US3330340A

US3330340A - Marine conductor pipe assembly

Info

Publication number: US3330340A
Application number: US401488A
Authority: US
Inventors: William J Hayes; Robert C Visser; Glenn D Johnson
Original assignee: Shell Oil Co
Current assignee: Shell USA Inc
Priority date: 1964-10-05
Filing date: 1964-10-05
Publication date: 1967-07-11
Anticipated expiration: 1984-07-11
Also published as: NL6512828A; DK112231B; NO115467B; GB1060818A; BE670490A; ES318104A1; DE1262936B

Description

July 11, 1967 W. J. HAYES ETAL MARINE CONDUCTOR PIPE ASSEMBLY Filed Oct. 1964 5 Sheets-Sheetl INVENTORS WILLIAM J. HAYES ROBERT C. VISSER GLENN D. JOHNSON 1-4 m I THEIR AGENT July 11, 1967 w. J. HAYES ETAL 3,330,340

MARINE CONDUCTOR PIPE ASSEMBLY Filed Oct. 5, 1964 3 Sheets-Sheet 2 FIG.2C

INVENTORS:

WILLIAM J. HAYES ROBERT C. VISSER GLENN D. JOHNSON BY: H

THUR AGENT July 11, 1967 w. J. HAYES ETAL 3,330,340

MARINE CONDUCTOR PIPE ASSEMBLY Filed Oct. 1964 5 Sheets-$heet 5 FIG. 7

as as INVENTORSI s9 8? WILLIAM J. HAYES ROBERT c. VISSER 1: 1 9 GLENN o. JOHNSON BY: H k 6 EIR AGENT United States Patent 3,330,340 MARlNE CONDUCTOR PIPE ASSEMBLY William J. Hayes, Torrance, Robert C. Visser, San Dimas,

and Glenn D. Johnson, Downey, Calif assignors to Shell Oil Company, New York, N.Y., a corporation of Delaware Filed Oct. 5, 1964, Ser. No. 401,488 5 Claims. (Cl. 166-.6)

This invention relates to apparatus for use in drilling, completing and working-over operations in oil and gas wells at ofishore locations, and pertains more particularly to apparatus adapted to provide full-flow fluid communication between a vessel at the surface of a body of water and a wellhead assembly positioned on the ocean floor or at a substantial depth below the surface of the water.

In an attempt to locate new oil fields, an increasing amount of well drilling has been conducted at offshore locations, such for example, as oflf the coast of Louisiana, Texas and California. As a general rule, the strings of casing in a well, together with the tubing string or strings, extend to a point about the surface of the water where they are closed in a conventional manner that is used on land wells, with a conventional wellhead assembly being attached to the top of the casing. Recently, methods and apparatus have been developed for drilling and completing wells wherein both the well casinghead, and subsequently the wellhead assembly and easing closure device, are located underwater at a depth suflicient to allow ships to pass over them. Preferably, the casinghead and wellhead closure assemblies are located close to the ocean floor. In order to install well drilling equipment underwater at depths greater than the shallow depth at which a diver can easily operate, it has been necessary to design entirely new equipment for this purpose.

Wells drilled in deep water are generally drilled from vessels of varying designs commonly known as drilling barges, vessels or platforms. Deep water wells are generally drilled by one of two methods. In one method the string of drill pipe extends downwardly from the drilling vessel to the drilling wellhead assembly, on the ocean floor, which is closed at the top by a circulation head with a flexible hose running from the circulation head back to the surface and to the drilling vessel so that drilling fluid may be circulated down the drill pipe, through the drill bit, and thence upwardly along the outside of the drill pipe, out the circulation head and up the flexible hose to the vessel again. In a second method, a large-diameter pipe known as a marine conductor pipe is put together and arranged to extend from the drilling Wellhead assembly near the ocean floor to the vessel on the surface of the Water. In the latter method, the drill pipe rotates within the conductor pipe with drilling fluid being circulated down through the drill pipe, through the bit at the bottom thereof, up the outside of the drill pipe and thence upwardly through the annular space between the conductor pipe and the drill pipe, returning to the barge in the conventional way. The present invention is concerned with apparatus to be used in the second method described hereinabove.

