Method and apparatus for electromagnetic logging with reduction of spurious modes

Patent · Tue Apr 21 04:00:00 EDT 1987

OSTI ID:6553722

Clark, B; Huchital, G S

Apparatus is described for determining properties of formations surrounding a borehole, comprising: an elongated logging device moveable in the borehole; a main transmitter and an auxiliary transmitter mounted on the device; a main receiver and an auxiliary receiver mounted on the device in spaced relationship to the transmitters; means for energizing the main transmitter to transmit electromagnetic energy at a first frequency; means for energizing the auxiliary transmitter to transmit transverse magnetic electromagnetic energy at a second frequency; means for frequency separating the energy received at the main receiver into a first frequency main receiver signal and a second frequency main receiver signal; means for frequency separating the transverse magnetic electromagnetic energy components received at the auxiliary receiver signal and a second frequency auxiliary receiver signal; and means for generating a corrected main receiver signal as a function of the main receiver signals and the auxiliary receiver signals.

• Assignee: Schlumberger Technology Corp., New York, NY
• Patent Number(s): US 4659992
• OSTI ID: 6553722
• 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
AUXILIARY SYSTEMS
BOREHOLES
CAVITIES
DATA TRANSMISSION SYSTEMS
ELECTRICAL SURVEYS
ELECTROMAGNETIC SURVEYS
ELONGATION
EQUIPMENT
FREQUENCY DEPENDENCE
GEOLOGIC DEPOSITS
GEOPHYSICAL SURVEYS
MINERAL RESOURCES
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
RESOURCES
SIGNALS
SPACE DEPENDENCE
SURVEYS
WELL LOGGING EQUIPMENT