US3220477A

US3220477A - Guide system for underwater wells

Info

Publication number: US3220477A
Application number: US245737A
Authority: US
Inventors: Marvin R Jones
Original assignee: Cameron Iron Works Inc
Current assignee: Cooper Industries LLC
Priority date: 1962-12-19
Filing date: 1962-12-19
Publication date: 1965-11-30
Anticipated expiration: 1982-11-30

Description

Nov. 30, 1965 M. R. JONES 3,220,477

GUIDE SYSTEM FOR UNDERWATER WELLS Filed Dec. 19, 1962 2 Sheets-Sheet 1 Marv/n 6. Jane;

INVENTOR.

Nov. 30, 1965 M. R. JONES GUIDE SYSTEM FOR UNDERWATER WELLS 2 Sheets-Sheet 2 Filed Dec. 19, 1962 Mar w/7 R z/amsu' INVENTOR.

ATTO/P/VEVJ United States Patent 3,220,477 GUIDE SYSTEM FOR UNDERWATER WELLS Marvin R. Jones, Houston, Tex, assignor to Cameron Iron Works, Inc., Houston, Tex., a corporation of Texas Filed Dec. 19, 1962, Ser. No. 245,737 20 Claims. (Cl. 166-46) This invention relates to apparatus and methods em ployed in the drilling, completion and servicing of underwater wells generally and, in particular, to apparatus and methods employed to guide equipment for these purposes as it travels from the surface of the water to a wellhead located below the surface. Specifically, this invention relates to improved apparatus and methods employed to anchor guide lines which are used to guide the drilling, completion and servicing equipment as it travels from the surface of the water to the wellhead.

Wells are drilled in water either from a stationary platform supported by means extending to the bottom of the water or from a floating platform held in position by anchors. Wells drilled from stationary platforms usually have their wellhead equipment located above the surface of the water, whereas wells drilled from floating platforms have their wellhead equipment located near the bottom of the water. As used herein, wellhead equipment includes all items connected to and supported by the well casing, such as blowout preventers, circulating heads, etc., for drilling the well, and easing heads, tubing heads, Christmas trees, etc., completing the well.

Since wells are drilled from floating platforms only when the water is too deep for stationary platforms, there is usually a considerable amount of water between the wellhead and the stationary platform or vessel on the surface which supports the hoisting equipment, pumps, etc., used to drill and service the well. Since it is seldom feasible to anchor this platform or vessel rigidly so that it will not move relative to the well, flexible means must be provided between it and the wellhead to guide the drill bit and drill pipe to the entrance to the well and other equipment to its proper position on the casing. This is usually done by means of flexible guide lines which extend from the wellhead upward to the surface vessel and which are maintained under tension so that they will be as straight as possible. Guide arms are arranged to slide up and down these guide lines and the equipment being lowered to the wellhead is directed either into the well opening or to its proper position on the well casing, as the case may be, by means of these guide arms.

These guide lines are useful, not only during the initial drilling and completion operations, but also whenever it is necessary to rework or service the well. Heretofore, they have been connected to the well by means of an anchor which is either permanently attached to the well casing or connected to the wellhead equipment in such a way that, when the well was completed, they had to be either left at the well or released from the anchor in some manner. When they were left, they were either simply tied together and dropped to the bottom or they were attached to a buoy for ease of recovery. When they were released from the anchor, either they were cut adjacent the anchor and recovered or a latch arrangement was used whereby they could be released and then later relatched to the anchor. For a description of this latter system, see US. Patent Nos. 3,050,139 and 3,050,140 issued August 21, 1962.

All of these systems have serious disadvantages. Where the guide lines are left attached to the well and dropped to the bottom, as in the first instance, it is usually very difficult to locate and recover them because they are moved about by currents and often covered with silt and mud. In addition, they are exposed to the corrosive action of the water and may be unfit for use even when recovered. This is particularly true where there is the usual considerable lapse of time between the drilling and servicing of the well. This latter problem is also existent where the guide lines are secured to a floating buoy, which makes them easy to recover but still subjects them to the corrosive action of ocean water. The alternative situation, where the guide lines are either severed from the anchor or released by means of a latch arrangement and recovered, makes relocating the well extremely difficult. Also, it is very difficult and complicated to reanchor the guide lines to the wellhead equipment. Where the lines are cut, they can be re-attached only by a diver, which precludes the use of this system for wells in deep water. The relatch system requires a complicated procedure employing underwater lights and television cameras, remotely releasable buoys, etc.