One of the problems in drilling underwater wells from floating vessels is that of providing suitable means for suspending and/or supporting a large-diameter marine conductor pipe and auxiliary smaller-diameter equipment or well-control pipes in the water beneath the drilling vessel while the lower ends thereof are secured to a wellhead assembly positioned near the ocean floor. A further problem is encountered at times when drilling at offshore locations due to the possibility of a violent storm which necessitates moving the drilling vessel away from the well being drilled or having it moved away by abnormal 3,333,346 Patented July 11, 1967 wind and wave action. In the cases where the vessel has to be moved or is liable to be moved, it is necessary to quickly disconnect the marine conductor and auxiliary lines from the drilling well head assembly near the ocean floor and withdraw them to the vessel prior to the vessel moving off location.

It is therefore a primary object of the present invention to provide a marine conductor pipe assembly which can be quickly disconnected from a wellhead drilling assembly at the ocean floor while control of the well being drilled is maintained by suitable blow-out equipment left on the ocean floor.

A further object of the present invention is to provide a marine conduct-or pipe assembly of rugged design which can be built in sections small enough to be handled easily on a drilling vessel while being provided with means for connecting the various sections together easily and quickly.

Another object of the present invention is to provide a sectionalized marine conductor pipe assembly wherein all of the sections are substantially and individually buoyant so that the major portion of all of the marine conductor pipe is substantially self-supporting within a body of water.

Still another object of the present invention is to provide a sectionalized buoyant marine conductor pipe assembly provided with means for accommodating one or more smaller-diameter well control or equipment control pipelines which are protected by the conductor pipe assembly while extending from the vessel down to the equipment at the ocean floor.

A further object of the present invention is to provide means on the sectionalized marine conductor pipe assembly whereby smaller-diameter auxiliary pipes extending from the vessel to the drilling equipment at the ocean floor may be readily removed or replaced in case of emergency or damage without pulling the marine conductor pipe assembly back to the vessel.

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

FIGURE 1 is a diagrammatic view taken in longitudinal projection illustrating a floating drilling vessel positioned at the surface of the ocean with an underwater wellhead assembly positioned on the ocean floor;

FIGURES 2A, 2B and 2C are longitudinal views adapted to be arranged end-to-end to show enlarged detail sections of the marine conductor pipe assembly of the present invention as it is positioned on a wellhead at the ocean floor;

FIGURE 3 is a view in enlarged detail illustrating the upper end of the marine conductor pipe of FIGURE 2A as well as the upper end of a bundle of hydraulic control cables positioned alongside the marine conductor p FIGURE 4 is a longitudinal view taken in partial cross section illustrating interconnecting ends of two sections of the marine conductor pipe of the present invention together with smallerdiameter auxiliary pipes arranged in guide tubes on either side of the marine conductor p p FIGURE 5 is a partial longitudinal view taken at to the view shown in FIGURE 4 so as to illustrate auxiliary connections between two sections of the marine conductor pipe assembly;

FIGURE 6 is an enlarged cross-sectional longitudinal view showing in enlarged detail the manner in which an auxiliary smaller-diameter pipeline is coupled to a drilling wellhead assembly in communication with a suitable conduit thereto; and,

FIGURE 7 is a longitudinal view taken in partial cross section of a sealing and connector unit between the marine conductor pipe assembly and the drilling wellhead assembly.

Referring to FIGURE 1 of the drawing, a drilling vessel, barge or platform is generally represented by numeral 11. The drilling vessel is of any suitable type preferably,

as illustrated, floating at the surface of a body of water 12 and being substantially fixedly positioned over a preselected drilling location by suit-able' barge-positioning means or by being anchored to the ocean floor 13 by suitable anchors (not shown) connected to the anchor lines -14 and 15. Equipment of this type may be used when carrying on well drilling operations in water depths vary located or extend in from one edge. However, drilling operations may be carried out over the deck of the vessel which is cantilevered out over one end. Additionally, it is to be understood that the equipment of the present invention may be also used when drilling a well from any suitable operational base positioned above the surface of the water, such for example, as from a drilling barge having legs extending to the ocean floor or from a platform permanently positioned on the ocean floor.

