Central cutting region of a drilling head assembly
OwnerDavid R. Hall, Thomas Morrisinventors
Life of this patent
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Abstract
In one aspect of the invention, a drilling assembly comprises a head located on a rotational axis of the assembly and comprises at least one head element. At least one blade extends distally from the head. A plurality of blade degradation elements are rotationally supported on the blade. Each degradation element comprises an attack angle that affects the penetration rate of each degradation element and a laterally offset angle that primarily affects the rotational rate of each degradation element within their holders. The drilling assembly comprises a central cutting region. The blade degradation elements within the central cutting region form an attack angle of 15 to 20 degrees with the rotational axis of the drilling assembly.
Claims14
A drilling assembly, comprising:
- a head located on a rotational axis of the assembly;
- at least one blade extending distally from the head;
- a plurality of blade degradation elements being rotationally supported on the blade;
- each degradation element comprising an attack angle formed between a central axis of the degradation element and the rotational axis of the assembly that affects the penetration rate of each degradation element and a laterally offset angle formed between the central axis of the degradation element and a line tangent to a helical cutting path of the degradation element that primarily affects the rotational rate of each degradation element within their holders fixed to the blade;
- wherein the plurality of blade degradation elements comprise a wear resistant tip comprising a pointed sintered polycrystalline diamond compact supported on a cemented metal carbide support;
- and
- a central cutting region of each blade;
- wherein the attack angle of each blade degradation element within the central cutting region is between 15 and 20 degrees.
A drilling assembly, comprising:
- a head located on a rotational axis of the assembly;
- at least one blade extending distally from the head;
- a plurality of blade degradation elements being rotationally supported on the blade;
- each degradation element comprising an attack angle formed between a central axis of the degradation element and the rotational axis of the assembly that affects the penetration rate of each degradation element;
- wherein the plurality of blade degradation elements comprise a wear resistant tip comprising a pointed sintered polycrystalline diamond compact supported on a cemented metal carbide support;
- and
- a central cutting region of each blade;
- wherein the attack angle of each blade degradation element within the central cutting region is between 15 and 20 degrees.
Dependencies are inferred from the claim text.