Curved offshore well conductors

Abstract

Apparatus and method for producing hydrocarbons from a subterranean hydrocarbon-bearing formation located beneath the floor of a body of water. A platform structure is installed on the floor over the formation and well conductors are extended down the structure and penetrate into the floor of the body of water. The conductors may include an upper vertical portion, then continually curve downwardly and outwardly through the structure above the floor in a manner maintaining a relatively smooth bore throughout the entire extent of the conductors. The conductors are extended into the floor of the body of water and wells are drilled, via the conductors, down into communication with the formation. Formation fluids are then produced from the formation via the conductors.

We claim as our invention: 
     
       1. A method for producing hydrocarbons from a subterranean hydrocarbon-bearing formation located beneath the floor of a body of water, said method comprising the steps of: installing a platform structure on the floor of said body of water above said formation;   extending at least one well conductor downwardly with respect to said platform structure, then curving said conductor outwardly and downwardly through said platform structure above the floor of said body of water in a manner maintaining a relatively smooth bore throughout substantially the entire extent of said conductor;   drilling via said conductor down through said floor and into fluid communication with said formation; and   producing formation fluids from said formation via said conductor.   
     
     
       2. The method of claim 1 wherein the step of curving said conductor includes the steps of: providing guide means at a plurality of vertically spaced locations on said platform structure adapted to curve said conductor; and   extending said conductor into communication with said guide means thereby curving said conductor through said guide means.   
     
     
       3. The method of claim 1 wherein the step of extending at least one well conductor downwardly with respect to said platform structure includes the step of extending a plurality of well conductors downwardly with respect to said platform, at least some of said well conductors being extended outwardly and downwardly with respect to said platform structure in a direction different from that of an adjacent well conductor in a predetermined pattern with respect to said platform structure. 
     
     
       4. The method of claim 1 wherein the step of curving said conductor includes the step of continually curving said conductor up to approximately 6° every 100 feet. 
     
     
       5. The method of claim 1 wherein the step of curving said conductor includes the step of pre-forming the desired curvature in said conductor prior to the step of extending said conductor downwardly with respect to said platform structure. 
     
     
       6. The method of claim 1 wherein the step of extending said well conductor downwardly with respect to said platform structure includes the step of extending the upper portion of said conductor first vertically downwardly with respect to said platform structure, then curving said conductor. 
     
     
       7. Apparatus for producing hydrocarbons from a subterranean hydrocarbon-bearing formation located beneath the floor of a body of water, said apparatus comprising: a platform structure disposed on the floor of said body of water;   at least one well conductor extending downwardly with respect to said platform structure, then curved outwardly and downwardly through said platform structure above the floor of said body of water, said conductor having a relatively smooth bore throughout substantially the entire extent thereof;   a drilled well communicating with both said conductor and said formation; and   formation fluids recovery means associated with said conductor for recovering formation fluids produced from said formation via said conductor.   
     
     
       8. The apparatus of claim 7 wherein said platform structure includes a plurality of conductor guide means disposed vertically thereof for curving said conductor and said conductor engages said guide means in a manner curving said conductor. 
     
     
       9. The apparatus of claim 7 including a plurality of said conductors extending downwardly with respect to said platform structure, at least some of said conductors extending outwardly and downwardly with respect to said platform structure in a direction different from that of an adjacent well conductor in a predetermined pattern with respect to said platform structure. 
     
     
       10. The apparatus of claim 7 wherein said conductor continually curves approximately up to 6° every 100 feet. 
     
     
       11. The apparatus of claim 7, wherein said well conductor extends first vertically downwardly with respect to said platform structure, then curves outwardly and downwardly. 
     
