Dual Purpose Radial Drilling Tool String for Cutting Casing and Rock in a Single Trip

Abstract

A downhole apparatus for cutting casing and rock when radial drilling defined by a cutting head that includes three or more cutting edges positioned around the cutting head's axis of rotation, at least three of the cutting edges in continuous contact with the face of the material being cut, thereby providing lateral and angular stability to the cutting head, one or more internal fluid passageway within the cutting head and one or more orifices for ejecting drilling-fluid out of the cutting head.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The present filing claims priority to U.S. provisional patent application 62 / 285,419 filed on Oct. 29, 2015.FIELD[0002]The present disclosure generally relates to drilling wellbores into a subterranean formation utilizing short radius lateral drilling. This disclosure has application to oil, gas, water and geothermal wells. More specifically, this disclosure discusses a dual purpose radial drilling tool string capable of cutting casing, cement and rock in a single trip of a radial drilling tool string.BACKGROUND[0003]Natural resources such as oil and gas located in a subterranean formation can be recovered by drilling a wellbore down to the subterranean formation, typically while circulating a drilling fluid in the wellbore. The wellbore is drilled with the use of a tool string consisting of drill pipe, various tools and having a drill bit on the distal end. During the drilling of the wellbore drilling fluid is typically circulated throug...

AI Technical Summary

Benefits of technology

The patent describes a tool and method for drilling a new wellbore that comes out from an existing wellbore. The tool can cut through the casing, cement, and rock in a single trip. This tool allows for more efficient and effective drilling of radial boreholes. The technical effect is improved wellbore construction in a cost-effective and efficient way.

Problems solved by technology

While most of these inserts can reliably drill a single hole in the steel wellbore casing, often they cannot reliably drill multiple holes.

Moreover, if one were to try using such a system to drill into a rock formation, especially abrasive ones like sandstone, the drill bit would quickly dull.

First, the failure to provide fluid to the cutting head to cool the cutting bit and assure any hard coating remains intact is not presently practiced.

And, second, the inherently poor bit stability due to their only having two cutting edges on a spade bit allows for the drill bit inserts to quickly dull.

Unfortunately, known PDCs are not well suited for drilling through metal (casing) as they can easily fracture or chip.

Thus, known PDCs do not present a viable solution for one-step radial drilling.

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