Multi-well hydrocarbon development system

• US 4,630,681 A
• Filed: 02/25/1985
• Issued: 12/23/1986
• Est. Priority Date: 02/25/1985
• Status: Expired due to Fees

• Current Assignee: Decision-Tree Associates Incorporated
• Original Assignee: Decision-Tree Associates Incorporated
• Inventors: Iwamoto, William T.
• Primary Examiner(s): Leppink, James A.
• Assistant Examiner(s): Neuder, William P.
• Application Number:
  US06/705,092
• Time in Patent Office: 666 Days
• Field of Search: 166/358, 166/366, 175/5, 175/7, 175/8, 175/9, 405/201
• US Class Current: 166/366
• CPC Class Codes: E21B 43/017 Production satellite stations, i.e. underwater installations comprising a plurality of satellite well heads connected to a central station
• CPC Class Codes: E21B 7/136 from non-buoyant support E21B7/124 takes precedence

Abstract

A multi-well hydrocarbon development system is economically established and operated by drilling cluster wells through the piles securing the base structure which supports a semisubmersible tension leg buoy through a single leg assembly. The buoy includes a turntable with skid beams on which a drilling rig is slidably mounted so that the rig can be positioned over the piles and cluster wells can be drilled through the piles. Produced fluids are transported into a containment means for separation and storage within the buoy. A captive processing vessel may be moored to the buoy and a means is provided to dispose processed water and/or gas responsibly.

Claims

1. An offshore structure for development of a multi-well system by drilling through at least one of a plurality of piles securing a base structure for a center well to the seabed, comprising

a buoyant body connected to said base structure through at least one universl joint means such that vertical motion of said buoyant body is substantially attenuated, said buoyant body including a containment means adapted to store and separate produced fluids, a compartmentalized external shell surrounding said containment means for ballasting and deballasting, a turntable above said containment means, skid beams affixed onto said turntable, a drilling rig mast means slidably mounted on said skid beams, and a jack means for moving said drilling rig means with respect to said skid beams, said turntable and said jack means being adapted to function cooperatively to position said drilling rig means over one of said piles.

2. The structure of claim 1 wherein said drilling rig means further includes a flare tip.

3. The structure of claim 2 wherein said drilling rig means further includes a heat shield below said flare tip.

4. The structure of claim 1 further comprising a central tension anchor leg assembly attached to and disposed between said base structure and said buoyant body.

5. The structure of claim 1 wherein said buoyant body further includes a mooring turntable.

6. The structure of claim 1 wherein said buoyant body further includes a dry tree means.

7. The structure of claim 1 wherein said buoyant body further includes a pipeline riser assembly.

8. A method for development of a multi-well system comprising the steps of

providing a base structure secured to the seabed by piles, a buoyant body connected to said base structure and including a containment means adapted for storage and/or processing, a production riser assembly passing through said containment means, a turntable with skid beams affixed thereonto, and a drilling rig movably disposed on said skid beams,

positioning said rig over one of said piles by rotating said turntable and moving said rig with respect to said skid beams,

drilling a cluster well through said one pile, and

transporting produced fluids from said cluster well through said riser assembly into said containment means.

9. The method of claim 8 further comprising the step of mooring a processing vessel to said buoyant body and transporting fluids from said containment means to said processing vessel.

10. The method of claim 9 further comprising the step of transporting processed fluids from said vessel for disposal through a manifold provided on said floating body.