US3217805A - Marine well completion apparatus - Google Patents

Description

Nov. 16, 1965 a. c. HOWARD 3,217,805

MARINE WELL COMPLETION APPARATUS Filed May 16, 1965 5 Sheets-Sheet 1 l2 GEORGE C. HOWARD INVENTOR fifwd/KX/M ATTORN E Y.

Nov. 16, 1965 G- c. HOWARD 3,217,805

MARINE WELL COMPLETION APPARATUS Filed May 16, 1963 3 Sheets-Sheet 2 W J 7 V H 1 x I 2 V I i M I y A 1N Akl \I \I 1 31 55* 38 1 GEORGE 0. HOWARD INVENTOR ATTORNEY.

Nov. 16, 1965 G. c. HOWARD 3,217,805

MARINE WELL COMPLETION APPARATUS Filed May 16, 19 63 s Sheets-Sheet 5 GEORGE 0. HOWARD INVENTOR- ATTORNEY- United States Patent 3,217,805 MARINE WELL COMPLETION APPARATUS George (J. Howard, Tulsa, Okla, assignor to Pan American Petroleum Corporation, Tulsa, Okla, a corporation of Delaware Filed May 16, 1963, Ser. No. 280,930 11 Claims. (Cl. 16666.5)

This invention relates to completing wells in marine locations. More particularly it relates to apparatus for use at the top of the well to permit completing the well without the use of a platform but still allowing workover of the well from a floating ship or barge.

When completing wells in marine locations, it would be desirable to perform the operation in such a way that no expensive permanent platform was required. This problem has been partially solved by marine floor completions with flow lines along or under the marine floor from the well head. The principal problem with wells of this type arises when it is necessary to workover the wells as by squeeze cementing, cleaning out the wells, perforating at a new interval, or the like. Another problem is to make marine floor completions without the use of expensive and highly specialized equipment and possibly divers.

An object of this invention is to provide a well head system permitting marine floor completions which will still allow easy manipulation of the well. Another object is to provide a marine floor well head arrangement which minimizes the use of specialized equipment and techniques for completing the well in the first place.

In general, I accomplish the objects of my invention by providing a slip joint at the top of the casing string. This joint is long enough to permit raising the well head above the surface of the water where is can be supported by a workover barge or ship and the workover operations can be carried out much as if the well was on land. The technique also permits the original well head to be made up and connections to the well head to be made on the barge or ship so that ordinary well head completion equipment and techniques can be used. The entire assembly can then be lowered to the marine floor by collapsing the casing slip joint. The well head need not be lowered completely to the marine floor as long as it is placed below the level affected by ships, Wave action and the like.

In the drawing FIGURE 1 is a view, partly in cross section, of the top portion of a marine well completed in accordance with my invention. FIGURE 2 is another view, partly in cross section, of a preferred embodiment of my invention in which a seal is established between the tubing and casing below the casing slip joint and a positive seal is established between the two parts of the slip joint. FIGURES 3 and 4 are views, in cross section, of portions of embodiments in which the slip joint may be below the marine floor.

Considering the drawing in more detail, in FIGURE 1 a flat plate or pad rests on the marine floor. A well casing 11 passes through a hole in plate 10. The casing is supported by a flange 12 which rests on plate 10. On the top end of casing 11 is a tapered enlargement 13. This enlargement is one-half of a matching pair, the other half 14 of which is on the bottom of outer section or barrel 15 of the slip joint. Clamping ring 16 completes the joint between casing 11 and barrel 15. A sealing gasket 17 is included between the faces of the flanges. A connection of this type is shown and described in more detail in the Composite Catalog for 1960-61, pages 1146 and 1147, published by World Oil.

