Patent ID: 9103935
Filing Date: 2015-08-11
Classification: G01V

Abstract:
1. A method of first arrival picking of seismic refraction data, comprising the steps of: obtaining field records of seismic data detected at a plurality of seismic receivers in an area of interest, the seismic data including signal amplitude data recorded over time and containing both first arrival reflection signals and unwanted noise; calculating the signal amplitude data in an offset-time domain, the signal amplitude data being formulated as energy ratio amplitude data characterized by the relation: where ER j is the energy-ratio value associated with a sampling window starting with the j th sample of a trace of the energy ratio amplitude data and A i is the signal amplitude of the i th sample of the trace; applying a Radon transform to the energy ratio amplitude data, thereby transforming the energy ratio amplitude data from the offset-time domain to a time-slowness domain; selecting a corresponding first arrival energy data from the time-slowness domain energy ratio amplitude data, the selection generating a binary mask wherein a binary 1 indicates a required first-arrival picks region with a τ-p energy ratio map and a binary 0 indicates that the region is not a required first-arrival picks region; multiplying the Radon transformed energy ratio amplitude data with the binary mask to form a Radon transform energy ratio amplitude data-binary mask product; applying an inverse Radon transform to the Radon transform energy ratio amplitude data-binary mask product, thereby transforming the Radon transform energy ratio amplitude data-binary mask product into the offset-time domain; and binary thresholding in the offset-time domain the inverse Radon transform of the product, thereby producing an enhanced binary image in the offset-time domain of the selected first arrival region.