US3326285A

US3326285A - Apparatus for running equipment into and out of offshore wells

Info

Publication number: US3326285A
Application number: US390157A
Authority: US
Inventors: Clarence J Coberly
Original assignee: Kobe Inc
Current assignee: Kobe Inc
Priority date: 1964-08-17
Filing date: 1964-08-17
Publication date: 1967-06-20
Anticipated expiration: 1984-06-20

Description

June 20, 1967 c. J. COBERLY 3,326,285

APPARATUS FOR RUNNING EQUIPMENT INTO AND OUT OF OFFSHORE WELLS I Filed Aug. 17, 1964 4 Sheets-Sheet 1 FIG. 1.

f3 /0 4 s ,J /4 34 INVENTOR.

CLARENCE J. 60552 5y H/S ATTOEA/EYS HARRIS, MEG/f, Russ/54L 8c KERN C. J. COBERLY 3,326,285

APPARATUS FOR RUNNING EQUIPMENT INTO AND OUT OF OFFSHORE WELLS June 20, 1967 Filed Aug. 17, 1964 4 Sheets-Sheet 2 7 FIG. 40 .P'i'z'a. 2.

. y 4a 2 E.

J 52 54 22 flfi INVENTOR CZA BEA/CE J. COBERLY 5) /-//S ATTORNEYS fl ee/s, A750 Russ/ELL & Mae/v June 20, 1967 c. J. COBERLY 3,326,285

APPARATUS FOR RUNNING EQUIPMENT INTO' AND OUT O F OFFSHORE WELLS Filed Aug. 17, 1964 4 Sheets-Sheet 5 FIG. 3.

' INVENTOR.

CLARENCE J. 605520 54 BY HIS ATTO/QA/EYS //4E/$7 A756, P055544 & KER/ll June 20, 1967 c. J. COBERLY 3,326,285

APPARATUS FOR RUNNING EQUIPMENT INTO AND OUT OF OFFSHORE WELLS 4 Sheets-Sheet 4 Filed Aug. 17', 1964 .ZZQ

INVENTOR. CLAQEA/CE J. COBERLY 5y H/S A 7'7'0P/l/E Y5 HAez/s, M507; P053544 & A ERA/ United States Patent 3,326,285 APPARATUS FOR RUNNENG EQUIPMENT INTO AND OUT 0F OFFSHORE WELLS Clarence J. Coberly, San Marino, Calif., assignor to Kobe, Inc., Huntington Park, Califl, a corporation of California Filed Aug. 17, 1964, Ser. No. 390,157 13 Claims. (Cl. 166-.6)

The present invention relates in general to apparatus for running equipment of various types into and out of oil wells, and particularly completed oil wells, in locations which are either entirely inaccessible to personnel, or which do not provide normal accessibility.

For example, the invention finds particular utility in connection with submerged offshore wells in ocean depths which do not permit the use of divers, although the in vention may, of course, be practiced in shallower water. For convenience, in disclosing the invention, it will be considered herein in connection with such a submerged, offshore well.

As general background, the invention contemplates a submerged, offshore well completion comprising a system of tubular members set in a Well drilled into the ocean bottom. This system of tubular members may comprise a conventional casing having one or more tubings therein. Alternatively, the well completion may be of the casingless type in some instances, in which event the system of tubular members may comprise one or more tubings cemented in place in the well without a casing.

The primary object of the invention is to provide a submerged, offshore well completion of the foregoing nature incorporating means for bringing to the surface of the water the upper end of that tubular member, or the upper ends of those tubular members, to which access is required in performing a particular servicing or remedial operation, or the like.

More particularly, the basic object of the invention is to provide a submerged well completion which includes at least one tubular member set in the well and provided at its upper end with a telescoping section of a length sufficient to project above the surface of the water when the telescoping section is fully extended upwardly, and which includes means for extending the telescoping section upwardly to bring its upper end above the surface of the 'water. This makes the upper end of the telescoping tubular member accessible from above the surface of the water for the purpose of servicing or remedial operations, or the like, which is an essential feature of the invention.

Another and important object of the invention is to provide means for extending the telescoping section upwardly which acts on the telescoping section adjacent its upper end to avoid column loading of the telescoping section.

Still another object is to provide buoyant means connected to the telescoping section adjacent its upper end for extending same upwardly and for lowering same into its retracted position in the well.

A further object is to provide means for varying the buoyancy of the aforementioned buoyant means to vary the upward force applied thereby to the upper end of the telescoping section of the telescoping tubular member. With this construction, the telescoping section can be extended upwardly, or retracted downwardly into the well, as required.

An additional object of the invention is to anchor the buoyant means against excessive horizontal displacement when it has extended the telescoping section upwardly so that its upper end is above the surface of the water.

Yet another object is to provide means for latching the telescoping section in its retracted position, and to provide means for unlatching the telescoping section when it is desired to extend same upwardly to bring its upper end above the surface.

