强振动旋转钻具弱SNR信号的随机共振提取

In practical drilling process, the strong vibration and rapid rotation of the bottom drilling tool makes the attitude measurement signal contain high frequency and high amplitude noise. Extracting signal with weak amplitude and very low signal-to-noise ratio has been a difficulty problem in steering drilling area. The existing filters based on noise retraining mechanism may in a certain extent do harm to the useful signal either, which may lose the signal having almost the same frequency with noise and result in the attitude measurements invalid. This project will study on the extraction of the signal with weak signal-to-noise ratio (SNR) of the strong vibration and rotation drilling tool, and effectively utilize the high frequency and high amplitude noise rather than restrain it, based on the mechanism that noise energy can transform to signal in the stochastic resonance technology. Firstly, according to the characteristics of noise, the discrete reconstruction and reconstruction of the periodic signal is realized through discrete wavelet transform. Firstly, the stochastic resonance model and the description of parameters are established taking advantage of multi-scale noise regulation; then, the system inertance and known information of the drilling system are considered, and two kinds of specific weak signal extraction methods are proposed; Finally, the effectiveness of provide methods are verified by the vibration platform system experiment. The results of the study not only can be applied to the petroleum field, but also can provided the references for the navigation positioning, attitude measurement and weak signal extraction in the national defense military field.

实际钻井过程中，底部钻具的强烈振动和快速旋转导致姿态测量信号中含有高频高幅值的干扰信号。原始信号幅度微弱及极低信噪比问题一直是导向钻井技术领域的难点。现有的基于噪声抑制机制的滤波方法在抑制噪声的同时，一定程度上使被测信号也不可避免的受到抑制或损害。甚至出现信号频率与噪声接近的微弱信号很难提取出来，导致姿态测量信号无效。本项目基于随机共振技术中噪声能量能够向信号能量转换的机理，研究井下随钻强振动旋转钻具弱信噪比信号的提取问题，有效利用而非抑制井下高频高幅值的干扰信号。首先，针对井下噪声信号特性，利用离散小波变换实现对含噪周期信号的分解重构，建立基于多尺度噪声调节的随机共振模型及各参数描述；进一步结合井下系统的惯性及已知特征信息，提出两种具体的弱信号提取方法；并通过振动平台系统实验验证其有效性。该研究成果不但可以应用到石油能源领域，而且对国防军事领域的姿态测控、弱信号检测等提供参考和借鉴。

实际钻井过程中，底部钻具的强烈振动和快速旋转导致姿态测量信号中含有高频高幅值的干扰信号。原始信号幅度微弱及极低信噪比问题一直是导向钻井技术领域的难点。现有的基于噪声抑制机制的滤波方法在抑制噪声的同时，一定程度上使被测信号也不可避免的受到抑制或损害。甚至出现信号频率与噪声接近的微弱信号很难提取出来，导致姿态测量信号无效。本项目基于随机共振技术中噪声能量能够向信号能量转换的机理，研究井下随钻强振动旋转钻具弱信噪比信号的提取问题，有效利用而非抑制井下高频高幅值的干扰信号。首先，针对井下噪声信号特性，利用离散小波变换实现对含噪周期信号的分解重构，建立基于多尺度噪声调节的随机共振模型及各参数描述；进一步结合井下系统的惯性及已知特征信息，提出两种具体的弱信号提取方法；并通过振动平台系统实验验证其有效性。本项目提出的方法具有一定通用性，可广泛应用于常规油气田钻井及非常规油气田钻井中的相关领域。本项目的研究成果还对国防军事领域的姿态测控、弱信号检测与提取具有潜在的应用价值。