Reamer for horizontal directional drilling

Abstract

A method and drilling system for forming an underground bore from a first location (112) to a second location (116). The method comprises drilling a pilot hole (PH) from the first location toward the second location using a pilot drill string (128) and advancing a reamer (204) over the pilot drill string. The method can further include coupling a pipe (PP) to the pilot drill string or reamer and pulling the pilot drill string or reamer out of the bore at the first location. The drilling system includes a pilot drill including the pilot drill string and a reamer adapted to slide over the pilot drill string such that, after the pilot drill forms a pilot hole, the reamer can be advance along the pilot drill string to form the reamed hole (RH). The drilling system can further comprise a seal (264, 272) positioned between the pilot drill and the reamer to inhibit the passage of fluid past the seal.

Dependencies are inferred from the claim text.