Hybrid bit

A bit comprising:

• a fixed cutting structure including a plurality of fixed cutting elements and a journal cavity disposed in the fixed cutting structure, wherein the fixed cutting structure comprises a first blade having a first rolling slot between a first leading edge and a first trailing edge, and a second blade having a second rolling slot between a second leading edge and a second trailing edge, wherein the first rolling slot and the second rolling slot are open to a central cavity of the bit comprising a central fluid port;
• wherein each of the first and second rolling slots each have a plurality of sleeves disposed on either side of the first and second rolling slots such that a portion of each of the plurality of sleeves abuts against an inner surface of each of the first and second rolling slots and wherein each of the plurality of sleeves extends partially into the journal cavity and
• a rolling cutting structure including a plurality of cutting elements, the rolling cutting structure comprising a first rolling cutting structure arranged in the first rolling slot such that a portion of the plurality of sleeves are configure to support the first rolling structure and a second rolling cutting structure arranged in the second rolling slot such that another portion of the plurality of sleeves are configured to support the second rolling structure, wherein each of the rolling cutting structures is wheel-shaped with a journal bore extending through the respective rolling cutting structure, the plurality of cutting elements being located on a radially outer surface of each of the rolling cutting structures.

A method of forming a hybrid drill bit, comprising:

• selecting a bit body, wherein the bit body comprises:
• a first fixed cutting structure including a first journal cavity and having a first fixed cutting element disposed on a first leading edge of the first fixed cutting structure;
• a first rolling slot between the first leading edge and a first trailing edge of the first fixed cutting structure;
• a second fixed cutting structure having a second journal cavity and including a second fixed cutting element disposed on a second leading edge of the second leading cutting structure;
• a second rolling slot between the second leading edge and a second trailing edge of the second fixed cutting structure;
• a central cavity of the bit body open to the first slot and the second slot, the central cavity comprising a central fluid nozzle;
• a first rolling cutting structure comprising a first plurality of cutting elements extending in a first radial direction from a first outer surface of the first rolling cutting structure, wherein the first rolling cutting structure is wheel-shaped;
• and
• a second rolling cutting structure comprising a second plurality of cutting elements extending in a second radial direction from a second outer surface of the second rolling cutting structure, wherein the second rolling cutting structure is wheel-shaped;
• and
• installing the first rolling cutting structure in the first rolling slot, comprising:
• arranging a first plurality of sleeves between the first rolling cutting structure and the first fixed cutting structure in the first rolling slot such that the first plurality of sleeves are positioned on either side of the first rolling slot and a portion of the plurality of sleeves abuts an inner surface of the first rolling slot and wherein the first plurality of sleeves extends partially into the first journal cavity;
• and
• inserting a first journal through the first plurality of sleeves, the first journal cavity, the first rolling cutting structure, and the first slot;
• installing the second rolling cutting structure in the second slot, comprising:
• inserting a second journal through the second plurality of sleeves, the second journal cavity, the second rolling cutting structure, and the second rolling slot;
• arranging a second plurality of sleeves between the second rolling cutting structure and the second fixed cutting structure in the second rolling slot such that the second plurality of sleeves are positioned on either side of the second rolling slot and a portion of the second plurality of sleeves abuts an inner surface of the second rolling slot and wherein the second plurality of sleeves extend partially into the second journal cavity;
• and
• securing the first rolling cutting structure and the second rolling cutting structure to the bit body.