Outer pipe or barrel 15 of the slip joint surrounds inner portion or mandrel 18 of the joint. The bottom of the inner mandrel is threaded to receive packing com- 3,217,805 Patented Nov. 16, 1965 pressing ring 19. Above ring 19, and filling a portion of the space between barrel 15 and mandrel 18, is packing 21. against flange 22 near the bottom of inner mandrel 18. Mandrel 18 passes through the top of barrel 15 and is attached to a well head connection 22. This is a standard well head connection except that some of the bolts which clamp cone 23 into bowl 24 are eye bolts so that cables 25 can be attached. The cables are attached to a marking buoy (not shown) floating on the surface of the water or held at some depth below the surface but retrievable with suitable search and find devices. Cone 23 of the well head supports well tubing 20.

Also attached to the marking buoy is flexible tube 26 or a retrievable line for the flexible tube which extends down to a connection 27 passing through the wall of barrel 15 near the bottom of this pipe. Connection 27 includes a flapper valve 28 which permits flow of liquid down the flexible tubing 26 and into the space above packing 21 between barrel 15 and mandrel 18. The flapper or check valve prevents flow out of the space between the barrel and mandrel. Any other check valve such as a ball check may also be used, of course. The top of the barrel is preferably turned in to form an inwardly directed flange 29. A small clearance is provided between flange 29 and mandrel 18.

In FIGURE 2 the bottom of the figure is like FIGURE 1 except that a second string of casing 31 is shown within outer surface casing 11. Cement 32 fills the space between the casing strings, port 33 being provided through casing 11 to permit filling to the top the annular space between the casing strings.

In the apparatus of FIGURE 2, inner portion or mandrel 34 of the slip joint is fixed to casing 11 by clamping ring 16 while the barrel portion 35 moves up and down permitting raising and lowering of the well head attached to the top of barrel 35. The apparatus of FIGURE 2 is designed for use in high pressure wells. In this case, the weight of the tubing and well head may not be quite enough to pull down the outer portion of the telescoping joint. Therefore, seals 36 and 37 are provided at the top of mandrel 34 and the bottom of barrel 35 respectively. A tube 38 passes through the wall of mandrel 34 just above seal 37. Flexible hose 39 is attached to tube 38. Hose 39 passes to the buoy at the surface of the water so hydraulic pressure can be applied through the hose to help force barrel 35 down.

At the bottom of barrel 35 a clamping mechanism is provided to hold barrel 35 down once it is forced to its bottom position. In this clamping mechanism, bevelled flanges 41 and 42 are provided on mandrel 34 and barrel 35 respectively. These flanges are held together by clamping elements 43. The outer surface of each element 43 is curved, so as solid ring 44 is raised by hydraulic cylinders 45, beveled flanges 41 and 42 are released. When ring 44 is lowered, flanges 41 and 42 are locked together. Hydraulic cylinders 45 are operated by hydraulic pressure applied through flexible hoses 46. At the bottom of mandrel 34, a portion 51 of smaller internal diameter is provided. An enlarged portion 52 on tubing string 53 is provided at a level which will be opposite portion 51 of mandrel 34 when the tubing is seated in the well head. A sealing element such as O-ring 54 is placed in enlarged portion 52. This seal holds at least most of the pressure off of sliding seals 36 and 37.

When the seal formed by sealing element 54 is broken by lifting the tubing, the entire pressure may be applied across seals 36 and 37. It may be desirable in some cases, therefore, to provide an additional positive seal across sliding seals 36 and 37. This is accomplished by internal sleeve 55 with enlarged ends 56 and 57. The

The packing can be compressed by ring 19,

face to make a sliding seal with the cylinder.

ru 63 enlarged ends 56 and 57 carry sealing elements 58 and 59 respectively. These elements protect sliding seals 36 and 37 from the full well pressure when the tubing is lifted so sealing element 54 is raised above cylinder 51. It will be apparent that sleeve 55 can be used without seal 54 and seal 54 can be used without sleeve 55 if desired.

A production packer, for example of the type shown in the Composite Catalog for 196061, pages 544 and 545, may also be used at the bottom of the well. This packer is set in the casing and provides a cylinder in which an enlarged portion or piston on the tubing slides. The piston has sealing elements around the outer sur- If the cylinder is long enough, the well head can be lifted from its lowest to its highest position without removing the tubing piston from the cylinder of the production packer at the bottom of the well. In this way pressure can be kept off of the casing above the packer until after the well head has been raised to the surface of the water. Then, if desired, the well can be killed with mud or other heavy liquid before the tubing is pulled.