It is one of the principal objects of this invention to overcome these problems by providing apparatus which permits guide lines to be quickly and easily engaged and disengaged from the well casing.

It is a further object of this invention to provide an anchor for guide lines which is removably attached to the well casing.

It is also a principal object of this invention to provide a guide line anchor which can be easily and quickly replaced in position on the well casing to again support the guide lines for drilling, servicing and completing operations after having once been removed.

For these purposes, I provide a guide line anchor which, in its preferred form, is moved laterally into and out of position on the well casing. More particularly, and as will be described in more detail to follow, my preferred form of guide line anchor comprises a body having an opening to receive the casing and a laterally extending passageway through which the well casing can pass into and out of the opening as the body is moved laterally with respect to the casing. Means are also provided for attaching guide lines to the body and for moving the body laterally into and out of engagement with the casing. The well casing and body are preferably provided with interengaging means for preventing relative movement between the anchor body and the casing when the anchor is in position on the casing.

The invention will now be described in connection with the attached drawings in which:

FIG. 1 is an isomeric view showing the guide line anchor in position to engage an underwater well and illustrating how the anchor can be moved along in such a way that it will automatically locate itself in position on the well casing;

FIG. 2 is a side view illustrating the anchor in position on the well casing; and

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2 illustrating the interengaging guide means located on the well casing and the anchor which serve to prevent relative movement of the anchor with respect to the well casing when the anchor is in the position shown in FIG. 2.

In the drawings, the well is illustrated as it would appear either at the completion of drilling operations or just prior to the beginning of servicing operations. It consists of the surface casing 10 which is usually cemented in the surface formations adjacent the bottom of the water. The casing extends up from the bottom a sufficient distance to allow the anchor, generally indicated by the number 11, ample room to move vertically up and down on the casing so that it can be easily removed therefrom in the manner to be described below.

Attached to the top of the casing is a casing head 12 which supports a Christmas tree 13 which houses the

control valves

14 and 15. Extending from the top of the Christmas tree 13 are U-shaped flow line connectors 16 which serve to connect the Christmas tree with the flow line head 17. Also connected into the flow line head 17 are flow lines 18, which travel away from the .well along the bottom either to the shore or to some gathering station located in the vicinity of the Well. The flow line head 17 is supported by the well casing by means of bracket 22 on the well casing.

The U-shaped flow line connector 16 and the attendant structure comprising the horizontal bracing member 23 and the two

latching heads

24 and 25 are releasably connected to the tree 13 and the flow line connector 17 and are run into position and removed by means of the fishing neck 26. A complete description of this removable flow line apparatus is set out in copending application, Serial No. 130,387, filed August 9, 1961, by Arthur G. Ahlstone, entitled, Well Completion Apparatus, and assigned to the assignee of the present application.

The removable guide line anchor 11 comprises a body 29 provided with an opening 30 to receive the well casing 10. In the structure illustrated, the opening 30 is located in two

horizontal plates

31 and 32 of the body. The plates are held in parallel spaced relationship by means of vertical members 33 and 34. The plate 31 is provided with

slots

35, 36 and 37 extending away from the opening 30 at 90 angles from each other. The plate 32 is provided with a similar group of

slots

38, 39 and 40 arranged so that they are in vertical alignment with

slots

35, 36 and 37, respectively.

