Offshore platform with removable modules

A permanently fixed offshore platform apparatus from which at least one well is drilled, said apparatus comprising:

• a jacket having a plurality of legs anchored to and upwardly extending from the ocean floor to a selected level above the water surface;
• modular deck means formed by a plurality of container modules and being provided with landing surfaces for landing on said jacket, said modular deck means comprising a plurality of elongated box-like framed equipment container modules of a length sufficient to span said outer legs of said jacket when seated thereon, at least one of said modules being of a height to extend above and contain a wellhead assembly of a well drilled through said module by a well-drilling assembly when it is positioned on and above said module, whereby a wellhead module is formed;
• matable orienting means for aligning and orienting said modular deck means on said jacket, said orienting means comprising first and second portions, the first portion carried by said jacket and the second portion carried by said modular deck means;
• a well drilling derrick and associated equipment mounted on a portion of said modular deck means and located above a point where a well is to be drilled;
• and

For use on a permanently fixed offshore drilling platform apparatus from which at least one well is drilled, the apparatus having a plurality of legs anchored to and upwardly extending from the ocean floor to above the water surface, modular deck means being a framework of beams in a box-like configuration, the floor of the interior of the box forming one portion of a platform deck and the top of said box forming a portion of the second deck at a selected elevation above the first deck, said deck means comprising:

• wellhead module means adapted to be removably secured to the top of the legs of said platform apparatus,
• drilling equipment module means adapted to be removable secured to the top of the legs of said platform apparatus in a side-by-side configuration with respect to said wellhead module means,
• matable orienting means for aligning and orienting said module means on said platform apparatus, said orienting means being of a selected spacing and configuration sufficient to mate said module means on said platform apparatus, and
• connector means for connecting said module means to said platform apparatus, said connector means carried by each of said drilling equipment module means for removably connecting each of said drilling equipment module means to said platform apparatus and connector means carried by said wellhead module means for connecting said wellhead module means to said platform apparatus.

A method of drilling offshore multiple wells at spaced locations from a permanently fixed offshore platform, the method comprising the steps of:

• positioning a well jacket anchored to and extending from the ocean floor to a point above the water surface at a selected offshore location to form the base of an offshore platform having upper and lower decks;
• lowering a substructure on said jacket above the water surface and fixedly securing the bottom of said substructure to the top of said jacket;
• providing a plurality of double deck modules of sufficient length to span the entire substructure in one direction, at least one of said modules being empty and adapted to subsequently receive well apparatus, at least one of said modules containing previously installed drilling equipment therein, and at least one substitute module contaning previously installed equipment associated with the production of well fluids to form a production equipment module said substitute module being of a size and arrangment to replace said drilling equipment module next to the wellhead module after drilling operations on the platform apparatus have been completed;
• installing a derrick and drilling equipment on the top of said empty module forming a portion of the upper deck of said platform;
• forming a deck by installing a plurality of double deck modules on said substructure arranged in a side-by-side configuration;
• and
• connecting the double deck modules to said substructure.

A method for drilling and producing at least one well on an offshore platform comprising:

• mounting a removable drilling equipment module on said offshore platform;
• drilling said at least one well with said removable drilling equipment module;
• and
• replacing said removable drilling equipment module with an interchangeable production equipment module.

A method for drilling and producing at least one well on a permanent offshore platform comprising:

• mounting a removable drilling equipment module on said offshore platform;
• drilling said at least one well with said removable drilling equipment module;
• and
• replacing said removable drilling equipment module with an interchangeable production equipment module.

An apparatus for drilling and producing at least one well on an offshore platform comprising:

• means for mounting a removable drilling equipment module on said offshore platform;
• means for drilling said at least one well with said removable drilling equipment module;
• and
• means for replacing said removable drilling equipment module with an interchangeable production equipment module.

An apparatus for drilling and producing at least one well on a permanent offshore platform comprising:

• means for mounting a removable drilling equipment module on said offshore platform;
• means for drilling said at least one well with said removable drilling equipment module;
• and
• means for replacing said removable drilling eqiupment module with an interchangeable production equipment module.