초록 ▼

This invention relates to a method of increasing resolution of high-intensity amplitude events in seismic records provided by common midpoint collection methods (CMP) wherein nonsymmetrical travel paths of incident and reflected rays of the generated conventional waves (due to dip and depth) are tak

This invention relates to a method of increasing resolution of high-intensity amplitude events in seismic records provided by common midpoint collection methods (CMP) wherein nonsymmetrical travel paths of incident and reflected rays of the generated conventional waves (due to dip and depth) are taken into account prior to trace stacking. Then, in accordance with the invention, the converted phases of the conventional seismic wave, are processed as to define a series of common reflection point (CRP) coordinates each associated with a gather of converted traces as if a source associated with a given corrected trace was placed at each CRP and activated followed immediately by the relocation of a detector at the CRP and the reception of converted phases of the generated wave comprising the trace wherein the equation of coordinate transformation is selected from the group comprising: CRP=kD+(1-k)SP: for conversions of P-waves to Sv-waves at the target reflector; CRP=(1-k)D+kSP: for conversions of Sv-waves to P-waves at said target; [Figure] where [Figure] Vp and Vs are the P-wave and Sv-wave velocities, respectively, of the overburden; X is the source-receiver offset distance; h is the depth of the target reflector; a

대표청구항 ▼

In a method of improving resolution of seismic data collected by conventional common midpoint collection (CMP) methods including sequentially activating a conventional seismic source at a series of sourcepoint locations (SP) along a line of survey and redundantly collecting reflections of both the c

In a method of improving resolution of seismic data collected by conventional common midpoint collection (CMP) methods including sequentially activating a conventional seismic source at a series of sourcepoint locations (SP) along a line of survey and redundantly collecting reflections of both the conventional waves and the converted phases thereof via a series of multicomponent detectors at a plurality of detector stations (D) along said line of survey each detector simultaneously but separately recording the motion of the earth in the radial horizontal direction and in the vertical direction, wherein each resulting convention and converted traces is associated with a sourcepoint-detector station pair of known (SP,D) coordinates, the improvement thereof related to processing both conventional and converted traces in a systematic manner whereby resulting conventional and converted gathers of such traces each samples a reflection point of a target reflector in the subsurface common to each gather irrespective of dip and depth of said target reflector, comprising the steps of (i) generating seismic field records including at least separate conventional and converted seismic records, by positioning and employing an array of source and multicomponent detectors such that individual sourcepoint-detector station coordinates can be redundantly associated with a selected number of conventional and converted traces of said records, said converted and conventional traces being the simultaneous output of said detectors, (ii) establishing for said conventional and converted traces a series of separate common reflection points (CRP\s), each CRP being for gathering traces common thereto as if a source associated with a given trace of a common gather was placed at said each CRP and activated followed immediately by the relocation of a detector at said each CRP and the reception of conventional or converted waves comprising said conventional or converted trace; (iii) each CRP associated with said common gather of conventional traces being made to account for different travel paths of the wave due to depth and dip of each target reflector; (iv) each CRP associated with said common gather of converted traces undergoing dynamic sourcepoint-detector station coordinate transformation to account for nonsymmetrical travel paths of incident and reflected ray, dip as well as depth of said target reflectors, wherein the equation of coordinate transformation is selected from the group comprising: CRP=kD+(1-k)SP: for conversions of P-waves to Sv-waves at said target; CRP=(1-k)D+kSP: for conversions of Sv-waves to P-waves at said target; [Figure] where [Figure] Vp and Vs are the P-wave and Sv-wave velocities, respectively, of the overburden; X is the source-receiver offset distance; h is the depth of the target reflector; a