Claims
- 1. A casing guide apparatus, comprising:
- a well template having a template housing with a housing bore therethrough defining a well opening;
- a cylindrical well casing received through said well opening; and
- bushing means, operably associated with said template and said casing, for permitting relative vertical movement between said template and said casing and for preventing relative lateral movement between said template and said casing at said well opening wherein said bushing means includes:
- a cylindrical bushing member having a cylindrical inner bushing bore within which said casing is closely received; and
- latch means, operably associated with said bushing member and said well opening of said template, for latching said bushing member into a fixed position within said well opening upon insertion of said casing and said bushing means downwardly into said well opening of said template said latch means including:
- an annular latching groove defined in said housing bore; and
- radially outwardly biased locking means, connected to said bushing member and extending radially outwardly from said bushing member, for receipt in said latching groove of said housing bore of said template.
- 2. The apparatus of claim 1, wherein:
- said template is a gravity base template which will gradually settle into a floor of a body of water during its operating life;
- said casing has a lower portion thereof cemented within said floor of said body of water, and said casing has an upper portion thereof extending above said floor and through said well opening of said template; and
- said bushing means is further characterized as a means for permitting said gravity base template to settle into said floor relative to said casing without imposing substantial compressive loads on said upper portion of said casing, thus eliminating a danger of buckling of said upper portion of said casing upon settling of said gravity base template.
- 3. The apparatus of claim 1, wherein:
- said template further includes upwardly open conical guide means concentrically disposed about said housing bore above said housing bore.
- 4. The apparatus of claim 1, wherein:
- said bushing member has a cylindrical outer surface closely received in said housing bore of said template housing.
- 5. The apparatus of claim 1, further comprising:
- releasable connecting means, operably associated with said casing and said bushing member, for initially limiting vertical movement of said bushing member relative to said casing until said bushing member is latched into said fixed position thereof within said well opening of said template.
- 6. The apparatus of claim 5, wherein:
- said releasable connecting means is further characterized as a means for initially preventing any substantial vertical movement of said bushing member relative to said casing.
- 7. The apparatus of claim 6, wherein:
- said releasable connecting means includes a plurality of shear pins connected between said casing and said bushing member.
- 8. The apparatus of claim 1, wherein:
- said casing includes a sleeve fixedly connected thereto and defining an outer cylindrical surface thereof, said sleeve being snugly received in said inner bushing bore so as to prevent any substantial lateral movement of said casing relative to said bushing member and so as to permit vertical sliding motion of said casing and said sleeve relative to said bushing member.
- 9. A method of constructing an underwater well, said method comprising the steps of:
- (a) placing a well template having a well opening defined therein on a floor of a body of water;
- (b) assembling a bushing means with a well casing;
- (c) lowering said well casing downward through said well opening of said template until a lower portion of said casing is received in a well bore;
- (d) connectably engaging said bushing means with said well template so that said bushing means is substantially fixed relative to said template for preventing lateral movement of said casing relative to said template at said well opening;
- (e) fixing said lower portion of said casing into said well bore; and
- (f) allowing said bushing means to slide downward relative to said casing as said well template settles into said floor, thus eliminating a danger of buckling of an upper portion of said casing upon settling of said well template.
- 10. The method of claim 9, wherein:
- step (b) is further characterized as releasably connecting said bushing means and said casing and thereby initially limiting vertical movement of said bushing means relative to said casing; and
- said method further comprises a step, after step (d), of releasing said bushing means so that said bushing means is free to slide vertically along said casing.
- 11. The method of claim 10, wherein:
- step (b) is further characterized as initially preventing vertical movement of said bushing means relative to said casing.
- 12. The method of claim 11, wherein:
- step (b) is further characterized as frangibly connecting said bushing means and said casing with a plurality of shear pins; and
- said releasing step is further characterized as applying a vertical force to said casing to shear said shear pins.
- 13. The method of claim 10, wherein:
- said releasing step is performed prior to step (e).
- 14. The method of claim 9, wherein:
- said step (e) is further characterized as cementing said lower portion of said casing into said well bore.
Parent Case Info
This is a continuation of application Ser. No. 917,763 filed in-part Oct. 10, 1986 now abandoned.
US Referenced Citations (9)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
917763 |
Oct 1986 |
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