随着常规油气勘探资源的日益紧缺，储备量丰富的非常规油气资源已经成为近年来全球油气资源勘探开发新亮点。微地震技术是非常规油气储层开采的重要手段，然而微地震信号一般呈现“弱信号，强干扰”的特征，微地震监测所采集到的数据有效信号能量极其微弱，给数据的处理解释带来较大困难，本项目立意开展基于Shearlet变换的微地震噪声压制技术研究。针对井中和地面的微地震资料，利用Shearlet变换特点（多尺度、多方向等），获得该方法可应用微地震有效信号提取及噪声压制的应用条件；分析微震有效信号和噪声在Shearlet变换域中尺度、方向和位置的特征；研究Shearlet变换域系数重建的数学模型；构建适用于非常规油气开采中微地震微弱有效信号的多方位变时窗检测与复杂非规则噪声滤波方案。为微地震有效信号的识别与震源的准确定位、提高非常规油气藏开发成效以及油气盆地精细结构重建提供可靠的技术支撑。

The rich reserves of unconventional oil and gas resources have been a new highlight in the global oil and gas exploration recent years with the shortage of conventional hydrocarbon resources increasingly getting serious. Microseismic technique is the important mean in unconventional oil and gas reservoir exploration. However, the energy of effective signals in microseismic data is extremely weak and the signals are contaminated by strong interference which brings difficulties for data processing and interpretation. This project aims to develop shearlet transform based microseismic noise attenuation technique. For the microseismic data from well and surface, we first achieve the condition of the proposed method applied to microseismic signals extraction and noise suppression by taking the multiscale and multidirectional characteristic of shearlet transform. Then we analyze the characteristic of microseismic signals and noise in shearlet domain at different scales, directions and locations and study mathematic model for shearlet coefficients reconstruction. Finally we construct a filtering scheme and make it suitable for microseismic signals multidimensional detection with variable window and irregular noise attenuation. Techniques in this project will provide reliable support for the identification of microseismic signals, accurate source localizations and oil and gas basin fine structure reconstruction, which also raises development effectiveness of unconventional oil and gas reservoirs.