US3508609A - Washout joint - Google Patents

Description

J. H. FOWLER ET WASHOUT JOINT April 28, 1970 Filed Sept. 19, 196'? :llb

3 Sheets-Sheet 1 1/0 64 F0 w/e r fla r/d P. f/e/ a INVENTORS April 28, 1970 J. H. FOWLER ET AL 3,508,609

WASHOUT JOINT Filed Sept. 19. 196' 3 Sheets-Sheet 2 (/afi/l few/er .Da wd P, Herd [NVENTORS A ril 28, 1970 J. H. FOWLER ET AL WASHOUT JOINT 3 Sheets-Sheet 5 Filed Sept. 19, 196' I NVENTOR.

United States Patent O US. Cl. 166.5 20 Claims ABSTRACT OF THE DISCLOSURE A washout joint and method of using same for cementing pipe strings in an underwater well. A first cylindrical coupling is provided at one end with means for connecting to a hanger-head in an underwater wellhead. Radial ports are drilled through the walls of the coupling approximately midway between its ends. An O-ring seal is placed in a circumferential groove on the exterior of said coupling below the radial ports. The other end of said first coupling is provided with threads for connection to a second cylindrical coupling. The second coupling is provided at one end with means for connecting to a running pipe string. Afiixed to said second coupling is a cylindrical sleeve which surrounds a portion of said first coupling in a sliding fit. In its furthest extended position the sleeve cooperates with said first coupling O-ring to prevent fluid flow through the ports. In an intermediate position an internal recess in the sleeve and a relieved external portion of said first coupling form an annular passage communicating with the ports through which fluid may be circulated. In its innermost position another portion of the sleeve cooperates with the first coupling O-ring and a portion of said second coupling engages a portion of said first coupling to again seal the ports against fluid pasage therethrough.

In cementing operations a hanger-head is connected to a casing string. The washout joint is connected to the hanger-head. A running string is connected to the joint and the whole assembly is lowered into an underwater wellhead until the hanger-head is seated therein. Cement is then passed through the casing string and up through an annulus between the string and an outer string which surrounds it. The running string and washout joint are then rotated until the ports are opened. Water is circulated through the joint washing cement away from the hangerhead and joint. Further rotation then seals the ports and allows continued drilling or completion. The washout joint may subsequently be removed.

BACKGROUND OF THE INVENTION Field of the invention This invention is related to underwater petroleum drilling operations and more specifically to extended casing drilling. Even more specifically it is related to cementing procedures and apparatus for use in extended casing operations.

Description of the prior art Underwater drilling for oil and gas has increased considerably over the past few years. It is also becoming increasingly popular to complete these underwater wells at the subsurface with an underwater production tree which is free of the hazards of ocean going trafiic, ocean currents and hurricanes.

One of the latest methods of completing an underwater well at the subsurface is the extended casing method. Such a method is fully described in our copending application U.S. Ser. -No. 572,599, now U.S. Patent No. 3,421,580. In this method a conductor casing is anchored to the sub- 3,508,609 Patented Apr. 28, 1970 sea floor to provide support for a special underwater wellhead. This wellhead, in turn supports a multiple number of hanger-heads, hangers and their respective casing and tubing strings. The drilling platform is thus relieved of much of the structural support responsibilities of other methods. Casing is extended from the underwater wellhead to the drilling platform where conventional wellhead equipment may be used during drilling. After drilling, the well may be permanently abandoned, temporarily abandoned or immediately completed for production by installing a production tree and removing the casing extensions.

A standard procedure in well drilling is the cementing of casing strings to provide support and to isolate production zones. Usually cement is pumped down through a casing string and up around the annular space between that string and the next larger string in the well. It is desirable that cement extend upwardly as close to the wellhead as possible. It is extremely difiicult and usually impossible to estimate the exact amount required. This is, of course, more difiicult in underwater wells. Usually a generous amount of cement is supplied so that in extended casing operations cement may extend upwardly around the wellhead and sometimes in the casing extension area. If left to set, the cement presents difficulties when the casing extension is removed or when for various reasons, the wellhead is desired to be removed.

