The Coherence Cube Computing Method with Self-adaptive Time Window Based on Wavelet Transform

Thecoherencecubetechnologyhasbecomeanimportanttechnologyfortheseismicattributeinterpretation,whichextractsthediscontinuitiesoftheeventsthroughanalyzingthesimilaritiesofadjacentseismicchannelstoidentifythefaultform.Thecoherencecubetechnologywhichusesconstanttimewindowlengthscannotbalancetheshallowlayersandthedeeplayers,becausethefrequencybandofseismicdatavarieswithtime.Whenanalyzingtheshallowlayers,thetimewindowwillcrossoveralotofevents,whichwillleadtoweakfocusingabilityandfailuretodelineatethedetails.Whilethetimewindowwillnotbelongenoughforanalyzingdeeplayers,whichwillleadtolowaccuracybecausethecoherencesnearthezeropointsoftheeventsareheavilyinfluencedbynoise.Forsolvingtheproblem,weshouldmakearesearchonthecoherencecubetechnologywithself-adaptivetimewindow.Thispaperdeterminesthesamplepoints’timewindowlengthsinrealtimebycomputingtheinstantaneousfrequencybandswithWaveletTransformation,whichgivesacoherencecomputingmethodwiththeself-adaptivetimewindowlengths.Theresultshowsthatthecoherencecubetechnologywithself-adaptivetimewindowbasedonWaveletTransformationimprovestheaccuracyoffaultidentification,andsupressesthenoiseeffectively.Themethodcombinestheadvantagesoflongtimewindowmethodandshorttimewindowmethod.