A typical underwater wellhead structure is illustrated in FIGURES l and 2C as comprising a base member 21 which is positioned on the ocean floor 13 and is fixedly secured to a conductor pipe or a large-diameter well casing 22 by means of a ball-and-socket joint 23. During drilling operations a drilling wellhead assembly is removably secured to the top of a foundation pile 24 which in turn is secured to the top of the ball-and-socket joint 23. In the wellhead structure illustrated, the drilling wellhead is secured to the top of a 'two-piece'casinghead 25-26 which in turn is mounted at the top of the foundation pile 24. The combined casing 22, foundation pile 24 and casinghead 25-26, form a continuous tubular member or pipeextending up from the ocean floor through which drilling operations are conducted.

I The drilling wellhead assembly illustrated includes a detachable wellhead connector or drilling bonnet 27 of any type well known to the art. Fixedly secured above the wellhead connector 27 is a ram-type blowout preventer :unit 28, a bag-type blowout preventer unit 29, a flexible joint 30, a remotely-operable quick-disconnect coupling and sealing apparatus 31, and a sectionalized marine conductor pipe assembly 32 (FIGURE 1) extending to the vessel 11 at the surface.

As shown in FIGURE 2A, the marine conductor pipe an enlarged telescoping section 34 into which the upper 7 end section '35 of the marine conductor pipe is arranged for sliding vertical movement, thus compensating for rise and fall of the vessel with wave action or tides. Most or all of the marine conductor pipe sections below the telescoping joint 34 are provided with buoyancy tanks 36 of suflicient capacity to float or nearly float the individual sections of the conductor pipe. As shown in FIGURE 4, the buoyancy tanks 36 surround the marine conductor pipe 33 in a fluidtight manner. Extending longitudinally through each of the buoyancytanks 36 in a direction parallel to the marine conductor pipe 33 are one or more guide sleeves 37 in which small-diameter'pipe strings 39. and 40 can be contained and be freely insertable therethrough. Any suitable type of couplings may be employed to connect two sections of marine conductor pipe 4 the locking bolts 44 carried by the female section 42 of the coupling. It is apparent that the bolts 44 are of a form that may be turned by a diver with a wrench or by an underwater robot. If desired, as shown in FIGURE 5, auxiliary safety means may be provided by means of

chains

45 and 46 whichrcan hold the sections of marine conductor pipe together after the bolts of the coupling have been unscrewed. V p As shown in FIGURE 2A, the upper end of the telescoping pipe section may be securedto the drilling vessel 11 in any suitable manner, as by

cables

47 and 48.

The upper end of the marine conductor pipe assemblybelow the upper telescopingsection 35 is supported from a the vessel by means of

cables

49 and 50 which extend to any suitable type of constant tension hoist means 51 and 52 which are mounted on the vessel 11. If desired,

additional cables

53 and 54 may be provided whichare.

temporarily connected to the marine conductor pipe assembly at 55 and 56 and which run downwardly along the outside of the entire marine conductor pipe assembly and are anchored to the drilling wellhead assembly below the disconnect coupling 31, as shown in FIGURE 7. These

cables

53 and 54 serve as guide means in the event that the marine conductor pipe assembly has been removed from' the drilling wellhead assembly and it is desired to run it down into'place again on the top of the drillingwellhead assembly. Since it is'cumbersome to provide the telescoping section 34 of the marine conductor pipe assembly with a buoyancy tank, guide sleeves 37a'and 38a are secured outside the telescoping-pipe section 34 byrneans of lateral supports 57 and 58. These guide

sleeves

37a and 38a are in axial alignment with each of the

guide sleeves

37 and 38 passing down through the'buoyancy tanks 36 of the marine conductor pipe as} sembly, thus serving as guides for small-diameter

auxiliary pipes

39 and 40, which in this ,case may be choke and kill lines.

, The coupling and sealing apparatus 7 between the lower end of the marine conductor pipe 32 and the upper end of the flexible joint 30 is rovides with suitable remotely

actuatable latches

60, 61 and 62 which are normally disengaged'or in aninoperative posi tion. while'drilling so that the marine conductor'pip'e above the flexible joint 30 can be pulled away and disconnected from the drilling wellhead assembly in an emergency. Since the marine conductor pipe is disconnected at this point,

the'auxiliary lines

39 and 40 are also provided with readily

diseonnectible couplings

63 and 64 so that they may be readily disconnected adjacent the coupling device 31. In the event that a flexible joint is employed in the drilling wellhead assembly, it

