Drill bit mask having sub-millimeter size apertures for reentrant cavitation jet drilling

Abstract

A tricone drill bit having a hollow housing and leg sections holding rotatable cones for drilling rock. The drill bit encloses a cavitation reactor. The cavitation reactor includes liquid and being capable of receiving a laser beam. The cavitation reactor forms cavitation bubbles fin the liquid in response to the laser beam. The cavitation reactor includes a mask having sub millimeter sized apertures for directing cavitation jets formed on the collapse of the cavitation approximately 0.1-10 microns. These reentrant cavitation jets pass easily through the apertures of the mask and to the rock to enable the tricone drill be to operate more efficiently.

Description

RELATED ART[0001]The present invention relates in subject matter to: Criteria for Jet Cavitation and Cavitation Jet Drilling, Zifeng Li, International Journal of Rock Mechanics & Mining Sciences 71 (2014) 204-207; and U.S. Pat. No. 7,517,430, to LeClair, issued Apr. 14, 2009 the disclosures of which are incorporated herein by reference and appended hereto.FIELD OF THE INVENTION[0002]The present invention pertains to drill bits for mining natural resources, and particularly to drill bits and methods of using the same that include a cavitation jet mask enabled with reentrant cavitation jet capability.BACKGROUND OF THE INVENTION:[0003]Cavitation Jet Drilling has been known about for some time, but it has not yet had widespread commercial acceptance or use. Essentially a stream of cavitation bubbles are directed towards earth to erode the rocks away. This has used simply spraying a fluid at high pressure through a nozzle at the substrate surface to erode. The bubbles formed in the fluid...

AI Technical Summary

Benefits of technology

The patent describes a system using laser technology to improve the efficiency and function of drill bits in excavating rocks and earth. The system includes a cavitation reactor with a cavitation mask that directs cavitation jets at high speed from the reactor through the drill bit, mitigating shock waves created by the jets. Using a low energy laser, the system can produce cavitation bubbles and jets having precise direction and energy to assist the drill bit in excavating rock and earth, resulting in longer drill bit life, faster drilling speeds, lower heat production, and lower cost of ownership of the drill bit. Additionally, the system can use a laser to produce infrared wavelengths in the cavitation reactor fluid, resulting in the creation of cavitation bubbles with a smaller mean diameter that easily pass through the mask.

Problems solved by technology

Cavitation Jet Drilling has been known about for some time, but it has not yet had widespread commercial acceptance or use.

The inner burst impact pressure of the bubbles on the rock cause erosion of the rock.

There are also problems using a nozzle because the ambient pressures in a bottom hole are typically high and not uniform.

Thus formation of utilizable cavitation bubbles for mining applications is difficult and not yet commercially viable.

The cavitation number often cannot be used to accurately determine if cavitation will occur.

It is known that the impulse pressure due to the cavitation bubbles varies, because the bubbles form cavitation jets that are unpredictable and undirected.

The challenge is to utilize these reentrant jets in a drill bit for the mining industry.

Images