Method and apparatus for percussion drilling
AssigneeEpiroc Drilling Solutions, LLC
InventorPeter D. Miller
Life of this patent
Estimating the term…
Abstract
A method for maintaining a penetration rate of a drilling operation, where the drilling operation is carried out by a drilling rig having a hammer drill apparatus. A reference penetration rate for the hammer drill bit is chosen. A starting depth of cut is computed from the reference penetration rate, the measured hammer frequency, and the drill bit parameters. The system measures the actual penetration rate of the drill bit and computes an actual depth of cut. From the actual depth of cut a target bit rotation speed is computed. The target rotation speed is compared to the actual rotation speed, and the rotation speed is adjusted up or down to set the bit rotation speed at a value that will maintain the target rotation speed, notwithstanding changes in hammer frequency or ground conditions.
Claims21
A method for maintaining a target rotation speed RS of a hammer drill apparatus in a drilling operation, wherein the drilling operation is carried out by a drilling rig having a drill motor and the hammer drill apparatus;
- the hammer drill apparatus having a reference penetration rate PR for a hammer drill bit, a bit diameter Dbit, a bit button diameter Dbutton, and a hammer frequency HF;
- the method comprising:
- choosing the reference penetration rate PR for the hammer drill bit;
- measuring the hammer frequency HF;
- computing a starting depth-of-cut DOC for the hammer drill bit equal to PR I (HF*Dbutton/(Dbit*π));
- measuring an actual penetration rate PRm of the hammer drill bit;
- computing the target rotation speed RS for the hammer drill apparatus equal to PRm I DOC;
- and,
- sending a command to actuate the drill motor at the target rotation speed RS.
A method for maintaining a target rotation speed RS of a hammer drill apparatus in a drilling operation, wherein the drilling operation is carried out by a drilling rig having a drill motor and the hammer drill apparatus;
- the hammer drill apparatus having a bit rotation speed RS, a bit diameter Dbit, a bit button diameter Dbutton, and a hammer frequency HF;
- the method comprising:
- choosing a reference penetration rate PR for a hammer drill bit;
- measuring the hammer frequency HF;
- computing a starting depth-of-cut DOC for the hammer drill bit equal to PR I (HF*Dbutton/(Dbit*π));
- measuring an actual penetration rate PRm of the hammer drill bit;
- computing the target rotation speed RS for the hammer drill apparatus equal to PRm/DOC;
- measuring an actual rotation speed RSa for the hammer drill apparatus;
- comparing the target rotation speed RS to the actual rotation speed RSa;
- adjusting the actual rotation speed RSa of the hammer drill apparatus downward if RSa>RS;
- adjusting the actual rotation speed RSa of the hammer drill apparatus upward if RSa<RS;
- maintaining the actual bit rotation speed RSa of the hammer drill apparatus if RSa=RS;
- continue measuring the hammer frequency HF.
A drilling machine for drilling through rock, the drilling machine comprising:
- a hammer drill bit;
- the hammer drill bit further comprising a bit diameter, and bit buttons;
- the bit buttons further comprising a bit button diameter;
- a motor for rotating the hammer drill bit while causing the hammer drill bit to strike a rock face;
- a sensor for detecting a penetration rate of the hammer drill bit;
- a sensor for detecting a frequency of striking of the hammer drill bit;
- a computer operatively connected to the sensor for detecting the penetration rate of the hammer drill bit, and further connected to the sensor for detecting the frequency of striking of the hammer drill bit;
- the computer further connected to the motor for rotating the hammer drill bit;
- the computer programmed to:
- compute an actual depth of cut of the hammer drill bit from the bit diameter, the bit button diameter, the penetration rate of the hammer drill bit and the frequency of striking of the hammer drill bit;
- compute a target rotation speed from the penetration rate of the hammer drill bit and the actual depth of cut of the hammer drill bit;
- and,
- cause the motor for rotating the hammer drill bit to adjust a rotation speed of the hammer drill bit to maintain the rotation speed of the hammer drill bit equal to the target rotation speed.
Dependencies are inferred from the claim text.