Time ramped gain for borehole televiewer
This patent describes an improvement in a borehole imaging apparatus wherein a rotating acoustic transducer means is periodically pulsed to emit a sequence of acoustic pulses into the borehole fluid toward the borehole wall and the reflected response of the acoustic pulse is received by the transducer means and converted to a related electrical signal. The improvement comprises: electrical signal compensating means located in the borehole for compensating substantially each of the electrical signals. The compensating means including variable gain amplifier means controllable from the surface for continuing to increase the amount of gain applied to each electrical signal as a function of the propagation time of the acoustic energy through the borehole fluid, to reduce the effects such as initial ringdown, mud reflections, and time-dependent borehole fluid attenuation of the acoustic energy.
- Assignee:
- Shell Oil Co., Houston, TX
- Patent Number(s):
- US 4855965
- Application Number:
- PPN: US 6935422A
- OSTI ID:
- 5322962
- Country of Publication:
- United States
- Language:
- English
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