粘砂套管特性对声波幅度的影响研究

On Effects of Characters of Adhering Sand Casing on Acoustic Amplitude

建立超声波在套管、粘胶剂及粘砂砂粒中的反射模型，计算超声波在每个介质层问的声波能量，并根据超声波的能量变化，分析粘砂套管的粘胶剂厚度和粘砂砂粒分布密度对反射波声幅大小的影响。理论分析与实验结果均表明，粘胶剂厚度与声幅成反比，当其厚度大于等于粘砂砂粒半径时，声幅值最小，表示固井质量评价结果最好；粘砂砂粒分布密度为70％～85％时，接收到的声幅值很小，表示固井质量评价结果最好。

Established are reflection models of ultrasonic waves in casing, adhesion agent and adhesion sand layers, and calculated is the wave energy in every medium layer. According to the energy alternation of ultrasonic waves, analyzed is the influence of the adhesion agent thickness and the density distribution of adhesion sand on the acoustic amplitude. The theoretical analysis and experimental results show that the thickness of adhesion agent is inversely proportional to the acoustic amplitude, the acoustic amplitude is least when the thickness of the adhesion agent is greater than or equal to the adhering sand casing radius, which indicates that the result of cement evaluation is best. When the density distribution of the adhesion sand is 70%-85%, the received numerical value of acoustic amplitude is least, which indicates that the result of cement evaluation is best.