taken thereon. As previously described, when this strain is taken on the casing, the same moves upwardly through the hanger, which remains in its seat 54. It is preferable to leave the retaining screws in place .until after the strain is taken on the casing. At this time, the hanger can be checked in the casing head bowl with the slips retracted. With the amount of stretch in the casing thus determined, the hanger may be lifted out of its seat, the screws 32 removed, and the hanger then again seated. The strain taken on the casing by the draw works is released, and the weight or tension of the casing is thus taken by the hanger, whose slips are moved downwardly in their chamber to grip the casing and rigidly support it in the casing head. By taking the strain on the casing, it is insured that a suilicient force is exerted downwardly on the hanger to force it tightly against its seat.

After the strain on the casing by the draw works has been released, and the casing is acting to force the hanger against its seat, and while the slips are supporting the casing, the weld is made 'at 34 as previously described. As stated, this weld is primarily to form a seal between the case ing and the hanger. There is no strain on the metal of the casing at the time the weld is being made. After the weld is completed, the remaining length of casing above the same is cut off, and the hanger is in position to receive the next casing'head to be built above the same, or to receive a tubing head if thelast string of casing has been set.

The above procedure may be modified, if desired, by removing the control equipment with the hanger in the position of- Figure 6, without lowering the same through the control equipment. The hanger can then be moved downwardly into its seat, the strain taken on the casing, and the hanger then lifted out of its seat to remove retaining screws 32, after which the hanger may again be seated with the slips ready to take the load of the casing when the pull thereon is released.

The procedure outlined above may, of course, be varied, depending on circumstances. If it is found to be convenient to remove the attaching collar from the upper end of the last string of casing, the casing may be run into the well through the control equipment and cemented before the hanger H is applied thereto. Whenthe cement is set, the control equipment is removed, and at this time the hanger H may be slipped downwardly over the upper end of the last string of casing and moved to its seat. Thereafter, the preferred procedure previously described is followed.

If it is not desired to wait until the control equipment is removed before welding the hanger in place, the hanger may be moved downwardly through the control equipment after the cementing operation, and disposed in its seat 84. Thereafter, the lower flange 84 of the master valve Ill may be loosened from the flange of the casing head 48, and the control equipment hoisted upwardly by a cat-line auxiliary hoist from the derrick to leave a space sufflciently large to perform-the welding operations described in connection with Figure 8. If this procedure is followed, after the control equipment is hoisted, the strain on the casing is taken by the draw works, the strain is released to set the slips, and the hanger is welded to the casing, after which the upwardly extending portion of the casing is cut off and removed, and then the control equipment may be merely moved laterally from its position on the top of the well.

The above-described procedures for employ,-

ing the invention are, of course, preferred. However, in field operations it is often necessary to adapt the procedure to the limited equipment available. It is, of course, desirable to use hangers of the type described herein, but in some fields, the control equipment available does not have a large enough bore to pass the casing hanger. This situation is illustrated in Figures 10, 11 and 12. -When such a situation is encountered, and after the casing has been run in and cemented through the control equipment shown at 56 and 58', the latter is elevated, after unilanging the master valve 50 from the casing head 48, a sufficient distance to perform operations between the same. The casing may then be severed as at 10 and the hanger H slipped downwardly over the upper end of the portion of the casing which extends down into the well. The severed section of easing may be lifted up through the control equipment and the latter removed, or the control equipment may be merely left in place. The hanger is moved downwardly over this casing until it engages in the seat of the casing head 48, after which the casing is again welded together above the hanger as shown at I! (Fig.- 11). If the control equipment is still present, it is kept hoisted and with strain taken on the casing, the hanger is welded to the casing in the usual way at 34, in Figure 11. When this has been done, the'upwardly extending portion of the casing used to take a strain on that portion in the well is then cut of! as at ll (Fig. 12), above the hanger, and the cut-away portion is lifted up through the control equipment and removed. Thereafter, the control equipment may be moved laterally from above the casing head.

Of course, the control equipment in the above procedure may have been removed immediately 'after the casing was out at 10 in Fig. 10.

The hanger of the present invention may be used to carry out older methods of procedure, in the following manner, and with reference again to Figure 6. After running the casing through the control equipmentin the usual way, and cementing the same, the top joint of the casing may be backed off from the coupling 60 and removed through the control equipment,

asomeo which may then be removed. The hanger K may then be slipped upwardly over the lower end of this Joint of casing which has been removed, and then said casing may be moved downwardly and screwed back into the joint 80. The hanger will then be preferably slid down into its seat, after which the strain can be taken on the casing and the welding of the hanger upon the casing can be performed as described above. Of course, the welding could be done before removal of the control equipment by hoisting the latter a short distance on a cat-line, if desired.

It will be apparent that there may be considerable variation from the procedures outlined above, and various of the steps described may be eliminated and the respective procedures combined in different ways. i

In Figure 9, the low nest of casing head resulting from the practice of the present invention is illustrated. The first casing head is shown at 48, into which is seated the hanger H in the manner previously described. After this hanger is seated, a second casing head 16 is mounted above the same. This casing head also has appropriate side outlets II and a hanger seat I0. Proper size control equipment is then mounted on this second casing head, and drilling and the running of casing then proceeds in the manner described in the Mueller and Yancey Patent No. 2,117,444. The hanger H is then positioned on the next string of easing, strain is taken and the hanger is welded to the casing as previously described. If. further casing is to be run, the casinr, head 82 equipped similarly to the other casing heads may be positioned above the casing hanger H or a tubing hanger if the oil sands have been penetrated.