It is also possible to use a storm choke at the bottom of the well so that when the tubing is pulled a valve closes to confine the pressure to the bottom of the well.

For the sake of simplicity, a simple clamp ring 16 has been shown in both FIGURES 1 and 2 to attach the slip joint assembly to the top of casing 11. It will be apparent, however, that locking elements such as 43 operated by hydraulic cylinders such as 45 fixed to plate may be used to facilitate making or releasing this connection by application of hydraulic pressure from the surface of the water.

However the slip joint assembly is attached to the top of casing 11, once this connection is made, the well head in FIGURE 1 can be lowered to the position shown. In this position, the well head is far enough below the surface of the water to permit ships to pass over the well head without touching it. Cables and hose 26 or retrieving line for hose 26 are attached to a buoy, not shown, so that if it is desired to workover the well, it is only necessary for a drilling ship or barge to come to the buoy and lift on the cables and hose to raise the well head to the deck of the ship or barge. The well can then be cleaned out or otherwise manipulated in much the same way as if the well was on dry land.

The tubing sections extending upwardly and outwardly from the well head should usually include flexible portions to facilitate handling of the well head. When the well head is again lowered into the position shown in FIGURE 1, an oil or grease, preferably heavier than the water outside the assembly, is introduced through hose 26 and connection 27 into the annular space between barrel 15 and mandrel 18 to avoid corrosion. If a seal is provided between the top of barrel 15 and the outer surface of mandrel 18, then the oil can, of course, be lighter than the water. If such a seal is used, however, the liquid between the barrel and mandrel must be displaced through hose 26 as the well head is raised and must be added to the space as the well head is lowered. To permit such movement, flapper valve 28 must be removed; The liquid between pipes 15 and 18 can also, of course, be an aqueous solution or gel containing a corrosion inhibitor if desired.

Many variations and modifications are possible. For example, while my invention is principally applicable to open sea locations where large ship traflic and serious wave actions are problems, it will be apparent that the invention is also applicable to inland waters such as rivers and lakes. When the term marine is used, I intend the term to include any water-covered area where a well may be drilled.

In FIGURE 1 a particular type of well head is shown. One of the advantages of my invention is that since the well head is always made up above the water, almost any type of well head can be used. The only requirement is that some means such as eye bolts be used to which a lifting cable can be attached.

In some wells the tubes extending from the sides of the well head may be closed by valves, or the well head openings may be closed by plugs. An example of such an arrangement is found in the Composite Catalog of Oil Field Equipment and Services for 1960-1961, page 880. The main tubing extending from the top of the well may be curved to lie on the marine floor along which it may extend to separators, flow tanks, and the like. An arrangement of this type is shown in US. Patent 3,052,299. The separators and tanks may be on marine platforms as shown in the Oil and Gas Journal for July 10, 1961, page 59, or on shore, for example. The tubing may also be attached to a flexible high pressure line (not shown) which extends to the water surface to the buoy which supports cables 25. The flexible highpressure line can be closed by a valve so that a tanker or barge can drop anchor and take production through the tubing without raising the well head. Examples of such equipment are illustrated in US. Patent 3,004,612 and Oil and Gas Journal, September 24, 1962, page 107.

