Stabilizer and reamer system having extensible blades and bearing pads and method of using same

A stabilizer and reamer system for enlarging a borehole in a subterranean formation, comprising:

• a tubular drill string assembly having a longitudinal axis, an upper segment, a mid segment and a drilling fluid flow path therethrough;
• at least one movable reamer blade carried by the mid segment;
• at least one movable bearing pad carried by the upper segment having an up-hole edge carrying at least one trim cutter element thereon for selective engagement with a formation upon rotation of the tubular drill string assembly, wherein the at least one movable bearing pad is outwardly extensible with respect to the longitudinal axis by fluid flow or pressure;
• and
• at least one lower bearing pad carried by a lower segment of the tubular drill string assembly below the at least one movable reamer blade of the mid segment, wherein the at least one lower bearing pad comprises a down-hole portion having at least one trim cutter element positioned thereon for selective engagement with a formation upon rotation of the tubular drill string assembly.

A reamer-stabilizer system for enlarging a borehole in a subterranean formation, comprising:

• a drill string portion comprising:
• a longitudinal axis;
• an expandable reamer;
• an expandable stabilizer axially associated above the expandable reamer;
• and
• a drilling fluid flow path extending through the expandable reamer and the expandable stabilizer, the expandable stabilizer comprising:
• a tubular body;
• and
• at least one bearing pad carried by the tubular body being outwardly extensible with respect to the longitudinal axis responsive to a pressure of drilling fluid passing through the drilling fluid flow path, wherein the at least one bearing pad carries cutting structure thereon positioned on an up-hole portion of the at least one bearing pad for up-hole trimming and wherein the at least one bearing pad includes a bearing surface extending from the cutting structure to a down-hole portion of the at least one bearing pad.

An assembly for trimming a subterranean borehole, comprising:

• at least one laterally movable blade;
• and
• at least one laterally movable bearing pad longitudinally spaced above the at least one laterally movable blade and comprising:
• at least one trimming element configured for up-hole drilling and positioned on an up-hole portion of the at least one laterally movable bearing pad;
• and
• a bearing surface positioned adjacent to the cutting structure, a down-hole portion of the bearing surface being substantially devoid of cutting structure.

A method for trimming a subterranean borehole, comprising:

• positioning in a borehole, with a drill string, a first tubular body carrying at least one generally laterally movable blade and a second tubular body carrying at least one generally laterally movable bearing pad longitudinally spaced above the at least one laterally movable blade and comprising at least one trimming element configured for up drilling;
• moving the at least one generally laterally movable blade into contact with a wall of the borehole with a pressure or fluid flow from within the drill string;
• moving the at least one generally laterally movable bearing pad into contact with the wall of the borehole with the pressure or fluid flow from within the drill string;
• and
• rotating the drill string in the up-hole direction to trim formation material from the wall of the borehole with an up-hole cutting structure positioned on the at least one generally laterally movable bearing pad and to contact the wall of the borehole with a bearing surface on the at least one generally laterally movable bearing pad extending from the up-hole cutting structure to a down-hole portion of the at least one generally laterally movable bearing pad.