Remotely operable underwater drilling system and drilling method

A method of drilling, the method comprising:

• (a) providing a drilling system, wherein the drilling system is comprised of a drill head, wherein the drill head has an upper drill head end and a lower drill head end, wherein the drill head defines a drill head bore extending fully through the drill head from the upper drill head end to the lower drill head end and wherein the drill head is comprised of a drill head bore closure device adjacent to the upper drill head end, wherein the drill head bore closure device is actuatable between a closed position in which the drill head bore is closed and an open position in which the drill head bore is open, and wherein the drilling SYS tem further comprises a guiding surface located at the upper drill head end, for guiding an inner core barrel and an inner core barrel retrieval device into the drill head bore;
• (b) positioning the drill head so that the drill head is aligned with a drilling axis defined by the drilling system;
• (c) connecting the drill head with a drill string, wherein the drill string is comprised of a first inner core barrel secured at a drilling position within an interior of the drill string;
• (d) drilling by actuating the drill head and longitudinally advancing the drill head along the drilling axis;
• (e) guiding the inner core barrel retrieval device into the drill head bore with the guiding surface and passing the inner core barrel retrieval device through the drill head bore and into the interior of the drill string while the drill head is connected with the drill string;
• (f) attaching the first inner core barrel with the inner core barrel retrieval device in the interior of the drill string;
• (g) removing the first inner core barrel and the inner core barrel retrieval device from the interior of the drill string through the drill head bore while the drill head is connected with the drill string;
• (h) guiding a second inner core barrel into the drill head bore with the guiding surface and passing the second inner core barrel through the drill head bore and into the interior of the drill string while the drill head is connected with the drill string;
• (i) closing the drill head bore by actuating the drill head bore closure device to the closed position after passing the second inner core barrel through the drill head bore and into the interior of the drill string.

A remotely operable underwater drilling system for use with a drill string comprising at least one drill rod and for use with an inner core barrel which is adapted to be contained within an interior of the drill string, the drilling system comprising:

• (a) a frame;
• (b) a deployment connector attached to the frame, for connecting the drilling system with a deployment cable so that the drilling system may be suspended from the deployment cable in a body of water;
• (c) an adjustable support mechanism attached to the frame, for enabling the drilling system to be supported on an underwater ground surface at a substantially level orientation;
• (d) a mast structure mounted on the frame, wherein the mast structure defines a drilling axis for the drill string;
• (e) a drill head mounted on the mast structure such that the drill head is aligned with the drilling axis and longitudinally reciprocable along the drilling axis, wherein the drill head has an upper drill head end and a lower drill head end, wherein the drill head defines a drill head bore extending fully through the drill head from the upper drill head end to the lower drill head end, wherein the drill head bore is substantially coaxial with the drilling axis, and wherein the drill head is comprised of:
• (i) a drill head connector for connecting the drill head with the drill string along the drilling axis;
• (ii) a drill head bore closure device adjacent to the upper drill head end, wherein the drill head bore closure device is actuatable between a closed position in which the drill head bore is closed and an open position in which the drill head bore is open, and wherein the inner core barrel may be inserted into and removed from the interior of the drill string through the drill head bore when the drill head is connected with the drill string and the drill head bore closure device is actuated to the open position;
• and
• (iii) a drill head swivel located between the drill head connector and the drill head bore closure device so that the drill head connector is rotatable relative to the drill head bore closure device;
• and
• (f) a clamping mechanism mounted on the mast structure, for supporting the drill string along the drilling axis when the drill head is not connected with the drill string.

A method of drilling, the method comprising:

• (a) providing a drilling system, wherein the drilling system is comprised of a drill head, wherein the drill head has an upper drill head end and a lower drill head end, and wherein the drill head defines a drill head bore extending fully through the drill head from the upper drill head end to the lower drill head end, and wherein the drill head is comprised of:
• (i) drill head connector for connecting the drill head with a drill string;
• (ii) a drill head bore closure device adjacent to the upper drill head end, wherein the drill head bore closure device is actuatable between a closed position in which the drill head bore is closed and an open position in which the drill head bore is open;
• and
• (iii) a drill head swivel located between the drill head connector and the drill head bore closure device so that the drill head connector is rotatable relative to the drill head bore closure device;
• (b) positioning the drill head so that the drill head is aligned with a drilling axis defined by the drilling system;
• (c) connecting the drill head with the drill string with the drill head connector, wherein the drill string is comprised of a first inner core barrel secured at a drilling position within an interior of the drill string;
• (d) drilling by actuating the drill head so that the drill head connector and the drill string rotate relative to the drill head bore closure device and longitudinally advancing the drill head along the drilling axis;
• (e) passing an inner core barrel retrieval device through the drill head bore and into the interior of the drill string while the drill head is connected with the drill string;
• (f) attaching the first inner core barrel with the inner core barrel retrieval device in the interior of the drill string;
• and
• (g) removing the first inner core barrel and the inner core barrel retrieval device from the interior of the drill string through the drill head bore while the drill head is connected with the drill string.