Optimized reaming system based upon weight on tool
AssigneeSmith International, Inc.
InventorPraful C. Desai
Life of this patent
Estimating the term…
Abstract
A drilling apparatus includes a tubular body including an upper connection and a lower connection with a drill bit disposed thereon, and an axial borehole therethrough, wherein the upper connection is configured to attach to a drillstring, primary cutter blocks coupled to the tubular body and configured to selectively expand radially therefrom. The drilling apparatus further includes backup cutter blocks coupled to the tubular body and configured to selectively expand radially therefrom, and an activation system configured to selectively expand and collapse the primary and backup cutter blocks in response to changes in weight applied to the primary and backup cutter blocks.
Claims18
A drilling apparatus comprising:
- a tubular body including an upper connection configured to attach to a drillstring, a lower connection coupled with a drill bit, and an axial borehole therethrough;
- primary cutter blocks coupled to the tubular body and configured to selectively expand radially therefrom;
- backup cutter blocks coupled to the tubular body and configured to selectively expand radially therefrom;
- and
- an activation system, which in response to changes in weight on the primary and backup cutter blocks, is configured to:
- expand the primary cutter blocks and collapse the backup cutter blocks in a first operation sequence;
- and
- collapse the primary cutter blocks and expand the backup cutter blocks in a second operation sequence.
A method of selectively activating cutter blocks in a drilling apparatus, the drilling apparatus having a tubular body with an axial borehole therethrough, the method comprising:
- expanding primary cutter blocks;
- detecting an increased weight applied to the primary cutter blocks;
- collapsing the primary cutter blocks;
- and
- expanding backup cutter blocks;
- detecting a reduced weight applied to the backup cutter blocks;
- collapsing the backup cutter blocks;
- and
- expanding primary cutter blocks;
- wherein the expanding and contracting of the primary and backup cutter blocks is performed with a closed loop control system based on the detected increased applied weight and the detected reduced applied weight.
A method of enlarging a borehole drilled by a bit, the method comprising:
- inserting a drilling apparatus in the borehole wherein the drilling apparatus comprises a tubular body, primary cutter blocks, backup cutter blocks, and a drill bit;
- rotating the drill string and applying a weight on the drill bit;
- and
- alternatingly expanding the primary cutter blocks and the backup cutter blocks in response to a detected weight applied to at least one of the primary cutter blocks and the backup cutter blocks, such that the primary cutter are expanded when the backup cutter blocks are collapsed, and the primary cutter blocks are collapsed when the backup cutter blocks are expanded.
Dependencies are inferred from the claim text.