物探与化探Issue(4)：596-602,632,8.DOI:10.11720/j.issn.1000-8918.2013.4.06
川西坳陷地震波衰减定量估算及分析
QUANTITATIVECALCULATIONANDANALYSISOFSEISMICWAVEATTENUATION INWESTERNSICHUANBASINDEPRESSION
涂远艮 1王达远 1李华科1
作者信息
- 1. 中国石化西南油气分公司 勘探开发研究院，四川 成都 610000
- 折叠
摘要
Abstract
InwesternSichuanbasindepression,themarinefaciestargetlayersareburiedingreatdepth,resultinginnarrowfrequency bandofreflectedseismicdata.Henceseiemicresolutioncannotmeettheneedofprospectinggoals,andlowseismicresolutionisre-sponsibleforstratigraphicabsorptionattenuation.Inordertounderstandcompletelythereasonfortheattenuationofseismicwaves,the authorsbuiltamodelforwesternSichuanbasindepressionstrata,thencalculatedquantitativelysphericaldivergence,absorptionand transmissionattenuationofseismicwavebasedonthemodel,andcombinedthecalculatedattenuationvalueswithseismicdata,VSP andWalkway-VSPdatatoanalyzethefactorsaffectinghighfrequencyreflectedsignalacquisitionrecordingofdeeplayers.Itturnsout thattheseriousabsorptionattenuationofshallowstrataabove1500metersisthefundamentalcauseresponsibleforhighfrequencycom-ponentlossesofdeeplayersinwesternSichuanbasindepressionand,asforthemarinefaciestargetlayersburieddeeperthan5000me-ters,fieldacquisitiondatacanonlyreachabout40Hzfrequencyband.Therefore,thefieldacquisitionmethodsaimingatdeeptarget layersshouldfocusonreducingbackgroundnoisesandincreasingacquisitiondensitytoenhanceweakreflectionsignalsofdeeplayers soastoimprovetheseismicprospectingprecision,ratherthansolelyfocusonimprovingtheseismicresolution.关键词
地震波/吸收衰减/品质因子/球面扩散/VSPKey words
seismicwave/absorptionattenuation/qualityfactor/sphericaldivergence/VSP分类
天文与地球科学引用本文复制引用
涂远艮,王达远,李华科..川西坳陷地震波衰减定量估算及分析[J].物探与化探,2013,(4):596-602,632,8.