To guide the casing in and out of the opening 30, the anchor is provided with a V-shaped laterally extending opening 41. Forming part of the V-shaped opening are the laterally extending

slots

42 and 72 in

plates

31 and 32 which are provided with diverging sides so that they open outwardly away from the opening 30-. Attached to the plates and extending outwardly therefrom on more or less the same angle as the diverging sides of the

slots

42 and 72 are

horizontal members

43, 44, 45 and 46. As illustrated, these members extend from the plates to the

vertical guide rods

47 and 48. The remainder of the V-shaped passageway consists of the

members

49, 50, 51 and 52 which extend on out past the

vertical guide rods

47 and 48 at approximately the same angle of divergence as had members 43 through 46. These latter members can extend out any distance desired which is practical and, of course, the further they extend, the less chance there will be that the anchor will miss the well as it moves along horizontally.

Attached to the end of the

members

50 and 51 are

tow lines

53 and 54 which serve to move the anchor along horizontally through the Water. These lines, of course, also help locate the anchor on the well casing since they are .extending out in approximately the same horizontal plane as the anchor for a considerable distance ahead of the anchor. If they are attached to a drilling barge on the surface, for example, they will probably be spaced further apart at the surface than they are at the anchor and consequently, they wil diverge and help extend the effect of the V-shaped passageway 41 and thereby help guide the anchor onto the well casing.

Also forming a part of the anchor are the

vertical guide rods

47, 48, 55 and 56. These vertical guide rods provide means for anchoring the

flexible guide lines

57, 58,59 and 60. The

guide rods

55 and 56 are rigidly attached to the body by means of the horizontal braces indicated by the number 61. These horizontal braces not only attach the guide rods to the anchor body but they also rigidly fix the location of each of these rods with respect to the other and to the

guide rods

47 and 48 so that the relationship of the rods and the guide lines which are attached thereto is predetermined. 7

When the anchor is in position so that the Well casing 10 is located in the opening 30 of the anchor body, some means must be provided to limit its vertical movement along the well casing so that an upward force can be exerted on it through the guide lines 57, 58, 59 and 60. This upward force is preferably greater than the total weight of the anchor body and guide lines so that the guide lines will tend to remain straight as they extend from the drilling vessel on the surface to the well.

In the preferred form illustrated, this is accomplished by means of the flange 65 which is attached to the casing 10 adjacent the casing head 12. This laterally extending flange engages the plate 31 of the anchor body and stops its upward travel on the well casing, thereby allowing the desired upward force to be placed in the guide lines. Once in position against the flange 65, the anchor body would probably not move laterally out of position due to the frictional forces existing between the plate 31 and the flange 65 and therefore, no additional means would have to be provided to make sure that the anchor body did not move laterally. However, it is preferred not to rely on this frictional force but to have some positive means for insuring that the well casing 10 is accurately located Within the opening 30 so that the guide lines will be positioned properly with respect to the center of the well. In other words, the equipment guided toward the well by means of the guide lines is arranged on the guide arms which travel up and down the guide lines on the assumption that the guide lines are located at a given point with respect to the well. If this is not true, then the equipment being lowered on the guide lines would not be accurately guided to the well. Also, in producing wells of the type illustrated in the drawings, the well will be equipped with flow lines which extend otf in some direction from the well and it is desirable not to have the anchor swinging around into engagement with the flow lines when it is being positioned on the well and removed therefrom or during the servicing and workover operations. For these reasons, in the preferred form of the invention, means are provided to accurately locate the anchor body with respect to the well casing and to also prevent lateral and relative movement of the anchor body once it is in place on the well casing and against the stop means which limits its upward travel.

This is accomplished by means of the

key members

62, 63 and 64 which are located on the casing 10 and which are spaced so as to engage the slots 35 through 42 'in the

plates

31 and 32 of the anchor body. The key 62 extends all the way from the stop 65 down to the point where the casing passes below the bottom of the water. The other two

keys

63 and 64 are much shorter and are only long enough to engage the slots in both plates when the anchor body is in position against the flange 65. This allows the anchor body to be moved horizontally into position so that the well casing 10 is located in the opening 30 and the elongated key 62 is located in the

slots

36 and 39 without engaging the

keys

63 and 64. When the anchor body is raised by means of the guide lines, the key 62 will maintain the anchor body properly aligned so that it will not hit the flow line equipment extending out on the opposite side of the well casing from the elongated key 62, and the slots 3537 and 38-40 will be in position to engage the

keys

63 and 64. Since the keys are long enough to engage

body plates

31 and 32, the anchor body is also prevented from rocking on the flange 65.

