Method and apparatus for the working of underwater deposits

• US 4,249,618 A
• Filed: 12/18/1978
• Issued: 02/10/1981
• Est. Priority Date: 12/19/1977
• Status: Expired due to Term

• Current Assignee: Compagnie Generale Pour Les Developpements Operationnels Des Richesses Sous-Marines
• Original Assignee: Compagnie Generale Pour Les Developpements Operationnels Des Richesses Sous-Marines
• Inventors: Lamy, Jacques E.
• Primary Examiner(s): Leppink, James A.
• Assistant Examiner(s): Favreau, Richard E.
• Application Number:
  US05/970,108
• Time in Patent Office: 785 Days
• Field of Search: 405/203, 405/204, 405/205, 405/207, 405/210, 175/5, 175/8, 175/9, 166/362
• US Class Current: 175/9
• CPC Class Codes: E02B 17/00 Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor construction methods for floating platforms B63B75/00; anchoring floating platforms B63B21/00; floating platforms, e.g. anchored, B63B35/44; underwater reservoirs B65D88/78
• CPC Class Codes: E21B 15/02 specially adapted for underwater drilling E21B15/04 takes precedence

Abstract

A method of working an underwater deposit comprises the following stages:

(a) constructing and positioning a platform structure, equipped before or after positioning with drilling devices and installations,

(b) executing drilling using these devices and installations,

(c) constructing and equipping, during stages (a) and (b), a production bridge fitted with devices and installations required for production,

(d) transporting the production bridge to, and positioning it on, said platform structure, and

(e) commencing production from deposit.

The drilling bridge may remain in position on the platform structure during stages (d) and (e), or it may be removed to make way for the production bridge.

Claims

1. Apparatus for working an underwater deposit comprising:

a platform structure for location resting on the bed of an area of water;

drilling devices and installations fitted on said platform structure;

supports on the platform structure capable of receiving a production bridge;

a production bridge;

production devices and installations fitted on the production bridge;

means for transporting the production bridge to the platform structure and of placing it on the said supports;

wherein the platform structure comprises a base enclosing a chamber suitably divided into water-tight compartments forming ballastable floats, a hollow shaft rising vertically at one end of the base, a drilling bridge supported by the hollow shaft, devices and installations, supported by the drilling bridge, enabling drilling to be carried out through the hollow shaft, and a plurality of columns rising vertically and designed to carry the production bridge next to the drilling bridge; and

wherein the columns are separated into two groups with sufficient room between them to allow a float to pass supporting the production bridge in order to place this on said columns.

4. Apparatus according to claim 1 or 2 or 3, wherein the drilling devices and installations are mounted on a drilling bridge, and wherein the drilling bridge is adapted to be placed on the structure.

5. Apparatus according to claim 1 or 2 or 3, wherein the supports have means to receive at least one other bridge at a later date.

2. Apparatus for working an underwater deposit comprising:

a platform structure for location resting on the bed of an area of water;

drilling devices and installations fitted on said platform structure;

supports on the platform structure capable of receiving a production bridge;

a production bridge;

production devices and installations fitted on the production bridge;

means for transporting the production bridge to the platform structure and of placing it on the said supports;

wherein the platform structure comprises a base enclosing a chamber suitably divided into water-tight compartments forming ballastable floats, a hollow shaft rising vertically at one end of the base, a drilling bridge supported by the hollow shaft, devices and installations, supported by the drilling bridge, enabling drilling to be carried out through the hollow shaft, and a plurality of columns rising vertically and designed to carry the production bridge next to the drilling bridge; and

wherein the drilling devices and installations are located on the drilling bridge which is supported by the hollow shaft and by two columns with a distance between them equal to the diameter of the said hollow shaft so that the said production bridge can be placed in position by means of two floats forming with it a catamaran which straddles the said hollow shaft and the said columns.

3. Apparatus for working an underwater deposit comprising:

a platform structure for location resting on the bed of an area of water;

drilling devices and installations fitted on said platform structure;

supports on the platform structure capable of receiving a production bridge;

a production bridge;

production devices and installations fitted on the production bridge;

means for transporting the production bridge to the platform structure and of placing it on the said supports;

wherein the platform structure comprises a base enclosing a chamber suitably divided into water-tight compartments forming ballastable floats, a hollow shaft rising vertically at one end of the base, a drilling bridge supported by the hollow shaft, devices and installations, supported by the drilling bridge, enabling drilling to be carried out through the hollow shaft, and a plurality of columns rising vertically and designed to carry the production bridge next to the drilling bridge; and

in which the base has on its underside a plate forming a strengthening floor, wherein this plate stops at the hollow shaft, so that drilling rods emerging from the lower end of the hollow shaft are not restrained by said plate and do not risk being sheared by seismic shocks.