Induction well logging apparatus with transformer coupled phase sensitive detector
This patent describes an induction well logging apparatus for investing earth formations surrounding a borehole. It comprises: a logging device movable in the borehole; an induction transmitting antenna and first and second induction receiving antenna coils mounted on the logging device; means for electronically energizing the transmitting antenna to induce currents in the earth formations, the currents inducing voltages in the receiving antenna coils; a phase-sensitive detector having a measurement signal input terminal and a reference signal input terminal, for determining the magnitude of a signal applied to the measurement signal input terminal that is in a given phase relationship with a signal applied to the reference signal input terminal; a transformer balanced/unbalanced circuit; the output of the phase-sensitive detector providing indications of the conductivity of the earth formations surrounding the borehole.
- Assignee:
- Schlumberger Technology Corp., New York, NY
- Patent Number(s):
- US 4857852
- Application Number:
- PPN: US 7186986A
- OSTI ID:
- 5464116
- Country of Publication:
- United States
- Language:
- English
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ANTENNAS
DESIGN
ELECTRIC LOGGING
ELECTRICAL EQUIPMENT
EQUIPMENT
EXPLORATION
GEOLOGIC DEPOSITS
INDUCTION LOGGING
MINERAL RESOURCES
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
RESOURCES
TRANSFORMERS
WELL LOGGING
WELL LOGGING EQUIPMENT