In attaching the anchor to an underwater well, the an- .chor is supported at the desired depth by means of the

flexible guide lines

57, 58, 59 and 60. The anchor can be located above the bottom and moved along at that depth or it can be lowered to the bottom and moved along on the bottom until it engages the well, depending to a large extent on the condition of the bottom.

Once the anchor is located at the proper depth, it is moved along horizontally toward the well by means of the tow lines 53 and 54. When the angle between the tow lines and the bottom is small, the tow lines are better able to guide the anchor into position on the well casing.

It is important in this operation to know the position of the flow lines with respect to the well and also the position of the elongated key 62 so that the anchor can be moved in the proper direction. This information, of course, will be recorded when the well is initially drilled and completed so that when the time comes to attach the anchor, the direction it should move will be known. Also, it should be pointed out that the well is preferably equipped with a casing which has attached thereto the

keys

62, 63 and '64 and the flange 65. However, for wells which were drilled and not equipped with such a special joint of casing, the anchor can still be used by so designing the opening 30 that it will engage a portion of the wellhead to limit its upward travel. Such an arrange ment, of course, would not have the feature of the elongated keys to fix the anchor so that it would be prevented from moving laterally. In such a situation, it would be necessary to either rely on the friction between the anchor and the wellhead or some other means to limit its lateral or relative movement.

However, in the preferred form, as pointed out above, the well will be equipped with the

elongated keys

62, 63 and 64 and the flange 65. The anchor then moves into position against the well casing, the well casing being guided into the opening 30 by means of the V-shape-d passageway 41 in the anchor. The elongated key 62 engages the

slots

36 and 39 and the anchor body is in position to be raised along the casing until it engages the flange 65. Once against the stop 65, all the keys will be locked in position on the well casing. The proper amount of upward force can then be placed in the flexible guide lines and the servicing or workover operations can begin.

The condition of the Well at that time is illustrated in FIG. 2. The anchor is in position on the well and a retrieving tool 66 is being lowered by means of the guide arms 67 down the guide lines to engage the fishing neck 26 on the retrievable flow line connector. During the workover .or servicing operations, all four guide lines need not be used to lower equipment into and out of the well or onto the wellhead or flow line head. For example, the guide lines 57 and 59 are located diametrically opposite the center line of the well, whereas

guide lines

58 and 60 are located diametrically opposite the flow line connector 17. This arrangement allows equipment which is going to be run either into the hole or into position on the wellhead to be lowered by means of the guide lines 57 and 59 alone and equipment to be connected into the flow lire connector 17 to be run on the guide lines 58 and 60 alone. This greatly simplifies the design of the guide arms.

As described above, this invention has particular utility in connection with the servicing or reworking of underwater wells where it is necessary to re-attach the guide lines to the well before the work can begin. The invention, however, is not limited to such operations since it is also very useful in the initial drilling of Wells. In the initial drilling operations, the anchor can be installed in place on the well casing prior to its being run and cemented in the usual manner. Then when the well is completed and in the condition shown in FIG. 1, the anchor can be lowered by means of the guide lines, moved laterally away from the well casing and recovered, thus eliminating not only the expense of using a guide anchor which must be permanently attached to the well casing and therefore left with the well, but also eliminating the problem of what to do with the guide lines when the well is completed.

From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus and method.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1. Apparatus for guiding drilling, completion, and servicing equipment from a surface vessel to an underwater well having a well casing extending into the earth below the water and a Christmas tree supported on the well casing for controlling the flow of fluid from the well, said guiding apparatus comprising, anchor means movable laterally into and out of engagement with the well casing, interengaging means on the anchor and the well casing to releasably attach the anchor means to the well casing when the anchor means is moved laterally into engagement with the casing and upwardly relative thereto, .and guide lines attached to and extending upwardly from the anchor means to the surface vessel.

