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A method for drilling with a buoyant structure having a hull, a planar keel defining a lower hull diameter, a lower cylindrical portion connected to the planar keel, a lower frustoconical portion disposed above the lower cylindrical portion with inwardly-sloping wall at a first angle, an upper frust

A method for drilling with a buoyant structure having a hull, a planar keel defining a lower hull diameter, a lower cylindrical portion connected to the planar keel, a lower frustoconical portion disposed above the lower cylindrical portion with inwardly-sloping wall at a first angle, an upper frustoconical portion directly connected to the lower frustoconical portion. The method uses a ballasted chambered buoyant storage ring which is either dockside and connected to the buoyant structure for drilling at a subsea location, or the ballasted chambered buoyant storage ring is preinstalled at a subsea location and then the buoyant structure is mounted to the ballasted chambered buoyant storage ring at sea.

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1. A method for drilling with a buoyant structure comprising: a. loading drilling equipment, drilling pipes, marine risers, casings, single/dual blow out preventers onto the buoyant structure while deballasted in port, wherein the buoyant structure defines a center of gravity below a center of buoya

1. A method for drilling with a buoyant structure comprising: a. loading drilling equipment, drilling pipes, marine risers, casings, single/dual blow out preventers onto the buoyant structure while deballasted in port, wherein the buoyant structure defines a center of gravity below a center of buoyancy, the buoyant structure comprising: (i) a hull defining a vertical axis, whereby the hull has an outer hull side connected to an inner hull side, and the outer hull side is characterized by an outer hull side shape selected from the group: circular, elliptoid, and geodesic in horizontal cross sections at all elevations; and the hull has an upper hull diameter and the inner hull side characterized by a shape selected from the group: circular, elliptoid, and geodesic;(ii) a planar keel defining a lower hull diameter;(iii) a lower cylindrical portion connected to the planar keel, wherein a lower cylindrical portion diameter is identical to the lower hull diameter, and the lower hull diameter is the largest diameter of the hull, and further wherein the lower cylindrical portion diameter is from 105 percent to 130 percent of the upper hull diameter;(iv) a lower frustoconical portion disposed above the lower cylindrical portion formed with an inwardly sloping wall at a first angle ranging from 50 degrees to 70 degrees with respect to the vertical axis;(v) an upper frustoconical portion directly connected to the lower frustoconical portion, the upper frustoconical portion with an outwardly sloping wall sloping at a second angle with respect to the vertical axis ranging from 3 degrees to 45 degrees, and wherein the lower frustoconical portion inwardly sloping wall, abuts the outwardly sloping wall forming a hull neck with a hull neck diameter;(vi) a main deck connected over the upper frustoconical portion;(vii) a moon pool formed by the inner hull side characterized by a shape selected from the group: circular, elliptoid, and geodesic having a first moon pool diameter proximate the main deck which increases to a second moon pool diameter proximate the planar keel, wherein the second moon pool diameter is less than the upper hull diameter; and(viii) at least one ballast tank in communication with a control center in the hull, the ballast tank for ballasting and deballasting the hull;b. identifying a drilling location having a subsea drilling location for destination;c. leaving port in a deballasted/transit condition for the identified drilling location;d. either mooring the buoyant structure at the location or engaging a dynamic positioning system of the buoyant structure to maintain the buoyant structure over the drilling location;e. ballasting the buoyant structure to an operation draft ensuring that the lower cylindrical portion of the buoyant structure, the lower frustoconical portion of the buoyant structure, and a portion of the upper frustoconical portion of the buoyant structure are under water filling the at least one ballast tank at least partially with a fluid to create the center of gravity lower than the center of buoyancy and contribute to maintaining at all times a positive stability curve for the buoyant structure;f. using a first tunnel extending through the lower cylindrical portion to the moon pool, wherein the first tunnel has a first tunnel side wall, a second tunnel side wall and a first tunnel top connecting the tunnel side walls for ingress and egress of water; andg. commencing drilling operations through the moon pool while the buoyant structure is centered over the drilling location. 2. The method of claim 1, using a plurality of propellers attached to the planar keel operated by a motor and a generator, with the motor and the generator connected to a fuel tank, the propellers, the motor, and the generator communicate with a navigation system, the navigation system for dynamically positioning the buoyant structure over a well for drilling or propulsion for transit. 3. The method of claim 1, using tunnels in the hull to improve the overall displacement of the moon pool water thus increasing the stability and operational envelope of the buoyant structure. 