To solve this problem a washout joint is sometimes connected near the wellhead with means for circulating water down through the easing into the annular space near the wellhead and back to the surface. This will wash away most of the excess cement surrounding the wellhead. One such washout joint is manufactured by the Gray Tool Company of Houston, Tex. and is shown at page 2062 of the 1966-67 edition of the Composite Catalog of Oil Field Equipment and Services published by World Oil.

However, to the knowledge of the applicants all existing washout joints which require rotation to open circulating ports require rotation in the opposite direction to close these ports. When it is necessary to reverse rotation during drilling, the possibility of disengaging connections arises which may require costly fishing operations to retrieve lost equipment.

Usually, the washout joints now used are made with open horizontal ports so that water circulation is directed horizontally and then upwardly. Consequently, since most washout joints are connected directly above the wellhead washing out of cement around the wellhead is not substantially accomplished.

In addition, most washout joints depend on resilient type seals such as rubber. As a result these seals are subject to deterioration and destruction by fires, etc.

SUMMARY OF THE INVENTION The invention disclosed herein is a washout joint which is connected at its lower end directly to a hanger-head in an underwater wellhead. The upper end is connected to a casing extension. A portion of the joint is provided with radial ports which in. the running position are covered by a sleeve and sealed from the annular space between its casing string and the surrounding larger string. It is in this position that cement is passed through the casing string and upwardly in the annular space. Then byrotating the sleeve to an intermediate position these ports register with a recess in the sleeve and allow circulation through the ports and downwardly through an annular passageway formed by the sleeve and a lower portion of the joint. Thus, a downwardly directed swirling or jet action is attained which is very efiicient in washing cement away from the hanger-head.

When circulation is completed, further rotation in the same direction activates a metal to metal seal between portions of the joint inwardly of the ports to again seal the ports against circulation for continued drilling operations.

Thus, a simple, economically manufactured washout joint is provided which requires rotation in only one direction providing efficient washing out of cement around a wellhead. The joint also provides maintenance free sealing for continued drilling.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a somewhat schematic elevational view showing a drilling rig and platform in place, with casing, wellhead, and extended casing therebelow, the drilling rig and platform being purposely made small in proportion;

FIGURE 2 is a vertical elevation, partly in section showing an underwater wellhead, conductor casing, surface casing, casing hanger, extended casings, and a washout joint according to a preferred embodiment of the invention;

FIGURE 3 is a vertical half-section of the washout joint of FIGURE 2 shown in running position;

FIGURE 4 is another vertical half-section of the same washout joint of 'FIGURES 2 and 3 shown in circulating position; and

FIGURE 5 is still another vertical half-section of the washout joint of FIGURES 2, 3 and 4 shown in its sealed position.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGURE 1 of the drawings schematically portrays a drilling rig mounted on a drilling platform 11 above a body of water 12. A conductor riser 23 extends from above the water to near the subsurface 13 and is surmounted by a landing base 14 which in turn supports conventional casing heads and drilling control equipment indicated generally at 15. The lower end of conductor riser 23 is supported on an underwater wellhead 21, which is in turn supported on a conductor casing 20.

Referring now to FIGURE 2, conductor casing is shown driven or jetted into place in subsurface 13. Mounted on conductor 20 is wellhead 21 and mounted on wellhead 21 is casing riser 23 which extends upwardly as shown in FIGURE 1 to the drilling platform.

Wellhead 21 comprises an upper cylindrical portion 25 and lower cylindrical portion 26 joined together by flange lips 27 and a suitable clamp 28. Normally, the wellhead 21 and riser 23 are lowered into position along with conductor 20 as it is installed.