2. Apparatus for guiding drilling, completion, and servicing equipment from a surface vessel to an underwater well comprising, in combination, flexible guide lines extending from the surface vessel to the underwater Well, an anchor for the guide lines movable laterally into and out of engagement wit-h the underwater well, and interengaging means on the anchor and the well to limit upward travel of the anchor relative to the well when the anchor is in engagement with the well, while allowing the anchor to move downwardly and laterally of the well to move out of engagement with the well when the anchor is to be removed from the well.

3. The combination of claim 2 including means to prevent rotation of the anchor when the interengaging means are in engagement.

4. The combination of claim 3 including means to prevent lateral movement of the anchor when the interengaging means are in engagement.

5. The combination of claim 4 including means to prevent pivotal movement of the anchor in a vertical plane when the interengaging means are in engagement.

6. A removable anchor for guide lines employed in the drilling and servicing of underwater wells, comprising, in combination, a body having a vertical opening therethrough and an open-ended vertical passageway which connects the opening with the exterior of the body to allow the body to be moved laterally to position the body with the well in the opening, means for attaching a plurality of guide lines to the anchor body, and interengaging means on the body and the Well to limit upward travel of the anchor body relative to the well when the well is located in the opening in the anchor body.

7. A removable anchor for guide lines used to guide equipment during the drilling and servicing of underwater wells, comprising, a body having a vertical opening therethrough to receive the well and a tapered open-ended, vertical slot providing a passageway for the well to allow the body to be moved laterally into and out of position with its opening engaging the well, means for attaching the guide lines to the body, and interengaging means on the body and the well to limit upward movement of the body when the well is located in the opening of the body.

8. The combination of claim 7 in which means are provided to prevent lateral movement of the anchor body when its upward movement is limited by the interengaging means.

9. Apparatus for use in the drilling and servicing of underwater wells having casing anchored in the formation below the bottom of the water, comprising, in combination, a guide line anchor body having a vertical opening therethrough to receive the casing and an open-ended, vertical, passageway extending laterally from the opening to the exterior of the anchor body to allow the casing to move into and out of the opening, a plurality of guide lines attached to the body, an elongated, laterally extending key member on the ca-sing, a key slot in the anchor body arranged to receive the key member to prevent the anchor body from rotating relative to the casing, and stop means on the casing to limit the upward travel of the anchor body when in position with the casing in the opening provided therefor.

10. The combination of claim 9 including a second key member on the casing and a second key slot in the anchor body to engage the second key and thereby prevent any lateral movement of the anchor body when the anchor body is in position against the stop means.

11. Apparatus for use in the drilling, producing, and servicing of underwater wells, comprising, a well casing extending into the earth below the water and having laterally extending portions near its upper end, an anchor having a vertical opening therethrough to engage the well casing, an open-ended vertical passageway connecting the casing engaging opening with the exterior of the anchor, and openings to engage the laterally extending portions, a plurality of guide members supporting the anchor, and means to move the anchor laterally into engagement with the well casing below the laterally extending portions and to raise it into engagement with the laterally extending portions, the laterally extending portions being engageable with the openings provided therefor in the anchor to hold the anchor against all but vertically downward movement relative to the well casing.

12. The combination according to claim 11 in which the passageway is provided with sides which diverge laterally outwardly from the opening provided to receive the well casing.

13. The combination of claim 12 further provided with diverging flexible members attached to each side of the passageway which curve upwardly from the anchor to help guide the anchor into position on the well casing.

14. The combination of claim 13 in which the anchor is further provided with elongated members to allow the anchor to move along the bottom of the water into engagement with the well casing.

15. A method of attaching guide lines to an underwater well for guiding well tools to the underwater well from the surface of the water, said well including a well casing supporting a Christmas tree, comprising the steps of lowering an anchor with the guide lines attached to a depth below the Christmas tree, moving the anchor laterally into engagement with the well casing, raising the anchor along the casing limiting the distance the anchor can move up wardly along the casing, and pulling upwardly on the guide lines to hold the anchor at the upper end of its travel along the well casing and in engagement with the underwater well.

