Disclosed is a hammer reamer that comprises similar features to prior art reamers such as cutting wheels and a product-pulling feature. An exemplary hammer reamer, however, also includes a hammer component operable to deliver a percussive cycle of an internal piston component. Notably, an internal impact surface within the head of the hammer reamer is positioned relative to the piston component in the hammer consistent with a sweet spot position of a drill bit used in a pilot boring configuration. Unlike a slidably engaged drill bit, however, the internal impact surface in the hammer reamer is fixed in place so that the impact surface remains in the sweet spot of the piston stroke range. In this way, even though the hammer reamer is being pulled back through a bore while the drill string is being retracted, the hammer component may continue to deliver percussive blows to the hammer reamer head to introduce a vibratory force that contributes to the efficiency of the reaming process.

An underreamer for increasing a diameter of a wellbore. The underreamer includes a body having an axial bore extending at least partially therethrough. A sleeve is arranged and designed to move a first axial distance within the body. A cutter block is movably coupled to the body. The cutter block is arranged and designed to move at least the first axial distance with respect to the body to contact the sleeve in response to hydraulic pressure in the bore. The cutter block moves from a first outer diameter to a second outer diameter as the cutter block moves the first axial distance.

An underreamer for increasing the diameter of a bore. The underreamer includes a substantially cylindrical body. A mandrel may extend axially through the body. One or more cutter blocks are movably coupled to the body. A ratio of a height of the cutter block to a diameter of the body is between about 0.35:1 and about 0.50:1.

Methods of performing a reaming operation at a wellsite are disclosed. The method involves measuring surface drilling parameters (e.g., surface torque and surface weight on bit) from surface sensors positioned about a rig, measuring downhole drilling parameters (e.g., downhole weight on bit and downhole torque) from downhole sensors positioned about a downhole tool, generating weight on reamer from the measured surface weight on bit and the measured downhole weight on bit, generating frictional torque by detecting from the surface sensors when the drilling tool is in a rotating off bottom state and selecting a portion of the measured surface torque measured during the rotating off bottom state, generating torque on reamer from the frictional torque, the downhole torque parameters, and the surface torque parameters, and detecting reamer performance by monitoring changes in reamer performance metrics (e.g., reamer aggressiveness) including integrated torque on reamer with weight on reamer.

A reaming tool for enlarging an underground borehole has a plurality of cutter assemblies distributed azimuthally around a longitudinal axis of the tool. First, second and possibly more cutter assemblies each have an axially extending length comprising supporting structure bearing a sequence of cutters which have hard surfaces facing in a direction of rotation of the tool and are distributed axially along the length. A plurality of the cutters on the second cutter assembly are at axial positions relative to the tool which are intermediate between axial positions of the cutters on the first cutter assembly. Cutters on further assemblies may also be at intermediate axial positions. Cutters in the overall plurality of sequences are positioned at radial distances from the tool axis which increase as axial distance from an end of the tool increases.

In one embodiment, a radio-frequency identification device for use in a wellbore includes a housing made of a polymer; and an antenna disposed in the housing. The polymer may be selected from the group consisting of an elastomer, a plastic, a rubber, a thermoplastic elastomer, and combinations thereof. The RFID device may also include a fill material disposed in the housing.

A method and system for directional drilling while conveying a liner, with latching parking capabilities for multiple trips, is disclosed. As the wellbore is drilled, each casing and liner is installed having upper and lower interior latch couplings. A liner to be installed below a parent casing includes an exterior latch assembly dimensioned for connection to the interior latch couplings of the parent casing. A bottom hole assembly may include upper and lower exterior inner string latch assemblies for connection to the upper and lower interior latch couplings of the liner to be installed. Such arrangement allows the liner to be conveyed and installed with the bottom hole assembly while directional drilling and for the liner to be temporarily hung from the parent casing for bottom hole assembly change-out while drilling. Float plugs dimensioned to be landed at lower liner interior latch couplings may be provided for cementing operations.