US2087528A - Well seal - Google Patents

Description

H. C. OTIS July 20, 1937.

WELL SEAL Filed Sept. 3, 1935 5 Sheets-Sheet l Herbs/ f C Of/lr H. C. OTIS Jilly 20, 1937.

WELL SEAL 5 Sheets-Sheet 2 Filed Sept. 3, 1935 fierberf C 0/711" 5 July 20, 1937. H. c. OTIS WELL SEAL Filed Sept. 3, 1955 5.Sheets-Sheet 3 July 20, 1937. H. c. OTIS.

WELL SEAL Filed Sept. 5, 1955 5 Sheets-Sheet 4 July 20, 1937. c, 0115 2,087,528

- WELL SEAL Filed Sept. 5, 1955 5 Sheets-Sheet 5 M r fierbem C Of/lr f JZ /7 y 1 Patented July 20, 1937 UNITED STATES PATENT OFFICE WELL SEAL Herbert o. Otis, Dallas, Tex.

' Application September'3, 1935, Serial No. 38,862

9 Claims. (01. 166-15) This invention relates to new and useful improvements in tubing. and sealing wells.

One object of the invention is to provide an improved seal whereby tools, packers and the like may be introduced into, or removed from, a well i which is under pressure, without opening up the I well to the atmosphera Another object of the invention is to provide improved means for introducing, or removing tubing and landing or removing a s'tufilng box where the casing contains well fluids under pressure, and in so doing without opening up the well to the atmosphere.

A further object of the invention is to provide improved means for inserting or removing tubing carrying a packer, into a well under pressure and also landing or removing a stufling box for packing off the tubing, without rotating the tubing or opening the well to the atmosphere.

Still another object of the invention is to land or remove supporting slips associated with, but

- separate from, the stuffing box. I

Another object of the invention is to provide an improved stufiing box having means whereby it may be fastened on a tubing and lowered, landed and screwed into a supporting fixture.

A further object of the invention is to provide equipment for running tubing and tools into a casing or removing the same therefrom, and packing off the tubing in a new and novel manner, said equipment being adapted to be removed after the tubing is packedofhall without opening the well to the atmosphere.

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanyi drawings in which an example of the invention is shown, and

wherein:

Figure 1 is a view partly in elevation and partly in section showing an apparatus for carrying out the invention;.

5 Figure 2 is a .view partly in section and partly in elevation showing a stufling box and slips on the tubing between the closures.

Figure 3 is a similar view showing the stufilng box landed, 50 Figure 4 is a view partly in section and partly in elevation showing the stufllng box and slips landed and the closure fixtures removed,

Figure 5 is a plan view of the parts shown in Figure4, q 55 Figures 6, 7 and 8, are horizontal cross-sectional views taken on their respective lines of Figure 4,

Figure 9 is an elevation of the upper end of the stuffing box,

Figure 10 is a view similar to Figure 1 showing equipment for landing the stuffing box when the 5 tubing is supported by a packer,

Figure 11 is an enlarged view of a portion of the same,

Figure 12 is a view similar to Figure 4 showing a stuffing box which supports the tubing without 10 4 the aid of slips,

. Figure 13 is a plan view of the same,and

Figure 14 is a horizontal cross-sectional view taken on the line IL-I4 of Figure 12.

Inthe drawings the numeral [5 designates a 15 tubing head, (Figure 4) having an internally screw-threaded collar H5 at its lower end adapted to. receive the upper end of a well casing ll. At its mid-section the head has the usual internally screw-threaded outlets l8 receiving pipes I9 for 20 carrying ofi fluids and liquids which flow up the casing.

The head also has an upstanding flange or collar 20 (Figure 4) provided with external screw threads 2| and internal screw threads 22. The flange is reduced in thickness toward its upper end, whereby the threaded portions are tapered. The head has an internal downwardly inclined annular seat or shoulder 24. It is to be noted that the head has a bore as large as the casing so that 30 tools may be freely passed therethrough. A packing unit or stuffing box 25 has an externally screw-threaded pin 26 at its lower end adapted to screw into the flange 20 and engage the threads 22. The lower end of the pin may have a bevel 26 and a reduced counter bore 30 is thereby formed below said shoulder. A metallic split packing ring 3! is beveled to rest on the shoulder 29 and loosely fits around a section of tubing T. A plurality of packing rings 32 (Figures 4 and 8) split or otherwise, or any suitable packing, are

supported on the ring in the bore 28 so as to snugly embrace the tubing and pack ofi therearound.

