碳酸盐岩不同含水饱和度对声波传播特性影响

Water Saturations Effect of Carbonate Rock on Acoustic Wave Propagation

碳酸盐岩储层缝洞发育,结构复杂,利用声波传播特性预测均质砂岩含水饱和度的方法并不一定适用于碳酸盐岩储层。选择四川盆地龙王庙组不同孔洞发育程度的碳酸盐岩样品,测量了同一岩石样品在不同围压、不同含水饱和度时的纵横波波速。在实验基础上,研究了不同围压条件下纵横波波速、纵横波速比及声波衰减特性随含水饱和度的变化规律,并解释了该变化规律的内在机理,对比分析了声波波速、纵横波速比和衰减特征与含水饱和度敏感性,为声波测井资料应用于碳酸盐岩储层内气层的识别和含气饱和度及孔隙度的评估与预测提供了理论基础,对该类地层井下工程稳定性研究及储层评价都具有重要意义。

Since carbonate reservoir are pores, crack development and complicated structures to realize homogeneous sandstone reservoir characteristics with the acoustic responses is not applicable to this carbonate reservoir. We choose the different development degree carbonate rocks holes samples of Longwangmiao group, Sichuan basin to measure the same rock samples under different confining pressures and water saturations at vertical and horizontal wave velocity. On the basis of test data, we study vertical and horizontal wave velocity, and vertical and horizontal wave velocity ratio and acoustic attenuation characteristics changing with the water saturations under the condition of different confining pressures, and explained the internal mechanism of the change rule. The research of carbonate rocks acoustic wave propagation characteristics under different confining pressures and water saturations provides a theoretical basis for gas layer recognition and gas saturation and the porosity evaluation and prediction in carbonate reservoir by acoustic logging data, it is significance to the formation underground engineering stability study and reservoir evaluation.