地震波形分类技术在红浅一井区的应用

地震波形分类技术在红浅一井区的应用李　强　戴鸿鸣(西南石油大学,四川成都610500) 摘　要　20世纪90年代以来,地震油气储层预测新技术取得了巨大发展,Strati m agic地震波形分类技术就是其中之一。

该技术是研究各沉积相单元发生变化时的地震反射特征,然后利用神经网络技术把地震信号的总体趋势变化定量地反映出来(对波形进行分类),形成地震波形异常,即地震相图。

在综合地质分析基础上,针对目前红浅一井区勘探实际情况,应用这一技术对该地区主要目的层段辫状河道砂体进行了准确预测,并取得了良好效果。

关键词　地震波形分类　Strati m agic　红浅一区　辫状河道 随着油气勘探开发的不断深入,寻找有利储层是油气勘探的重要内容。

目前主要采用波阻抗反演等储层预测技术,但对于储层薄、横向变化快等情况,仅利用波阻抗反演可能会由于地震资料分辨率不高,使得预测精度大大降低。

Strati m agic 波形地震相技术可以很好地解决这个问题,它的核心是利用神经网络技术对层段内的地震道反射波形进行分类,并与测井曲线进行对比,得出相应的地震相图,从而进行更详细的储层解释[13]。

文章以克拉玛依红浅一井区齐古组稠油油藏为例,采用Strati m agic波形地震相分析技术,确定砂体分布范围,为有利目标钻探提供地质依据。

31　工区概况红浅一区齐古组油藏位于准噶尔盆地西北缘红山嘴油田东段。

构造运动表现为逆掩断裂,断裂活动始于海西运动,后受印支运动的影响,沿低角度断裂雏形向盆地掩冲推覆。

油藏边界由3条大断裂控制,总体构造格局为向南东缓倾的单斜断层遮挡油气藏。

根据沉积旋回和砂层组合特征,采用分级对比将该区齐古组分为J3q1、J3q2、J3q3三个砂层组,油层主要分布在J3q3层中。

该区1991年投入开发,截至2003年12月,投产齐古组开发井787口,动用含油面积813k m2,动用地质储量1602×104t,全区齐古组油藏累积注汽011578×108m3,累积产油量20918×104t,含水率81%,累积油汽比0117,采出程度1311%。

目前,在地震勘探开发中的技术难点为砂体薄,地震资料分辨率低,不易识别。

由于储层常常泥砂互层接触,岩性横向变化快,常规地震剖面显示不出来,且很难连续追踪解释,测井约束反演等手段效果不理想,河道砂体的描述精度比较低,不能单一使用强反射特征预测砂体。

针对勘探的技术难点,应用Strati m agic波形地震相分析方法,用叠前反褶积和偏移后分频处理等手段,对三维地震资料进行连片处理以提高分辨率。

同时,进行层位及储层精细标定,对已知井旁道目的层段反射波统计归类,建立不同反射波与储层沉积微相、渗透砂岩发育程度及含油性的对应关系,确定储层发育分布范围。

2　波形分类法应用211　原理Strati m agic波形地震相技术的基本原理是用于形状识别的人工神经网络算法,模拟人脑思维来识别不同目标的特征,并使相似的种类保持关系。

神经网络算法分前馈神经网络、自组织神经网络、反馈神经网络、自适应共振网络、随机神经断块油气田2007年1月 F AULT2BLOCK O I L&G AS F I ELD 第14卷第1期3收稿日期:2006-09-20。

作者简介:李强,男,1980年生,矿产普查与勘探专业在读硕士研究生,主要从事油气地质和油气藏精细描述等研究工作。

电话:(028)83030560。

基金项目:本文受到四川省重点学科建设基金项目(编号:SZ D0414)资助。

网络与视觉神经网络等。

根据其学习过程是否需要先验知识,神经网络可以分为有监督和无监督两大类。

定量地震道波形分类方法利用无监督神经网络算法,将井点处地震信息变化程度通过地震相与地震信息的总体变化度相联系,以波形相似性为基础在等时窗内分析地震波波形的变化特征。