The apparatus in FIGURE 1 is shown extending above the marine floor. It will be apparent, however, that the top portion of casing 11 can serve as barrel 15 as shown in FIGURE 3. In this case, everything but the well head will be below the marine floor. A top plate 62 is simply clamped on top of enlarged portion 13 of casing 11. This prevents pulling mandrel 18 from the well without releasing clamp 16, but still allows mandrel 18 to be raised or lowered in barrel 11 (FIGURE 3) to the limits imposed by packing gland stop 22 (FIGURE 2). If the top section of casing 11, or of casing 31 in FIG- URE 2, is to serve as the barrel for the slip joint, it cannot be subjected to wear during the drilling operation. Therefore, during drilling operations, a wear sleeve (not shown) should be used inside the portion of the casing which is to serve as the barrel of the slip joint. This is most simply done by hanging a short liner string through the top casing joint as shown, for example, in US. Patent 2,683,086. The wear sleeve is then removed before the mandrel of the slip joint is inserted. The top section of the casing (barrel of the slip joint) may be attached to the remainder of the well casing by an ordinary collar or by any other suitable means. The collar may have a lefthand thread, permitting the top portion of the casing to be standard casing easily removed after the drilling operation and cementing operation are completed. Such a lefthand thread detachable connection is shown, for example, in the Composite Catalog of Oil Field Equipment and Services for 1960-1961, page 5248. This top portion can then be replaced by a new length which can serve as the slip joint barrel.

Still another arrangement is shown in FIGURE 4. Here the top plate 62 is like in FIGURE 3 except that hanging from the bottom of the plate is a liner sleeve 63 which serves as the outer barrel of the slip joint. Still other arrangements are, of course, possible.

In case of deep water, more than one slip joint may be employed. These joints may be arranged on top of each other or they may be nested together with each mandrel acting as the barrel for the next internal mandrel as in a spy glass having several telescoping sections. It is also possible to lengthen casing 11 between flanges 12 and 13 in order to use shorter slip joints in deep water.

In FIGURE 2 hydraulic cylinders 45 are shown attached to barrel 35. It will be apparent that the entire system of locking elements 43 and hydraulic cylinders 45 can be inverted so the cylinders can be attached to plate 10 or flange 12 on the marine floor.

Also in FIGURE 2, the bottom of mandrel 34 is shown with two sections 51 and 61 of reduced internal diameter near the bottom. It is possible to make the mandrel of uniform internal diameter and use packer and slips systems such as those shown in the Composite Catalog for 1960-61, pages 544 and 545, to provide the cylinders of reduced diameter in which sealing elements 54 and 59 can be set. Such packers may be set in casing 11 or 31 as well as in mandrel 34.

The pad or plate on the marine floor may be of metal, as shown, or of other materials such as reinforced concrete. The plate may be turned up on the edges to form a pan which may be filled with heavy materials such as barite to stabilize the equipment at the top of the well.

Many other variations will be apparent to those skilled in the art. I do not wish, therefore, to be limited to the specific embodiments shown and described, but only by the limitations of the following claims.

I claim:

1. Apparatus for completing a well at a marine location comprising a slip joint made up of an inner cylindrical hollow mandrel and an outer barrel, means for forming a sliding seal between said mandrel and said barrel, means for connecting the bottom of said slip joint to the well casing, a well head attached to the top of said slip joint, said Well head including means for supporting a tubing string therein, and means for raising and lowering said well head, the length of said slip joint being sufficient to permit said well head to be lifted above the surface of the water, and lowered to a level sufficiently low to avoid ships, serious wave action and the like.

2. The apparatus of claim 1 in which the external diameter of the hollow mandrel is sufficiently smaller than the internal diameter of the outer barrel to provide an annular space between the mandrel and barrel, a pas sage into the annular space between the barrel and mandrel, and means to fill this space with a protective material such as a non-corrosive liquid.

3. The apparatus of claim 1 in which said means for raising and lowering said well head includes cables attached to a buoy floating on the surface of the water.

4. Apparatus for completing a well at a marine location comprising a slip joint made up of an inner cylindrical hollow mandrel and an outer barrel, means for forming a sliding seal between said mandrel and said barrel, means for connecting the bottom of said slip joint to the well casing, a well head attached to the top of said slip joint, said well head including means for supporting a tubing stn'ng therein, a sleeve inside said slip joint, said sleeve having at one end a seal against the internal surface of said mandrel and at the other end a seal against the internal surface of said barrel, thus forming a seal across the slip joint, and means for raising and lowering said well head, the length of said slip joint being sufiicient to permit said well head to be lifted above the surface of the water, and lowered to a level sufiiciently low to avoid ships, serious wave action and the like.

