Drilling bit for drilling while running casing
First Claim
Patent Images
1. A drill bit for drilling with casing in a wellbore, comprising:
- a nose; and
cutting members disposed on the nose and made from a combination of a relatively soft base material, a relatively soft intermediate material, and a relatively hard material, wherein;
the hard material is suitable for cutting earth or rock,the combination of materials is in such proportion and in such arrangement to allow a standard earth drill bit to drill through said drill bit without substantially damaging said standard earth bit,the cutting members are substantially made from the base material,the intermediate material is amenable to the base material and disposed between the hard material and the base material;
the hard material is applied to the cutting members as preformed elements,the cumulative effect of said preformed elements is to cover the surface of the cutting members, thereby acting as a coating thereof, andthe performed elements are chips or fragments of the hard material.
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Abstract
A drill bit for drilling casing in a well bore. The drill bit is constructed from a combination of relatively soft and relatively hard materials. The proportions of the materials are selected such that the drill bit provides suitable cutting and boring of the well bore while being able to be drilled through by a subsequent drill bit. Methods of applying hard materials to a soft material body are provided.
672 Citations
38 Claims
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1. A drill bit for drilling with casing in a wellbore, comprising:
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a nose; and cutting members disposed on the nose and made from a combination of a relatively soft base material, a relatively soft intermediate material, and a relatively hard material, wherein; the hard material is suitable for cutting earth or rock, the combination of materials is in such proportion and in such arrangement to allow a standard earth drill bit to drill through said drill bit without substantially damaging said standard earth bit, the cutting members are substantially made from the base material, the intermediate material is amenable to the base material and disposed between the hard material and the base material; the hard material is applied to the cutting members as preformed elements, the cumulative effect of said preformed elements is to cover the surface of the cutting members, thereby acting as a coating thereof, and the performed elements are chips or fragments of the hard material. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. A drill bit for drilling with casing in a well bore, comprising:
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a nose; and cutting members; disposed on the nose, having preformed elements made from a relatively hard material, and made from a combination of a relatively soft base material and a relatively soft bonding material, wherein; the hard material is suitable for cutting earth or rock, the cutting members are made substantially from the base material, and the bonding material is disposed on at least a leading edge or cutting surface of each cutting member between the hard material and the base material so that, when the nose is drilled through by a standard earth bit, the bonding material will not substantially impede separation of the preformed elements, thereby allowing the standard earth bit to drill through the drill bit without substantially damaging the standard earth bit. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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33. A drill bit for drilling with casing in a wellbore, comprising:
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a nose; and cutting members disposed on the nose and made from a combination of a relatively soft base material, a relatively soft intermediate material, and a relatively hard material, wherein; the hard material is suitable for cutting earth or rock, the combination of materials is in such proportion and in such arrangement to allow a standard earth drill bit to drill through said drill bit without substantially damaging said standard earth bit, the cutting members are substantially made from the base material, the intermediate material is amenable to the base material and disposed between the hard material and the base material; the hard material is applied to the cutting members as preformed elements, the cumulative effect of said preformed elements is to cover the surface of the cutting members, thereby acting as a coating thereof, and the preformed elements have a reinforced structure to aid drilling of hard formations. - View Dependent Claims (34, 35, 36, 37, 38)
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Specification