Method for 2D and 3D electromagnetic field measurements using a towed marine electromagnetic survey system

• Main Authors: ANDRAS ROBERT JUHASZ, GUSTAV GORAN MATTIAS SUDOW, ULF PETER LINQVIST
• Format: Patent
• Language: English
• Published: 19.02.2014
• Subjects: DETECTING MASSES OR OBJECTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; MEASURING; PHYSICS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TESTING

A method for acquiring electromagnetic data in at least two dimensions includes towing a first streamer cable behind a vessel in a body of water, the first streamer cable including a reference line extending substantially along the entire length thereof, a plurality of spaced apart measuring electrodes electrically insulated from the reference line and a voltage measuring circuit functionally coupled between each measuring electrode and the reference line. At least a second streamer cable is towed at corresponding distance from the vessel. The second streamer cable is configured substantially as the first streamer cable. The second streamer cable is displaced from the first streamer cable in one of a horizontal plane and a vertical plane. At selected times an electromagnetic field is imparted into the water. Voltage difference is determined between each measuring electrode and the reference line, and a difference between voltages measured at least one electrode on each of the first and second streamer cables is determined.