地震相研究首先利用神经网络技术对某一层内实际地震数据道的对比、训练、模拟人脑思维方式识别不同目标的特征,得到代表地震层段中地震信号形状多样性的模型道,各典型地震道按顺序渐变(指波形)排列,然后每一个道指定一个值或一种颜色,形成一组模型道。

在目的层段内估算地震信号的可变性,利用神经网络算法对地震道形状进行分类,根据分类结果形成离散的地震相。

依据拟合度准则,将实际地震道与地震相对比、分类,使相似的地震道具有相同或相近的值或颜色,形成了地震相分布图,从而认识地震信号横向变化,得出地震异常体平面分布特征。

并根据储层的发育与围岩形成波阻抗界面,从而引起地震反射振幅相对增强的原理[24]。

212　特征根据区内波形统计,将红浅一井区齐古组主力层段J 3q 3地震反射波所对应的波形分为3类,依次对储层砂体的波形标定和分类(见图1)。

图1　齐古组地震波形分类 Ⅰ类区域:主要分布在东南部,面积大,对应的地震波形为低频、较连续、弱振幅的平行反射,岩性剖面上为泥岩与中细砂岩构成反旋回沉积,砂体较发育,单层厚度较小,一般在3m 左右,渗透率为(200260)×10-3μm 2,反映了分流河道沉积波形特征。

Ⅱ类区域:主要分布在红3区、红1区大部及红2区和红4区结合部,近南北向透镜带状展布,面积大,对应的地震波形为中频、断续、强振幅反射,砂体发育比较集中,单层厚度大,一般为1420m ,渗透率为(230400)×10-3μm 2,主要反映心滩砂坝沉积波形特征。

Ⅲ类区域:主要分布在东南部红1区和红4区连接附近,呈大面积连续分布,对应的地震波形为中频、时断时续、振幅强弱变化的平行反射,砂体单层厚度约2m ,反映了河漫滩地震波形特征。

区内研究表明,河道在地震剖面上的波形特征明显,河道砂体顶部形成连续性较好的强振幅,以辫状河流沉积为主。

平面上南北相带差异明显,发育不同类型的砂体,其中第Ⅱ类波形反映储层砂体发育,物性好,含油的可能性较大。

第Ⅰ类波形对应的储层较发育,含油的可能性次之,第Ⅲ类储层物性条件不好,砂体不发育,含油性最低。

213　应用效果根据波形分类预测结果,对工区进行综合地质研究,在Ⅱ类储层附近钻H4007、检407、Dh4428加密井均发现了油气显示,其中H4007井油层厚度18m ,产油量218t/d,Dh4428井油层厚度9m ,产油量319t/d,生产效果良好。

