US 8,136,612 B2 · Constant-mode auto-drill with pressure derivative control

Abstract

Some embodiments of the invention concern HDD in an automatic drilling mode. Such embodiments can include maintaining a constant output parameter while performing a drilling operation using an HDD rig (20) having a thrust pump, generating hydraulic fluid pressure measurements from one or more pumps of the HDD rig, comparing the hydraulic fluid pressure measurements to a variable pressure limit, calculating a derivative value using the measured hydraulic fluid pressure measurements, comparing the derivative value to a derivative threshold, decreasing the variable pressure limit when the derivative value exceeds the derivative threshold, wherein the amount that the variable pressure limit is decreased is based on one or more of the hydraulic fluid pressure measurements, and reducing output of the thrust pump when the comparison of the hydraulic fluid pressure measurements to the variable pressure limit indicates that one or more of the hydraulic fluid pressure measurements exceed the variable pressure limit.

Claims28

Dependent claims

An horizontal directional drilling (HDD) system having one or more automatic drilling modes, comprising:

a drill pipe configured to attach to a boring tool;
a thrust pump configured to linearly advance the drill pipe;
a rotation pump configured to rotate the drill pipe;
one or more pressure sensors configured to measure hydraulic fluid pressure;
and
a controller coupled to the thrust pump and pressure sensor, the controller configured to execute program instructions stored in memory to cause the HDD system to:
perform drilling operations in a constant parameter mode in which an output parameter is maintained at a constant level;
compare the hydraulic fluid pressure measurements to a variable pressure limit while the HDD system is operating in the constant parameter mode;
calculate a derivative value of the hydraulic fluid pressure measurements and compare the derivative value to a derivative threshold;
decrease the variable pressure limit if the derivative value exceeds the derivative threshold, wherein the amount that the variable pressure limit is decreased is based on one or more of the hydraulic fluid pressure measurements;
and
reduce output of the thrust pump when the comparison of the hydraulic fluid pressure measurements to the variable pressure limit indicates that one or more of the hydraulic fluid pressure measurements exceed the variable pressure limit.

9 more elements

A method of horizontal directional drilling (HDD) in an automatic drilling mode, comprising:

maintaining a constant output parameter while performing a drilling operation using an HDD rig having a thrust pump;
generating hydraulic fluid pressure measurements from one or more pumps of the HDD rig;
comparing the hydraulic fluid pressure measurements to a variable pressure limit;
calculating a derivative value using the measured hydraulic fluid pressure measurements;
comparing the derivative value to a derivative threshold;
decreasing the variable pressure limit when the derivative value exceeds the derivative threshold, wherein the amount that the variable pressure limit is decreased is based on one or more of the hydraulic fluid pressure measurements;
and
reducing output of the thrust pump when the comparison of the hydraulic fluid pressure measurements to the variable pressure limit indicates that one or more of the hydraulic fluid pressure measurements exceed the variable pressure limit.

5 more elements

Dependencies are inferred from the claim text.

Constant-mode auto-drill with pressure derivative control

Life of this patent

Constant-mode auto-drill with pressure derivative control

Life of this patent

Abstract

Claims28