Submudline drivepipe whipstock method and apparatus
AssigneeAtlantic Richfield Company
InventorSamuel C. Lynch
Life of this patent
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Abstract
In order to salvage a slot path on an offshore platform wherein the original conductor pipe has become clogged or otherwise rendered unusable, the original conductor is cut off below mudline, thereby leaving a stub forming a base upon which a suitably oriented deflector trough is attached. A new or replacement conductor is installed along the same slot path until the deflector trough causes the new conductor to follow a deviated path so as to avoid the original conductor. The direction of the deflector trough is selected to avoid existing wells already driven from such structure.
Claims11
A method of installing a replacement well conductor from a fixed structure above a body of water to replace an abandoned well conductor previously installed from said structure along a predetermined path through said body of water so as to penetrate the substratum below the floor of said body of water comprising the steps of:
- (a) severing said abandoned conductor at a predetermined depth below the floor of said body of water, said depth being such that the upper end of said abandoned conductor will yield under lateral pressure;
- (b) retrieving the portion of said abandoned conductor extending above said depth;
- (c) positioning means in fixed engagement with the upper end of the remaining portion of said abandoned conductor for deflecting the path of said replacement conductor;
- and
- (d) directing said replacement conductor along said predetermined path through said body of water until interaction with said deflecting means causes said replacement conductor to advance into the substratum in the direction of said deflected path so as to bypass said abandoned conductor and also causes the application of lateral pressure to the end of said abandoned conductor sufficient to cause the end of said abandoned conductor to shift position.
A method of installing a new driven conductor on a fixed structure above a body of water as a replacement for a prior driven old conductor installed along a given slot path through said body of water comprising the steps of:
- (a) retrieving the old conductor to a selected depth below the mudline, said depth being such that the upper end of said abandoned conductor will yield under lateral pressure;
- (b) positioning a deflector trough in fixed engagement with the remaining portion of said old conductor for deflecting the path of said new conductor;
- and
- (c) directing said new conductor along said slot path through said body of water until interaction with said deflector trough causes said new conductor to advance into the substratum in the direction of said deflecting path and also causes the application of lateral pressure to the end of said abandoned conductor sufficient to cause the end of said abandoned conductor to shift position.
Dependencies are inferred from the claim text.