Electromagnetic survey systems and methods with rotation-corrected motion compensation

US8754649B2 · kind B2 · utility

Assignee

• PGS Geophysical AS · NO

Inventors

• Gustav Göran Mattias Südow · Solna, SE
• Ulf Peter Lindqvist · Stuvsta-Snättringe, SE
• Andras Robert Juhasz · Stockholm, SE
• Carl Joel Gustav Skogman · Sollentuna, SE

Key dates

• Filing date: May 12, 2010
• Grant date: Jun 17, 2014
• Expiry date: Feb 21, 2032

Classification

• Technology area (CPC G): Physics
• CPC primary: G01V1/3835
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A disclosed electromagnetic survey system includes one or more streamer(s) having multiple electromagnetic sensors and motion sensing units. Each motion sensing unit has one or more accelerometer(s) to measure motion perpendicular to an axis of the streamer, and a rotation sensor to measure rotation about the axis. The measurements of the accelerometer are adjusted based on measurements from the rotation sensor. The survey system also includes one or more processor(s) that determine, for each electromagnetic sensor, a motion signal based on the adjusted measurements. A described electromagnetic survey method includes processing acceleration and rotational motion measurements to obtain an orientation of motion sensing units as a function of time. The measured acceleration is manipulated based on the orientation to obtain one or more velocity signal(s) for each motion sensing unit. Interpolation is performed on the velocity signals to determine at least one velocity signal for each electromagnetic sensor.