Abstract:
Methods and systems for deriving S-wave velocity information from the low-frequency content of ambient noise are described. The ambient noise can be collected on a dedicated record or on a production record associated with the receivers of a three-dimensional seismic survey. The methods and systems use one of a plurality of analysis models selected based on quality factors of the ambient noise data. The methods and systems analyze the data at a plurality of single frequencies then transform the velocity versus frequency data into velocity versus depth data.
Abstract:
Methods for seismic exploration of a subsurface formation increase productivity by simultaneously actuating closely located vibratory sources. Individual vibrations generated by different sources actuated simultaneously are encoded to enable separation of seismic data corresponding to each of the individual vibrations.
Abstract:
Apparatus, computer instructions and method for controlling an energy output of a source array to be used in a seismic survey for illuminating a subsurface. The method includes generating a model (β) based on up-going (U) and down-going (D) components of seismic waves generated by source elements that form the source array; calculating the amplitudes and phases of each source element based on the model (β); and driving the source array based on the calculated amplitudes and phases for the source elements so that a ghost generated by the source array is reduced at emission.
Abstract:
According to an embodiment, a method for analyzing microseismic events associated with hydraulic fracturing detects a new microseismic event and assigns it to a cluster of other events having similar characteristics. Cluster characteristic(s), e.g., average event(s), average source mechanisms, and/or average locations, are updated and used to characterize a future microseismic events.
Abstract:
Device and method for locating a microseismic event taking place in a subsurface of the earth. The method includes receiving a location of a well; identifying inaccessible locations for seismic receivers on a surface next to the well; distributing patches of the seismic receivers on the surface above the well, and around the inaccessible locations; and recording seismic data with the seismic receivers.