Determining impedance of material behind a casing in a borehole

Device and method for generating a beam of acoustic energy...

Device for acquiring seismic data in a borehole and transmission

Device for locking a set of gimbal-mounted detectors

Device for receiving seismic waves and method for coupling...

Differential energy acoustic measurements of formation character

Differential noise logging method and apparatus

Differential pressure fluid density instrument

Digital acoustic logging method and apparatus

Dipmeter displacement processing technique

Dipole shear anisotropy logging

Directional acoustic logger apparatus and method

Directional long array for logging vertical boundaries

Discrete-frequency multipole sonic logging methods and apparatus

Discriminating natural fracture- and stress-induced sonic...

Downhole casing inspection system

Downhole doppler flowmeter

Downhole fracture analysis

Downhole fracture detection and characterization

Downhole seismic exploration device and apparatus