基于FPGA的HDB3编解码方法及其在阵列电导探针流动测井中的应用  

Research on HDB3 coding technique based on FPGA and its application in flow logging with mini-conductance array probes

作　　者：郝志强[1] 刘兴斌[2] 胡金海[2] 孙跃义[2] 

机构地区：[1]东北石油大学研究生院 [2]大庆油田有限责任公司测试技术服务分公司

出　　处：《石油仪器》2012年第2期76-79,9,共4页Petroleum Instruments

摘　　要：了解决高速长距离传输中电缆测井数据的衰减、干扰等问题,设计了基于FPGA的HDB3编解码电路,HDB3码具有无直流分量、低频分量少、便于提取时钟、具有一定的检错能力、传输速度是曼彻斯特码的2倍等优点。该电路应用在阵列电导探针流动成像测井中,可以保证井下数据传输的速度和准确性,从而实现在PC机的上位机软件中实时显示井下油水流动的状态。设计中以FPGA为核心部件,完成了采集、编解码、时钟提取以及与PC机的数据交互,分析了HDB3编解码模块的原理和设计,以及PC端软件的功能和实现方法。结合实验表明,该方案稳定可靠、切实可行,可以应用于实际项目中。To solve the problems such as interference rejection and the attenuation in the high speed communication of long distance in logging cable,the encoder circuit of the HDB3 based on FPGA is designed.HDB3 code has many advantages, such as no direct current,less low frequence spectrum,easy picking-up timing signal capable of correcting itself,and its transmission speed is 2 times the manchester code.This circuit is applied in flow imaging logging with mini-conductance array probes,and can guarantee the speed and accuracy of downhole data transmission,thus displaying the state of oil/water flowing in downhole on the PC software real-time.The design is based on FPGA and aim to achieve collecting,coding and decoding,picking-up timing signal as well as interacting data with PC.Besides,this paper analyses principles of coding and decoding modular,and designs the PC software function and implementation methods. Experiments show that the scheme is stable and reliable,and it can be applied in practical projects.

关 键 词：流动测井 阵列电导探针 FPGA HDB3码 

分 类 号：P631.81[天文地球—地质矿产勘探]