A still further object is to provide cushioning means for terminating the upward and downward strokes of the telescoping section to minimize shock.

Another object is to provide controls for various components of the installation, such as controls for varying the buoyancy of the buoyant means, controls for the latching means, and the like, located at some suitable control station, such as a marker buoy above the well location, an onshore station, or the like.

An important object of the invention in connection with one embodiment thereof is to provide a telescoping tubular member which is simply a tubing having a telescoping section to be extended upwardly above the surface of the water for access to the interior thereof. A re lated object is to provide such a telescoping tubing comprising a pump tubing for running a fluid operated pump into and out of an operating position adjacent the bottom of the submerged well. With this construction, the upper end of the telescoping section of the pump tubing is rendered accessible, from a point above the surface of the water, to permit insertion of a fluid operated pump thereinto, or removal of such pump therefrom.

Another object of the invention in the foregoing connection is to utilize a fluid operated pump which is capable of being circulated hydraulically between its operating position in the well and the upper end of the telescoping section of the pump tubing.

Still another object is to provide a pump tubing having a telescoping upper section which includes at its upper end a tubing head incorporating a pump catcher for engaging and holding the fluid operated pump after it has been circulated upwardly into the upper end of the telescoping section of the pump tubing from its operating position in the well. Once the fluid operated pump has been caught by the pump catcher in the tubing head at the upper end of the telescoping section of the pump tubing, such telescoping section may be extended upwardly to project the tubing head above the surface of the water so that the fluid operated pump may be removed.

An important object of the invention in connection with another embodiment thereof is to provide a sub merged well completion wherein the telescoping tubular member is a casing having one or more tubings suspended therein from a casing head mounted on the upper end of the telescoping section of the casing. With this construction, the casing head and the upper end of any tubing or tubings suspended therefrom are projected upwardly above the surface of the water, upon upward extension of the telescoping section of the casing, so that any desired servicing or remedial operations may be performed. In other words, the entire well is rendered accessible from a point above the surface of the water for any desired servicing or remedial work, this being accomplished readily merely by providing the buoyant means with sufficient capacity to lift the telescoping section of the casing, the casing head, and any tubing or tubings suspended from the casing head.

Another and important object is to provide a buoyant meanscarrying a superstructure which is located above the surface of the water when the telescoping section of the casing is extended upwardly, and which includes a working platform from which servicing or remedial operations, including pulling of the tubing or tubings in the casing, may be carried out. With this construction, all of the operations which are normally carried out at the well head of an onshore completion may be performed with an offshore completion from the working platform carried by the buoyant means for lifting the casing head and the upper end of the tubing or tubings above the ;urface of the water, which is an important feature of :he invention.

The foregoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results thereof which will be evident to those skilled in the art to which the invention relates in the light of this disclosure, may be achieved with the exemplary embodiments ofthe invention described in detail hereinafter and illustrated in the accompanying drawings, in which:

FIG. 1 is a view, partially in elevation and partially in vertical section, of a submerged, offshore well completion incorporating means for projecting upwardly above the surface of the water a single telescoping tubing section carrying a tubing head;

FIG. 2 is an enlagred, vertical sectional view of the upper end of the apparatus of FIG. 1;

FIG. 3 is a downward continuation of FIG. 2;

FIG. 4 is a downward continuation of FIG. 3;

FIG. 5 is a fragmentary vertical sectional view duplicating a portion of FIG. 3, but illustrating alternate operating positions of the components shown; and

FIG. 6 is a view similar to FIG. 1, but illustrating a submerged, offshore well completion incorporating means for projecting upwardly above the surface of the water a casing head carried by a telescoping casing section and having suspended therefrom a complete fluid-operatedpump tubing system.

Submerged well completion with upwardly extensible tubing head Referring to FIGS. 1 to 5 of the drawings, illustrated therein is a submerged, offshore oil well completion 10 comprising a well bore 12 drilled into the submerged bottom 14 of body of water 16 the surface of which is designated by the numeral 18. The well bore 12 may, for example, be drilled into the ocean bottom. The well or well completion 10 is characterized by the fact that it includes a tubing set in the well bore 12 and having a telescoping upper section 22 which carries a tubing head 24 and which is upwardly extensible to project the tubing head above the surface 18 of the water 16. Preferably, the tubing 20 is a pump tubing through which a fluid operated pump 26, FIG. 2, may be circulated between the tubing head 24 and an operating position in a bottom hole assembly, not shown, set in the well bore 12. As will be described in more detail hereinafter, when the telescoping section 22 of the pump tubing 20 is extended upwardly to project the tubing head 24 above the surface of the water, the fluid operated pump 26 may be removed for servicing, repair, or replacement. As will be apparent, this may be accomplished from a boat, or the like.

