【作者】 闫向宏；

【导师】 孙建孟；

【作者基本信息】 中国石油大学 ， 地质资源与地质工程， 2010， 博士

【摘要】 集地质导向钻井、随钻测井、高速数据传输技术等于一体的自动化、智能化钻井是现代钻井的最高水平。开展随钻测井声波沿钻柱系统传输特性研究,有助于为利用钻柱系统进行随钻数据声波传输技术开发和随钻声波测井仪器的研发等提供理论基础,对推动我国智能化钻井技术发展、提升随钻服务水平具有一定的实际应用价值。为了消除随钻测井中沿钻柱传播的高频钻铤模式波对地层纵波测量的影响,文中基于定常结构发生截面突变会引起结构的阻抗失配,从而起到隔离弹性波的声学原理,通过在钻铤上开槽的方式实现截面突变,达到抑制钻铤模式波传播的目的,结合数值模拟主要研究了周期性环状凹槽隔声结构的声学特性、力学特性与切割凹槽参数之间的关系以及隔声结构的存在对井孔斯通利波的影响规律。研究结果表明:周期性环状凹槽隔声系统的结构周期决定了阻带位置及宽度,隔声结构的延时量、隔声量都随着凹槽数量、凹槽深度的增加而增大;隔声结构上的最大应力随凹槽深度增加而增大,随过渡弧半径的增加而减小;隔声结构的存在会对井孔斯通利波产生影响,测井全波响应中斯通利波包前、后出现了干扰信号,斯通利波“幅度高、前窄后宽”的特征不再明显。相关研究结果对随钻声波测井仪器研发具有一定参考价值。为了防止钻井过程中因钻柱共振引起的钻柱疲劳破坏、断裂等现象的发生,文中基于一维纵向振动和扭转振动方程,利用等效网络法推导出了钻柱系统纵向振动和扭转振动的等效机械阻抗表达式,给出了利用等效机械阻抗方程确定纵向振动、扭转振动机械谐振频率的原理和方法。计算结果表明:等效网络法具有直观、简便、易用、结果可靠的优点,对钻井过程中设计减振器、选择合理的钻速具有重要参考价值。以沿钻柱系统传播的声波为载波进行随钻数据传输是一种有发展前途的高速数据传输技术。文中采用理论与有限元数值模拟相结合的方法,研究了低频声波在周期性理想钻柱系统、非周期型理想钻柱系统以及实际钻柱系统的传播特性。结果表明:周期性钻柱系统都具有通、阻带交替出现的梳状滤波器特性,而非周期型钻柱系统的阻带区域变宽,通带变窄,钻杆、接箍长度决定了通、阻带位置及宽度;当声波沿处于充液井孔中的钻柱系统传播时,会向井孔流体、井外地层中辐射声波,导致其沿钻柱的传播衰减增大。基于钻柱系统的声学特性,对随钻测量数据经编码后形成的二进制数据序列,分别采用振幅键控、频移键控及相位键控三种方式进行调制,在无噪声干扰的钻柱信道中进行了随钻测量数据的声波传输数值模拟。模拟结果表明:利用振幅键控、频移键控及相位键控三种调制方式分别将随钻测量数据调制到沿钻柱传播的声波上,经传播、接收、解调后的信号与原始信号符合良好。本文工作得到了山东省自然科学基金项目和中国石油天然气集团公司中青年创新基金项目的资助。更多还原

【Abstract】 The modern drilling is the high level of drilling which included geosteering drilling、logging while drilling and high-speed data transmission technique. Study on the transmission characteristics of acoustic along drillstrings can help to exploit the high speed data transmission techniques using drillstrings,research the acoustic logging instrument while drilling. All these have practical application values for upgrading the intelligent drilling technique in our conutry.In order to eliminate the collar wave’s effect on compresional wave of formation, the groove’s drill collar were used to reduce the collar wave based on the principle of wave isolating with breaking structure section, the relationship between groove parameters with acoustic characteristics and mechanical characteristics of isolator made up of periodic ring groove structure were calculated. The results show that groove’s structure periodic decided the position and width of stop bands. The time-delayed and the sound insulation increased with the number and depth of the grooves; maximum Von Mises stress increase with deepening the depth of the groove but decrease with increasing the radius of the transition arc. Isolator can influence the stonely wave, interfering signal appeares pre-and-after stonely wave, the high amplitude and the“pre narrow and after wide”characters no more clearly.Avoiding the drill string fatigue failure caused by the resonance, this paper use the equivalent network method to derive the drillstring’s equivalent mechanical impedance of longitudinal vibration and torsional vibration, and then the principles and methods for determining the mechanical resonance frequency of torsional and longitudinal vibration using the mechanical equivalent impedance have been given. The conclusions indicate that using the equivalent network method to calculate the resonant frequency of drill string system is an effective method, it is easy to use and its calculating results are reliable.It’s very useful for LWD data transmission using drillstrings as the channel for carrier propgation. The low frequency acoustic propagation characteristics in periodic drillstring、non periodic drillstring and real drillstring were calculated using finite elements method and theory computation method in this paper. The results show that periodic drillstrings have pass band and stop band just like the comb filter, but the nonperioic drillstrings pass band become narrow while stop band become wide. The position and width of pass band and stop band were determined by the length of the drill pipe and coupling. It also excites wave propagate in fluid and formation when acoustic wave propagate along the drillstrings in borehole filled with liquid, this will increase the wave attenuation along the drillstrings.Based on the acoustic characteristics of drill string, after modulating with three different methods such as amplitude shift keying、frequency shift keying and phase shift keying, respectively the binary date, which produced by coding the LWD data, were tansmited along drillstrings without noise. After modulating、propagation、receiving and demodulating, the demodulated signals were in good with original signal.This paper is financed by the Shandong Province Natural Science Foundation of China and China National Petroleum Corporation (CNPC).更多还原