A split metallic follower ring 33 rests upon the uppermost packing ring. The upper portion of the bore 28 is internally screw-threadedatfl to receive an annular pack- I upper blowout preventer 49. These blowout preing nut having ample clearance around the tubing and screwed down to engage the ring 33, whereby the packing rings are compressed. The upper end of the box 25 has an enlarged counterbore 36 to provide clearance for the upper end of the nut. The upper end of the box is slightly tapered and provided with external screw threads 31. Horizontal openings or slots 38 in opposite sides of the upper end of the box gives access to the nut (Figures 4, 7 and 9) The nut has radial holes 39 for receiving a suitable tool (not shown) which may be inserted through one of the openings 38, whereby said nut may be rotated.

The upper edge 40 of the box is finished flat to form a rest for an annular slip housing 4|. The housing has the usual inclined bore 42. A plurality of slips 43 are mounted in the bore and have teeth 44 engaging the tubing and supporting the latter. The slip housing may be placed upon and removed from the box when desired.

In Figure 1 I have shown an ordinary full-opening gate valve 45 screwed onto the flange '20 of the head l5 and engaging the threads 2|. This gate valve is connected with a lower blowout preventer 46 by a casing-size nipple 41. The lower preventer supports an elongate casing-size nipple 48 onto the upper end of which is screwed an venters are now in common use in the oil fields and it is not considered necessary to describe them. When the preventers are opened, any tool, packer or other device which the casing I! will accommodate may be passed through the ele-,

ments f5, 45, 46, 41, 46 and 49.

fluids or liquids under pressure and the gate valve I9 and preventers 46 and 49 are closed to maintain the pressure and it is desired to run the tubing T into the well, the valve I9 is kept closed. The preventers 46 and 49 are opened and the first section of tubing is passed down through said preventers and the nipples 41 and 48. The openings are large enough to pass a working barrel, tubing catcher or other tool which may be carried by the first or subsequent sections of the .tubing. After the tool or other device has passed through the upper preventer 49, the latter is closed around the tubing. The gate I9 is then opened and the tubing run down through the head l5 into the casing l1. When a coupling between two sections of tubing is introduced the lower preventer 46 may be closed and the upper preventer 49 is "opened to permit passage of the coupling. When the coupling arrives in the nipple 48, the upper preventer is .closed and the lower one opened permit passage of the coupling.

When the last joint or section of tubing is picked up, the stufllng box 25 is sleeved over said section and the nut 35 (Figures 4 and '1) is tightenedto compress the packing rings 32 around the tubing. The box is fastened on the tubing at the Properplace by steel set screws 59 engaged in two of the holes 39 which are screw-threaded for this purpose. The heads of the screws project into the openings 35. If necessary an extra length of tubing is added.

a After the coupling on the lower end 01' this section of tubing has been run into the casing as described, the upper preventer 49 is opened and the box 25 is lowered therethrough into the nippie 46,.(F'igures 1 and 2) the lower preventer being closed. The upper preventer is next closed and the lower one opened and the tubing lowered 'lliitil the pin 25 of the stumng b0! 2 fiitelS the flange 20 of the head. By rotating the tubing the pin is screwed into the head and the box thus landed, as is shown in Figures 3 and 4. When the tubing is rotated the heads of the screws 50 engage the ends of the openings 36 and cause the box to rotate with the tubing.

While the slip housing 4| may be lowered with the box, it is convenient to sleeve it over the tubing after the box is landed. The fixtures v45 to 49 inclusive may now be removed leaving the structure as shown in Figure 4. It is obvious that in coming out of the well, after the fixtures are tubing T. In running in a pafcker it is necessary to snub the tubing and this may be done by fastening a cross head 5| on the upper preventer 49, as is shown in Figure 10, and providing it at its ends with sheaves 52. When the tubing is being run, cables 53 each having one end fastened to one side of a split collar 54, are pasged under said sheaves'and connected to a suitable snubbing apparatus. When a pull is exerted on the cables the collar 54 will bepulled down against the tub ing coupling and. the tubing forced into the well.

When the tubing has been run and it is desired v to land the stuiiing box 25, said box is sleeved over Assuming that the casing I1 is, filled with the tubing, but the screws 50 are omitted, and a bell nipple 55 is used instead.- The tubing is supported entirely by the packer This nipple is screwed into a collar 56 which in turn is screwed onto'the threads '31 of the box as is shown in Figures 10 and 11. The upper end of said nipple is connected to the lower end of an oversize length of tubing 51 by a coupling 58. This tubing 51 is sleeved over the tubing T and another length 59 is connected thereto by a coupling 60.