Continuing to consider the well completion 10 in a general way, the telescoping tubing section 22 is adapted to be extended upwardly by a buoyant means 28 which is connected to such tubing section adjacent its upper end to avoid imposing any column loading thereon. The buoyant means 28 comprises a float 30 of the buoyancy of which may be varied, to extend the telescoping tubing section 22 upwardly and to retract it downwardly into the well bore 12, byintroducing air thereinto and discharging air therefrom in a manner to be described. To avoid excessive flexing of the telescoping tubing section 22 when it is in its upwardly extended position, horizontal movement of the float 30 is minimized, as by means of chain guys 32 connected to the float and to anchors 34 on the bottom 14. It will be understood that such guying of the extended telescoping section 22 is necessary since it may have a length in excess of one thousand feet in some instances. The float 30 is shown as having a marker buoy 36 attached thereto by a cable 38 to mark the location of the well 10. The marker buoy 36 may also carry various control means to be described hereinafter, such as control means for varying the buoyancy of the float 30. However, such control means may also be located at a nearby onshore control station, or at any other suitable control location.

Turning now to a more detailed consideration of the well completion 10, and referring particularly to FIGS. 3 and 4 of the drawings, it is shown as including a surface casing 44 set in the upper end of the well bore 12 and having therein an inner casing 46. Production fluid may enter the inner casing in various ways. For example, the productive zone may be left uncased, where it is sufficiently consolidated to permit this, in which event the production fluid enters the inner casing 46 through its lower end. Alternatively, production fluid may enter the inner casing through perforations therein, through a perforated liner, not shown, connected to the inner casing, or the like.

As shown in FIG. 3, connected to the upper end of the surface casing 44 is a suitable well head 48, the inner casing 46 being suspended from and sealed relative to the well head by a suitable slip and sealing arrangement 50. Disposed in the inner casing 46, and suspended from the well head 48 in a manner to be described, is a fluid-operated-pump tubing system 52 which includes as one component thereof the hereinbefore-discussed pump tubing 20. In the particular construction illustrated, the tubing system 52 is a closed system which includes

tubings

54 and 56 in side-by-side parallel relation with each other and with the pump tubing 20. It will be understood that the

tubings

20, 54 and 56 are interconnected at their lower ends by a bottom hole assembly, not shown, which receives the fluid operated pump 26 when the latter is in its operating position in the well bore 12. The

tubings

54 and 56 are supply and return tubings, respectively, for delivering operating fluid under pressure to the pump 26 from the well head 48 and for returning spent operating fluid to the well head. Production fluid discharged by the pump flows upwardly to the well head 48 through the pump tubing 20. It will be understood that although the fluid-operatedpump tubing system 52 has been disclosed as a closed system, wherein the production fluid and the spent operating fluid are returned to the well head 48 separately, it may also be an open system if desired.

As shown in FIG. 3 of the drawings, the upper end of the stationary section of the pump tubing 20 is connected to a sleeve 58 of a tubular supporting member 59 having at its upper end an annular flange 60 seated on the well head 48 to support the tubing system 52. Surmounting the supporting member 59 is a manifold housing 62 having connected thereto supply and return lines 64 and 66 which communicate with the upper ends of the supply and return

tubings

54 and 56, respectively, through supply and return

passages

68 and 70 in this housing. Also formed in the housing 62 is a production fluid chamber 72 into which production fluid discharged by the fluid operated pump 26 flows in a manner to be described. From the chamber 72, the production fluid flows through a passage 74 into a production fluid line 76. The supply, return and production fluid lines 64, 66 and 76 extend along the ocean bottom 14 to a suitable operating station, which may be an onshore station, or which may be located on an artificial island, an operating platform, or the like.

Considering now the relationship between the telescoping section 22 of the pump tubing 20 and the stationary section thereof, the latter includes at its upper end an enlarged section 80 of a diameter and length suflicient to house the telescoping section 22 when it is retracted downwardly thereinto. The inside diameter of the sleeve 58 of the supporting member 59 for the tubing system 52., and the inside diameter of the enlarged tubing section 80, are sufficient to provide a small annular clearance around the external surface of the telescoping section 22. (The inside diameter of the sleeve 58 is less than that of the enlarged tubing section 80 for a reason to be explained later.) This annular clearance minimizes any possibility of damaging the external surface of the telescoping section 22, which is preferably a polished surface for cooperation with a sealing means which will be described hereinafter. The telescoping section 22 of the pump tubing 20 terminates at its lower end in a guide collar 82 which, as shown in FIG. 4, seats on an annular shoulder 84 when the telescoping section is fully retracted downwardly. The annular shoulder 84 is provided by a coupling 86 at the junction of the enlarged section 80 of the pump tubing 20 with the portion 88 of the pump tubing beneath such enlarged section. It will be noted that the inside diameters of the telescoping section 22 of the pump tubing 20 and the portion 88 thereof are equal to provide for hydraulic circulation of the fluid operated pump 26 between the tubing head 24 and the operating position of the pump in the bottom hole assembly at the lower end of the tubing system 52.

