【作者】 孙浩玉；

【导师】 李增亮；

【作者基本信息】 中国石油大学(华东) ， 机械设计及理论， 2014， 博士

【摘要】 在当今的油气勘探开发过程中,随着各种复杂结构井、特殊工艺井不断涌现及迅速发展与推广应用,要求在钻井过程中可以实时采集和传输地质、工程参数等井下信息,进而能够及时调整施工工艺,确保钻井过程的安全快速高效,因此对随钻测量技术的要求越来越高。为了尽可能获得详尽的井下地质、工程等参数信息,随钻测量仪器采集的参数不断增多,数据量也越来越大,那么在井下和地面之间的信息通道的数据传输能力就必须相应提高。国外已经成功研制出智能钻杆系统,该系统可实现信号的非接触式传输,有效解决了有线传输方式的线路磨损和接触不良等应用问题。该系统的最高通信速率可达2Mbps,远远高于目前随钻测量应用的电磁波或泥浆脉冲等传输方式,突破了随钻数据传输的技术瓶颈,真正实现了钻井过程中井下与地面之间信息的高速传输。但目前还只能了解到该传输系统的大体结构组成,其核心的磁感应传输方法尚未公开,本文就对该技术进行系统的基础理论研究和实验验证。建立磁感应传输的信道模型、设计信号传输钻杆,制作样机、搭建实验系统,缩短我国在该技术领域与国外先进技术的差距,为该技术在我国的创新发展及下一步推广应用打下基础。首先研究分析了感应耦合线圈的磁感应传输机理,以成熟的高频变压器电路模型为基础,采用软件仿真与实际耦合器测量结果比对和修正的研究方法,获得了感应耦合器的电路模型,进而建立了磁感应信道的传输模型。研究了多级耦合器信号传输衰减的补偿这一关键技术问题,给出了整个信道的信号传输频率特性曲线,确定了磁感应传输系统的信号传输频率。在磁感应传输系统中,若信息的传输以传统载波方式,则至少要用十几个波形周期表示一个信息位才能保证通信的可靠性。如果信道的传输频带位于低频段,则磁感应传输系统的通信速率将会很低。基于类正弦原理的通信技术则通过构造与正弦波极其相似的波形来表示要传输的信息,信号解调时则利用波形间极其微小的差异来区别信息位0和1;一个波形周期就可以表示一位信息,在相同的频带内可极大提高信号传输速率。深入研究了类正弦通信的工作原理,结合磁感应信道特有的频带特性,在磁感应传输系统中实现了类正弦通信方式,进而在同样的信道传输频带内,大幅度提高了磁感应传输系统的通信速率。根据对钻杆和接头磁感应信号传输功能的需求,对钻杆和磁感应接头的结构进行了全新设计。并建立力学仿真模型,对磁感应接头、钻杆等的强度进行了分析校核,仿真结果证明结构设计及强度可满足施工需求。对磁感应传输耦合器的结构、磁芯材料以及耦合线圈进行了详细的研究与设计优选,利用有限元仿真的方法分别构建了磁感耦合器的二维和三维模型,得到了耦合器的磁场分布。设计了基于频移键控原理和类正弦技术的调制、解调电路,搭建了磁感应传输技术实验平台,分别对两种通信方式进行了测试。制作了全尺寸磁感应信号传输钻杆样机。在多功能钻井实验平台,模拟钻井井下工况对采用全尺寸磁感应信号传输钻杆样机搭建的传输系统进行了实验研究与通信验证。更多还原

【Abstract】 In modern oil/gas exploration and development industry,there are many new technologys develop for complex wells and non-conventional wells.To make the adjustments of operating process more reliable and make sure the effectiveness and safety of drilling,these new technologys require the appliaction of real-time acquisition and transmission of downhole operating datas and geological parameters.With the increasing demands for the measurements-while-drilling(MWD)technique,the capacity of data transmission should be increased to acquire downhole informations as much as possible.The intelligent drill pipe system has been realized abroad and it adopt non-c ontact signal transmission techniques,which avoids many common problems(wire wear,poor contact,etc)in conventional wire transmission technology.And this data transmission system can realize high transmission rate reach 2Mbps,which is sufficiently higher than present transmission techniques using electromagnetic wave or mud-pulse.It achieves non-contact signal transmission and breaks the technology bottleneck of dat a transmission while drilling.Although the general structure of the intelligent drill pipe has been understood,the magnetic transmission method which is the key part is still not public.Therefore,building the chanel model of magnetic transmission and designing the signal transmission drill pipe are essential for the future application.The purpose of this paper is to study the fundamental theory of this advanced transmission system and perform experimental verifications,which will promote the development of this technology and form the basis for the future application.This paper first analyzes the transmission mechanisms of magnetic coupling coil.The circuit model for magnetic coupler is built based on the matured circuit model for high frequency transformers and improved by the comparison study between numerical results and measured results for real coupler.Then the transmission model of magnetic inductive transmission channel is obtained.To solve the problem of attenuation of the multistage signal transmission,capacitance compensation is adopted to increase the amplitude of the resonant frequency.The frequency characteristic curves of the signal transmission for the whole channel are given and the frequency of magnetic induction transmission is obtained.The sine-like wave technology is studied and adopted in this paper.The sine-like wave is more effective and reliable than traditional ways in terms of carrying signals.The sine-like wave shows great advantages for transmitting information.In this paper,the mechanisms of sine-like wave modulation were deeply studied and this effective technique also is introdued into present magnetic inductive transmission system,which highly improves the communication efficiency.According to the demands for the signal transmission function of drill pipe and joints,new designs of these two parts are made.The mechanical simulation model is built and this model was used to analyze the strengths of the joints and drill pipe.The simulation results demonstrate that the structure and strength can meet the requirements of operations.Besides,structure of the magnetic transmission coupler,magnetic material and coupling coil are also deeply studied and optimized.Using the multi-physics coupling analysis software to simulate the electromagnetic field of the coupler,the magnetic field distribution and signal transmission frequency characteristics are obtained.Based on the principles of Frequency-Shift Keying and Sine-like technology,the circuits of modulation and demodulation are developed,and full size prototype of drill pipe for Signal transmission experiment is manufactured.The the experimental system is established for testing the two different communication model.Based on experimental platform for drilling,the communication in the magnetic induction transmission channel is further verified.更多还原