With the tubing projecting as shown in Figure 10, the rams in the preventer 49 are changed to fit the oversize tubing 51. The snubbing collar 54 is applied and pulled down against the coupling 60, whereby the tubing 51 is forced down, whereby the box- 25 is sleeved over the tubing T. Whenthe box assembly arrives in the nipple 46, as is shown in Figure 10, the upper. preventer 49 is closed against the tubing 51 and the lower preventer 45 is opened. The box is now forced down to the head.|5 and screwed thereinto by rotating the tubing 51-59. This is accomplished without rotating the-tubing T. After the fixtures 46 to 49 inclusive are removed the elements 55 to 60 are removed and the sliphousing 4| may then be placed.

supports a plurality of packing rings I2 in the bore 69 embracing the smooth outer surface of the pin 10. A coupling sleeve or nut 13 is screwed onto the pin 10 and is carried by the packing rings, whereby the tubing is supported.

The sleeve 13 extends above the box to receive the next joint of tubing T. Retaining screws 15, mounted horizontally in the top of the box, engage in vertical slots in the sleeve. These screws do not bind the sleeve and while holding it against rotation, permit it to freely move vertically. In using the packing unitshownin Figures 12, 13 and 14, the stufiing box 65 is sleeved onto the section of tubing T ,and the coupling 13 is screwed onto the pin 10 so as to rest upon the upper packing ring 12. The set screws 15 are then inserted and their inner ends extended into the grooves 14. An extra section of tubing I6 is screwed into the coupling 13 and the lowering of the tubing into the well continued. The box 65 is passed through the closures 49 and 46 and thepin 66 of said box is spotted in the flange 20 of the head IS. The box is then landed and the job completed as in Figures 1 to 9 inclusive.

WhatI claim and desire to 'secure by Letters,

Patent is:

1. A well seal including .in combination, a casing, a tubing head having a fluid-tight connection with the casing, a packing unit having a fluid-tight connection with the head, and a packing within the unit for sealing off the tubing and the unit to retain a pressure in the casing and head, the head having external screw threads at its top for receiving a fixture, the packing unit having external threads at its top for receiving a fixture.

2. A well seal including in combination, a casing, a tubing head having a fluid-tight connection with the casing, a packing unit having a fluid-tight connection with the head, a packing within the unit for sealing off the tubing and the unit to retain a pressure in the casing-and head, the head having external screw threads at its top for receiving a fixture, the packing unit having external threads at its top for receiving a fixture, and a slip housing resting on the packing unit and having slips therein for gripping the tubing.

3. A well seal including in combination, a casing, a tubing head having a depending collar screwed onto the casing and provided with an upstanding annular flange internally and externally screwthreaded, a packing-unit externally'screwthreaded at its top and bottom and having its bottom screwed into the flange of the head, and a packing supported in the unit for sealing oil the tubing and the unit, the external threads of the head and the unit being adapted to receive fixtures.

4. A well seal including in combination, a casing, a. tubing head having a depending collar screwed onto the casing and provided with an upstanding annular flange internally and externally screwthreaded, a packing unit externally screwthreaded at its top and bottom and having its bottom screwed into the flange of the head, a packing supported in the unit for sealing off the tubing and the unit, the external threads of the head and the unit being adapted to receive fixtures, and a slip housing resting on the packing unit and having slips therein for gripping the tubing. r

5. A well sealing packing unit including, an elongated tubular member having external screw threads at its top and bottom, packing elements supported within the tubular member, a packing nut screwthreaded into the upper end of the member, and set screws mounted in the nut for fastening it to a tubing, the tubular member having side openings in its upper end for receiving said set screws for giving access to said screws and also for causing rotation of the tubular memher when said nut is rotated.

6. A well sealing apparatus including, a tubing head having internal screw threads, a packing unit having external screw threads at its upper and lower ends and internal packing means, a bell nipple connected with the upper threads of the unit, and an oversize tubing attached to nipple, said unit and nipple and oversize tubing being adapted to sleeve over a tubing extending through said head, whereby the threads on the lower end of said unit may be screwed into the head without rotating the tubing.

7. The combination with tubing having par tially threaded pins at its ends, of a stufiing box having an externally screwthreaded pin at its lower end for screwing into a head, a metallic ring supported-in the box, packing rings fitting the tubing and carried by said supporting ring, said packing rings embracing the pin at one end of a section of tubing, a coupling screwed onto said pin and having an upright groove, said coupling resting on the packing rings for hanging the tubing, and'a set screw carried by the box and extending into the groove of the coupling to cause the box to rotate when the coupling is rotated and permitting said coupling to undergo vertical movement.

8. A well seal including in combination, a casing, a tubing head mounted .on the casing, means on the upper portion of the tubing head for removably mounting and fastening a well closure fixture on the exterior of said head of such size as to permit a stufiing box to pass therethrough, means in the tubing head for landing and securely fastening a stufiing box in said head against upward displacement by the pressure of the well, a trapping enclosure removably carried by the closure fixture and coacting with the closure fixture to pass the stuffing box therethrough with substantially no loss of well pressure, and

means for rotating said stuffing box to fasten it in

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