【作者】 孙志峰；

【导师】 唐晓明； 苏远大；

【作者基本信息】 中国石油大学(华东) ， 地质资源与地质工程， 2020， 博士

【摘要】 随钻四极子横波测井技术有效的解决了地层横波速度实时测量问题,广泛应用于海上及陆地石油勘探开发,大有取代电缆声波测井之势,然而该技术目前一直被国外油田服务公司垄断。本文针对关键传感器设计、封装及随钻四极子实验室刻度等一系列重大课题,从理论、实验和传感器制作方法等方面开展了深入、细致的研究,明确了随钻四极子低频测量横波优势频率,解决了四极子发射及多极接收传感器最优化设计及制作方法,特别地提出了一种实验室对随钻四极子声波测井仪简易刻度方法和技术,在此基础上成功研制了随钻四极子声波测井仪器样机,并进行了三种实验环境验证。最后提出了一种随钻四极子横波频散校正数据处理新方法。全文主要共分以下四部分:第一部分研究了随钻四极子横波测井理论,讨论了采用低频四极子声源激励可消除钻铤模式波干扰。在这一理论基础上,首先考察了有无金属基片结构的圆弧状压电晶体一阶弯曲模式的振动效率,提出了含金属基片结构的随钻四极子发射换能器可有效提高四极子低频振动响应。考察分析了瓦片状压电晶体及金属基片的物理属性对其声学性能的影响,优化设计了一种谐振频率为4kHz左右的随钻四极子复合发射换能器。接下来,研究了适用于井下高温高压环境的环氧树脂封装材料,设计了一种真空封装随钻四极子发射换能器的装置和方法,并进行四极子发射换能器的封装。在此基础上,针对封装后的四极子发射换能器进行高温实验、压力实验及声学实验等。验证了该随钻四极子复合发射换能器满足低频大功率的辐射要求,且具有典型的四极子声场辐射特征。第二部分设计了一种三叠片型的随钻多极子接收换能器,并对随钻多极子声波接收声系进行了最优化设计。首先对三叠片型的随钻多极子接收换能器进行了有限元分析,重点考察了边界条件对其接收灵敏度的影响,确定了两端钳定边界条件适用于随钻高强度振动环境且具有良好的接收灵敏度响应。在此基础上,设计了一种长条方形薄壁铝壳的接收换能器封装结构,实验验证了薄壁结构有助于提高接收信号质量,采用3D打印技术进行了超薄壁铝壳加工,消声水池实验表明该接收声系灵敏度响应与理论计算结果有很好的一致性。进一步设计了一种近探头采集电路系统,可以提高多极子信号质量,空气中的方位四极子实验表明了该近探头采集系统的优势,另外方位四极子实钻实验结果也验证了近探头电路系统可以采集高质量地层波信号。第三部分主要研究了随钻四极子测井仪在实验室水槽非对称复杂介质中的波场。首先采用三维有限差分方法模拟了随钻四极子声波测井仪在封闭充液圆管模型中的四极子波场,通过与解析频散曲线对比,提出了利用0阶模式管波,有望实现随钻四极子测量模式实验室刻度方法。接下来对开口水槽这种非对称复杂模型进行了进一步数值研究,认为开口水槽中四极子声源同样能激发0阶模式管波,且其相速度不随开口角度变化,但影响其幅度。进一步理论研究了随钻四极子在水槽中的四方位模拟结果,认为相位合成信号更有助于提高测量信号质量。最后研究了水槽的物理属性对0阶模式管波的影响规律,最优化设计了一种适用于外径为6.75In随钻四极子仪器的实验室刻度装置,实验室测量结果与理论模拟结果有很好的一致性,从而验证了利用随钻四极子0阶模式管波进行实验室刻度的思想。第四部分提出一种随钻四极子横波频散校正数据处理新方法。该方法通过等效仪器理论获取泄露纵波及四极子横波的理论频散曲线,构造两种模式波的联合反演目标函数同时获得地层纵横波慢度。采用实测数据对该方法进行了数据处理验证,结果表明该方法可快速、准确提取地层横波慢度。更多还原

