基于优化变分模态分解和互相关的钻井液脉冲信号处理方法

A Pulse Signal Processing Method for Drilling Fluid Based on Optimal Variational Mode Decomposition and Cross-Correlation

随着油气勘探开发不断深入,钻井技术逐渐向深井、超深井和小井眼方向发展,对钻井液脉冲信号处理提出了更高的要求。通过分析脉冲位置调制编码的基本原理,提出了一种基于优化变分模态分解和互相关的钻井液脉冲信号处理方法,并利用在苏北地区某页岩油井采集的钻井液脉冲信号验证了该方法的可行性。基于优化变分模态分解算法,实现了在低信噪比条件下有用信号的有效提取;基于同步头相关器对去噪后的信号进行互相关处理,实现了数据帧起始位置的可靠计算;基于数据块相关器对数据块内波形进行互相关处理,实现了码值的准确获取。与传统的钻井液脉冲信号处理方法相比,上述方法具有可靠性高和误码率低的特点,能够很好地满足复杂井眼环境下钻井液脉冲信号处理的需求。

With oil&gas exploration and development going ever deeper,drilling technologies are gradually advancing towards deep and ultra-deep wells and slim holes,which puts forward high requirements for the processing of pulse signals of drilling fluid.By analyzing the principle of pulse position modulation coding,a pulse signal processing method was proposed for drilling fluid based on optimal variational mode decomposition(VMD)and crosscorrelation.And the feasibility of the method was later verified by using pulse signals of drilling fluid collected from a shale oil well in the northern Jiangsu region.Through the optimal VMD algorithm,the useful signals were effectively extracted under low signal-to-noise ratio conditions;based on the synchronization correlator,the de-noised signals were cross-correlated to reliably calculate the starting position of the data frame;according to the data block correlator,the waveforms in the data block were cross-correlated to accurately acquire the code values.Compared with the traditional pulse signal processing methods for drilling fluid,the proposed method exhibits characteristics of high reliability and low bit error rate,and it can well satisfy the needs of pulse signal processing for drilling fluid in complex wellbore environments.