泥质砂岩在干燥与饱和流体状态下纵波速度之间的关系

发布时间：2018-03-11 03:15

本文选题：泥质砂岩　切入点：纵波速度　出处：《地球物理学进展》2017年04期 　论文类型：期刊论文

【摘要】：岩石从干燥状态下到饱和流体后纵波速度的变化情况对于地震速度预测、AVO分析以及流体识别具有重要意义,而有关泥质砂岩在干燥与饱和流体状态下纵波速度之间关系的研究甚少.因此本文利用三组实验数据研究了泥质砂岩在干燥与饱和流体状态下纵波速度之间关系的影响因素,并通过多元线性回归分析方法建立泥质砂岩饱和流体后的纵波速度与干燥状态下的纵波速度、孔隙度以及黏土含量之间的关系.研究表明:泥质砂岩在干燥与饱和流体状态下纵波速度之间的简单线性关系容易受到固结程度、孔隙流体性质以及围压的影响,而多元线性回归分析与简单线性分析相比,其拟合结果的判定系数明显提高,标准误差明显减小.此外,本文首次提出黏土含量与孔隙度比的概念(CPR),发现CPR与泥质砂岩饱和流体前后纵波速度差之间有很好的正相关性,随着CPR的增加,纵波速度差也表现出增大的趋势,CPR的提出为解释流体替换过程中岩石物理属性的变化情况提供了新的思路.
[Abstract]:The variation of longitudinal wave velocity in rock from dry state to saturated fluid is of great significance for AVO analysis and fluid identification of seismic velocity prediction. However, there is little research on the relationship between the longitudinal wave velocity of shaly sandstone under the condition of drying and saturated fluid. Therefore, three groups of experimental data are used to study the influencing factors of the relationship between the velocity of the longitudinal wave in the dry state and the saturated state of the shaly sandstone. The velocities of compressional waves in shaly sandstone saturated fluid and those in dry state were established by multivariate linear regression analysis. The relationship between porosity and clay content. The results show that the simple linear relationship between compressional wave velocities of shaly sandstone under dry and saturated fluid conditions is susceptible to the influence of consolidation degree, pore fluid properties and confining pressure. Compared with simple linear analysis, multivariate linear regression analysis can improve the judging coefficient and decrease the standard error. In this paper, the concept of clay content and porosity ratio is proposed for the first time. It is found that there is a good positive correlation between CPR and the velocity difference of compressional wave before and after saturated shaly sandstone fluid, with the increase of CPR. The velocity difference of P-wave also shows an increasing trend. CPR provides a new way to explain the change of rock physical properties during fluid replacement.
【作者单位】：中国石油大学(北京)地球物理与信息工程学院;中国石油大学(北京)油气资源与探测国家重点实验室;中国石油大学(北京)CNPC物探重点实验室;大庆钻探工程公司地球物理勘探一公司;
【基金】：国家科技重大专项(2016ZX05007-006) 国家自然科学基金(41474112)联合资助
【分类号】：P618.13;P631.4

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