US3177942A

US3177942A - Well head assembly with telescoping tubing

Info

Publication number: US3177942A
Application number: US711457A
Authority: US
Inventors: John A Haeber
Original assignee: Shell Oil Co
Current assignee: Shell USA Inc
Priority date: 1958-01-27
Filing date: 1958-01-27
Publication date: 1965-04-13
Anticipated expiration: 1982-04-13

Description

April 13, 1965 J. A. HAEBER 3, 7,

WELL HEAD ASSEMBLY WITH TELESCOPING TUBING Filed Jan. 27, 1958 2 Shee s- 1 l4 so a INVENTORI 32 JOHN A. HAEBER FIG 2 BY:

HIS AGENT April 13, 1965 JJA. HAEBER WELL HEAD ASSEMBLY WITH TELESCOPING TUBING 2 Sheets-Sheet 2 Filed Jan. 2'7, 1958 FIG.

HIS AGENT United States Patent f 3,177,942 WELL HEAD AdSEMBLY W111i TELESQQEING TUBING .l'ohn A. Haeber, Houston, Tenn, assignor to Sheil Gil Company, a corporation of Delaware Filed Jan. 27, 1953, er. No. 711,457 6 Claims. (Cl. 166-665) This invention relates to methods and apparatus used on oil and gas wells and pertains more particularly to a well head assembly adapted to seal and allow production of an oil and gas well at an off-shore location which is covered by a body of water.

After drilling a well on dry land, a series of two or three or more strings of pipe are normally hung in the well from a well head which seals the annular spaces between the concentric pipe strings and closes the innermost pipestring. The well head normally comprises a number of hanger-spools, from which the pipe strings are hung, together with the necessary valves, gauges, etc. used to control the flow of fluid through the various pipe strings.

When a well is drilled at an offshore location, it is a general practice to have the outermost tubular member or string of pipe extend from the ocean floor to a height well above the wave level of the body of water. The necessary hanger-spools are fixedly secured to the top of this outermost pipe or casing and the other strings of pipe are hung from these spools together with the necessary control valves.

It may be seen that when a structure of this type stands unsupported say in 40 feet of water, it forms a slender, willowy structure overloaded at the top by the well head assembly, which structure is exposed to lateral forces normally applied thereto by wind and wave action as well as possible collision with vessels. in order to stabilize a structure of this type it is a general practice to surround it with a lattice-type platform, the legs of which are driven deep into the earth around the well location. While a platform structure of this type prevents bending or collapse of the well structure above the ground, it does not obviate the possibility of damage to the well structure or its surrounding platform due to collision with an ocean-going vessel.

It is therefore a primary object of the present invention to provide a wellhead apparatus for off-shore locaa tions which is not subject to wind or wave action, or to possible collision with vessels.

The further object of this invention is to provide a suitable well-head assembly for closing a well at off-shore locations while allowing production therefrom in a manner such that the production equipment is not subject to destructive forces due to nature or floating objects.

Another object of this invention is to provide a wellhead apparatus adapted to be positioned on the floor of a lake or ocean, said well-head assembly being designed to allow servicint or reworking operations such as swabhing, removal of parafiin, change of control valves, etc.

Another object of the present invention is to provide a process for installing such a well-head assembly on the floor of a lake or ocean by operations adapted to be conducted from a floating structure.

These and other objects of this invention will be understood from the following description taken with reference to the drawing, wherein:

FlGURE 1 is a diagrammatic view, taken in partial vertical cross section, of the well-head assembly of the present invention in its extended position.

FIGURE 2 is a view taken along the line 2-2 of FIG- URE 1.

FEGURE 3 is a longitudinal view, partly in cross section, of the well tubing of the present assembly secured to a hanger head in its extended position.

3,177,942 Patented Apr.13, 1965 FIGURE 4 is a longitudinal view, taken partly in cross section, of the lower end of the tubing of the present assembly, once the tubing is in its retracted position and is locked in place.

FEGURE 5 is a longitudinal view, taken partly in cross section, of a typical well-head assembly of the present invention with the tubing thereof extending therefrom.

