论文中英文摘要
作者姓名：崔士波
论文题目：钻头破岩振动及其沿钻柱的传播
作者简介：崔士波,男，1983年9月出生，2006年09月师从于中国地震局地球物理研究所葛洪魁研究员，于2009年8月获硕士学位。
中
文
摘
要
安全、高效施工是石油钻井追求的目标，工程技术人员迫切需要井下工矿诊断和钻前预测的实用技术。在现有方法中最有发展前景的是随钻地震（SWD-Seismic While Drilling）和钻柱振动录井。SWD以钻头为震源，在井场周围布置地震观测仪器收集井下钻头破岩产生的地震波，进行钻头前方地层探测，实现钻前预测。钻柱振动录井利用钻柱顶部测量的振动信号，分析钻进过程中的钻柱振动特征，获得井下钻头、所钻地层和钻柱的信息，进行井下工矿实时监测。
钻柱是连接井底钻头与地面的信息通道，SWD利用钻柱顶端振动记录估计钻头震源函数，与地面记录道互相关建立地震剖面，获得钻头前方地层反射界面和地层波速。钻柱振动录井利用钻柱顶端的振动记录提取钻头运动的频谱特征、钻柱运动与井壁的接触情况、钻头与井底岩石的反射系数，进行井下工矿诊断与实时监测。钻头破岩振动特征、钻柱传输特性和振动特征、钻柱振动信号分析方法成为发展SWD和钻柱振动录井技术的关键。
本文在国内外研究的基础上，开展了钻头破岩振动室内与矿场实验、钻柱受迫振动传播方程建立与钻头振动信号分析方法研究，初步掌握了钻头破岩振动特征及影响因素，钻柱振动类型、传播规律和影响因素，建立了传递矩阵和单边反褶积自相关两种钻柱振动信号分析方法，初步建立了钻柱振动分析方法的框架。
研究认为钻柱振动是一受迫振动问题，需要将井底岩石-钻头-钻柱-水龙头作为一个“钻柱振动系统”来对待；钻头振动频谱包含了钻头工矿的信息，与钻头几何结构、地层特性和钻进参数密切相关，并具有较宽的频带；钻柱具有轴向、旋转和横向振动三种类型，钻柱截面变化形成了钻柱多次波，钻柱结构、顶底边界条件对钻柱波的传播具有重要影响；建立了钻柱振动的传递矩阵计算模型，数值模拟与室内管柱传播模拟实验结果吻合较好；采用单边反褶积自相关，获得了钻柱反射界面的多次波图像和传播速度。 研究表明钻头振动的频谱、钻柱振动的频谱与钻柱反射界面成像、井底反射系数可作为钻头工矿、钻柱工矿与地层特性的主要诊断参数，钻柱多次波成像可获得钻柱波速度（时延），传递矩阵是钻柱振动分析的良好模型，可利用传递矩阵给出的钻柱理论脉冲响应（传递函数），反演井底反射系数，恢复钻头震源函数。
ABSTRACT
Drilling a well safely and efficiently is the aim of petroleum engineers, the drilling needs the downhole diagnosis and forecast techniques.The most promising existing methods are Seismic While Drilling (SWD) and Drill String Vibration Logging.SWD takes the working drill-bit as seismic source, acquires the drill bit seismic wave propagating through the formation by the geophone to predict formation property ahead of the drill-bit and reduce the drilling risk.The drill string vibration logging is a new technology to monitor the state of health of downhole tools, formation and drill string by analyzing the vibrations measured on the top of the drill string.It can be used to evaluate the formation drillability in real time.
a On the basis of former research, we did the lab and well site experiments of drill bit vibration during breaking rock, built the propagation equation of drill string forced vibration and gave the drill string vibration analysis method; obtained some basic understanding of drill bit vibration property, drill string vibration modes and propagation characteristics; built up the drill string vibration analysis frame with the propagation matrix method and one-side deconvolved autocorrelation method.
Our research demonstrate that the drill string vibration is forced vibration, it needs to consider the rock-drill bit-drill string-swivel as the “drill string vibration system”; the drill bit spectrum, with broad frequency band, is related to drill bit geometry ,formation property and drilling condition and gives the drill bit working condition information; drill string has axial, torsional and lateral vibration modes; changes of drill string cro-sections generates drill string multiples.There is a significant influence of drill string structure, top and bottom boundary condition to drill string wave propagation; We built up the drill string vibration propagation matrix, the numerical simulation match well with lab experiment results; obtained the drill string multiples image and wave velocity with one-side deconvolved autocorrelation method. Our research shows that the spectrums of drill bit and drill string vibration, drill string reflected interface imaging and downhole reflected coefficient can be used as the main diagnosis parameters of drill string and drill bit working condition and formation characteristics; drill string multiples imaging can be used to calculate the drill string wave velocity; propagation matrix method is a good method for drill string vibration analysis.We can get drill string theoretical impulse response and transfer function, the bottom reflection coefficient and the drill bit seismic source function on the basis of drill string vibration propagation matrix.
