Compound suspension linkage

Continuous shear wave logging apparatus

Controlled implosive downhole seismic source

Deadweight dropping type wave source

Deadweight dropping type wave source

Decoupled borehole sensor

Device for coupling a receiver system with the wall of a well

Device for generating acoustic waves by causing a falling mass t

Device for generating acoustic waves by means of a falling mass

Device for generating seismic impulses inside a drilling through

Device for generating sound pulses inside a well, by percussion

Device for receiving sound waves in a well

Dipole logging tool

Dipole/monopole acoustic transmitter, methods for making and usi

Displacement amplified acoustic transmitter

Distributed seismic energy source

Down hole periodic seismic generator

Down hole seismographic source

Downhole electro-hydraulic vertical shear wave seismic source

Downhole electromagnetic seismic source