叠前弹性波阻抗反演技术在煤层顶板砂岩富水性预测中的应用研究

发布时间：2018-06-23 22:44

本文选题：砂岩富水性预测 + 叠前弹性波阻抗反演　；参考：《西安科技大学》2017年硕士论文

【摘要】：叠前弹性波阻抗反演技术是地震勘探中的一项核心技术,能够获得比叠后反演更为丰富的弹性物理参数,可以解译出地下流体各种地质信息。论文基于叠前弹性波阻抗反演方法预测了煤层顶板砂岩富水性。论文从岩石物理基础入手,根据煤层顶板砂岩的特点,建立了五层地质波阻抗模型,正演分析了煤层顶板砂岩在距煤层不同距离和厚度上的AVO响应,分析了砂岩在富水情况下的AVO正演振幅响应情况,以及富水后的反射波特征。研究发现砂岩富水时,随着炮检距的增大,纵波振幅值逐渐减小,其反射系数的绝对值减小趋势明显。论文以黄陵二号煤矿某采区为研究对象,利用叠前弹性波阻抗反演技术研究分析了煤层顶砂岩富水情况。在已有地震资料和测井信息的基础上,为有效识别砂岩进行了测井数据交汇图分析;采用Xu-White模型方法获取了测井中缺失的横波资料;运用叠前弹性波阻抗反演方法获得关于砂岩的纵横波速度比及孔隙度的弹性信息,解译了煤层顶板砂岩富水区域。研究表明,煤层顶板含有4套砂岩,由于2、3、4号砂体比较零散且面积较小,故不作考虑;其中1号砂体全区分布,整体趋势是东厚西薄,1号砂在N35井处位于Vp/Vs低值区域,综合分析得出N35井附近是1号砂富含水区。
[Abstract]:Prestack elastic wave impedance inversion technique is a core technique in seismic exploration. It can obtain more elastic physical parameters than post-stack inversion and can interpret various geological information of underground fluid. Based on the prestack elastic wave impedance inversion method, the wateriness of coal seam roof sandstone is predicted. According to the characteristics of coal seam roof sandstone, a five layer geological wave impedance model is established, and the AVO response of coal seam roof sandstone in different distance and thickness from coal seam is analyzed in this paper. The amplitude response of AVO forward modeling and the characteristics of reflection wave after rich water are analyzed. It is found that when sandstone is rich in water, the amplitude of P-wave decreases gradually with the increase of offset, and the absolute value of reflection coefficient decreases obviously. In this paper, a mining area of Huangling No. 2 Coal Mine is taken as the research object, and the water-rich situation of sandstone on the top of coal seam is studied and analyzed by using pre-stack elastic wave impedance inversion technique. Based on the existing seismic data and logging information, the intersection map of logging data is analyzed to identify sandstone effectively, and the missing shear wave data in logging are obtained by using Xu-White model method. The prestack elastic wave impedance inversion method is used to obtain elastic information about the velocity ratio and porosity of sandstone, and the water-rich area of coal seam roof sandstone is interpreted. The study shows that there are 4 sets of sandstone in the roof of coal seam, and the sand bodies of No. 2 and No. 4 are scattered and small, so they are not taken into account. The distribution of sand body No. 1 in the whole area is thick and thin in the east and west, and the sand No. 1 is located in the low value area of VP / Vs at well N35. The comprehensive analysis shows that near well N35 is the rich water area of Sand No.1.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD74;P631.4

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