When the casings have been run, cemented, and welded to their hangers, and the hangers locked down by the next casing head or tubing head, above, the casings are held against any subsequent tendency to move upwardly. That is, conditions in a well may be such as to cause the casing to expand, and this problem may be in certain circumstances just as troublesome as getting the right amount of tension in the casing string.

- The condition sought for is to have the casing supported in the well so that one half of its weight is carried by the cement at the bottom of the hole, while the other half of its weight is carried by the casing hanger. Under these ideal conditions, the casing acts like a spring which is capable of contracting and expanding without putting undue strain on either the equipment at the surface of the well orthe cement at the .bottom of the hole.

The above description relates principally to the construction of the hanger which facilitates its use in completing a well. The present application further discloses improvements in the hanger and slip construction which facilitate assembly of the slips into the hanger.

The novel construction of the slip segments which facilitates their assembly with the hanger is illustrated in Figs. 3 and 4. While any convenient number of slip segments may be used in carrying out this improvement, I have shown an arrangement using four such segments. Each of these segments has inner and outer concentric surfaces -curved to conform with the casing C, and their inner curved surfaces flare, of course, provided with the serrations or other means to grip the pipe as previously described. Each slip section has a pair of side faces. and each of these side faces is disposed in juxtaposed relation with respect to a side face of an adjacent slip section.

Referring to Figure 3, the side faces of the slip section 99 are shown at 9| as cut in planes radial with respect to the axis of the casing C. Each of the slip sections 93 has opposite side faces, one of which is also cut in a plane radial with respect to the axis of the casing C. This radial face 94 opposes the side face 9| of the slip section 90. However, the opposite faces 95 of the slip sections 93 are cut in planes nonradial with respect to the axis of the casing C. When the slips are assembled in the hanger, as shown in Fig. 3, the planes of the respective faces 95 are parallel.

The slip section 96, which is disposed between the slip sections 93, has both of its side faces 91 cut in planes non-radial with respect to the axis of the casing C. The side faces 91 of the slip section 96 are cut in parallel planes.

In the prior art, it was conventional to cut all of the side faces of slip sections radially with respect to the axis of the well pipe. If the slip sections of the present invention were cut in this manner, considerable space would have to be left between their side faces in order to insert them into their chamber. By employing the present method of cutting the slips, I am able to reduce the space required between the segments.

When assembling slips of this type in the hanger, segments and the two segments 93 are first inserted in the chamber of the hanger. Thereafter, the slip segment 96 can be inserted into the chamber between the surfaces of the slip segments 93, forming a circular ring around the casing.

The difliculty which this slip design overcomes will be apparent from an examination of the construction of the hanger H. Referring to Figure 1, the bore of the hanger at its top and bottom is shown only slightly larger than the casing C over which the hanger is placed. Therefore, the problem of inserting conventional slips into the hanger is a difficult one, unless a great many slip segments are used, or unless the slip segments are not disposed closely adjacent to one another. The disadvantage of necessarily using a great many slip segments is obvious, and if wide spaces are left between the segments the gripping efliciency of the assembly is thereby greatly reduced.

It will be obvious that various changes may be made in the constructions described herein without departing from the invention.

I claim: 1. A hanger for suspending casing in a well having a curved outer surface to conform with I support the casing, and releasable means on said hanger for retaining said slip means in inoperativeposition while said hanger is being moved of a casing head, and having an upwardly tapered curved upper portion to engage an upwardly tapered interior of a second casing head, said hanger having means at its upper end above said upper tapered portion for there welding the hanger to the casing, said hanger having a longitudinal bore therethrough of diameter to permit sliding movement of the hanger along the outside of the casing, said bore being enlarged below the upper end of the hanger providing a chamber, slip means in said chamber for gripping and supporting the casing, said slip means being arranged for movement in said chamber from inoperative position to position to engage and support the casing, and releasable means on said hanger for retaining said slip means in inoperative position while said hanger is being moved along the casing.

3. A hanger for suspending casing in a well having a curved outer surface to conform with and seat in the curved bowl of a casing head, said hanger being of size and shape adapting it for lowering through a blowout preventer and a master drilling valve, means on said outer surface for forming a seal with the bowl of the casing head around the hanger, said hanger having means at its upper end for there welding the hanger to the casing, said hanger having a longitudinal bore therethrough. of diameter to permit sliding movement of the hanger along the outside of the casing, said bore being enlarged below the upper end of the hanger providing a chamber, slip means in said chamber for gripping and supporting the casing, said slip means being arranged for movement in said chamber from inoperative position to position to engage and support the casing, and releasable means on said hanger for retaining said slip means in inoperative position while said hanger is being moved along the casing.

4. In apparatus of the character described, an outer string of casing having a casing head at the upper end thereoi', said casing head having an inside boreformed to provide a hanger seat, an inner string of casing extending through said casing head, a hollow hanger surrounding the upper end of said inside string of casing, and supported in said seat, said hanger having an inside recess and slip means in said recess which engages the outer wall ofsaid inside string of casing and supports the latter in said hanger. said hanger having means wherebysaid slip means are held in inoperative position while the hanger is being positioned on said inner string of casing, said hanger being welded to said inner string of casing above the point where the latter is supported by said slip means, the weight of the inner string of easing being carried by said hanger through said slips, said weld serving as a sec-- ondary support for said inner string of casing and serving to close or the space between the same and said han r- RICHARD T. ROYE.