Turning to FIG. 3 of the drawings, the telescoping section 22 of the pump tubing 20 extends upwardly through latch means 90 for releasably securing the float 30 to the well head 48 with the telescoping section 22 in its retracted position. The latch means 90 comprises a housing 92 surmounting the manifold housing 62. Within the housing 92 are diametrally opposed cylinders 94 containing pistons 96 biased inwardly by springs 98. The pistons 96 are provided at their inner ends with plungers 100 disposed in plunger bores 102 and terminating at their inner ends in latches 104 insertable into an annular groove 106 in a latching sleeve 108. The latter is connected at its upper end to the bottom of the float 30 and surrounds the telescoping section 22 of the pump tubing 20. When the telescoping section 22 is in its downwardly retracted position, an annular shoulder 110 on the latching sleeve 108 is seated on a complementary annular shoulder 112 on the latch housing 92.

As will be apparent, the latches 104 are always biased inwardly by the springs 98 so that the float 30 and the telescoping section 22 of the pump tubing 20 cannot be released without the application of external forces. Such external forces are preferably hydraulically applied to the inner ends of the pistons 96 through passages 114 formed in the latch housing 92 and leading to the inner ends of the cylinders 94 from a control line 116. The latter leads to a suiatble control station, which may be the marker buoy 36, an onshore control station, a control station on an artificial island or platform, or the like. As will be apparent, by delivering fluid under pressure through the control line 116, the latches 104 may be disengaged from the groove 106 in the latching sleeve 108 in opposition to the action of the springs 98. To permit such retraction of the latches 104, the outer ends of the cylinders 94 are vented to the production fluid chamber 72 through

passages

118 and 120. With the float 30 thus unlatched, its buoyancy may be increased, in a manner to be described hereinafter, to project the tubing head 24 above the surface 18 of the water 16. The lower end of the latching sleeve 108 is beveled, as indicated at 122, to. provide a tapered surface which is engageable with the latches 104 to force them outwardly upon downward movement of the latching sleeve into the latch housing 92 when retracting the telescoping section 22 of the pump tubing 20. The springs 98 insert the latches 104 into the groove 106 when the latching sleeve 108 is seated in the latch housing 92.

Within the manifold housing 62, and projecting downwardly into the production fluid chamber 72, is a lip seal l24biased inwardly by a garter spring 126. When the telescoping section 22 of the pump tubing 20 is in its retracted position, a downward tubular extension 128 of the latching sleeve 108 holds the lip seal 124 away from the telescoping tubing section 22. This keeps open an annular passage 130 between the latching sleeve 108 and the telescoping section 22 of the pump tubing 20 so that production fluid discharged by the pump 26 may' flow downwardly through such'annular passage, and past the lip seal 124, into the production fluid chamber "72 leading to the production fluid line 76. (The manner in which production fluid discharged by the pump 26 enters the annular passage will be described later.) Upon upward movement of the latching sleeve 108 in bringing the tubing head 24 to the surface of the water, the latching-sleeve extension 128 disengages the lip seal 124 to permit the garter spring 126 to urge it inwardly into fluidtight engagement with the polished external surface of the telescoping pump-tubing section 22. This prevents the escape of production fluid from the chamber 72 into the water 16, which is an important feature.

The upper end of the latching sleeve 108 is provided with an annular seat 132 which, as shown in FIG. 5, is engaged by an annular valve member 134 at the upper end of the telescoping section 22 of the pump tubing 20. Engagement of the annular valve member 134 with the annular seat 132 occurs upon slight upward movement of the float 30 relative to the telescoping pump-tubing section 22. This action closes the upper end of the annular passage 130 to prevent the escape of production fluid into the water 16 from above the annular seat 132. Thus, with this construction, the only production fluid which can possibly escape into the water 16 is the small quantity trapped in the annular passage 130 between the lip seal 124 and the annular seat 132.

It will be noted that the annular seat 132 supports the Weight of the telescoping pump-tubing section 22 once the collar 82 at the lower end of such section has been lifted off its supporting shoulder 84. When the telescoping pump-tubing section 22 is in its fully retracted position, the collar 82 again seats on its supporting shoulder 84 to permit the annular valve member 134 to disengage its annular seat 132, thereby reopening the upper end of the annular passage 130 so that production fluid discharged by the pump 26 may flow downwardly therethrough in a manner to be described.

It should be pointed out that although the lip seal 124 strips the production fluid from the polished external surface of the telescoping pump-tubing section 22 as it is extended upwardly to project the tubing head 24 above the surface of the water 16, nevertheless a thin plating of oil remains on the external surface of the telescoping section to minimize the possibility of corrosion upon exposure to the water.

