Dielectric well logging system with at least three transmitter coils and at least two receiver coils for determining resistivity and dielectric constant of a subsurface formation adjacent a fluid

Patent · Tue Sep 02 04:00:00 EDT 1986

OSTI ID:5179505

Cox, P T; Meador, R A; Riedesel, Jr, R G; Savage, K D

A dielectric well logging apparatus is described for obtaining amplitude ratios and phase differences between electromagnetic wave energy signals which have passed different distances through a subsurface formation adjacent a well borehole, so that an analyst may determine resistivity and dielectric constants for the different distances of travel through the formation. The apparatus consists of: (a) sonde means for moving through the well borehole; (b) at least three transmitter coils for emitting radio frequency energy into the formation at different depths in the borehole, the coils being spaced from each other in the sonde means for disposition at different depths in the borehole; (c) control means for controlling the activation of the transmitter coils; (d) receiver coils for receiving energy from the transmitter coils after passage through the formation and borehole, the receiver coils being spaced from each other and from the transmitter coils in the sonde for disposition at different depths in the borehole; (e) the receiver coils forming in groups of two different transmitter-receiver pairs, differently spaced from the other receiver pairs, with each of the transmitter coils; (f) receiver circuit means for forming signals representing the electromagnetic wave energy received in the receiver coils; and (g) processing circuit means for forming output signals representative of the phase difference and amplitude ratio for each of the different transmitter-receiver pairs so that the analyst may determine the resistivity and dielectric constants for the different distances of travel to determine if fluid invasion is present in the formation.

• Assignee: Texaco, Inc., White Plains, NY
• Patent Number(s): US 4609873
• OSTI ID: 5179505
• 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
440400 -- Well Logging Instrumentation
47 OTHER INSTRUMENTATION
AMPLITUDES
BOREHOLES
CAVITIES
DEPTH
DIELECTRIC PROPERTIES
DIMENSIONS
DISTANCE
ELECTRIC COILS
ELECTRIC CONDUCTIVITY
ELECTRIC LOGGING
ELECTRIC PROBES
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
ELECTROMAGNETIC RADIATION
EQUIPMENT
GEOLOGIC DEPOSITS
MINERAL RESOURCES
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
PHYSICAL PROPERTIES
PROBES
RADIATIONS
RESISTIVITY LOGGING
RESOURCES
SIGNALS
SPACE DEPENDENCE
WELL LOGGING
WELL LOGGING EQUIPMENT