EARTH-BORING TOOL HAVING BACK UP CUTTING ELEMENTS WITH FLAT SURFACES FORMED THEREIN AND RELATED METHODS

摘要

An earth-boring tool includes primary and secondary cutting elements mounted to a tool body. The secondary cutting elements define a secondary cutting profile. The secondary cutting profile is recessed relative to the primary cutting profile, which is defined by the primary cutting elements. In an unworn condition, the primary cutting elements engage and cut a formation material while the secondary cutting elements do not. Each secondary cutting element includes a flat surface oriented at an angle relative to a longitudinal axis thereof and extending between a front cutting face and a peripheral side surface thereof. The secondary cutting elements are oriented on the tool body such that a surface area of the flat surface thereof will engage the formation material at least substantially simultaneously when the primary cutting elements reach a worn condition. Methods of forming the earth-boring tool and methods of using the earth-boring tool are also disclosed.

主权项

1. An earth-boring tool for forming a wellbore in a subterranean formation, comprising:
a tool body; and cutting elements mounted on the tool body, the cutting elements comprising:
primary cutting elements defining a primary cutting profile of the earth-boring tool; andsecondary cutting elements defining a secondary cutting profile recessed relative to the primary cutting profile such that, upon initial cutting action of the earth-boring tool in an unworn condition, the primary cutting elements will engage and cut a formation material while the secondary cutting elements do not engage and cut the formation material, and such that the secondary cutting elements will engage the formation material only after the primary cutting elements reach a worn condition, each secondary cutting element comprising a flat surface oriented at an angle relative to a longitudinal axis of the secondary cutting element and extending between a front cutting face and a peripheral side surface of the secondary cutting element, the secondary cutting element oriented such that a surface area of the flat surface of the secondary cutting element will engage the formation material at least substantially simultaneously.