波形指示反演在储层预测中的应用

Application of thewaveform inversion in reservoir prediction

本文以地震精细解释为基础,利用研究区已有的地震和测井资料,采用地震波形指示反演的方法,对研究区主要目的层段进行了储层的精细预测.在预测中通过对地震波形指示反演方法的适用性及主要相关参数(有效样本数,最佳截止频率)的优选,综合分析不同方向的反演成果剖面,东西走向的反演成果剖面横向上砂岩的连续性相对于南北走向反演成果剖面较好,没有发生较为明显的间断,砂岩整体厚度左厚右薄;但是纵向上东西走向反演成果剖面砂岩出现的叠置现象较少或者没有出现;平面上,研究区目的层段砂岩储层经历了水进和水退的沉积变化,并在不同的沉积环境中,发育了不同规模和不同位置的砂岩储层,通过切片演化分析砂岩储层的变化特征,为下一步油气勘探提供储层预测的依据.

Based on the detailed seismic interpretation,seismic and logging data are used to predict the reservoir of the main target strata by waveform indicates inversion method in the study area.Through the application of waveform indicates inversion and the selection of main parameters in reservoir prediction,there are four key parameters for waveform indicates inversion in the study area.The main parameters are selected as follows： the effective sample number is 5,the optimal cut-off frequency is 200 ~ 250 Hz,the smoothing radius is 1,and the target sampling rate is 0. 5. By the comprehensive analysis of the inversion results section in different directions,the inversion results from the east to the west is better than that of the south to the north in continuity of sandstone. There is no obvious discontinuity and the overall thickness of sandstone is thick on the left side and thin on the right side. However,there is little or no the overlap phenomenon of sandstone in the inversion results from the east to the west. On the stratigraphic section,the sedimentary process of the sandstone reservoir area has experienced the process of water inlet and water retreat in the study. In different depositional environments,sandstone reservoirs of different sizes and different locations were developed, and the variation characteristics of sandstone reservoirs were analyzed by slice evolution. At the same time, the evolution and distribution of sandstone is the basis of reservoir prediction for the next oil and gas exploration.