Projecting upwardly from the upper end of the telescoping pump-tubing section 20 is a tubing which has the same inside diameter and which is secured at its upper end, FIG. 2, to a fitting 142 at the upper end of the tubing head 24. The latter takes the form of a tubular housing 144 which is secured to the top of the float 40. The lower end of the tubular housing 144 is connected, by another tubular housing 146 extending downwardly through the float 30, to the upper end of the latching sleeve 108, the float being welded to, or otherwise secured to, the tubular housing 146 at the top and bottom of the float. In order to permit the relative vertical move-- ment of the tubing 140 and the telescoping tubing section 22 necessary to engage the annular valve member 134 with and disengage it from its annular seat 132, a slip joint 148, FIGS. 3 and 5, connects the lower end of the tubing 140 to the upper end of the telescoping tubing section 22.

The fitting 142 at the upper end of the tubing head 24 is provided therein with passages 152 through which the production fluid flowing upwardly through the tubing 140 may flow into the annulus around this tubing. The production fluid then flows downwardly through the annulus around the tubing 140 into the annular passage 130 between the telescoping pump-tubing section 22 and the latching sleeve 108. From the annular passage 130, the production fluid flows into the chamber 72, and thence through the passage 74 into the production fluid line 76. It should be pointed out that an annular seal 154, FIG. 3, engages the telescoping pump-tubing section 22 below the production'flu'id chamber 72 to prevent upward flow of production fluid into this chamber by way of the annular clearance between the telescoping pump-tubing section 22 and the enlarged section 80 of the pump tubing 20. This is necessary to insure that the fluid operated pump 26 can be circulated all the way to the top of the tubing head 24, as will be described. Therefore, it is necessary to cause the production fluid discharged by the fluid operated pump 26 to flow all the Way to the upper end of the tubing 140, as described.

As shown in FIG. 2 of the drawings, the tubing head 24 is provided at its upper end with a pump catcher 156 threadedly connected to the fitting 142. The pump catcher 156 includes a latch 158 engageable with a tapered nose 160 at the upper end of a packer mandrel 162 with which the fluid operated pump 26 is customarily provided. Any fluid introduced into the supply and return

tubings

54 and 56 after the pump 26 engages the latch 158 escapes through ports 170 in the tubing 140 at a point below the packer mandrel 162. The construction of the latch 158 is such that it releases the pump 26 upon application of fluid pressure above the pump.

Once the fluid operated pump 26 has been caught by the latch 158, the pump catcher 156 may be unscrewed to permit removal of the pump. For convenience in removing the pump 26 from the tubing head 24, the pump catcher 156 is provided with an eye for engagement by a hook, or the like, associated with suitable hoisting equipment, not shown, on a service boat, or the like.

In order to vary the buoyancy of the float 30 to permit upward extension and downward retraction of the tubing head 24, the float has connected thereto a line 166 through which compressed air may be introduced into the float, or through which air may be discharged from the float. The air line 166 may be connected to the marker buoy 36, or to any other control station. The bottom wall of the float 30 is provided with a vent 168, FIG. 3, through which water is discharged as compressed air is introduced into the float, and through which water enters as air is discharged from the float.

Operation of submerged well completion of FIGS. 1 to It will be assumed initially that the tubing head 24 and telescoping pump-tubing section 22 are retracted and latched in place by the latch means 90. It will also be assumed that the fluid operated pump 26 is in its operating position in the bottom hole assembly, not shown, supported by the tubing system 52.

Under such conditions, the pump 26 may be operated by operating fluid, usually clean crude oil, delivered thereto under pressure through the supply line 64 and the supply tubing 54. The spent operating fluid is returned to the operating station, wherever it may be located, through the return tubing 56 and the return line 66. The production fluid discharged by the pump 26 flows upwardly through the portion 88 of the pump tubing 20, the enlarged section 80 thereof and the telescoping section 22 thereof into the tubing 140 leading to the upper end of the submerged tubing head 24. The production fluid them flows downwardly around the tubing 140 and through the annular passage 130 into the production fluid chamber 72, from which it is conveyed to a suitable point of disposal by the production fluid line 76.

If it is necessary to remove the fluid operated pump 26 from the well for service, repair, or replacement, the pump is first circulated upwardly to the pump catcher 156 by reversing the flow through the tubing system 52 in the customary manner. More particularly, the pump 26 is first unseated by flowing fluid under pressure downwardly through the return tubing 56, and in then circulated upwardly into the submerged tubing head 24 by flowing fluid under pressure downwardly through both the supply and return

tubings

54 and 56. Ultimately, the tapered nose 160 at the upper end of the packer mandrel 162 engages and is caught by the latch 158 of the pump catcher 156.