【Abstract】 The logging while drilling quadrupole wave technology effectively solves the problem of real time shear wave velocity measurement in the formation.It is widely used in offshore and land oil exploration and development,and has potential to replace wireline acoustic logging.However,LWD quadrupole wave technology is monopolized by foreign oilfield service companies.As the design and production of key sensors,laboratory calibration of LWD quadrupole wave issues,this study focuses on the key technology of theory,experiment and sensor production methods.The measurement advantages of LWD quadrupole wave of low frequency are clarified,and the optimization design and manufacturing method of transmitting and multipole receiving sensors are solved.In particular,a simple calibration method and technology for LWD quadrupole wave logging tool in the laboratory is proposed.Finally,we design the LWD quadrupole acoustic logging tool,and develop new method for dispersion correction methods for quadrupole data.The major work of this paper consists of four parts as follows.In the first part,we study the LWD quadrupole wave theory,and discuss that quadrupole source of low frequency can eliminate the interference of drill collar mode waves.Based on this theory,vibration efficiency of the low-frequency bending mode of arcuate shaped piezoelectric vibrator with or without metal substrate structure is investigated,and it is proposed that the LWD quadrupole transmitter transducer with metal substrate structure can effectively improve low frequency vibration response.The effects of the physical properties of arcuate shaped piezoelectric vibrator and metal substrate on its acoustic response were investigated and analyzed,and a LWD quadrupole composite transmitter transducer with resonance frequency of about 4 kHz is optimized.In the following,a kind of encapsulation material with epoxy resin which is suitable for downhole high temperature and pressure is studied,and a device and method of vacuum encapsulation for quadrupole transmitter transducer is developed.High temperature experiments,pressure experiments and acoustic experiments is carried out for the LWD quadrupole composite transmitter transducer.It is verified that this transducer meets the low frequency and high power radiation requirements,and has typical quadrupole acoustic field radiation characteristics.In the second part,three laminated plate receiver transducer is designed,and the multipole receiver sonde is also optimized.Firstly,three laminated plate receiver transducer is analyzed by applying finite element method,and influence of boundary conditions on receiving sensitivity is investigated.The simulation results show that clamped boundary condition at both sides is suitable for LWD environment and it has good receiving sensitivity.And then we design receiving transducer packaging structure which is rectangular thin-walled aluminum shell.The experiments shows that the thin-walled structure helped to improve the quality of the received signal.Receiver sensitivity is also measured in the anechoic tank,which is consistent with theoretical simulation result.Further we design near probe acquisition circuit system,which can improve quality of the multipole signals.The azimuth quadrupole signals in the air show the advantages of the near probe acquisition system.In addition,azimuth quadrupole results which is also measured in real drilling conditions show the near probe can collect high quality formation wave signals.In the third part,we mainly study the wave field of LWD quadrupole logging tool where is put in laboratory tank.Firstly,3D finite difference method is used to simulate the quadrupole wave field in closed liquid-filled pipe.By comparing with the theoretical dispersion curve,it is proposed to use 0-order mode pipe wave to realize calibration of LWD quadrupole logging tool in the laboratory.Next,numerical simulation is further carried out in asymmetric model of arcshaped trough.It is believed that LWD quadrupole can also excite the 0-order mode pipe wave in open trough,and its velocity does not change with opening angle,but affects its amplitude.Further,we study azimuth quadrupole wave field in the arc-shaped trough,and it shows that composite signal is more helpful to improve quality of the measurement signal.Finally,influence of physical properties of arc-shaped trough on the 0-order mode pipe wave is studied,and we optimize calibration device which is suitable for LWD quadrupole logging tool of 6.75in outside diameter in laboratory.So it verifies that calibration method of LWD quadrupole logging tool is feasible by using 0-order mode pipe wave int the laboratory.In the fourth part,we develop a kind of dispersion correction method for quadrupole data.This method is obtaining theoretical dispersion curves of leaked longitudinal wave and quadrupole wave through equivalent instrument theory,and then constructs joint inversion objective function of the two modes of waves to simultaneously inverse slowness of compressional wave and shear wave.It can quickly and accurately extract real shear wave slowness.更多还原