3　结论(1)辫状河道在地震剖面上的波形特征明显,外型为透镜状,顶平底凹;河道砂体顶部形成连续性好的强振幅反射,表现为亮点特征。

因此,利用Strati m agic 对地震道形状进行分类形成地震相图,进行相带和河道砂体预测研究是可行的。

(2)本区以辫状河流相沉积为主,Strati m agic 波形地震相研究准确圈定了河道范围,心滩河道砂体厚度大,是新井钻探的首选目标。

参考文献1　刘雯林1油气田开发地震技术[M ]1北京:石油工业出版社,1996182～922　王西文,刘全新,吕焕通等1储集层预测技术在岩性油气藏勘探开发中的应用[J ]1石油勘探与开发,2006,33(2):189～1913　陈宝书,杨午阳,刘全新等1地震属性组合分析方法及其应用[J ]1石油物探,2006,45(2):173～1764　于红岚,王英民,李雪1Strati m agic 波形地震相分析在层序地层岩性分析中的应用[J ]1煤田地质与勘探,2006,34(1):64～66(编辑　姬美兰)第14卷第1期 李　强等1地震波形分类技术在红浅一井区的应用 2007年1月FAU L T2B LOCK O I L&GAS F I E LDVol.14　No.1　Jan.2007ABSTRACTA Quan tit a ti ve Study M ethod of Verti ca l Sea li n g Evoluti on of Fault and Its Appli ca ti onFu Guang(Daq i n g Petroleu m I n stitute,Daq i n g 163318,Ch i n a),W ang Y ougong.P.124Based on the study of vertical sealing mechanis m of fault and its evaluati on method,a method studying quantitatively the evoluti on of vertical seal of fault is put f or ward by the angle bet w een the oritentati on of maxi m u m p rinci pal comp ressive stress in different geol ogical peri ods and the strike directi on of fault is set up.The result indicates that five faults have different vertical sealing in the sa me geol ogical peri od and evoluti on la ws of their vertical sealing are different in different geol ogical peri od.These differences causes the difference of them in oil2gas accu mulati on and distributi on. The matching relati onshi p bet w een the evoluti on of vertical sealing of F76fault and the hydr ocarbon expulsi on hist ory is good,which is favorable for oil2gas t o accu mulate and p reservati on.There are the most industrial oil2gas wells t o distribute al ong F76fault.The second is F39and F21fault and there are a fe w industrial oil2gas wells t o distribute al ong F39and F21fault.The worst are F80and F16faults,there are no industrial oil2gas wells t o distribute al ong the m.Field app licati on indicates that the method is p ractical t o study quantitatively the evoluti on of vertical sealing of fault.Key W ords:Strike directi on of fault,Vertical sealing, Evoluti on,Quantitative study,Maxi m u m maj or p ressure stress.I nfluence and Eva lua ti on of O verpressure on O il and Ga s Reservo i r Form i n gYang Y i m i n g(Daq i n g Petroleu m I n stitute,Daq i n g 163318,Ch i n a).P.527The over p ressure is widely distributed in the oil2bearing basin of the world,and it has great influence on the oil and gas exp l orati on.Thr ough the study of s ome over p ressured basins in china,it is considered that over p ressure has different effect on the evoluti on of organic matter in different area.The weak mechanical compacti on caused by the l ow effective stress in over p ressured conditi ons leads t o the p reservati on of relatively high por osity and per meability f or the deep ly2buried sandst one.The over p ressure p r ovides motive and bigger access for the oil and gas m igrati on. Over p ressure has als o i m p r oved the sealing ability of cap r ock. The influence of over p ressure on the oil and gas accu mulati on can be evaluated by the neural net w ork.Key W ords:Over p ressure,Accu mulati on,O il and gas,Neural net w ork.Per m eab ility S i m ul a ti on of Coa l Reservo i r:Tak i n g Ta i yuan For ma ti on Coa l2Bed i n Q i n shu i Ba si n a s an Exam pleSun L i dong(College of Geo2Resources and I nfor ma ti on,Ch i n a Un i versity of Petroleu m,D ongy i n g 257061,Ch i n a),Zhao Y ongjun,Ca iD ong m e i.P.829 Per meability para meter is very i m portant in evaluating the per meability of coal reservoir.This paper researches on the nu merical si m ulati on of coal2bed cleat,effective stress, dep th that affects the per meability of coal reservoir.The results show that devel oment of clrat deter m ines the per meability of coal reservoir,while the opening and cl osing of cleat relies on the stress field.Key W ords:Coal reservoir,Per meability,Si m ulati on.Study on Reserves D istr i buti on by Usi n g the Favorable Sed i m en t ary Fac i es Tract of Conglo m era te Reservo i rSong Z i q i(X i′an Sh i you