Long-distance core drilling method suitable for a horizontal geological core drilling rig

Patent metadata

Field	Value
Publication number	US-2022010640-A1
Application number	US-202117485861-A
Country	US
Kind code	A1
Filing date	Sep 27, 2021
Priority date	Apr 9, 2021
Publication date	Jan 13, 2022
Grant date	—

Abstract

A long-distance core drilling method suitable for a horizontal geological core drilling rig. (1) An active drill rod is connected to a drill rod, which is connected to a wireline-coring outer-tube drilling tool. (2) A steel-pipe string is connected to a fishing device, and the fishing device is connected to a spearhead on a core tube, which is placed to a designated position through a pipe-feeding mechanism. (3) A washing pump is started. (4) A core drilling is carried out. (5) A core is pulled out. (6) The steel-pipe string and the fishing device are reconnected. (7) The core tube is salvaged. (8) The core tube and drill pipe are replaced. (9) A hole is swept. (10) Steps (1)-(9) are repeated until the hole is drilled to a designated depth. (11) The core tube and the wireline-coring outer-tube drilling tool are recovered.

First claim

What is claimed is:

1 . A long-distance core drilling method suitable for a horizontal geological core drilling rig, a coring device adopted in the core drilling method comprising a horizontal wireline core drilling rig, a steel pipe storage rack, a plurality of steel pipes, a drill pipe, a core tube and a fishing device; the horizontal wireline core drilling rig being provided with a pipe-straightening mechanism, a pipe-feeding mechanism, a washing pump, a power head, a thrust cylinder, an active drill pipe, a rotating chuck and a gripper; the pipe-straightening mechanism and the pipe-feeding mechanism being fixed on a support frame; one end of the thrust cylinder being hinged to the support frame; the other end of the thrust cylinder being connected to the power head through a connection block; the power head being arranged on a slide rail of the support frame; a piston rod of the thrust cylinder being configured to drive the power head to move on the slide rail by extension and contraction; the power head being connected to a rear end of the drill rod through the active drill rod and being configured to drive the drill rod to rotate; both ends of each of the plurality of steel pipes being provided with an external thread; the plurality of steel pipes being sequentially connected via a double-end stud to form a steel-pipe string; the steel-pipe string being wound on the storage rack; an end of the steel-pipe string passing through the pipe-straightening mechanism, the pipe-feeding mechanism and a sealing joint to be connected to the fishing device in the drill pipe; the sealing joint being arranged on the power head; the sealing joint being communicated with an inner cavity of the active drill rod; a fishing head of the fishing device being connected to a spearhead of the core tube; a water outlet of the washing pump being communicated with the inner cavity of the active drill rod through a rotating water-supply device; the rotating water-supply device being arranged on the power head; the rotating chuck and the gripper being arranged near a front end of the support frame; the rotating chuck being configured to connect the drill rod with a wireline-coring outer-tube drilling tool; and the gripper being configured to clamp and fix the drill rod; and the core drilling method comprising:
(1) threadedly connecting the active drill rod to the rear end of the drill rod; placing a threaded part of a front end of the drill rod in the rotating chuck; connecting the drill rod to the wireline-coring outer-tube drilling tool through the rotating chuck; and clamping and fixing the drill rod through the gripper; (2) passing the steel-pipe string through the sealing joint; connecting the steel-pipe string to the fishing device; connecting the fishing device to the spearhead of the core tube in the wireline-coring outer-tube drilling tool; and lowering the core tube to a designated position through the pipe-feeding mechanism; (3) turning on the washing pump to send wash water to the inner cavity of the active drill pipe through the rotating water-supply device; (4) disassembling the steel-pipe string at the sealing joint into an inner steel-pipe string of the active drill pipe and an outer steel-pipe string of the active drill pipe; driving the power head through a motor to perform rotary drilling; and at the same time, driving the piston rod of the thrust cylinder to stretch out to drive the power head to move forward on the slide rail of the support frame; (5) when the core tube is filled with a core sample, stopping stretching out the piston rod of the thrust cylinder forward; stopping rotating the power head; allowing the washing pump to stop pumping water; operating the power head to move back, so as to drive the drill rod and the wireline-coring outer-tube drilling tool to pull out the core sample; (6) unscrewing a connecting thread between the active drill rod and the drill rod through the rotating chuck; transporting the outer steel-pipe string of the active drill pipe through the pipe-feeding mechanism to connect with the inner steel-pipe string of the active drill pipe at the sealing joint, so as to connecting the steel-pipe string with the fishing device; (7) retracting the piston rod of the thrust cylinder to drive the power head to move back to an initial position before the drilling; and lifting the core tube grasped by the fishing device to an entrance of a hole to complete a fishing operation; (8) replacing the core tube with a new core tube; and connecting a new drill rod to the active drill rod through rotating the rotating chuck; (9) sweeping the hole after the new drill rod is connected to the active drill rod; (10) repeating steps (1)-(9) until the core drilling is performed to reach a designated depth; and (11) recovering the core tube and the wireline-coring outer-tube drilling tool.

2 . The long-distance core drilling method of claim 1 , wherein in step (2), the core tube is lowered through the pipe-feeding mechanism at a speed of 0.9 m/s; and in step (7), the core tube is lifted at a speed of 1.1 m/s.

3 . The long-distance core drilling method of claim 1 , wherein in step (4), in the rotary drilling, a rotating speed of the power head is 300-1020 r/min, and a drilling speed of the power head is 4.5±2 mm/s.

4 . The long-distance core drilling method of claim 1 , wherein in step (3), a pumping capacity of the washing pump is 44-160 L/min.

5 . The long-distance core drilling method of claim 1 , wherein in step (5), a diameter of the core sample is no less than 49 mm.

6 . The long-distance core drilling method of claim 1 , wherein in step (9), a sweeping speed is 2.5 mm/s.

Assignees

• Univ Hunan Science & Technology

Inventors

• Wan Buyan
• Jin Yongping
• Peng Fenfei
• Wang Jialiang
• Liu Huan

Classifications

• E21B25/02 Primary

  the core receiver being insertable into, or removable from, the borehole without withdrawing the drilling pipe · CPC title

• E21B3/02

  Surface drives for rotary drilling · CPC title

• E21B15/04

  specially adapted for directional drilling, e.g. slant hole rigs · CPC title

• E21B25/16

  for obtaining oriented cores · CPC title

• E21B25/08 Primary

  Coating, freezing, consolidating cores (E21B25/06 takes precedence); Recovering uncontaminated cores or cores at formation pressure · CPC title