Underground high pressure continuous flow jet drilling tool and rock drilling method thereof

Abstract

The invention discloses an underground high pressure continuous flow jet drilling tool and a rock drilling method thereof, comprising a drill lever, a filtering device, a turbine device, a centrifugalpump or an axial-flow pump and a drill. The drill lever is drived by a ground ane rotary disc or a top drive device. The drill is arranged at the bottom of the drill lever, which is fixed with a highpressure flow jet nozzle and a low pressure flow jet nozzle. Inside the drill lever along the axes of the drill lever is provided with a filtering device, a turbine device and multiple-stage centrifugal pump or axial-flow pump. The turbine device adopts the mode that a hollow axle, the filtering device and the hollow axle of the turbine device are connected and the axle input terminal of the centrifugal pump or the axial-flow pump is connected with the output terminal of the turbine device hollow axle. The invention can improve the well drilling speed.

Description

technical field [0001] The invention relates to an underground high-pressure continuous-flow jet drilling tool and a rock-breaking method thereof. Background technique [0002] Chinese utility model patent ZL96207357.1 discloses an ultra-high pressure downhole pulse jet supercharger. hydraulic cylinder. The drilling fluid enters the inlet of the hydraulic cylinder through the turbine, and after being pressurized by the hydraulic cylinder, a pulsating ultra-high pressure jet is injected from the nozzle to break rock. Jet pressure reaches 100-200Mpa. [0003] This pulsating jet booster cannot provide continuous high-pressure jet, so the rock-breaking efficiency is low. Since the hydraulic cylinder adopts gap seal, the particle size of cuttings contained in the drilling fluid is required to be very small. Therefore, the drilling fluid needs to be strictly filtered before it can enter this high-pressure jet drilling tool. In addition, since the space inside the cylinder is ...

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Problems solved by technology

In addition, since the space inside the cylinder is isolated from the drilling fluid outside during the pressurization process using the hydraulic cylinder, the pressurization efficiency is low and it is easy to damage

[0004] Chinese patent application CN89101781.X discloses a supercharging device used in the drill pipe, this supercharging device is composed of a turbine, and this supercharging device cannot provide a rock-breaking jet with sufficient pressure

Like using a pressurized cylinder to increase the pressure of the drilling fluid, the pulse jet device according to US Patent No. 4,819,745 cannot provide continuous high-pressure rock-breaking jets

[0006] Chinese patent application CN00250432.4 discloses a downhole high-pressure jet drilling tool powered by a turbine, which is provided with a speed-increasing box that improves the rotational speed of the centrifugal pump to increase the injection pressure of the drilling fluid ejected. Although the drilling tool can Provides continuous high-pressure jet, but its rock-breaking efficiency is not high and wears heavily

[0008] However, the jet flow experiment in the United States only simulates the two-dimensional downhole confining pressure, and the three-dimensional high confining pressure experiment is very difficult to do on the ground, so it misleads the jet's crushing mechanism of the downhole rock

Under the understanding of this rock-breaking mechanism, the pursuit of increasing the jet pressure of the downhole drilling fluid is blindly pursued. Although increasing the pressure of the downhole drilling fluid jet helps to improve the rock-breaking efficiency, it has not achieved ideal results in practical applications. effect, and ultimately ended in failure

The reason for the above problems is that people have misunderstandings about the rock-breaking mechanism of downhole jet pressurization

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