| 摘要 |
<p>A seismic energy source apparatus (20) includes a stack (92,92 min ) of piezoelectric elements, means (58,96) for applying voltages thereto to cause the stack to vary in length. A hydraulic system including a power piston (90,90 min ) coupled to the stack, a drive piston (84,84 min ) and an incompressible fluid therebetween, amplifies the small movements of the stack, and the amplified movements are imparted to an earth formation. The amplified movements may be reciprocating torsional or radial, for example.</p> |
