基于阵列声波测井的套管井纵波时差获取方法

Method to Obtain Compressional Wave Slowness in Cased Hole Based on Array Acoustic Logging

分析套管井阵列声波测井提取纵波、横波的影响因素,纵波时差受套管尺寸、固井质量、扩径、地层性质影响。固井质量是主要影响因素。在固井质量较好的情况下,阵列声波测井提取纵波可以不作校正;对于套管井固井质量不好的情况,阵列声波测井提取纵波已经不能反映实际地层的纵波信息,需要进行校正。采用横波反演方法,应用鄂尔多斯盆地5个区块共34口井的阵列声波测井资料,回归得出具有地区经验的纵波时差重构方程,通过实例对比分析验证了该方法的可行性和实用性。

The factors affecting the extraction of P-wave and S-wave from through-casing array acoustic logging data are analyzed.The interval travel time of P-wave is affected by casing size,cement ring cementation,borehole enlargement and formation properties.Cementing quality is the main influencing factors.In the case of better cementing quality,the extracted P-wave by array acoustic logging needn’t to be corrected;For the bad cementing quality,the extracted P-wave by array acoustic logging can not reflect the P-wave information of actual formation,so it is necessary to make correction.By using shear wave inversion,a reconstruction method of compressional wave slowness is presented,regression equations of P-wave slowness reconstruction are established in five blocks,Ordos Basin.The verification and analysis of acoustic logging data of 34 wells shows the method is feasibility and practicability.