4. The method of claim 1, using a plurality of heave control terraces attached to walls of the moon pool to break up the water column inside the moon pool. 5. The method of claim 1, using a plurality of watertight compartments between the outer hull side and the inner hull side. 6. The method of claim 1, using the upper cylindrical portion connected between the main deck and the upper frustoconical portion. 7. The method of claim 1, using a first tunnel bottom connected between the first tunnel side walls. 8. The method of claim 1, using a second tunnel extending through the lower cylindrical portion to the moon pool, comprising a pair of second tunnel sides walls connected with a second tunnel top and the second tunnel is at an angle from 180 degrees to 270 degrees from the first tunnel for ingress and egress of workboats and material. 9. The method of claim 8, using a second tunnel bottom connected between the second tunnel side walls. 10. The method of claim 8, fluidly connecting the first tunnel and the second tunnel to each other through the moon pool for ingress and egress of workboats and material. 11. The method of claim 1, using the moon pool in the shape of a half ellipse with a minor radius of the ellipse being 10 percent to 30 percent of the diameter of the main deck and a major radius of the ellipse being 25 percent to 50 percent of the diameter of the main deck to provide a work space while stabilizing the buoyant structure. 12. The method of claim 1, using the first moon pool diameter proximate the main deck which gradually increases at a plurality of variable rates, a different rate of increase for a different height of the moon pool. 13. The method of claim 1, using a constant diameter portion for the moon pool in the shape of a bell up to 16 meters from the planar keel. 14. The method of claim 4, using the plurality of heave control terraces formed in a wall portion of the bell shaped moon pool proximate to the planar keel and adjacent the water in the moon pool, the plurality of heave control terraces extend from 1 percent to 30 percent along the wall portion to stabilize the buoyant structure. 15. The method of claim 14, using staggered heave control terraces positioned around the wall portion of the moon pool. 16. The method of claim 4, using a plurality of perforations in the plurality of heave control terraces. 17. The method of claim 4, using corrugated steel plate, smooth steel plate, or combinations thereof for the plurality of heave control terraces. 18. The method of claim 1, using a first displacement reduction device formed in the upper frustoconical portion or the lower frustoconical portion to reduce overall hull displacement. 19. The method of claim 2, further comprising the steps of: a. starting the motor and the plurality of propellers;b. coupling a computerized dynamic station keeping of the buoyant structure with computer instructions in the data storage for power management;c. dynamically positioning the buoyant structure when ballasting to operation draft; andd. using displacement reduction devices placed sufficiently below the surface water to trap water within the moon pool to enhance stability of the buoyant structure while operating drilling equipment. 20. The method of claim 1, comprising self-installing a chambered buoyant storage ring with an opening to the buoyant structure prior to leaving port to commence drilling operation by: a. deballasting the chambered buoyant storage ring to a neutral buoyant state;b. positioning the buoyant structure while deballasted over the neutral buoyant state chambered buoyant storage ring;c. connecting the deballasted buoyant structure to the neutral buoyant state chambered buoyant storage ring;d. either creating a flush mount between the deballasted buoyant structure and the chambered buoyant storage ring or suspending the chambered buoyant storage ring from the deballasted buoyant structure;e. using a navigation system on the buoyant structure to identify the drilling location;f. transiting simultaneously the deballasted buoyant structure connected to the chambered buoyant storage ring to the drilling location;g. ballasting the buoyant structure and the chambered buoyant storage ring simultaneously at the drilling location until the chambered buoyant storage ring rests on a seabed; enabling at least one of: a subsea operation and a reservoir operation through the moon pool of the buoyant structure and through the opening of the chambered buoyant storage ring, simultaneously, creating an environmentally safe condition for the subsea operation, the reservoir operation, or both the subsea operation and the reservoir operation. 21. The method of claim 1 comprising installing the buoyant structure over a preinstalled ballasted chambered buoyant storage ring with an opening at the drilling location resting on a seabed by: a. maneuvering a deballasted buoyant structure over the ballasted chambered buoyant storage ring;b. ballasting the buoyant structure while positioned over the ballasted chambered buoyant storage ring; andc. using weight of the ballasted buoyant structure to provide a flush fit between the chambered buoyant storage ring and the buoyant structure, enabling at least one of: a subsea operation and a reservoir operation through the moon pool of the buoyant structure and through the opening of the chambered buoyant storage ring, simultaneously, creating an environmentally safe condition for subsea or reservoir operations.