Logging tool and method for measuring resistivity of different radial zones at a common depth of measurement

Patent · Tue May 29 04:00:00 EDT 1984

OSTI ID:6528769

Meador, R A

A wireline logging system for measuring formation resistivity includes a longitudinal housing having three transmitters and three receivers arranged at measured distances on the housing, with about four feet between the outermost ends of the array. The transmitters are operated at three different frequencies, with each receiver receiving all three frequencies. The output of each receiver is the three received frequencies, which is amplified and fed to a mixer. A local oscillator frequency is also fed to each mixer. The output from each mixer of the three received frequencies mixed with a local frequency is passed through a filter to output one of the three received signals at a lower frequency. The frequency mix is arranged so that the output of each of the filters is at a common frequency. The filtered outputs from pairs of the filters are then passed to phase comparators and/or amplitude ratio determining devices to provide signals indicative of formation resistivity which are then passed to the surface on the wireline.

• Assignee: NL Industries Inc.
• Patent Number(s): US 4451789
• OSTI ID: 6528769
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
440400 -- Well Logging Instrumentation
47 OTHER INSTRUMENTATION
AMPLITUDES
COMPARATOR CIRCUITS
CONTROL
DEPTH
DESIGN
DIGITAL FILTERS
DIMENSIONS
ELECTRIC LOGGING
ELECTROMAGNETIC RADIATION
ELECTRONIC CIRCUITS
ELECTRONIC EQUIPMENT
EQUIPMENT
FREQUENCY CONTROL
OIL WELLS
OSCILLATORS
RADIATIONS
RESISTIVITY LOGGING
SIGNALS
WELL LOGGING
WELL LOGGING EQUIPMENT
WELLS
WIRES