阵列声波测井仪 毕业论文

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1、摘要在声波测井中，常常会因为地层的衰减，使得声波测井仪无法接收声波的首波信号。为了增强接收的声波信号，通常采用两种方法：一是通过增大换能器尺寸来降低声波的频率从而减小地层衰减；二是增大换能器的发射功率来增大声波信号的功率，但是由于换能器所能承受的最大激发电压和温度的限制，致使发射声信号功率有限。所以，可以通过相控阵技术使阵列发射探头发出的声信号同相位叠加，改善指向性达到增强首波信号的目的。阵列声波测井仪有两种组成方式：一是单接收器和一维阵列声源的组合；二是单声源和一维阵列接收器的组合。换能器为薄圆管形压电换能器。本

2、文采用了声波测井中的传输网络理论与指向性权系数的概念，推导出了换能器的几何形状与尺寸对线阵声源的导向系数的关系。通过改变阵列接收器接收到的声波信号的时间偏移量和线阵声源的激发延迟时间，可以令接收的首波幅度（阵列声源）与叠加波的首波幅度（阵列接收器）达到最大。通过本文提出的方法可以令声波测井中接收到的声波测井信号的首波幅度大大增加。关键词：阵列声波测井、相控阵、指向性、换能器、激发延迟时间24AbstractInacousticlogging,oftenbecauseofthedeclineofformationma

3、kessonictoolcannotreceivethefirstwaveofsoundwavesignal.Inordertoenhancethereceivedacousticsignal,usuallyadoptstwomethods:oneisthroughincreasedtoreducethefrequencyoftheacoustictransducerdimensionreducingformationattenuation;Secondistoincreasethetransmissionpowe

4、rofthetransducertoincreasetheacousticsignalofpower,butbecauseofthetransducercanbearthelimitofmaximumexcitationvoltageandtemperature,thesoundemissionsignalpowerco.,LTD.Socanmakethroughphasedarraytechnologyemissionprobearrayacousticsignalswiththephasesuperpositi

5、on,achievetheenhancementpurposetothefirstwavesignaltoimprovethedirectivity.Arrayacousticloggingtooliscomposedoftwoways:oneisthecombinationofsinglereceiverandaone-dimensionalarraysource;Thesecondissimplesoundsourceandthecombinationofaone-dimensionalarrayreceive

6、r.Transducerisathincirculartubeintheshapeofapiezoelectrictransducer.Thispaperadoptsthetransmissionnetworktheoryanddirectivityofacousticloggingweightcoefficient,theconceptofthegeometricshapeandsizeofthetransducerisdeducedontherelationshipbetweenthelineararraydi

7、rectionGuidecoefficientofsoundsource.Bychangingthearrayreceivertoreceivethetimeoffsetandlineararrayacousticsignalsourceexcitationdelaytime,canreceivethefirstwaveofsoundsource(array)andsuperpositionofwaveamplitudeofthefirstwaveamplitude(arrayreceiver)maximum.By

8、theproposedapproachcanmakesoniclogginginthereceivedthefirstwaveofacousticloggingsignalamplitudeincreasegreatly.Keywords:arraysoniclogging、phasedarray、directivity、transduc、Stimulate