【摘要】 针对车西洼陷北带中浅层砂砾岩体期次划分困难的问题,初步探索出一种在地质和地震资料约束下,基于测井曲线米氏旋回和小波变换技术的砂砾岩体描述方法。通过对测井曲线进行频谱分析,认为车西洼陷北带东营组砂砾岩体的沉积期次受米氏旋回的控制,偏心率404.0 ka和地轴倾角53.6 ka周期控制着四、五级层序的发育,是进行砂砾岩体期次划分与对比的基础。因此,依据米氏旋回和小波变换理论,在纵向上对车西洼陷北带东营组砂砾岩体进行了精细的划分,共识别出8~10个小的扇体期次。研究表明,应用米氏旋回和小波变换技术分析高频旋回,提高了沉积旋回研究的定量化水平。其中,设计的米氏旋回滤波曲线和选取的小波变换系数与高频旋回具有较好的对应关系,可有效地指导砂砾岩体期次的精细划分。更多还原

【Abstract】 In order to solve the problem of sedimentary cycle recognition of the middle-shallow sandbodies in the northern Chexi Subsag,we proposed a geologic-and seismic-constrained sedimentary cycle description method by using the Milankovitch cycle theory and wavelet transformation with well logging,constrained.Spectrum analysis of well logs shows that sedimentary cycle of sandbodies in Dongying Formation in the northern Chexi Subsag was controlled by the Milankovitch cycle.The fourth-and fifth-order sequences were controlled by the cycle of 404.0 ka eccentricity and 53.6 ka dip of earth’s axis,which is the foundation of the division and correlation of sandbody sedimentary cycle.According to the theories of Milankovitch cycle and wavelet transformation,we identified 8-10 small sedimentary fans vertically in the sandbodies of the Dongying Formation in the northern Chexi Subsag.The results show that analyses of high frequency cycles by using the Milankovitch cycle and wavelet transform can improve the quantificational level of sedimentary cycle division.The designed curves of Milankovitch cycle filters and the selected wavelet transformation coefficients correlate well with the high frequency cycles,and thus can be used to effectively recognize sedimentary cycles of sandbodies.更多还原