The present invention is schematically illustrated in FIGURE 1 wherein a well-head assembly is shown as closing a well 10 having at least a well casing string 11 and a well tubing string 12 positioned therein. The well casing 11 is fixedly positioned with regard to the ocean floor 13 by being cemented in place, while the tubing string 12 is hung by a doughnut-shaped hanger 14 from a hanging shoulder 15 formed within the closure means 16. The closure means 16 comprises the base of the well-head assembly and is fixedly secured to the top of the casing 11 to close the top of the annular space 17 between the casing 11 and the tubing 12.

Extending upwardly through the doughnut-shaped hanger is a section of tubing string 18 of a diameter which is less than the inner diameter of the tubing string 12 located below the closure means 16.

The upper tubing section 18 is slidably mounted within the hanger 14 in telescoping relation with the lower tubing section 12, thus forming a telescoping sleeve assembly. The length of this telescoping tube section 18 is such that the top of the tubing sect-ion 18 may extend above the surface of the. water 20 and preferably above any wave action thereof.

The tubing section 18 is closed at the top by means of a master valve 21 above which is mounted a production 1' 22 which is preferably closed by a swabbing valve 23. A flexible production conduit or pipe line 24 is provided having one end connected to the production T 22 while the other end is connected to a fixed production pipe line 25 which may be positioned on the ocean floor. When the tubing section 18 and the valve assembly 21-23 at the top thereof are lowered to their retracted position on the top of the well'casing 11, the flexible line 24 is adapted to lie fiat on the ocean floor. Secured to the top of the tubing section 18, or to the valve assembly 21-23 at the top thereof, is a ring 26 to which an anchor line 27 and a float 28 may be secured.

The closure means at the top of the well casing 11 is provided with a suitable type, preferably remotely operable, hold-down device to hold the doughnut-hanger 14 in place. As schematically shown in FIGURES 1 and 2, the closure means 16 at the top of the casing 11 are provided with two

bar elements

30 and 31 fixedly secured to the closure means 16 so that they extend radially over the doughnut hanger 14. The hanger 14 is provided with two slots 32. and 32a allowing the hanger to be inserted below the hold-down

element

30 and 31, after which the hanger is rotated to lock it in position.

As shown in FIGURE 3, the lower end of the upper section of tubing 18 is provided with stop means such as a flange or a portion of the tubing having a larger outside diameter 33 which is preferably provided with a remotely operable lock means such as external threads 34 adapted to mate with internal threads in the bore of the hanger 14. Thus, the flange 33 having threads thereon forms both a stop means for limiting the sliding action of the tubing section 18 and a lock means for locking the tubing in its extended position. While the connection between

threads

34 and 35 also forms a fluid seal, the hanger 14 is preferably provided with other suitable sealing means, for example, O-ring seals 36 positioned in recesses 37 in the hanger 14. Similar O-ring seals may be provided on the outside of the hanger 14 to form an effective fluidtight seal between the hanger 14 and the closure means 16 (PlGURE 1).

The lower tubing section 12 is fixedly secured to the hanger 14 in any suitable manner, as by threads 40. The threads '34 and 35 are preferably relatively coarse, steeppitched threads while the threads 40 on the end of the lower tubing 12 are preferably standard threads for a pipe of that size. If the distance between the well closure means 16 (FIGURE 1) and the surface of the water 20 is not too great, the upper tubing section 18 may be made of a single length of pipe. However, in the event that the upper tubing section 18 is made of more than one length of pipe, the lengths of pipe are preferably joined together in any suitable manner, as by welds, threads, or unions, so as to provide a smooth or flush exterior surface. The lower tubing section 12, on the other hand, may be joined together with conventional threaded couplings, it being understood that the lower tubing section 12 has an inside diameter slightly larger than the outside diameter of the upper tubing section 18.