is necessary that the portions of the auxiliary conduits 39a and 40a opposite the flexible joint30 bealso flexible assembly consists of a marine conductor pipe 33 having in order to prevent rupturing the lines. Thus, the conduits 39a and 40a may be made of flexible hose of any suitable type. Below the flexible joint 30 (FIGURE 2 C) the flexible conduit 39a becomes a rigid conduit 3% again which is preferably provided with a valve 65 which may be remotely operated either electrically or hydraulically'or may be operated by means of an underwater robotrIn the event that the conduit 39b is merely to be used as a choke or kill line 'for the drilling wellhead assembly, it

terminates by entering the blowout preventer'28'atflange 66 at a point below thelower-set of rams of the blowout preventer. If in addition the conduit 39b is to be used as a cement by-pass line so as to allow cement return from the ,well to by-pass strings of casing already seated in the casinghead 25, the conduit'39b terminates at flange 67 and is provided with a valve68 which is adapted to be operated in a manner similar to valve 65., i It is to be understood that all or the'variou's'cornponents of the wellhead drilling assembly maybe remotely actuatable, as by being operated by hydraulic pressure lines extending from the vessel at the surface. In the arrangement shown in FIGURE 2C, hydraulic hoses ex- 31 (FIGURE'ZB) tend downwardly from the vessel in the form of a bundle of hoses 70 which terminate at a hose clamp 71 which is secured by an arm 72 to the top of the blowout preventer 29 or the bottom of the flexible joint 30. The individual hydraulic conduit or hoses 73 extend downwardly to a central distribution panel 74 from which point they may run to the various hydraulically-actuatable components of the drilling wellhead assembly. This bundle of hydraulic pressure hoses runs up alongside the entire marine conductor pipe assembly and is secured to a support arm 75 (FIGURE 3) which in turn is supported from the vessel by means of a cable or suspension line 76. The upper end of the bundle of hoses or hydraulic conduit 70 may pass through a curved protective pipe 77 before they bend up again to the vessel.

One form of a quick disconnect coupling for use at the lower end of the auxiliary lines 39 and 40 (FIGURE 2B) is shown in FIGURE 6 as comprising a housing 78 in which auxiliary pipe 40 can be stabbed. The pipe 48 is provided with

seals

79 and 80 above and below discharge ports 81 in the side wall of the pipe and annular passage 82 is provided in the housing 78 and around the ports 81 with a discharge of fluid passing port 83 and thence downwardly to the flexible line 40a (FIGURE 2B). The lower end of the pipe 40 (FIGURE 6) is closed by a plug 84 adapted to seat on shoulder 85 within the housing 78. A second shoulder 86 is provided on the lower end of the housing 78 and is adapted to be engaged by spring-type latching fingers 87. The upper beveled surface 88 of the latching finger 87 is flatter than the beveled surface 89 thereof thus allowing the latching device to be stabbed and locked in place with only a 500 pound pressure while, say, a 2000 pound pull is needed to pull it out of its latched position.

Referring to FIGURE 7 of the drawing, one form of a coupling and sealing apparatus 31 is illustrated as comprising a body member 31 having a vertical axial bore 90 of a size sufiicient to receive therein an upwardly-extending tubular mandrel which is fixedly secured to the upper end of the flexible joint 30 in the marine conductor pipe assembly. It is to be understood that the mandrel 91 may be bolted at its lower end to the upper end of the flexible joint 39 while the upper end of the coupling housing 31 is bolted to the lower end of the section of the coupling 41. For ease of illustration the connecting bolts have been omitted. The outer surface of the mandrel 91 is provided with a latching groove or a series of latching recesses 92 adapted to receive the latching members 93 of the several latches carried by the coupling housing 31.

One form of latch is shown in FIGURE 7 as being spring actuated by a compression spring 94 which normally urges the latch 93 into the groove 92. A hydraulic line 95 is provided whereby a hydraulic fluid may be pumped into the latch device 61 to act against the piston 96 therein and move the latch member'93 out of the groove 92 into an inoperative position. Suitable retractable locking dogs 97 are carried on the shaft 98 and ar ranged to move outwardly and prevent the latch member 93 from being re-engaged in the groove 92 by the compression spring 94. Thus, once the latch member 93 has been disengaged from the groove 92 it can not re-engage the groove 92 until the apparatus has been returned to the surface and reset in a latching position.