The interior of cylindrical portion 26 is provided with an upwardly facing support shoulder 29 which supports hanger-head 30 through support lugs 31. Lugs 31 are integrally formed at intervals around the exterior of hanger-head 30. The spaces 34 between lugs 31 allow return of cementing fluids. Attached by means such as threads 32 to the lower end of hanger-head 30 is surface casing 33. Attached to the upper end of hanger-head 30 by quick connection means 35 is a washout joint indicated generally at which will be described subsequently in detail. Connected to the upper end of washout joint 40 is surface casing extension 36 which extends upwardly to the drilling platform.

Any suitable quick connection means 35 may be used to join joint 40 and hanger-head 30. However, the breechlock type joint described in the aforementioned copending US. patent application, Ser. No. 572,599, is extremely well suited for use with this washout joint. As described more fully in that application, breech-lock connection 35 comprises alternate rows of correlative thirty degree tooth segments and smooth wall segments on the interior of hanger-head 30 and the exterior of washout joint 40. Thus, only thirty degree rotation is required to engage and subsequently disengage the connection. For running surface casing 33, the breech-lock connection 35 is retained in full engagement by shear means 39.

For running operations, surface casing 33, hanger-head 30 and washout joint 40 are made up together in the position shown and are lowered to seat in wellhead 21 suspended from casing extension 36. Using conventional cementing equipment, cement is then pumped down through casing extension 36 and casing 33 and back up the annular space 37 between surface casing 33 and conductor 20 and may rise around hanger-head 30 and even washout joint 40.

To better understand washout joint 40 reference is now made to FIGURES 3, 4 and 5 which show the running, circulating and sealed positions respectively of joint 40. FIGURE 3 is the same position shown in FIGURE 2.

Joint 40 basically consists of three major parts, upper cylindrical coupling 41, lower cylindrical coupling 42 and cylindrical sleeve 43. Provided at the exterior base of coupling 42 is quick connection means 35 cooperating with hanger-head 30 as previously described. Frusto-conical surface 44 joins the upper and lower portions of coupling 42. An annular groove 45, directly above surface 44, receives O-ring seal 46. A plurality of radial horizontal holes 47 pass from the interior of coupling 42 to its exterior at a point directly above seal 46. Above holes 47 the exterior of coupling 42 presents a smooth cylindrical surface. The upper internal diameter of coupling 42 is slightly less than the middle internal diameter so that threads 48 may be machined thereon. Joining the larger diameter middle interior and smaller diameter lower interior of coupling 42 are upwardly facing shoulders 49, 50 and frusto-conical surface 51.

Upper coupling 41 has a generally cylindrical interior provided with threads 52 for connection to casing extension 36. The exterior of coupling 41 has a smooth wall portion 53 connected to a smaller diameter portion 54 by downwardly facing annular shoulder 55. Portion 54 is threaded correlatively with threads 48 of coupling 42 so that on rotation of one coupling with respect to the other causes lower portion 54 to telescopically engage or disengage the upper interior of coupling 42. The lower exterior of coupling 42 is tapered at 56, the purpose of which will be later explained.

Threadingly attached to coupling 42 is cylindrical sleeve 43 whose annular upper shoulder abuts coupling shoulder 55. Sleeve 43 is stationarily affixed to coupling 41 by means such as welding 61. The exterior of sleeve 43 is a smooth cylindrical surface. The internal diameter of sleeve 43 is slightly larger than the external diameter of coupling 42 to provide a close sliding fit. A downwardly facing annular shoulder 62 limits downward movement of sleeve 43 relative to coupling 42. A circumferential recess 63 is machined on the interior of sleeve 43 near its lower end.

In the running position as shown in FIGURE 3 couplings 41, 42 and sleeve 43 are retained in a stationary position relative to each other by shear means 65. In this position the interior and exterior of the washout joint are sealed off from each other by O-ring 46. It is in this position that washout joint 40 is connected to hanger-head 30 and casing 33 and lowered into the well bore suspended from casing extension 36. (See also FIGURE 2.)

