四川盆地泸州地区页岩气地层地震相分析研究及实际应用

Seismic Facies Analysis and Application of Shale Gas in Luzhou Area, Sichuan Basin

摘要: 地震相就是在地震反射时间剖面上所表现出来的反射波的面貌。地震相分析研究是利用地震属性提取地震信息，充分利用地震反射的内部结构，外部形态，结合振幅、频率、连续性等特点，研究蕴含在地震反射波中的有关地震波的几何形态、运动学特征、动力学特征和统计学特征的信息，能从多方面反映地下特殊地质现象、沉积现象、流体特征等，地震相分析已成为精细储层描述的重要手段。对于四川泸州地区页岩地层，虽然目前的地震分辨率还很难达到对单一小层的准确识别，但三维地震属性分析可以客观地反映储层的差异性特征，经过钻井标定和沉积相分析，这种差异性在一定程度上体现了储层的非均质性特征，反映了储层厚度的展布情况。均方根振幅(RMS)表示时窗内时间域能量(振幅平方)的平方根。用来显示孤立的或极值振幅异常，其横向变化可以用于研究地层岩性变化、物性及含气性。均方根振幅属性对地层振幅信息比较敏感，本次利用均方根振幅进行地震相预测。

Abstract: Seismic facies is the appearance of reflected wave in seismic reflection time profile. Seismic facies analysis which was studied by analyzing the shape, amplitude, frequency, and continuity of seismic wave reflects special geological phenomena, sedimentary phenomena and fluid characteristics from many aspects. Seismic facies analysis has become an important means of fine reservoir description. For the shale formation in Luzhou area, Sichuan Province, although the current seismic resolution is still difficult to achieve the accurate identification of a single small layer, 3D seismic attribute analysis can objectively reflect the difference characteristics of the reservoir. Through drilling calibration and sedimentary facies analysis, this difference reflects the heterogeneity characteristics of the reservoir to a certain extent, and reflects the distribution of the reservoir thickness. Root mean square amplitude (RMS) represents the square root of the energy (amplitude square) in the time domain in the time window. It can be used to show isolated or extreme amplitude anomalies, and its lateral variation can be used to study the formation lithology change, physical property and gas bearing property. The root mean square amplitude attribute is sensitive to the formation amplitude information. This time, the root mean square amplitude is used for seismic facies prediction.