CONSTANT AUTOMATIC DRILLING WITH CONSTANT PARAMETER CONTROLLED BY PRESSURE REDUCED PRESSURE

摘要

1. A horizontal directional drilling (HDD) system having one or more automatic drilling modes, comprising a drill pipe configured to be fastened to a drilling tool, an axial thrust pump configured to linearly advance the drill pipe, a rotation pump configured to rotate drill pipe, one or more pressure sensors for measuring the pressure of the hydraulic fluid; and! a controller connected to an axial pressure pump and a pressure sensor and configured to execute program instructions stored in a memory device for performing a horizontal directional drilling system, the following operations:! performance of drilling operations in the mode with a constant parameter, in which the productivity is maintained at a constant level; ! comparison of pressure measurements of the hydraulic fluid with a variable pressure limit when the horizontal-directional drilling system operates in a mode with a constant parameter; ! calculating the value of the derivative of the measurement of the pressure of the hydraulic fluid of the hydraulic system and comparing the value of the derivative with the threshold of the derivative; ! a decrease in the variable pressure limit if the value of the derivative exceeds the threshold of the derivative, while the amount of decrease in the variable pressure limit is based on one or more measurements of the pressure of the hydraulic fluid; and! a decrease in the pump performance of the axial pressure, when a comparison of the pressure measurements of the hydraulic fluid with a variable pressure limit indicates an excess of one or more pressure measurements