Microwave electromagnetic borehole dipmeter

Patent · Tue Jul 15 04:00:00 EDT 1986

OSTI ID:5435355

Baldwin, W F; Shen, L C

A method is described of microwave electromagnetic logging to determine the dip of subsurface earth formations surrounding a borehole, comprising the steps of: (a) advancing a borehole logging tool through a borehole, the logging tool including a source of microwave energy and at least three microwave antennas positioned from the longitudinal axis of the tool and spaced approximately equally around the axis, (b) applying microwave energy to the antennas for irradiating the formations surrounding the borehole as the logging tool is moved through the borehole, (c) measuring the loading effect of formation impedance on the at least three antennas and producing at least three signals proportional thereto, (d) measuring the complex impedance imposed on the at least three antennas and producing signals representing both the real and imaginary components of the complex impedance, (e) utilizing the measured loading effects in the determination of the dip of the formations surrounding the borehole in the absence of interfering mud-cake conductivity along the borehole wall, and (f) utilizing the real component of the measured complex impedance to determine the dip of the formations surrounding the borehole at those points along the borehole where the presence of mud-cake conductivity interferes with the determination of formation dip from the measurement of the loading effects of the formation impedance on the antennas.

• Assignee: Mobil Oil Corp., New York, NY
• Patent Number(s): US 4600887
• OSTI ID: 5435355
• 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
ANTENNAS
BOREHOLES
CAVITIES
DIPMETER LOGGING
ELECTRIC CONDUCTIVITY
ELECTRIC IMPEDANCE
ELECTRIC LOGGING
ELECTRICAL EQUIPMENT
ELECTRICAL PROPERTIES
ELECTRICAL SURVEYS
ELECTROMAGNETIC RADIATION
ELECTROMAGNETIC SURVEYS
EQUIPMENT
GEOLOGIC DEPOSITS
GEOPHYSICAL SURVEYS
IMPEDANCE
IRRADIATION
MICROWAVE RADIATION
MINERAL RESOURCES
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
PHYSICAL PROPERTIES
POSITIONING
RADIATIONS
RESOURCES
SIGNALS
SPACE DEPENDENCE
SURVEYS
WELL LOGGING
WELL LOGGING EQUIPMENT