Patent ID: 9115541
Filing Date: 2015-08-25
Classification: E21B

Abstract:
1. An impulse-type underground supercharged jet drilling method, the method comprising using up and down vibrations of a drill string or weight on a bit variation during a drilling process, so that an upper joint connected to the drill string drives a housing and a supercharging cylinder block disposed therein to move up and down relative to a supercharging piston, and the supercharging piston having a high pressure line connected thereto, and a drive shaft disposed outside the high pressure line making a reciprocally retractable movement relative to the housing, so that some working fluid entering the supercharging cylinder block is intermittently supercharged, and discharged from a high pressure fluid passage disposed in the supercharging piston and the high pressure line, wherein the discharged high pressure working fluid forms a high pressure jet through a nozzle, wherein other working fluid enters a drill bit through a normal pressure fluid passage between the housing, the supercharging cylinder block, the high pressure line, and the drive shaft thereby forming a normal pressure jet, wherein when the drill string moves upwards due to vibration of the drill string or weight on the bit decreases under hydraulic pressure of the working fluid, wherein an upper joint and the housing drive the supercharging cylinder block to move upwards relative to the supercharging piston, so that the drive shaft protrudes from the housing such that at the same time a negative pressure is produced in the supercharging cylinder block and the working fluid enters and fully fills the supercharging cylinder block through a one-way intake valve disposed on the supercharging cylinder block, wherein when the drill string moves downwards due to vibration of the drill string or weight on the bit increases under an impact force or a large weight on the bit, the upper joint and the housing drive the supercharging cylinder block to move downwards relative to the supercharging piston so that the drive shaft retracts into the housing, the pressure in the supercharging cylinder block rises and shuts down the one-way intake valve, and the supercharging cylinder block continues moving downwards, wherein when the hydraulic pressure in the supercharging cylinder block reaches a predetermined value, the supercharged working fluid compels a one-way drainage valve disposed at a lower end of the high pressure line to be opened, enters a high pressure channel embedded in the drill bit, and produces an ultrahigh jet through the nozzle.