碳酸盐岩孔洞模型中超声波传播特性

发布时间：2018-04-21 17:18

  本文选题：碳酸盐岩孔洞模型 + 超声波　； 参考：《科技导报》2017年18期

【摘要】：以孔洞型碳酸盐岩的小岩柱为对象,采用二维超声波数值模拟与物理模型实验相结合的方法,从运动学及动力学角度,研究了多频率下超声波在不同尺寸、形状及分布的孔洞模型中的传播特性。结果表明,不连续分布的单孔洞,其尺寸变化对声波速度几乎无影响但与衰减系数呈正相关,在相同尺寸下随测试频率的增加声波速度有增加的趋势,衰减系数与频率间呈幂函数递增关系;圆形孔洞、方形孔洞对声波速度影响与孔隙度有关,孔隙度9%为临界值,低于9%时影响不敏感(可忽略),高于9%时圆形孔洞对衰减系数的影响大于正方形孔洞的影响;椭圆形孔洞的影响与其纵横比有关,纵横比大于1时,随纵横比增加衰减系数的变化幅度较小,反之则衰减系数的变化幅度较大;随孔洞分布集中度的增加,声波速度呈线性规律减小,衰减系数呈线性规律增加。
[Abstract]:Taking the small rock column of porous carbonate rock as an object, using the method of numerical simulation of two-dimensional ultrasonic wave and physical model experiment, the different sizes of ultrasonic wave in multi-frequency are studied from the point of view of kinematics and dynamics. Propagation characteristics in the shape and distribution of the pore model. The results show that the size change of a single hole with discontinuous distribution has little effect on the acoustic velocity, but has a positive correlation with the attenuation coefficient. At the same size, the acoustic velocity increases with the increase of the measured frequency. The influence of circular and square holes on the acoustic velocity is related to the porosity, and the porosity of 9% is the critical value. When the ratio is lower than 9, the effect of circular hole is greater than that of square hole, and the effect of elliptical cavity is related to its aspect ratio, and the aspect ratio is greater than 1. The change of attenuation coefficient is smaller with the increase of aspect ratio, but the amplitude of attenuation coefficient is larger with the increase of the concentration of hole distribution, the velocity of sound wave decreases and the attenuation coefficient increases linearly with the increase of the concentration of hole distribution.
【作者单位】： 中国科学院重庆绿色智能技术研究院;重庆矿产资源开发有限公司;甘肃省油气资源研究重点实验室;中国石油川庆钻探工程公司地质勘探开发研究院;中国石油西南油气田分公司蜀南气矿;重庆科技学院石油与天然气工程学院;
【基金】：国家自然科学基金项目(41502287) 甘肃省油气资源研究重点实验室开放基金项目(SZDKFJJ20160605) 重庆市基础与前沿研究计划重点项目(cstc2015jcyj BX0120) 重庆市国土资源和房屋管理局科技计划项目(CQGT-KJ-2015044)
【分类号】：O426.2
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本文编号：1783355