Seismic acquisition system including a distributed sensor having an optical fiber
AssigneeSchlumberger Technology Corporation
InventorsEd Kragh, Everhard Muyzert, Johan Robertsson, Douglas E. Miller, Arthur H. Hartog
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Abstract
A seismic acquisition system includes a distributed optical sensor (having an optical fiber) and an interrogation subsystem configured to generate a light signal to emit into the optical fiber. The interrogation subsystem receives, from the distributed optical sensor, backscattered light responsive to the emitted light signal, wherein the backscattered light is affected by one or both of seismic signals reflected from a subterranean structure and noise. Output data corresponding to the backscattered light is provided to a processing subsystem to determine a characteristic of the subterranean structure.
Claims18
A seismic acquisition system, comprising:
- a distributed optical sensor having an optical fiber for positioning outside a subterranean structure to be surveyed;
- and
- an interrogation subsystem configured to:
- generate a light signal to emit into the optical fiber;
- receive, from the distributed optical sensor, backscattered light responsive to the emitted light signal, wherein the backscattered light is affected by one or both of seismic signals reflected from the subterranean structure and noise;
- and
- output data corresponding to the backscattered light to a processing subsystem to determine a characteristic of the subterranean structure,
- wherein the distributed optical sensor and interrogation subsystem are configured to provide a spatial resolution having a predefined relationship to wavelength(s) of one or both of the seismic signals and the noise, and
- wherein the spatial resolution is less than the wavelength of the seismic signals.
A seismic acquisition system, comprising:
- a distributed optical sensor having an optical fiber for positioning outside a subterranean structure to be surveyed;
- and
- an interrogation subsystem configured to:
- generate a light signal to emit into the optical fiber;
- receive, from the distributed optical sensor, backscattered light responsive to the emitted light signal, wherein the backscattered light is affected by one or both of seismic signals reflected from the subterranean structure and noise;
- and
- output data corresponding to the backscattered light to a processing subsystem to determine a characteristic of the subterranean structure,
- wherein the optical fiber has curved portions, wherein the curved portions allow for detection of components of the noise and/or components of the seismic signals in plural multiple different directions, and wherein the curved portions each has a curvature with a predefined relationship to wavelength(s) of one or both of the noise and the seismic signals.
A method comprising:
- providing a distributed optical sensor having an optical fiber for performing a seismic survey of a subterranean structure;
- emitting light into the optical fiber;
- receiving backscattered light responsive to the emitted light from the optical fiber, wherein the backscattered light is affected by noise;
- processing, by a processing subsystem, data relating to the backscattered light, wherein the data relating to the backscattered light represents one of:
- (1) the noise, (2) the noise and seismic signals reflected from the subterranean structure, and (3) the seismic signals reflected from the subterranean structure with the noise attenuated;
- and
- deriving a propagation speed of the noise using the data corresponding to the backscattered light.
Dependencies are inferred from the claim text.