Claims
- 1. A method of drilling a shallow-water offshore well from a drilling barge and subsequently reinforcing an unsupported columnar well installation to resist the effect of wind and wave forces encountered by said well installation, said method comprising the steps of:
- (a) installing a well conductor in the ocean floor at a shallow water location and anchoring it to the ocean floor,
- (b) drilling a well through said well conductor and closing the top of the well with a production wellhead, thereby forming an unsupported columnar well installation of an offshore unsupported well conductor,
- (c) providing a pile guide template frame comprising at least two spaced-apart pile guides connected together by laterally-extending support members with additional laterally-extending support members arranged to extend between and be connected at one end to each of the pile guides and at the other end to the well conductor when positioned thereagainst, with the pile guides being at a selected distance from the well conductor,
- (d) transporting the pile guide template frame to the offshore unsupported well conductor,
- (e) positioning said frame in a manner such that the other ends of the additional laterally-extending support members are operatively positioned adjacent a wall of said well conductor, said position being such that at least said other ends of said additional laterally-extending support members at the top of the frame are above the surface of the water,
- (f) lowering a pile through each of said pile guides of said frame and driving said pile into the ocean floor, and
- (g) forming an interconnected reinforcing structure by suspending the pile guide template frame above the ocean floor upon the piles and the well conductor, said step of forming the interconnected reinforcing structure comprising:
- (1) fixedly connecting each pile to its surrounding pile guide, and
- (2) operatively connecting at least said other ends of said laterally-extending support members at the top of the frame to the well conductor, whereby said frame forms the interconnecting reinforcing structure between the piles and the well conductor to resist the effect of wind and wave forces encountered by said well conductor.
- 2. The method of claim 1 including the steps of providing a work platform at the base of said wellhead, and
- fixedly securing said work platform to at least said well conductor.
- 3. The method of claim 2 including the steps of providing a helicopter pad and a depending support frame, and
- fixedly securing said helicopter pad support frame to at least said work platform.
- 4. The method of claim 1 wherein the operation carried out in step g(2) is accomplished by providing a sliding connection permitting limited movement between the well conductor and the reinforcing frame.
- 5. The method of claim 1 wherein in step (e) the frame is positioned by hanging it from a crane of a work barge positioned nearby.
- 6. The method of claim 1 including the steps of
- providing a work barge having a pair of positionable hoisting cranes thereon, and
- positioning the work barge adjacent the well conductor and within the working area of the barge cranes.
- 7. The method of claim 6 wherein step (e) of claim 1 is carried out by temporarily connecting the pile guide frame to the hook of one crane and moving the crane to suspend the frame against the well conductor during the pile driving operation of step (f).
- 8. The method of claim 6 including the step of utilizing a second crane on the work barge to suspend a length of pile and a pile driver operatively connected thereto above one of the pile guides of the frame prior to driving the pile through the pile guide.
- 9. The method of claim 1 wherein the step of connecting the pile guide frame to the well conductor is carried out after the pile driving operation.
- 10. The method of claim 9 wherein the step of connecting the pile guide frame to the well conductor is carried out by welding.
- 11. The method of claim 1 wherein the step of connecting the pile guide frame to the well conductor is carried out before the pile driving operation.
- 12. The method of claim 1 wherein each of said piles is connected to its surrounding pile guide by grouting.
- 13. A method in accordance with claim 1 wherein the spaced-apart pile guides are substantially vertical and receive substantially vertical piles therethrough.
- 14. A method in accordance with claim 1 wherein the laterally-extending support members are substantially horizontal.
- 15. Apparatus adapted for field reinforcement of an unsupported offshore shallow-water well having a large-diameter well conductor anchored in the ocean floor and extending upwardly in an unsupported and unbraced manner to terminate at a selected height above the wave action where it is closed by a production wellhead, said apparatus forming a pile guide template frame comprising:
- (a) at least two spaced apart, open-ended tubular pile guide sleeves of an internal diameter to pass therethrough and position therein a large-diameter offshore pile,
- (b) laterally-extending support members of selected length extending between the spaced-apart pile guide sleeves and affixed thereto, and extending a selected distance from each pile guide sleeve to terminate adjacent each other at a point above the water surface and against an unsupported well conductor when installed thereagainst,
- whereby, when taken in plan view, the arrangement of said pile guide template frame and said sleeves forms a substantially polygonal configuration when taken with and placed in contact with an unsupported well conductor, and
- (c) means for suspending the pile guide template frame above the ocean floor, comprising:
- (1) means for connecting the free ends of said outwardly-extending support members to the well conductor, and
- (2) means for connecting the pile guide sleeves to the piles.
- 16. An apparatus in accordance with claim 15 wherein the spaced-apart pile guides are substantially vertical to receive substantially vertical piles therethrough.
- 17. An apparatus in accordance with claim 15 wherein the laterally-extending support members are substantially horizontal.
- 18. An isolated offshore well installation comprising:
- (a) an unsupported well conductor installed in the ocean floor and having a well drilled therethrough and closed at the upper end above the wave height by a production wellhead assembly,
- (b) a pile guide template frame and laterally-extending support members fixedly secured at least above the water line to the outer surface of the well conductor below the wellhead assembly and extending outwardly to at least one side of said conductor,
- (c) said frame at a selected distance from the well conductor being provided with at least two spaced-apart open-ended and vertically-positioned tubular rigid pile sleeves at least 10 feet in height and extending at least 10 feet upwardly from the water surface,
- (d) A large-diameter pile extending through each of the spaced-apart pile sleeves with the lower end of each pile being anchored in the ocean floor and
- (e) means fixedly securing each pile within its surrounding sleeve and, together with the well conductor, supporting the frame above the ocean floor.
- 19. The apparatus of claim 18 wherein the means (e) comprises steel shims welded to each pile and its surrounding sleeve near the top thereof and
- cement grout filling the annular space formed between each pile and its surrounding pile sleeve.
- 20. The apparatus of claim 18 wherein the pile sleeves also extend downwardly from 5 to 40 feet into water that is at least twice as deep.
- 21. The apparatus of claim 18 including a work platform position adjacent said wellhead assembly and
- support means fixedly securing said work platform to at least the well conductor.
- 22. The apparatus of claim 21 including a second well conductor connected to the frame and anchored in the ocean floor.
- 23. The apparatus of claim 22 wherein said second well conductor is positioned on the periphery of the polygonal configured frame.
- 24. The apparatus of claim 22 wherein said second well conductor is positioned within the periphery of said polygonal configured frame and including additional lateral support members connecting the second well conductor to the frame.
- 25. The apparatus of claim 22 wherein said second well conductor is positioned outside the periphery of said polygonal configured frame and including additional lateral support members connecting the second well conductor to the frame.
- 26. The apparatus of claim 18 including a helicopter pad positioned over said wellhead assembly, and
- support means fixedly securing said helicopter pad to at least the well conductor.
- 27. The apparatus of claim 18 wherein the laterally-extending support members of said frame together with said pile sleeves and well conductor, when taken in plan view, are arranged in a polygonal configuration with the pile sleeves and the well conductor positioned on the periphery thereof.
Parent Case Info
This is a continuation of application Ser. No. 936,219, filed Dec. 1, 1986 now abandoned.
US Referenced Citations (16)
Foreign Referenced Citations (6)
Number |
Date |
Country |
019808 |
Feb 1985 |
JPX |
208513 |
Oct 1985 |
JPX |
8401934 |
Jan 1986 |
NLX |
628232 |
Oct 1978 |
SUX |
1563107 |
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GBX |
2153886 |
Aug 1985 |
GBX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
936219 |
Dec 1986 |
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