METHOD FOR INTERPRETATION OF SEISMIC RECORDS TO YIELD INDICATIONS OF GASEOUS HYDROCARBONS

摘要

ABSTRACT OF THE DISCLOSUREMETHOD FOR INTERPRETATION OF SEISMIC RECORDSTO YIELD INDICATIONS OF GASEOUS HYDROCARBONSThe present invention indicates that gas-containingstrata of an earth formation have low Poisson's ratios and thatthe acoustic contrast with the overburden rock has a surprisingeffect as a function of the angle of incidence on a seismic waveassociated with an array of sources and detectors: viz., asignificant -- and progressive -- change in P-wave reflectioncoefficient as a function of the angle of incidence occurs.Thus, differentiating between high-intensity amplitude anomaliesof nongas- and gas-containing media is simplified: progressivechange in amplitude intensity of resulting traces generated bythe field array as a function of offset between each source-detector pair, is associated with the last-mentioned medium only.