石油学报 ›› 2014, Vol. 35 ›› Issue (2): 353-358.DOI: 10.7623/syxb201402017

• 石油工程 • 上一篇    下一篇

基于自适应滤波的钻井液连续压力波信号噪声抑制

沈跃1, 张亨1, 张令坦1, 苏义脑2, 盛利民2, 李林2   

  1. 1. 中国石油大学理学院 山东青岛 266580;
    2. 中国石油集团钻井工程技术研究院 北京 100195
  • 收稿日期:2013-09-06 修回日期:2013-12-30 出版日期:2014-03-25 发布日期:2014-04-11
  • 通讯作者: 沈跃,男,1961年7月生,1990年获石油大学(华东)自动化专业学士学位,2009年获中国石油大学(北京)油气井工程专业博士学位,现为中国石油大学(华东)教授,主要从事井下系统、信息与控制工程及智能检测技术的研究。Email:sheny1961@aliyun.com
  • 作者简介:沈跃,男,1961年7月生,1990年获石油大学(华东)自动化专业学士学位,2009年获中国石油大学(北京)油气井工程专业博士学位,现为中国石油大学(华东)教授,主要从事井下系统、信息与控制工程及智能检测技术的研究。Email:sheny1961@aliyun.com
  • 基金资助:

    国家自然科学基金项目(No.51274236)和国家高技术研究发展计划(863)项目(2006AA06A101)资助。

Eliminating noise of drilling fluid continuous pressure wave signals based on the self-adaptive filtering method

Shen Yue1, Zhang Heng1, Zhang Lingtan1, Su Yinao2, Sheng Limin2, Li Lin2   

  1. 1. College of Science, China University of Petroleum, Qingdao 266580, China;
    2. CNPC Drilling Technology Research Institute, Beijing 100195, China
  • Received:2013-09-06 Revised:2013-12-30 Online:2014-03-25 Published:2014-04-11

摘要:

根据钻井液连续压力波信号频带传输特性及自适应滤波器数学原理,针对钻井液连续压力波信号的宽带特征,基于钻井液压力相移键控(PSK)信号数学模型,以最小均方误差(LMS)为评价标准构建自适应滤波器算法,从理论上研究了采用自适应滤波方法实现钻井液连续压力波信号噪声消除及信号重构的可行性。建立了以载波信号作为输入及含噪声井下信号为期望输入的适于宽带信号处理的自适应滤波器结构及数学模型,在自适应控制算法作用下,通过自适应地调整滤波器权系数,以载波延迟采样值的加权线性叠加来逼近井下连续压力波信号;通过建立滤波器权系数的自适应控制算法,分析了滤波器的自适应步长因子对重构信号信噪比及失真度的影响。数值计算及仿真结果表明,基于该数学模型的自适应滤波器可以有效消除进入信号频带的各种随机噪声并实现钻井液压力相移键控信号的重构,通过合理选择自适应步长因子可以降低重构信号的波形失真度,获得较高质量的重构信号。

关键词: 自适应滤波, 钻井液连续压力波信号, 噪声抑制, 载波, 数学模型, 滤波器算法

Abstract:

According to the frequency band transmission characteristics of continuous pressure wave signals (CPWS) in drilling fluid and the mathematical principle of self-adaptive filter (SAF), a SAF algorithm is established with the evaluation criterion of least mean square error to theoretically assess the feasibility of applying the SAF method for noise suppression and signal reconstruction of CPWS in drilling fluid by considering the broadband characteristic of CPWS based on the mathematical model of pressure phase shift keying (PSK) signals. SAF structure and mathematical model for processing broadband signals are built with the input signal of carrier wave and the expected input signal of downhole with noise. Under the self-adaptive control of SAF algorithm, downhole CPWS are gradually obtained by weighed linear superposition of the delay sampling values of carrier wave through self-adaptive adjustment of filter weight coefficient. The impacts of filter step-size factor on reconstructed CPWS regarding signal-noise ratio and distortion factor are analyzed by constructing the self-adaptive control algorithm of filter weight coefficient. Results of numerical calculation and simulation show that the SAF in the mathematical model efficiently suppresses random noises in signal frequency band and reconstructs pressure PSK signals in drilling fluid. Proper selection of filter step-size factor enables the reduction of signal distortion factor and thus achieves high quality reconstructed signals.

Key words: self-adaptive filtering, drilling fluid continuous pressure wave signals, eliminating noise, carrier wave, mathmatical model, filter algorithm

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