     
       12. The apparatus of claim 7 wherein said conductors extending downwardly with respect to said platform structure extend below said platform structure and into the floor of said body of water. .Iadd. 13. An anchored marine structure at an offshore body of water adapted for directional drilling of under-water wells which comprises: a working deck positioned above the water's surface and holding well drilling equipment;   at least one elongated leg supportably connected to said working deck and extending downwardly to the floor of said body of water;   pile means connected to said structure and depending from the lower end thereof being imbedded in the substratum of said body of water to rigidly fix said structure in place;   conductor guide means carried on said structure and being adapted to slidably receive and deflect a drill guide conductor passed downwardly therethrough;   said conductor guide means including, discrete guide units spaced vertically apart in substantial vertical alignment and being deviated horizontally from said substantially vertical alignment to define an arcuate center line along the common axis of said respective guide units. .Iaddend..Iadd. 14. In an apparatus as defined in claim 13 including; an elongated cylindrical conductor registered in said substantially vertically aligned discrete guide units, said cylindrical conductor being deformed thereby into an arcuate configuration. .Iaddend. .Iadd. 15. A method of installing a curved well conductor at an offshore location having a platform structure installed on the floor of a body of water, said method comprising:   extending with a downward movement at least one well conductor open at both ends downwardly with respect to said platform structure, then curving said conductor outwardly and downwardly through said platform structure within a plan view periphery thereof and above the floor of said body of water in a manner maintaining a relatively smooth bore throughout substantially the entire extent of said conductor. .Iaddend..Iadd. 16. The method of claim 15 wherein the step of curving said conductor includes the steps of:   providing guide means at a plurality of vertically spaced locations on said platform structure adapted to curve said conductor; and   extending said conductor into communication with said guide means thereby curving said conductor through said guide means. .Iaddend. .Iadd. 17. The method of claim 16 including the step of continuing the extending of the curved well conductor along its curve path and into the floor of the body of water. .Iaddend..Iadd. 18. The method of claim 17 including the step of conducting well drilling operations through said well conductor. .Iaddend..Iadd. 19. The method of claim 15 wherein the step of extending at least one well conductor downwardly with respect to said platform structure includes the step of extending a plurality of well conductors downwardly with respect to said platform, at least some of said well conductors being extended outwardly and downwardly with respect to said platform structure in a direction different from that of an adjacent well conductor in a predetermined pattern with respect to said platform structure. .Iaddend..Iadd. 20. The method of claim 15 wherein the step of curving said conductor includes the step of continually curving said conductor up to approximately 6° every 100 feet. .Iaddend. .Iadd.21. The method of claim 15 wherein the step of curving said conductor includes the step of pre-forming the desired curvature in said conductor prior to the step of extending said conductor downwardly with respect to said platform structure. .Iaddend. .Iadd. 22. The method of claim 15 wherein the step of extending said well conductor downwardly with respect to said platform structure includes the step of extending the upper portion of said conductor first vertically downwardly with respect to said platform structure, then curving said conductor. .Iaddend..Iadd. 23. Apparatus for use in drilling offshore wells to increase the lateral reach of the wells, said apparatus comprising:   
     
     
       a platform structure disposed on the floor of a body of water; and 
     
     
       at least one well conductor through which a well may be drilled, said conductor extending downwardly with respect to said platform structure, then curved for the major portion thereof outwardly and downwardly through said platform structure within the plan view periphery thereof above the floor of said body of water, said conductor having a relatively smooth bore throughout substantially the entire extent thereof. .Iaddend..Iadd. 24. The apparatus of claim 23 wherein said platform structure includes a plurality of conductor guide means disposed vertically thereof within the plan view periphery of said platform structure for curving said conductor and said conductor engages said guide means in a manner curving said conductor. .Iaddend. .Iadd. 25. The apparatus of claim 23 including a plurality of said well conductors extending downwardly with respect to said platform structure within the plan view periphery thereof, at least some of said conductors extending outwardly and downwardly with respect to said platform structure in a direction different from that of an adjacent well conductor in a predetermined pattern with respect to said platform structure. .Iaddend..Iadd. 26. The apparatus of claim 23 wherein said conductor continually curves approximately up to 6° every 100 feet. .Iaddend..Iadd. 27. The apparatus of claim 23 wherein said well conductor extends first vertically downwardly with respect to said platform structure, then curves outwardly and downwardly. .Iaddend..Iadd. 28. The apparatus of claim 23 wherein said well conductors extending downwardly with respect to said platform structure extend below said platform structure and into the floor of said body of water. .Iaddend. .Iadd. 29. A marine structure, adapted to be positioned on the floor of a body of water, for the directional drilling of underwater wells, which comprises: a substantially rigid structure of a height, when assembled, greater than the depth of water in which said marine structure is to be positioned,   means carried by said marine structure for receiving anchoring means for anchoring said structure to the floor of said body of water, and   conductor pipe guide means carried by said structure within the plan view periphery thereof to receive a drill guide conductor pipe adapted to pass downwardly therethrough along a path the major portion of which curves outwardly and downwardly through said marine structure. .Iaddend..Iadd. 30. The marine structure of claim 29 wherein said conductor pipe guide means includes a plurality of discrete guide units spaced vertically apart and being off-set horizontally from the vertical to define an arcuate line taken through the centers of successive guide means. .Iaddend.