Slew rate filter for logging cable signal pick-off

Patent · Tue Aug 26 04:00:00 EDT 1986

OSTI ID:5303246

Beals, R A

This patent describes a well logging system including a fluid tight body member or sonde sized and adapted for passage in a well borehole and supported downhole on an armored well logging cable and the sonde a pulse source connected to a pulse transmitting conductor in the logging cable, a surface located data output system connected to the conductor. The system consists of: (a) first and second amplifier means of similar construction, the first and second amplifier means both being operably connected to the transmitting conductor in the logging cable to receive a signal from the logging cable wherein electrical noise obscures the signal on the cable conductor; (b) the first and second amplifier means being operable at adjustable slew rates under control of slew rate control currents provided to the first and second amplifier means, and wherein first and second current sources are respectively connected to the first and second amplifier means to provide slew rate control currents thereto; and (c) summing means connected to the outputs of the first and second amplifier means, the summing means summing the output signals provided by the first and second amplifier means to form a differential signal therefrom, wherein the differential signal includes a signal of interest with reduced noise as a function of changes in the slew rate of the first and second amplifier means.

• Assignee: Halliburton Co., Duncan, OK
• Patent Number(s): US 4608636
• OSTI ID: 5303246
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
AMPLIFIERS
CABLES
CONDUCTOR DEVICES
CURRENTS
ELECTRIC CABLES
ELECTRIC CURRENTS
ELECTRIC FILTERS
ELECTRIC LOGGING
ELECTRIC PROBES
ELECTRICAL EQUIPMENT
ELECTRONIC EQUIPMENT
EQUIPMENT
FILTERS
NATURAL GAS WELLS
NOISE
OIL WELLS
PROBES
PULSES
SIGNALS
WELL LOGGING
WELL LOGGING EQUIPMENT
WELLS