The foregoing accomplished, fluid under pressure is introduced into the inner ends of the latch cylinders 94 through the control line 116, thereby disengaging the latches 104 from the latching sleeve 108. With the latch means thus unlatched, compressed air may be introduced into the float 30, through the air line 166, to increase the buoyancy of the float 30 sufliciently to cause it to rise to, or substantially to, the water surface 18. As the float starts to rise, the annular valve seat 132 on the latching sleeve 108 engages the annular valve member 134 on the telescoping pump-tubing section 22. At approximately the same time, the latching-sleeve extension 128 disengages the lip seal 124 to permit it to contract inwardly into sealing engagement with the polished extenral surface of the telescoping pump-tubing section 22. This minimizes the escape of production fluid into the water 16. The maximum quantity which can escape is that in the annular passage between the tubing section 22 and the latching sleeve 108. Actually, however, very little of this will escape since, being lighter than water, it will tend to remain in the annular passage 130.

As the float 30 and the telescoping pump-tubing section 22 approach their fully extended positions, the collar 82 at the lower end of the telescoping section 22 enters the reduced-diameter sleeve 58. This provides a restriction to the escape of fluid trapped above the collar 82 and thus hydraulically cushions the upward movement of the float 30 and the telescoping pump-tubing section 22 to minimize shock.

With the float 30 and the telescoping pump-tubing section 22 in their uppermost positions, the tubing head 24 projects above the water surface 18 so that the pump catcher 156 can be unscrewed to permit removal of the pump 26.

It will be noted that, while the float 30 and the telescoping pump-tubing section 20 are in their upper or extended positions, the guys 32 brace the float against excessive horizontal movement to prevent excessive flexing of the extended telescoping section 22.

To restore the well completion 10 to operation, the fluid operated pump 26, or a replacement pump, is inserted into the upper end of the tubing with the tapered nose on the pump engaged by the latch 158 of the pump catcher 156. The latter is then threadedly connected to the upper end of the tubing head 24.

The foregoing accomplished, air is bled off from the float 30 to permit it to descend and to thus return the telescoping pump-tubing section 22 to its retracted position. Ultimately, the latching sleeve 108 reenters the latch housing 92, the tapered surface 122 at the lower end of the latching sleeve automatically displacing the latches 104 outwardly. It will be noted that some fluid will be trapped in the latch housing 92 below the latching sleeve 108, which trapped fluid must escape between the latch ing-sleeve extension and the lip seal 124. This provides a hydraulic snubbing or shock absorbing means which prevents excessive shock upon arrival of the various movable components at their lowermost positions.

Ultimately, the latches 104 enter the groove 106 in the latching sleeve 108 to latch the float 30 in its retracted position. At this stage, the collar 82 at the lower end of the telescoping pump-tubing section 22 has seated on the annular shoulder 84 to disengage the annular valve member 134 from its annular seat 132. Also, the latchingsleeve extension 128 has disengaged the lip seal 124 from v the telescoping pump-tubing section 22. Thus, both ends of the annular passage 130 through the latching sleeve 108 are opened to downward flow of production fluid when the fluid operated pump 26 is placed in operation.

The foregoing accomplished, the fluid operated pump 26 may be disengaged from the latch 158, and circulated downwardly through the pump tubing 20 into its operating position in the bottom hole assembly, by introducing fluid under pressure above the pump by way of the production fluid line 76, the chamber 72, the annular passage 130, the annulus around the tubing 140, and the passages 152 in the fitting 142. Any fluid in the pump tubing 26 below the pump 26 as it is being circulated is displaced upwardly through the supply and return

tubings

54 and 56 in the usual manner. Once the fluid operated pump 26 has been circulated into its operating position in the bottom hole assembly, it may be placed in operation by supplying operating fluid under pressure thereto through the supply line 64 and the supply tubing 54.

It will thus be seen that the Well completion provides a relatively simple way of obtaining access to the fluid operated pump 26 to permit servicing, repairing, or replacing it. All of the necessary operations may be carried out from above the water surface 18, there being no necessity for using a diver at any time.

Submerged well completion with upwardly extensible casing head In the well completion 10, only the upper end of the pump tubing and its tubing head 24 are brought to the surface. Semidiagrammatically illustrated in FIG. 6 of the drawings is a submerged well completion 210 in which the upper end of a casing 212, a casing head 214 thereon, and the upper end of a tubing system 216 suspended from the casing head within the casing 212, may all be projected upwardly above the surface 218 of a body of water 220.

Considering the well completion 210 in more detail, it includes a well bore 222 drilled into the bottom 224 below the body of Water 220. Set in the upper portion of the well bore 222 is a surface casing 226 surmounted by a well head 228. The casing 212 is disposed within the surface casing 226 and projects downwardly in the well bore 222 below the lower end of the surface casing.

The casing 212 includes an enlarged upper section 230 receiving therein a telescoping casing section 232 of a length sufficient to project upwardly above the water surface 218. The casing head 214 is mounted on the upper end of the telescoping casing section 232. The tubing system 216 suspended in the casing 212 from the casing head 214, is shown as including a pump tubing 234 which serves as a production tubing, and as including operatingfluid supply and return

tubings

236 and 238. The pump, supply and return

tubings

234, 236 and 238 respectively communicate with production fluid, supply and return

lines

240, 242 and 244 which lead to some suitable operating station, not shown. These lines may lie on the bottom 14 and include flexible sections, as shown, which permit raising and lowering the casing head 214.

