Assembly for locking a polished rod in a pumping wellhead

Assembly for pressure control when drilling and method to...

Assembly for reducing the force applied to a slot and lug guide

Assembly for use in a tong, a belt holder and a belt anchor...

Assembly of hollow torque transmitting sucker rods and...

Assessment of drilling conditions

Assisted recovery by hydrogen sulfide injection

Assisted recovery by solvent flooding

Asymmetric gage insert for an earth boring apparatus

Asymmetric graded composites for improved drill bits

Asymmetric insert for inner row of an earth boring cutter

Asymmetrical drill stem for drilling oil wells

Atomic clock for downhole applications

Attachment for a percussive rock drilling machine

Attachment means for drilling equipment

Attenuation of unwanted acoustic signals by semblance...

Attenuator for borehole acoustic waves

Auger apparatus

Auger arrangement

Auger construction