The outer surface of the mandrel 91 is also preferably provided with a seating shoulder 99 on which a cooperating seating surface carried by the coupling housing 31 can land. Additionally, the outer surface of the mandrel 91 is also preferably provided with a series of grooves 100 into which an expandible hydraulically-actuatable annular sealing member 101, which is carried by the coupling housing 31, may be expanded. As shown in FIGURE 7, the hydraulic line 95 which actuates the latch 61 to retract its latch member 93 is preferably provided with a side outlet 102 which passes through the outer Wall of the coupling housing 31 and is in communication with a chamber 103 in back of the sealing member 101. Thus, a hydraulic pressure is applied to line from a control panel on the vessel 11 of the surface, the sealing member 101 is expanded inwardly and contracts around the grooved section of the mandrel 91 to form a fluidtight seal therearound and to provide a predetermined pull-off resistance of say 5000 pounds, that is, the force that is necessary to lift the coupling housing 31 off the mandrel 91 when the seal 101 is being actuated thereagainst. Simultaneously with the actuation of the seal 101 against the mandrel 91, the latches are energized so that their latch members 93 are retracted from the latching groove 92. If desired, individual actuating hydraulic pressure lines may be used.

Drilling operations are then carried out in the underwater well with the coupling and sealing apparatus 31 arranged in this manner, that is, with the seal activated and the latches retracted so that in an emergency the marine conductor pipe assembly can be readily pulled off the mandrel 91 at the top of the drilling wellhead assembly even though the hydraulic pressure line is plugged so that the seal cannot be de-activated. By employing this arrangement there is no danger of the

latching mechanism

61, 62 and 63 ticking or freezing in the latching groove 92 for any of several reasons. In the event that a well is being drilled for several weeks, say in Alaskan waters, there is always a possibility of the hydraulic lines 95 becoming plugged, frozen or damaged so that the latch member 93 could not be retracted if locking dog 97 were not provided on the latch device 61 to hold the latch in its inactive position, as illustrated. In the event that the marine conductor pipe assembly is removed from the underwater drilling wellhead assembly in an emergency, the guide lines 54 (FIGURE 7) which pass through guide blocks 103 in a slidingly engageable manner, may be utilized to align the coupling housing 31 at the lower end of the marine conductor pipe assembly with the mandrel 91 carried at the top of the drilling Wellhead assembly.

Prior to withdrawing the marine pipe conductor assembly of the present invention from a drilling Wellhead assembly, the

auxiliary pipes

39 and 49 are withdrawn upwardly to the barge. It may be seen that by utilizing the apparatus of the present invention any of the auxiliary small-

diameter pipes

39 and 40 which become plugged or otherwise damaged may be readily withdrawn to the vessel and a new one installed in place of it by forcing it down through the guide sleeves 37 and 38 (FIGURE 4).

We claim as our invention:

1. Apparatus for drilling, completing and working over an underwater well, said appaartus comprising operational platform means positioned above the surface of a body of water,

a well base positioned below the surface of the water and including substantially vertical well base pipe means having a lower portion thereof fixedly anchored to the formation below said body of water and a portion extending upwardly above said formation,

marine conductor means connectible at its lower end to the upper end of said well base pipe means with the upper end of said conductor means extending above the surface of the water in the vicinity of said operational platform means,

buoyancy tank means secured to said marine conductor means below the surface of the water and having suflicient buoyancy to support a major portion of the weight of said marine conductor means, and

open-ended sleeve means extending through said buoyancy tank means parallel to said marine conductor means for passing auxiliary pipe means through said buoyancy tank means,

said marine conductor means including a large-diameter marine conductor pipe and a drilling wellhead assembly secured to the lower end thereof,

said drilling wellhead assembly comprising blowout preventer means fixedly secured to a wellhead connector means, t

a disconnect coupling above said blowout preventor means which are adapted to be detachably secured to the lower end of said marine conductor pipe,

auxiliary conduit disconnect coupling means carried on the outside of said drilling wellhead assembly and in communication with the interior thereof, and

. auxiliary conduit means extending through said sleeve means of said buoyancy tank means, said auxiliary conduit means being connected at the lower end to said auxiliary conduit disconnect coupling means. 2. The apparatus, of claim I WhGIEiH aid auxiliary conduit means comprise individual choke and kill pipelines and wherein said choke and kill line disconnect coupling means comprise individual stab-type couplings at the bottom of said choke and kill pipelines.