Formed on the lower end of the upper tubing 18 are a second set of threads 41. As illustrated in FIGURE 4, the threads 41 on the lower end of the upper tubing secion 18 are adapted to form a remotely operable lock means I by engaging mating threads 42 in a special sub 43 which .s fixedly secured to the lower end of the outer tubing section 12 by a coupling 44. If desired, the special sub 13 may be a crossover sub. The sub 43 in turn is coniected by a coupling 45 to the tubing string 46 that exiends downwardly in the well to the producing zone. In FIGURE 4, with the threads 41 of the tubing 18 engaging :he threads 42 of the sub 43, the retractable upper tubing tection 18 is shown in its collapsed, or telescoped, position so that the master valve 21 (FIGURE 1) is locked-down an top of the well head closure means 16. Any other .ocking means well known to the art may be used in place at the threaded sections 41 and 42. With the threads 41 ind 42 in engagement they form a fluid seal which relieves nuch of the pressure from the O-ring seals 36 (FIGURE during normal production of the well when the upper ;ubing 18 is telescoped within the outer tubing 12.

In FIGURE 5 of the drawing a more detailed view of another well-head installation, similar to that shown in FIGURE 1, illustrates another manner in which the apaaratus of the present invention may be assembled. The Nell-head assembly of FIGURE 5 comprises a unitary pipe-hanging manifold 50 which extends above the mud .evel 13. The manifold 50 may be encased in an open- :op housing adapted to hold back the mud and embedded :elow the norrmal mud level. The pipe-hanging manifold 50 is provided with a plurality of tapered portions of pipeianging

shoulders

51, 52 and 53 adapted to

seat pipeianging rings

54, 55 and 56, respectively. The minimum diameter of the pipe hanging manifold 58 is preferably less than that of a water string 57 to which itjmay be ivelded, as at 58. Instead of the well installation comprising only a casing string 11 and a tubing string 12 that s shown in FIGURE 1, the installation illustrated in FIG- URE 5 comprises a water string 57, a protective string 50, an oil string 61, and outer and inner tubing members [2 and 18, respectively.

The hanger ring 54 provides a removable internal ex- :ension of shoulder 51 so as to permit the hanging of :

ubing strings

12 and 18 together with their hanger 14, felatively small pipes, without forming a permanent ob- ;truction in the manifold 50 which might be hit by tools hat may be run in the well. The manifold 50 is sealed lo the earth formation by the cemented water string 57. The protective string 60 and the oil string 61 are suspended From and sealed to

shoulders

53 and 52, respectively, by he sealing and hanging

rings

56 and 55, respectively, vhich in turn are provided with O-ring seals or other fricion sealing means on their outer surfaces.

Ports

62, 63 and 64 are connected to suitable conduits and valves, not ahown, which communicate with the respective annular :

paces surrounding pipes

60, 61 and 12 hanging in the nanifold.

The doughnut hanger 14 connected to tubing 12 is restricted from upward motion by a packer sleeve 65, the sides and bottom of which are provided preferably with friction sealing means 66 and 67 to augment the

seals

36 and 38 on the hanger 14. The packer sleeve 65 is removably locked in place within the pipe-hanging manifold 50 by the cooperation of a spring-loaded latch 76, contained in the packer sleeve, with a recess 77 formed in the inner wall of the manifold 50.

If desired, the inner tubing section 18 may have secured to its outer surface a plurality of friction-sealing means 68 of any suitable type to form a seal between the upper end of tubing 18 and the packer sleeve 65. This insures a tight seal between the formation and the inner tubing 18, which forms the innermost conduit in the well, and the annulus between the tubing 12 of the telescoping tubing assembly and the next larger pipe or oil string 61, which forms the next adjacent conduit that communicates with the lower portion of the well bore.

. The exterior of the pipe-hanging manifold 50 may also be provided with

flanges

70 and 71 for positioning and retaining remotely operable conduit connector means such as interior compression-type blow-out preventers in fluidtight connection with the outside of the manifold 50. In the conventional manner, the blow-out preventers (not shown) can be arranged in the form of an interconnected assembly that extends the fluidtight connection above the manifold to a form connection with the exterior of a pipe running into the manifold. The blowout preventers, for example, may be of the type shown in US. Patent 2,168,764, or a Type K preventer manufactured by, Regan Forge and Engineering Co. of San Pedro, California, 1957 Catalog.