Un i versity,X i′an710065, Ch i n a),Huo W e i,Y i Junfeng et a l.P.10213Based on the characteristics that congl omerate reservoir′s inhomogeneity and pore structure with composite model in Kara may oil field,the depositi onal feature of the f oothill2 p luvian facies of the l ower Kara may f or mati on in m iddle and east area of the D istrict NO.7is clarified.The pattern, scale,distributi on,p lanar devel opment of main tr ough m icr ofacies of fanhead and its sand and gravel in l ower Kara may for mati on,as well as oil2gas distributi on,are described.I n additi on,the para meters that unit of reserve esti m ate,oil2bearing area,effective thickness,por osity, saturati on and s o on are studied,and the oil2gas reserves of each single sand2gravel f or mati on in well bl ocks are esti m ated.The relati onshi p of favorable main tr ough m icr ofacies and distributi on of oil reserves is analyzed and distributi on of oil reserves is clarified under the contr ol of favorable main tr ough m icr ofacies,which p r ovides a reliable basis f or adding reservoir p r oducti on and adjust m ent and tapp ing potential.Key W ords:I nhomogeneous congl omerate reservoir, M ain tr ough m icr ofacies of fanhead,Favorable facies,O il2 bearing area,Effective thickness,Saturati on,D istributi on of oil reserves.Appli ca ti on of Se is m i c W avefor m C l a ssi f i ca ti on Technology i n HQ AreaL i Qi a ng(Southwest Petroleu m Un i versity,Chengdu 610500,Chi n a),Da i Hong m i n g.P114215Vol.14　No.1 ABSTRACT Jan.　2007Seis m ic reservoir p redicti on technol ogy has been greatly devel oped since90s.One of the m is Strati m agic seis m ic wavefor m classificati on technol ogy.This paper studies the characteristics of seis m ic reflecti on as sedi m entary facies change,and then quantifies general varying trends of seis m ic signal by neural2net w ork technol ogy,na mely seis m ic wavefor m classificati on and abnor mal seis m ic wavef or m or seis m ic facies map.Thr ough comp rehensive geol ogical analysis,the article describes the app licati on of above2 menti oned technol ogy and accurately p redicts braided channel sand of target stratigraphy in Hongqian area based on facts of exp l orati on in Hongqian dilling area.A good result has been achieved.Key W ords:Seis m ic wavef or m classificati on, Strati m agic,B raided channel,App licati on.Se is m i c Fac i es Study of Guan t ao Group i n Q i n gtuoz i HeaveW ang W e i(College of Geo2Resources and I nfor ma ti on,Ch i n a Un i versity of Petroleu m,D ongy i n g 257061,Ch i n a),Zhang Sh i q i,J iY ouli a ng.P.16218 Seis m ic facies is seis m ic cells which has certain distributi on range,and it is the su mmati on of main seis m ic characteristics of sedi m entary facies in reflecti on secti on. Guantao gr oup of Q ingtuozi heave is the potential p r os pecting area in Dongxin oilfield,but the strata distributi on and sedi m entary facies have not been researched s o far.There is fe w drilling well here,even coring and l ogging inf or mati on is much less.A s a result,sedi m ent research of this area should be based on the existing3D seis m ic data.This paper su mmarizes sedi m ent mode of Guantao gr oup of Q ingtuozi heave thr ough seis m ic facies research,which p r ovides guidance f or further p r os pecting.A ls o the work we did can be the use for reference of seis m ic facies research in other regi ons.Key W ords:Seis m ic facies,Fluvial facies,Dongxin, Guantao gr oup.C l a ssi f i ca ti on of Subl acustr i n e FanD epositi on Syste m i n L i a ngji a lou O ilf i eldL i n Chengyan(Ch i n a Un i versity of Petroleu m, D ongy i n g257061,Ch i n a),Gao Guoq i a ng.P.19220,49The continetal trubidite deposit of its side of ra mp is more different than the marine turbidite deposit in ter m s of contr ol fact ors of sedi m entary evoluti on.The turbidite syste m and turbidite stage of the marine deposit are mainly contr olled by relative change of sea level.W hile those of the continental fault lacustrine basin are contr