3. The apparatus of claim 1 wherein said marine conductor pipe includes a tubular mandrel extendible within said disconnect coupling above said blowout 'preventer means, said disconnect coupling including 4. The apparatus of claim 3 wherein said housing of said disconnect coupling is provided with laterally-movable latch means adapted to engage the outer suface of the tubular mandrel ofsaid marine conductor pipe to prevent relative axial movement of said mandrel with respect to said housing, hydraulic operator means in engagement with aid latch means for moving said latch means to an inoperative position out of engagement with said man: drel, and lock means operatively engageable with said latch means for holding said latch means in an inoperative position.

' 5. The apparatus of'claim 4 including pressure-fluid manifold means interconnecting the pressure fluid port means through the housing wall to said sealing member with aid hydraulic operator to said'latch means of said disconnect coupling whereby upon application of fluid under pressure to said manifold means the sealing mem her is sealed as the coupling is disconnected. V t 7 References Cited UNITED STATES PATENTS V -s74,17s 8/1961 Great Britain.

CHARLES E. OCONNELL, Primary Examiner.

V R. E. FAVREAU, Assistant Examiner.

Claims

1. APPARATUS FOR DRILLING, COMPLETING AND WORKING OVER AN UNDERWATER WELL, SAID APPARATUS COMPRISING OPERATIONAL PLATFORM MEANS POSITIONED ABOVE THE SURFACE OF A BODY OF WATER, A WELL BASE POSITIONED BELOW THE SURFACE OF THE WATER AND INCLUDING SUBSTANTIALLY VERTICAL WELL BASE PIPE MEANS HAVING A LOWER PORTION THEREOF FIXEDLY ANCHORED TO THE FORMATION BELOW SAID BODY OF WATER AND A PORTION EXTENDING UPWARDLY ABOVE SAID FORMATION, MARINE CONDUCTOR MEANS CONNECTIBLE AT ITS LOWER END TO THE UPPER END OF SAID WELL BASE PIPE MEANS WITH THE UPPER END OF SAID CONDUCTOR MEANS EXTENDING ABOVE THE SURFACE OF THE WATER IN THE VICINITY OF SAID OPERATIONAL PLATFORM MEANS, BUOYANCY TANK MEANS SECURED TO SAID MARINE CONDUCTOR MEANS BELOW THE SURFACE OF THE WATER AND HAVING SUFFICIENT BUOYANCY TO SUPPORT A MAJOR PORTION OF THE WEIGHT OF SAID MARINE CONDUCTOR MEANS, AND OPEN-ENDED SLEEVE MEANS EXTENDING THROUGH SAID BUOYANCY TANK MEANS PARALLEL TO SAID MARINE CONDUCTOR MEANS FOR PASSING AUXILIARY PIPE MEANS THROUGH SAID BUOYANCY TANK MEANS, SAID MARINE CONDUCTOR MEANS INCLUDING A LARGE-DIAMETER MARINE CONDUCTOR PIPE AND A DRILLING WELLHEAD ASSEMBLY SECURED TO THE LOWER END THEREOF, SAID DRILLING WELLHEAD ASSEMBLY COMPRISING BLOWOUT PREVENTER MEANS FIXEDLY SECURED TO A WELLHEAD CONNECTOR MEANS, A DISCONNECT COUPLING ABOVE SAID BLOWOUT PREVENTOR MEANS WHICH ARE ADAPTED TO BE DETACHABLY SECURED TO THE LOWER END OF SAID MARINE CONDUCTOR PIPE, AUXILIARY CONDUIT DISCONNECT COUPLING MEANS CARRIED ON THE OUTSIDE OF SAID DRILLING WELLHEAD ASSEMBLY AND IN COMMUNICATION WITH THE INTERIOR THEREOF, AND AUXILIARY CONDUIT MEANS EXTENDING THROUGH SAID SLEEVE MEANS OF SAID BUOYANCY TANK MEANS, SAID AUXILIARY CONDUIT MEANS BEING CONNECTED AT THE LOWER END TO SAID AUXILIARY CONDUIT DISCONNECT COUPLING MEANS.