During normal operations of a production well located off-shore and having a Well head assembly of the abovedescribed type, the

tubing sections

18 and 12 are telescoped together so that the master valve 21 rests on the permanent well-head assembly that is fixedly mounted on the ocean floor. At that time, the master valve would be open and swabbing valve 23 closed so that production fluid rising from the well would pass out through

tubings

12 and 18, valve 21, T 22, flexible production line 24 and into the permanent and fixed production line 25 which leads to shore or storage facilities. With the

upper valve assembly

21', 22 and 23 of the well head positioned adjacent the ocean floor, the anchor line 27 rises to the float 28 which marks the position of the well.

In the event that the well-head is to be serviced, a service barge or vessel (not shown) would float out to a position substantially over the well and drop suitable hoisting equipment which would latch on to the

valve assembly

21, 22 and 23 so as to raise it to the surface. If the float line 27 is a cable of suitable strength, this cable may be directly connected to the hoist for pulling the valve assembly and slidable tubing section 18 upwardly until the

valve assembly

21, 22 and 23 is above the surface of the water 20. Master valve 21 could then be adjusted, repaired or replaced, if desired. During the time that the Well or the

valve assembly

21, 22 and 23 is being serviced, the upper tubing 18 is latched in a raised position by engaging a latch means at the bottom of the tubing 18 with those in the hanger 14. Also, tubing 12 and hanger means 14 can be removed from the well if necessary to permit redrilling or other remedial operations. Blowout preventers can be reinstalled by lowering into position over tubing section 18 after valve assembly 21-23 has been removed from the top of tubing section 18. In the event that the latch means consists of the engagement of

threads

33 and 34 as described with regard to FIGURE 3, it will be necessary to provide a swivel 19 in the tubing string 18 below the master valve 20 so that the tubing 18 may be rotated until

threads

34 and 35 engage.

After servicing operations on the well, the latching means at the base of the tubing section 18 are disengaged and the tubing 18 is again telescoped within tubing 12 so that the

upper valve assembly

21, 22 and 23 again rest near the ocean floor in which position they are not exposed to wind and wave action and are out of danger of being involved in a collision with a vessel.

I claim as my invention:

1. A well installation for an ofi-shore well covered by a body of water, said well installation comprising a production well-head assembly fixedly mounted to a well casing adjacent the bottom floor of the body of water, well casing extending from said well-head assembly downwardly into a well bore hole, an outer production tubing string depending from said well-head assembly and positioned within said well casing, said tubing string being in communication through said well casing with a producing formation of said well, closure means in the wellhead assembly closing the space between the well casing and the outer tubing string, and an inner production tubing string section normally supported by said wellhead assembly and adapted to be telescoped within said outer tubing string and in open communication therewith, the length of said inner tubing string section being at least slightly greater than the distance between said wellhead assembly and the surface of the body of water.

2. A well installation for an ofi-shore well covered by a body of water, said well installation comprising a production well-head assembly fixedly mounted to a well casing adjacent the bottom floor of the body of water, well casing extending from said well-head assembly downwardly into a well bore hole, an outer production tubing string depending from said well-head assembly and positioned within said well casing, said tubing string being in communication through said well casing with a pro ducing formation of said well, closure means closing the space between the well casing and the outer tubing string, an inner production tubing string section normally supported by said well-head assembly and adapted to be telescoped within said outer tubing string and in open communication therewith, the length of said inner tubing string section being at least slightly greater than the distance between said well-head assembly and the surface of the body of water, and stop means on the lower end of the inner tubing string section limiting its upward travel.

3. A well installation for an off-shore well covered by a body of water, said well installation comprising a production well-head assembly fixedly mounted to a well casing adjacent the bottom floor of the body of water, well casing extending from said well-head assembly downwardly into a Well bore hole, an outer production tubing string depending from said well-head assembly and positioned within said well casing, said tubing string being in communication through said well casing with a producing formation of said well, closure means closing the space between the well casing and the outer tubing string, an inner production tubing string section normally supported by said well-head assembly and adapted to be telescoped within said outer tubing string and in open communication therewith, the length of said inner tubing string section being at least slightly greater than the distance between said well-head assembly and the surface of the body of water, stop means on the lower end of the inner tubing string section limiting its upward travel and latching means carried by the inner tubing string section for latching said section in fully extended and fully telescoped positions. 1

