PILOT BOREHOLE ROLLING CUTTER REAMER Russian patent published in 2024 - IPC E21B10/30 

FIELD: well drilling.

SUBSTANCE: invention relates to the field of well drilling with subsequent reaming, namely to a rolling cutter reamer of a pilot borehole. Pilot borehole rolling cutter reamer includes a hollow drive stock, in the front part of which there is a guide apparatus, and in the rear part of which there is a housing of the reamer. Housing of the reamer has legs with rotary cutters with cutting structure installed on them. Guiding device is made in the form of a centring ring with ribs. Hollow drive rod is made with possibility of connection with drill string before guide apparatus and connection of hollow drive rod cavity with cavity of drill string for passage of flushing fluid. Reamer housing and hollow drive rod have channels communicating hollow drive rod cavity with rolling cutter space for flushing of expansion zone of pilot borehole formed by rolling cutter cutting structure. At least one ejection chamber is arranged behind the outer side surface of the hollow drive rod. In each of at least one ejection chamber, the active flow is a flushing liquid coming through an additional channel of the hollow drive rod from its cavity, and the passive flow is the fluid flow with the drilled rock from the reaming zone of the pilot borehole formed by the cutters, wherein mixed flow from ejection chamber is discharged beyond pilot borehole expansion zone formed by rolling cutter cutting structure.

EFFECT: improving operating efficiency of the rolling cutter reamer by more intensive removal of the drilled rock from the reaming zone of the pilot borehole of the well.

6 cl, 3 dwg