30125.核磁共振測井正交檢波濾波器算法研究

1、華中科技大學(xué)碩士學(xué)位論文核磁共振測井正交檢波濾波器算法研究姓名：張良義申請學(xué)位級別：碩士專業(yè)：檢測技術(shù)與自動化裝置指導(dǎo)教師：劉文中20110222IIIAbstractInversionofnuclearmagicresonance(NMR)loggingechosignalcanacquiretheinfmationunrelatedwithrockproperties.Itcanalsoestimatespermeabilityde

2、terminetheacteristictypeofpefluid.Theresultoftheechosignalpeakdecaycurvedirectlyaffectstheaccuracyoftheinversionsotheeffectivedetectionoftheechosignalpeakisoneofthekeyissuesofnuclearmagicresonanceloggingmeasurement.Under

3、thepremiseofintroducingtheprincipleofnuclearmagicresonanceechosignaldetectionthispaperanalyzestheacteristicsofechosignalwhichwithvariableAMsignalbwidthdesignbytheacteristicoffluidsignaltonoiseratioislowdetectionofrealtim

4、erequirementsishigh.Onthisbasisthepaperdescribedtheprincipleofthogonaldetection.CombinationofMatlabsimulationthisthesisanalysistheperfmanceofaveragefilterindigitalphasesensitivedetectionalgithm.Theresultsshowthatthepasss

5、topbacteristicsoffilterispointhecaseofensuringsignalenergythatthesignalsamplingperiodislesssotheequivalentnoisebwidthislargertheabilityadaptstotheechocenteroffsetispo.Tosolvetheproblemsthethesisproposestodesignlowpassfil

6、terfmwaveletthogonaldetectionmeans.Byanalysistheprincipleofwaveletwavelettransfmhasavariabletimefrequencywindowtheoutputsignalfilteringwithoutdelaysoon.ThroughtheMatlabsimulationcomparedtotheaveragetypefilterthepassstopb

7、acteristicsoffilterisbettertheequivalentnoisebwidthissmallerinthecaseofensurethesamesignalenergytheequivalentnoisebwidthoflowpassfiltercanadjustbysettingthedecompositionleveltheabilityadaptstotheechocenteroffsetisbetter.

8、FinallytomeetsthehighrequirementofrealtimeechodetectionthispaperestimatedthecomputationofwaveletthogonaldetectionalgithmthepaperassumedthehardwarecomputingspeedrelyontheoperatingfrequencyofDSP2812ofTIcompany.Optimizedbyp