16. A method of connecting guide lines to an underwater well for guiding well tools to the underwater well from the surface of the water, said underwater well having a well casing supporting a wellhead, the steps of lowering an anchor for the guide lines having an opening to receive the well casing to a depth below the wellhead, moving the anchor laterally into engagement with the well casing with the well casing in the opening in the anchor, raising the anchor upwardly along the well casing, stopping the upward movement of the anchor along the casing, and pulling upwardly on the anchor through the guide lines to hold the anchor at the upward limit of its travel along the well casing and the guide lines in position to guide well tools to and from the underwater well.

17. A method of connecting and disconnecting guide lines to an underwater well having a well casing and a wellhead above it, comprising the steps of lowering an anchor with the guide lines attached to a depth below the wellhead, moving the anchor laterally into engagement with the well casing, raising the anchor along the well casing until it engages the wellhead which stops further upward movement of the anchor, tightening the guide lines to hold the anchor against the wellhead so that the guide lines can guide well tools to and from the well, lengthening the guide lines to move the anchor downwardly out of engagement with the wellhead, moving it laterally out of engagement with the well casing to disconnect the anchor from the well, and raising the anchor and the guide lines to the surface.

18. A method of removing an anchor for flexible guide lines from a well which is held attached to the well by an upward force exerted thereon by the flexible guide lines, comprising the steps of, releasing the upward force exerted on the anchor by the guide lines, lowering the anchor relative to the well to release the anchor therefrom, and moving the anchor laterally out of engagement with the well.

19. An anchor for flexible guide lines extending from a surface vessel to an underwater structure, comprising, in combination, a body having a vertical opening therethrough and an open-ended vertical passageway connecting the opening with the exterior of the body to allow the body to be moved laterally to position the body with said underwater structure in the opening, means for attaching said guide lines to the anchor body, and means on the body for engaging said underwater structure to limit upward travel of the anchor body when said underwater structure is located in the opening of the anchor body.

20. An anchor for guide lines extending from an underwater structure to a surface vessel, comprising, a body having a vertical opening therethrough to receive said underwater structure and a tapered, open-ended, vertical slot providing a passageway to allow the body to be moved laterally into position with its opening engaging said underwater structure, means for attaching said guide lines to the body, and interengaging means on the body and said underwater structure to limit upward movement of the body when said underwater structure is positioned in the opening of the body.

References Cited by the Examiner UNITED STATES PATENTS 1,189,864 7/1916 Paulson 114-51 1,378,843 5/1921 Drake 61-69 1,777,184 9/ 1930 Stamper 61-69 2,372,039 3/1945 Winkler 114-51 2,891,770 6/1959 Bauer et a1. -7 2,917,281 12/1959 Kofahl 175-7 3,025,916 3/1962 Prick 175-7 3,047,078 7/1962 Postlewaite 175-7 3,080,921 3/1963 Lacy 166-665 3,099,316 7/1963 Johnson 166-46 CHARLES E. OCONNELL, Primary Examiner,

Claims

15. A METHOD OF ATTACHING GUIDE LINES TO AN UNDERWATER WELL FOR GUIDING WELL TOOLS TO THE UNDERWATER WELL FROM THE SURFACE OF THE WATER, SAID WELL INCLUDING A WELL CASING SUPPORTING A CHRISTMAS TREE, COMPRISING THE STEPS OF LOWERING AN ANCHOR WITH THE GUIDE LINES ATTACHED TO A DEPTH BELOW THE CHRISTMAS TREE, MOVING THE ANCHOR LATERALLY INTO ENGAGEMENT WITH THE WELL CASING, RAISING THE ANCHOR ALONG THE CASING LIMITING THE DISTANCE THE ANCHOR CAN MOVE UPWARDLY ALON THE CASING, AND PULLING UPWARDLY ON THE GUIDE LINES TO HOLD THE ANCHOR AT THE UPPER END OF ITS TRAVEL ALONG THE WELL CASING AND IN ENGAGEMENT WITH THE UNDERWATER WELL.