4. A well installation for an off-shore well covered by a body of water, said well installation comprising a wellhead assembly fixedly mounted to a well casing adjacent the bottom floor of the body of water, well casing extending from said well-head assembly downwardly into a well bore hole, and outer production tubing string depending from said well-head assembly and positioned within said well casing, said tubing string being in com munication through said well casing with a producing formation of said well, closure means closing the space between the well casing and the outer tubing string, an inner production tubing string section normally supported by said well-head assembly and adapted to be telescoped within said outer tubing string and in open communication therewith, the length of said inner tubing string section being at least slightly greater than the distance between said well-head assembly and the surface of the body of water, stop means on the lower end of the inner tubing string section limiting its upward travel, latching means carried by the inner tubing string section for latching said section in fully extended and fully telescoped positions, a valve assembly fixedly secured to the top of said inner tubing string section, and fluid conduit means extending from said valve assembly.

5. A well installation for an ofi-shore well covered by a body of water, said well installation comprising a production well-head assembly fixedly mounted to a well casing adjacent the bottom floor of the body of water, well casing extending from said well-head assembly downwardly into a well bore hole, an outer production tubing string depending from said well-head assembly and positioned within said well casing, said tubing string being in communication through said well casing with a producing formation of said well, closure means closing the space between the well casing and the outer tubing string, an inner production tubing string section normally supported by said well-head assembly and adapted to be telescoped within said outer tubing string and in open communication therewith, the length of said inner tubing string section being at least slightly greater than the distance between said well-head assembly and the surface of the body of water, stop means on the lower end of the inner tubing string section limiting its upward travel, latching means carried by the inner tubing string section for latching said section in fully extended and fully telescoped positions, a valve assembly fixedly secured to the top of said inner tubing string section, fluid conduit means extending from said valve assembly, and a swabbing valve in line with said master valve and inner tubing string 7 section, and a float means secured to said well installation ductor and slidable therein soas to be extensible from the upper end of said conductor to an extended position with its upper end above the surfaceof the water and r etractable'into said conductor to a position in which the upper end of said extension is disposed adjacent the upper end of said conductor; means on said extension and said tubular conductor sealing therebetween when said extension is telescoped into said conductor and when said extension is extended therefrom; and means on said tubular conductor and said extension member for restraining said extension in each of said positions with respect to said tubular flow conductor.

References Cited by the Examiner UNITED STATES PATENTS 1,766,628 6/30 Grant -10 2,148,327 2/39 Smith etal 166-84XR 2,673,615 3/54 Humason 166-84 XR t 2,808,229 10/57 Bauer et a1 1757 BENJAMIN HERSH, Primary Examiner.

BENJAMIN BENDETT, CHARLES E. OCONNELL,

Examiners.

Claims

1. A WELL INSTALLATION OF AN OFF-SHORE WELL COVERED BY A BODY OF WATER, SAID WELL INSTALLATION COMPRISING A PRODUCTIOON WELL-HEAD ASSEMBLY FIXEDLY MOUNTED TO A WELL CASING ADJACENT THE BOTTOM FLOOR OF THE BODY OF WATER, WELL CASING EXTENDING FROM SAID WELL-HEAD ASSEMBLY DOWNWARDLY INTO A WELL BORE HOLE, AN OUTER PRODUCTION TUBING STRING DEPENDING FROM SAID WELL-HEAD ASSEMBLY AND POSITIONED WITHIN SAID WELL CASING, SAID TUBING STRING BEING IN COMMUNICATIOON THROUGH SAID WELL CASING WITH A PRODUCTING FORMATION OF SAID WELL, CLOSURE MEANS IN THE WELLHEAD ASSEMBLY CLOSING THE SPACE BETWEEN THE WELL CASING AND THE OUTER TUBING STRING, AND AN INNER PRODUCTION TUBING STRING SECTION NORMALLY SUPPORTED BY SAID WELLHEAD ASSEMBLY AND ADAPTED TO BE TELESCOPED WITHIN SAID OUTER TUBING STRING AND IN OPEN COMMUNICATION THEREWITH THE LENGTH OF SAID INNER TUBULAR STRING SECTION BEING AT LEAST SLIGHTLY GREATER THAN THE DISTANCE BETWEEN SAID WELLHEAD ASSEMBLY AND THE SURFACE OF THE BODY OF WATER.