With washout joint 40 in the running position of FIG- URES 2 and 3 cementing operations using conventional equipment and methods are initiated. The cementing mixture passes downwardly through casing extension 36 and casing 33 and upwardly in the annular space surrounding casing 33. To make sure that enough cement is provided, a generous amount may be introduced causing the cement to eventually rise around hanger-head 30 and even washout joint 40. If allowed to harden this may deter removal of hanger-head 30, washout joint 40 and even casing extension 36.

To prevent cement from hardening around hangerhead 30 and washout joint 40 water circulation is required.

To allow such circulation, casing extension 36 is rotated to the right first shearing shear pin 65 and then causing coupling 41 and sleeve 43 to move downwardly relative to coupling 42 which is held stationary by shear pin 39 (FIGURE 2), a stronger pin than pin 65. At a predetermined point rotation is ceased so that washout joint 40 is in the circulating position shown in FIGURE 4.

In the circulating position, fluid passage is permitted through ports 47 and directed downwardly through re- (268363 into the annular space 37 surrounding hangerhead 30. Since the fluid, usually water, first moves downwardly around hanger-head 30 and then upwardly around joint 40 and extension 36 a swirling action, indicated by arrows, results. This action effectively washes away excess cement around hanger-head 30 and washout joint 40 allowing it to be entrained in the upwardly moving flow for removal from the well. Thus, the cementing material is removed before hardening.

Since further drilling operations require isolating the interior of the surface casing from its exterior it is necessary to once again seal off ports 47. To accomplish this, extension 36 is rotated, again to the right, moving coupling 41 and sleeve 43 further downward. Recess 63 moves out of register with 'hole 47 and past O-ring 46 so that the seal of O-ring 46 against sleeve 43 is again activated. The tapered end 56 of coupling 41 engages frusto-conical surface 51 of coupling 42 to create a metalto-metal seal. Torque measurements are taken at the drilling platform to assure that the proper sealing force is applied. Thus, ports 47 are once again sealed ofi, the metal-to-metal seal assuring high pressure, deterioration resistant scaling for further drilling requirements.

To remove washout joint 40 further rotation to the right causes shear pin 39 to be sheared allowing the thirty degree rotation necessary to disengage the breech-lock connection 35 between hanger-head 30 and lower coupling 42 (see FIGURE 2). Washout joint 40 may then be raised to the surface attached to casing extension 36.

From the foregoing description of one embodiment of the invention, it can be seen that such a joint may be easily constructed and used with elfective results. The joint requires rotation in only one direction and provides a unique washing action and subsequent sealing which is not subject to deterioration and destruction inherent in other designs.

Although only one embodiment has been described in detail herein it is apparent that various changes in form, construction and use of the invention may be made without departing from the spirit and scope of the invention. It is therefore intended that the scope of the invention be limited only by the claims which follow.

We claim:

1. In a method of cementing well casing which is substantially disposed beneath the floor of a body of water, said method including the steps of pumping cement downwai-dly through said casing and back up through an annulus surrounding the casing to a point near said floor wherein the improvement comprises the steps of,

attaching a washout joint between said casing and a casing extension which extends to a space above said body of water,

after said pumping of cement, rotating a portion of said washout joint in one direction to open passage means providing flow communication between the interior and exterior of said casing, circulating washing fluid through said washout joint to remove excess cement surrounding said joint, and

rotating a portion of said washout joint in said one direction to close said passage means for further operations.

2. The method of claim 1 and the further step of rotating said washout joint in said one direction to release it for removal from said wellhead.

3. The method of claim 1 in which said washing fluid circulates downwardly through said casing extension,

through said passage means, then exits in a downwardly direction through flow direction means and finally returns upwardly through the space surrounding said extension.

4. The method of claim 1 and the additional step of providing a metal-to-metal seal in said washout joint which is activated on said rotating portion of said washout joint to close said passage means.

