Temperature compensation for seismic sensor and method
AssigneeSercel
InventorMarvin K. AMERINE
Life of this patent
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Abstract
A seismic sensor detects a characteristic of a medium during a seismic survey. The seismic sensor includes a casing; a magnet located inside the casing; a coil assembly located inside the casing, wherein the coil assembly moves relative to the magnet; and a temperature-sensitive device connected to terminals of the coil assembly and configured to improve the damping. The magnet and the coil assembly produce some intrinsic damping and the additional damping introduced by the temperature-sensitive device is selected to counterbalance the temperature-dependent intrinsic damping so that a phase of a recorded seismic signal is compensated for temperature induced magnetic field changes.
Claims20
A seismic sensor for detecting a characteristic of a medium during a seismic survey, the seismic sensor comprising:
- a casing;
- a magnet located inside the casing;
- a coil assembly located inside the casing, wherein the coil assembly moves relative to the magnet;
- and
- a temperature-sensitive device connected to terminals of the coil assembly and configured to generate a compensated damping,
- wherein the magnet and the coil assembly produce a temperature-sensitive intrinsic damping and the temperature-sensitive device produces an additional damping that is selected to counterbalance the temperature-sensitive intrinsic damping to obtain a compensated damping that reduces effects of a changing magnetic field so that a phase of a recorded seismic signal is compensated for temperature-induced magnetic field changes.
A method for detecting a characteristic of a medium during a seismic survey, the method comprising:
- placing a seismic sensor on ground, wherein the seismic sensor includes a casing, a magnet located inside the casing, a coil assembly located inside the casing, wherein the coil assembly moves relative to the magnet, and a temperature-sensitive device is connected to terminals of the coil assembly;
- measuring with the seismic sensor a seismic signal;
- generating with the magnet and the coil assembly an intrinsic damping;
- and
- generating with the temperature-sensitive device an additional damping that together with the intrinsic damping form a compensated damping so that a phase of a recorded seismic signal is compensated for temperature-induced magnetic field changes.
A method for adjusting a phase of a seismic signal recorded with a seismic sensor, the method comprising:
- receiving magnet characteristics of a magnet that is part of the seismic sensor;
- receiving the recorded seismic signal;
- receiving an ambient temperature of the seismic sensor;
- calculating, in a processor, a new phase for the recorded seismic sensor based on the magnet characteristics, the recorded seismic signal and the ambient temperature;
- and
- replacing an original phase of the recorded seismic signal with the new phase.
A seismic survey system configured to adjust a phase of a recorded seismic signal, the system comprising:
- plural seismic sensors configured to record seismic signals;
- plural remote acquisition units or base stations configured to receive the seismic signals from the plural seismic sensors;
- and
- a processor configured to,
- receive magnet characteristics of a magnet that is part of a given seismic sensor;
- receive the recorded seismic signal associated with given seismic sensor,
- receive an ambient temperature of the given seismic sensor,
- calculate a new phase for the recorded seismic signal based on the magnet characteristics, the recorded seismic signal and the ambient temperature, and
- replace an original phase of the recorded seismic signal with the new phase.
Dependencies are inferred from the claim text.