olled by the tect onic subsidence and change of debris flux res pectively,etc.This paper discusses sublacustrine fan in the m iddle and l ower parts of the third stage of Shahejie For mati on in the m iddle part of L iangjial ou oilfield combining with contr ol fact ors of the tect onic subsidence sedi m entary syste m.The sedi m entary cells in work area are classified.Key W ords:L iangjial ou oilfield,Tect onic subsidence, Sublacustrine fa m,Equiti m e contrast.Rev i ews on Fault Sea li n g and Flu i d FlowZhang Yunqi u(Guangzhou I nstitute of Geoche m istry, CAS,Guangzhou510640,Chi n a),Sun Yu.P121223The r ole of fault p laying in hydr ocarbon m igrati on,fault sealed trap and compart m entalizati on bet w een reservoirs are becom ing the hot research p r ojects in oil and gas exp l orati on and p r oducti on in the world.It is als o i m portant for high p r oporti on of faulted2bl ock reservoir evaluati on in east China t o highlight the study of relati onshi p bet w een fault sealing and fluid fl ow.For the pur pose,this paper su mmarizes the advances and future work on faulting,fault sealing and fluid fl ow in hydr ocarbon reservoirs fr om four as pects as foll owing: fault sealing features,mapp ing of fault zone and evoluti on, app licati on of fluid inclusi on stratigraphy t o understanding of hist ory of f ossil fluids in fault zone and fault sealing evaluati on,and analysis of reservoir structure and cap2r ock.Key W ords:Fault sealing,Fluid fl ow,Fault da mage zone.A Pred i cti on M ethod of Pore Pressure i n M ud Sha le For ma ti onZuo Xi n g(Southwest Petroleu m Un i versity,Chengdu 610500,Chi n a),He Shi m i n g,Huang Zhen et a l.P124226 The inaccurate p redicati on of the pore p ressure often da mages the borehole during the exp l orati on and the exp l oitati on.It not only obstacles the p r ocess of engineering p r oject,but als o engenders big econom ic da mages.So,the accurate p redicti on of pore p ressure not only p lays an i m portant r ole in deter m ining the mud density and the design of well bore structure in drilling,but als o is a key fact or for drilling successfully.This article e mphatically elaborates about a series of methods t o forecast pore p ressure,including the f orecast f or for mati on p ressure during the p r ocess of drilling,and it illustrates how t o accurately f orecast pore p ressure.Finally,this article p resents s ome suggesti ons pointing t o the li m itati ons of method of p redicti on.Key W ords:Exp l orati on and exp l oitati on,Predicti on, Pore p ressure,M ud density.Hydrocarbon Accu m ul a ti on Syste m and Its Resource Poten ti a l i n B i yang D epressi on of Nanx i a ng Ba si n Y u Gong m i n g(1.Ch i n a Un i versity of Geosc i ences, Be iji n g100083;2.Research I n stitute of Explora ti on and D evelop m en t,Henan O ilf i eld Co m pany,S I NO PEC, Nanyang473132,Ch i n a),W ang D efa,Zhang Shaohua et a l.P127229Source r ocks are devel oped in Hetaoyuan For mati on of B iyang dep ressi on,where organic matter abundance is high, the potential of hydr ocarbon genesis is high,most of the maj or s ource r ocks are mature and rich hydr ocarbon res ources are f or med.Both in the s outh and north,the fan delta syste m s extends mostly int o the oil s ource area,many sets of cr oss over and super posed asse mblages of s ource,reservoir and cap r ocks are for med vertically.The hydr ocarbon transferring syste m are mainly composed of sandbodies and fault syste m, the differences bet w een the pore structural distributi on within the sandbodies result in an advantageous hydr ocarbon m igrating path.So far,the exp l orati on and exp l oitati on of the oil and gas mainly concentrate on the above H3in B iyang Dep ressi on.A s it has been seri ously exp l ored and devel oped, t o find rich oil and gas trap s becomes more and more difficult.I n order t o increase the oil reserves and stabilize the yields,the exp l orati on visi on should be expanded and theJan.　2007 F AULT2BLOCK O I L&G AS F I ELD Vol.14　No.1。