5. Apparatus for use in cementing pipe strings in a well, said apparatus comprising,

first tubular member, and.

second tubular member,

said second tubular member having passage means through the walls thereof, said first tubular member having a portion which blocks flow through said pas sage means, said first member being adapted to unblock said flow passage means on rotation in one direction and to again block said flow passage on further rotation in said one direction.

6. The apparatus of claim 5 in which said first member is provided with an annular recess which is downwardly opened when said passage means is unblocked to direct fluid flowing through said passage means in a downwardly direction.

7. The apparatus of claim 5 in which said first and second members are provided with means for connecting between pipe string sections.

8. The apparatus of claim 7 in which said means for connecting between pipe string sections comprises release means adapted to disengage at least one of said pipe string sections on still further rotation in said one direction.

9. A washout joint for use in cementing casing in a well which is submerged in a body of water, said casing being supported in said Well with casing riser means installed thereabove, said riser means extending to the space above said body of water, said washout joint comprising,

first tubular means connected above said casing with flow passage means through the walls thereof, and second tubular means connected below said casing riser means,

said second tubular means being rotatingly connected to said first tubular means, said second tubular means having a portion thereon which blocks flows through said flow passage means, said portion being adapted to unblock said flow passages on rotation of said second tubular means in one direction.

10. The washout joint of claim 9 in which said portion comprises cylindrical sleeve means slidingly surround ing the exit of said passage means.

11. The washout joint of claim 9 in which said portion is adapted to block said flow passages on further rotation of said second tubular means in said one direction.

12. The Washout joint of claim 9 in which said por tion comprises skirt means surrounding said flow passages, said skirt means having flow direction means which register with said passage means in said unblocked position to direct flow of fluid out of said passage means in a downwardly direction.

13. The washout joint of claim 12 in which said flow direction means comprises an annular recess on the in terior of said skirt means and an annular space below said recess defined by the interior of said skirt means below said recess and the exterior of said first tubular means.

14. The washout joint of claim 13-, and annular seal means on the exterior of said first tubular means below said flow passage means and on the interior of said skirt means to block said flow through said flow passages on further rotation of said second tubular means in said one direction.

15. A washout joint for use in underwater well ex tended casing drilling operations, said washout joint com pIlSlIlg,

first tubular coupling means with pipe connection means on one end thereof,

second tubular coupling means having flow passage means through the walls thereof and means for con necting above a casing, said second coupling means being rotatingly connected to said first coupling means, and

tubular sleeve means afiixed to said first coupling means surrounding a portion of said second coupling means blocking the flow of fluid through said passage means and being adapted to unblock said flow on rotation of said first coupling means in one direction.

16. The joint of claim 15, and annular seal means on the lower interior of said sleeve means and the exterior 10 of said second coupling means.

17. The joint of claim 15 in which said sleeve means comprises groove means on the interior thereof registering with said passage means in said unblocked position, an annular space existing between the interior of the portion of said sleeve below said groove means and the exterior of said second coupling means to direct fluid flow downwardly therethrough.

18. The joint of claim 15 in which said first and second coupling means comprise metal sealing surfaces inwardly of said passage means, said sealing surfaces, being engageable on further rotation in said one direction to block said flow through said passage means.

19. The joint of claim 18 in which said means for connecting above a casing is adapted to release said joint for removal from said underwater well on further rotation in one direction.

20. The joint of claim 18 in which said metal sealing surface of said first coupling means is a frusto-conical surface on the lower end of a telescopic portion downwardly projected into the interior of said second coupling means and said metal sealing surface of said second coupling means is a cooperating frusto-conical surface on its interior.

References Cited UNITED STATES PATENTS 2,531,943 11/1950 Lee l66226 X 2,569,732 10/1951 Ragan l66226 2,598,396 5/1952 Lee l66226 3,216,452 11/1965 Williams l66226 X 3,273,646 9/1966 Walker 166-86 3,380,519 4/1968 Fowler 1757 X CHARLES E. OCONNELL, Primary Examiner R. E. FAVREAU, Assistant Examiner US. Cl. X.R. l66226

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