Drilling apparatus and method
AssigneeBoard of Regents of the Nevada System of Higher Education, on Behalf of the Univ. of Nevada, Reno
InventorGeorge L. Danko
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Abstract
The present disclosure provides a drilling method and drill. According to a disclosed method, multiple reciprocating rock-breaking elements, including a hammer drill bit, are used. The elements are moved in alternation to each other such that the net volume displacement by the moving parts is reduced for reducing compression work and thus for losing useful energy from the available amount from the drill bit engine for rock breaking. If desired, a small component of the net volume displacement is kept for enhancing PVW for enhancing rock chipping by tensile strength. The method also includes synchronizing the peak of the pressure depression wave with that of the impact moment of the drill bit's reciprocating motion to enhance, rather than hamper, rock breaking by the creation of PVW.
Claims6
(canceled)
A drilling method comprising, in a downhole environment, establishing a regular, repeating, synchronized hammering cycle, each cycle comprising:
- actuating a reciprocating rock-breaking element to impact a rock formation;
- as the reciprocating rock-breaking elements impacts the rock formation, actuating a pressure-cycling member to decompress fluid proximate the rock-breaking element;
- actuating the reciprocating rock-breaking element away from the rock formation;
- and
- as the reciprocating rock-breaking element is moved away from the rock formation, actuating the pressure-cycling member to compress fluid proximate the rock-breaking element;
- wherein decompression of the fluid proximate the rock formation as the reciprocating rock-breaking impacts the rock formation creates pressure and velocity waves to enhance rock breaking
Dependencies are inferred from the claim text.