5. The apparatus of claim 4 including a string of tubing passing through said slip joint and into said casing, and means for forming a seal between said tubing and the well wall at a level which isolates from well pressure the seal in said slip joint.

6. The apparatus of claim 5 including a sleeve inside said slip joint, said sleeve having at one end a seal against the internal surface of said mandrel and at the other end a seal against the internal surface of said barrel, thus forming a seal across the slip joint.

7. Apparatus for completing a well at a marine location comprising a slip joint made up of an inner cylindrical hollow mandrel and an outer barrel the external diameter of the hollow mandrel being sufliciently smaller than the internal diameter of the outer barrel to provide an annular space between the mandrel and barrel, a sliding seal at each end of the annular space between said mandrel and said barrel, a passage into said annular space, means to apply pressure to said annular space to collapse said slip joint to its closed position, means for connecting the bottom of said slip joint to the well casing, a Well head attached to the top of said joint, said well head including means for supporting a tubing string therein, and means for lowering and raising said well head, the length of said slip joint being suflicient to permit said Well head to be lifted above the surface of the water and lowered to a level sufiiciently low to avoid ships, serious wave action and the like.

8. The apparatus of claim 7 in which said means for raising and lowering said well head includes cables at tached to a buoy floating on the surface of the water.

9. Apparatus for completing a well at a marine location comprising a slip joint made up of an inner cylindrical hollow mandrel and an outer barrel, the external diameter of the hollow mandrel being sufliciently smaller than the internal diameter of the outer barrel to provide an annular space between the mandrel and barrel, a sliding seal at each end of the annular space between said mandrel and said barrel, a passage into said annular space, means to apply pressure to said annular space to collapse said slip joint to its closed position, means for connecting the bottom of said slip joint to the well casing, a well head attached to the top of said joint, said well head including means for supporting a tubing string therein, a sleeve inside said slip joint, said sleeve having at one end a seal against the internal surface of said mandrel and at the other end a seal against the internal surface of said barrel, thus forming a seal across the slip joint, and means for raising and lowering said well head, the length of said slip joint being sufiicient to permit said well head to be lifted above the surface of the water, and lowered to a level sufficiently low to avoid ships, serious wave action and the like.

10. The apparatus of claim 9 including a string of tubing passing through said slip joint and into said casing, and means for forming a seal between said tubing and the well wall at a level which isolates from well pressure the seal in said slip joint.

11. The apparatus of claim 10 including a sleeve inside said slip joint, said sleeve having at one end a seal against the internal surface of said mandrel and at the other end a seal against the internal surface of said barrel, thus forming a seal across the slip joint.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS 11/ 1960 Great Britain.

BENJAMIN HERSH, Primary Examiner.

Claims (1)

1. APPARATUS FOR COMPLETING A WELL AT A MARINE LOCATION COMPRISING A SLIP JOINT MADE UP OF AN INNER CYLINDRICAL HOLLOW MANDREL AND AN OUTER BARREL, MEANS FOR FORMING A SLIDING SEAL BETWEEN SAID MANDREL AND SAID BARREL, MEANS FOR CONNECTING THE BOTTOM OF SAID SLIP JOINT TO THE WELL CASING, A WELL HEAD ATTACHED TO THE TOP OF SAID SLIP JOINT, SAID WELL HEAD INCLUDING MEANS FOR SUPPORTING A TUBING STRING THEREIN, AND MEANS FOR RAISING AND LOWERING SAID WELL HEAD, THE LENGTH OF SAID SLIP JOINT BEING SUFFICIENT TO PERMIT SAID WELL HEAD TO BE LIFTED ABOVE THE SURFACE OF THE WATER, AND LOWERED TO A LEVEL SUFFICIENTLY LOW TO AVOID SHIPS, SERIOUS WAVE ACTION AND THE LIKE.

Images