可控震源在地震勘探激发条件复杂地区的应用

第43卷第5期煤田地质与勘探Vol.42No.52015年10月COALGEOLOGY&EXPLORATIONOct.2014收稿日期:2014-05-15作者简介:(1969—)[e-mail]引用格式:昇.[J].201543(5)108–112.文章编号:1001-1986(2015)05-0108-05可控震源在地震勘探激发条件复杂地区的应用张玉军1，田雪丰2昇，冷广2(1.甘肃煤田地质局综合普查队，甘肃天水741002；2.中国煤炭地质总局地球物理勘探研究院，河北涿州072750):甘肃张掖平山湖矿区浅表层地震勘探地质条件复杂。利用可控震源激发，从能量、信噪比、频率等方面对试验资料进行定量分析，确定适合该区可控震源施工参数：震动台次、扫描长度、扫描频率、震源出力；针对可控震源地震资料特征，着重研究弱化初至前干扰、采取提高初至波信噪比等方法，使得单炮初至更加容易识别；同时，采用反褶积增宽频带，从而提高地震剖面分辨率，取得了较好的地质效果。：地震地质条件；可控震源；施工参数；反褶积；地质效果：P631.4：ADOI:10.3969/j.issn.1001-1986.2015.04.025ApplicationofvibratorintheregionwithcomplexseismicexcitationconditionsZHANGYujun1,TIANXuefeng2,LENGGuangsheng2(1.ComprehensiveSurveyTeamofGansuBureauofCoalGeology,Tianshui741002,China;2.InstituteofGeophysicalProspectingofChinaAdministrationofCoalGeology,Zhuozhou072750,China)Abstract:TheseismicgeologicalconditionsofshallowstrataandsurfacearecomplexinPingshanhuminingarea,Zhangye,Gansu,thevibratorwasusedtocarryoutexcitation,quantitativeanalysiswasconductedfortestdatafromenergy,SNRandfrequencytodeterminetheoperationparameters(vibrationtimes,andscanlength,scanfrequency,sourceoutput)suitabletothearea,aimingatthecharacteristicsofseismicdataofthevibrator,focusingonweakeninginterferencebeforefirstarrivals,improvementofsignal-to-noiseratiowasmade,makingiteasiertoidentifyfirstarrivalsofthesingleshot.Atthesametimedeconvolutionwasadoptedtowidenthefrequencybandandenhancetheresolutionofseismicprofiles,achievinggoodgeologicaleffect.Keywords:seismicgeologicalconditions;vibrator;operationparameters;deconvolution;geologicresult1可控震源信号分析1.1–S(t)A(t)sin2π[F1±(F2–F1)t/2TD]t(0≤t≤TD)A(t)[1+cosπ(t/T1+1)]/2(0≤tT1)(1)1(T1≤tTD–T1){1+cosπ[1+(TD–t)/T1]}/2(TD–T1≤t≤TD)A(t)S(t)T1F1F2TD(1)第5期张玉军等:可控震源在地震勘探激发条件复杂地区的应用·109·1.2a.脉冲压缩b.滤波作用a(t)b(t)Φab(τ)=∑a(t)b(t+τ)ττττ()1a(t)b(t+τ)12s4s1Fig.1Schematicrelatedprocesse2试验工作(40m)(Q)50m4~6m(37)(T3T7)TE2.1(1)17表1试验参数统计表Table1Testparameters/1×32×3/×3×375%12s8~72Hz5m33×23×33×43×5/×3×6375%12s8~96Hz57075/%803×312s8~96Hz31012/s143×375%8~96Hz38~728~84/Hz8~9612s32.22.2.1震动台数试验5m123375%12s8~72Hz2·110·煤田地质与勘探第43卷(KLSeis)(a)2(b)3(c)42Fig.2Recordofsingleshotofdifferentvibrationtest3a3b231233c(20~50Hz)1~33d231233(a)(b)(c)(d)Fig.3Analysisoftimewindow(a)energy(b)SNR(c)frequency(d)ofdifferentnumberofvibrators2.2.2震动次数试验3234562.2.3震源出力试验3370%75%80%70%75%80%75%2.2.4扫描长度试验3375%10s12s14s12s10s14s12s2.2.5扫描频率试验3375%12s8~72Hz8~84Hz8~96Hz8~84Hz2375%12s第5期张玉军等:可控震源在地震勘探激发条件复杂地区的应用·111·8~96Hz2.314410m20m8~96Hz12s262445.7km2.3.1初至拾取方法“–”2.3.2反褶积方法选择452.3.3去噪方法()64(a)+(b)Fig.4Waveletofpredicteddeconvolution(a)predicteddeconvolutionpluszerophasetandemdeconvolution(b)5(a)(b)+(c)Fig.5Relevantresultswithoutdeconvolution(a)afterpredicteddeconvolution(b)andpredicteddeconvolutionpluszerophasedeconvolution(c)3应用实例“–”·112·煤田地质与勘探第43卷6(a)(b)Fig.6Comparisonofstackprofilesfromdynamitesource(a)andthevibrator(b)MERTZ2×610~96Hz12s428-DSU428XL1ms2s30dBSEG-D10m20m36144T3T63636(2)表2603号钻孔验证情况统计表Table2Statisticsofverificationbyborehole603/m/m/%3549.34562.002.36613.77609.500.74结论a.b.c.参考文献[1]LIXPHUBRALPEliminationofharmonicdistortioninvi-broseisdata[J]ExpandedAbstractsof64AnnualInternatSEGMtg1994886–889.[2]LIXPSOLLNERWPETERHEliminationofharmonicdistortioninvibroseisdata[J].Geophysics199560(2)503–516.[3]BRUCESROGERWMultiplevibratorseismicacquisi-tion[J]ExpandedAbstractsof54AnnualInternatSEGMtg1984822–824.[4]WERNERJApplicationofvibroseissimultaneousmultiplesourcerecording[J]ExpandedAbstractsof63AnnualInternatSEGMtg1993569–57l.[5]SAFARMHOnthesynchronizationandpolarityproblemsofthevibroseissystem[J]ExpandedAbstractsof55AnnualInternatSEGMtg1985516–517.[6].()[M].2009.[7].[J].200323(4)223–230.[8].[J].200616(4)33–41.[9].[J].200847(5)425–438.[10].[M].2006.[11][J]199429(3)306–315.[12].—2005[J].200742(2)127–130.[13].[J].201045(6)793–796.(责任编辑宋震炎)