The telescoping casing section 232, the casing head 214 and the tubing system 216 are adapted to be elevated to project the casing head above the surface 218 by a float 246 equipped with an air line 248 and a vent 250 corresponding to the air line 166 and the vent 168 of the float 30. For a typical well 210, providing the float 246 with a displacement of the order of fifty tons is suflicient, although this displacement may be increased or decreased as required.

In the particular construction illustrated, the casing head 214 is mounted on a working platform 252 forming part of a superstructure carried by the fioat 246, the telescoping casing section 232 extending downwardly through the float. If desired, the superstructure 0n the float 246 may also include a derrick 254 for performing various operations on the well 210, in areas where such a derrick will not be a hazard to navigation. For example, the derrick 254 may be utilized to lift a pump catcher 256 in pulling a fluid operated pump, not shown, from the pump tubing 234. The derrick 254 may also be utilized in pullin the tubing system 216, and/or in performing various other servicing or remedial operations.

The float 246, when in its elevated position, may be stabilized by means of guys 258 in much the same manner as the float 30. Also, the float 246, the telescoping 10 casing section 232 and the casing head 214 may be latched in their retracted positions in much the same manner as the analogous components of tthe well completion 10. For simplicity, no such latching means has been illustrated in FIG. 6 of the drawings.

As will be apparent, the principal advantage of the well completion 210 is that all of the operations normally carried out at the well head on land may be carried out from the working platform 252. Thus, any servicing or remedial work which the well completion 210 may require can be carried out from above the water level without the use of divers, or remotely controlled, submersible equipment. Furthermore, it is unnecessary to bring heavy equipment into position above the well completion since the float 246 carries its own working platform 252 and derrick 254.

Although exemplary embodiments of the invention have been disclosed herein for purposes of illustration, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiments without departing from the spirit of the invention as defined by the claims which follow:

1. In a submerged, offshore well, the combination of:-

(a) at least one tubular member set in the well;

(b) said tubular member being provided at its upper end with a telescoping section of a length sufficient to project above the surface of the water when said telescoping section is fully extended upwardly;

(c) variable-buoyancy buoyant means connected to said telescoping section adjacent its upper end; and

(d) means for varying the buoyancy of said buoyant means to raise and lower said telescoping section.

2. In a submerged, offshore well, the combination of:

(a) at least two tubular members set in the well;

(b) one of said tubular members being a casing and the other being a tubing in said casing;

(0) one of said tubular members being provided at its upper end with a telescoping section of a length suflicient to project above the surface of the water when said telescoping section is fully extended upwardly;

(d) variable-buoyancy buoyant means connected to said telescoping section adjacent its upper end; and

(e) means for varying the buoyancy of said buoyant means to raise and lower said telescoping section.

3. In a submerged, offshore well, the combination of:

(a) at least two tubular members set in the well;

(c) said tubing being provided at its upper end with a telescoping section of a length suflicient to project above the surface of the water when said telescoping section is fully extended upwardly;

4. In a submerged, offshore well, the combination of:

(a) at least two tubular members set in the well;

(c) said casing being provided at its upper end with a telescoping section which carries said tubing and which is of a length sufficient to project above the surface of the water when said telescoping section is fully extended upwardly;

.(d) variable-buoyancy buoyant means connected to said telescoping section adjacent its upper end; and

'5. In a submerged, offshore Well, the combination of:

(a) at least two tubular members set in the well;

(c) said casing being provided at its upper end with a telescoping section which carries said tubing and which is of a length suflicient to project above the surface of the water when said telescoping section is fully extended upwardly;

(d) variable-buoyancy buoyant means connected to said telescoping section adjacent its upper end;

(e) means for varying the buoyancy of said buoyant means to raise and lower said telescoping section; and

(f) a working platform for personnel carried by said buoyant means adjacent the upper end of said telescoping section of said casing and disposed above the surface of the water when said telescoping section is fully extended upwardly.

6. In a submerged, offshore Well, the combination of:

(a) at least three tubular members set in the well;

(b) one of said tubular members being a casing and the others being tubings in said casing;

(c) one of said tubings being a pump tubing of a size to-slidably' receive a fluid operated pump therein and being provided at its upper end with a telescoping section of a length suflicient to project above the surface of the water when said telescoping section is fully extended upwardly;

((1) means connected to said telescoping section adjacent its upper end for extending same upwardly; and

(e) latch means in said telescoping section adjacent its upper end for securing a fluid operated pump therein.

7. In a submerged, offshore well, the combination of:

(a) at least three tubular members set in the well;

() one of said tubings being a pump tubing of a size to slidably receive a fluid operated pump therein and being provided at its upper end with a telescoping section of a length sufficient to project above the surface of the water when said telescoping section is fully extended upwardly;

(d) means connected to said telescoping section adjacent its upper end for extending same upwardly;

(e) latch means in said telescoping section adjacent its upper end for securing a fluid operated pump therein;

(f) means providing a fluid passage communicating with the upper end of said telescoping section and extending downwardly alongside said telescoping section; and

(g) valve means responsive to upward movement of the upper end of said telescoping section for closing said fluid passage.

8. In -a submerged, offshore well, the combination of:

(a) at least three tubular members set in the well;

(c) said casing being provided at its upper end with a telescoping section which carries said tubings and which is of a length suflicient to project above the surface of the water when said telescoping section is fully extended upwardly;

(f) a working platform for personnel carried by said buoyant means adjacentthe upper end of said telescoping section of said casing and disposed above the surface of the water when said telescoping section is fully extended upwardly.

9. In a submerged, offshore well, the combination of:

(a) at least three tubular members set in the well;

(b) one of said tubular members being a casing and 'the others being tubings in said casing;

(c) one of said tubings being a pump tubing of a size to slidably receive a fluid operated pump therein;

(d) said casing being provided at its upper end with a telescoping section which carries said tubings and which is of a length suflicient to project above the surface of the water when said telescoping section is fully extended upwardly;

(e) variable-buoyancy buoyant means connected to said telescoping section adjacent its upper end;

(f) means for varying the buoyancy of said buoyant means to raise and lower said telescoping section; and

(g) a working platform for personnel carried by said buoyant means adjacent the upper end of said telescoping section of said casing and disposed above the surface of the water when said telescoping section is fully extended upwardly.

10. In a submerged, offshore well, the combination of:

(a) at least one tubular member set in the well;

(c) buoyant means connected to said telescoping section adjacent its upper end for extending same upwardly;

(d) said buoyant means providing a chamber having a vent in communication with the water to admit water thereinto for the purpose of sinking said buoyant means and of thus retracting said telescoping section downwardly; and

(e) means for blowing water out of said chamber through said vent to render said buoyant means buoyant and to thus extend said telescoping section upwardly.

11. In a submerged, offshore well, the combination of:

(a) at least one tubular member set in the well;

((1) said buoyant means providing a chamber having a vent in communication with the water to admit water thereinto for the purpose of sinking said buoyant means and of thus retracting said telescoping section downwardly;

(e) means for blowing water out of said chamber through said vent to render said buoyant means buoyant and to thus extend said telescoping section upwardly; and

(f) the means of (e) hereof comprising an air line connected at one end to said chamber and at its other end to a marker buoy on the surface of the water.

12. In a submerged, offshore well, the combination of:

(a) a casing set in the well and provided at its upper end with a telescoping section which is of a length sufficient to project above the surface of the water when said telescoping section is fully extended upwardly;

(b) a casing head carried by the upper end of said telescoping section;

(0) a tubing system suspended within said casing from said casing head;

(d) said tubing system including a pump tubing of a size to slidably receive a fluid operated pump for movement of said pump between the upper and lower ends of said pump tubing;

(e) said tubing system including at least one additional tubing for conducting a fluid flowing through said P p;

(f) 'a p mp catcher at the upper end of said pump tubing for securing said pump against downward movement through said pump tubing;

13 (g) flexible lines connected to said casing head in communication with said tubings, respectively; (h) variable-buoyancy buoyant means connected to said telescoping section adjacent its upper end; and (i) means for varying the buoyancy of said buoyant means to raise and lower said telescoping section. 13. A submerged, oflshore well as defined in claim 12 including a working platform for personnel and a derrick carried by said buoyant means adjacent the upper end of said telescoping section and disposed above the surface 1 of the water when said telescoping section is fully extended upwardly.

References Cited UNITED STATES PATENTS Voorhees 175-8 Lang 1758 Rhodes et al. 175-7 Haeber 166.5

LeRouax 166.5

Howard 166-.6 Coberly 166-.5

CHARLES E. OCONNELL, Primary Examiner.

R. E. FAVREAU, Assistant Examiner.

Claims

1. IN A SUBMERGED, OFFSHORE WELL, THE COMBINATION OF: (A) AT LEAST ONE TUBULAR MEMBER SET IN THE WELL; (B) SAID TUBULAR MEMBER BEING PROVIDED AT ITS UPPER END WITH A TELESCOPING SECTION OF A LENGTH SUFFICIENT TO PROJECT ABOVE THE SURFACE OF THE WATER WHEN SAID TELESCOPING SECTION IS FULLY EXTENDED UPWARDLY; (C) VARIABLE-BUOYANCY BUOYANT MEANS CONNECTED TO SAID TELESCOPING SECTION ADJACENT ITS UPPER END; AND (D) MEANS FOR VARYING THE BUOYANCY OF SAID BUOYANT MEANS TO RAISE AND LOWER SAID TELESCOPING SECTION.