斯通利波影响因素分析及渗透率反演

基于孔隙介质声学理论,对斯通利波影响因素进行研究,系统分析各因素对斯通利波相速度和衰减的影响程度。在利用正演模型进行灵敏度分析后,提出井孔内流体声速标定的方法,并对不同井径条件下斯通利波传播的正演模型传递矩阵进行重新推导,得出以测井间隔长度为变量的传播矩阵。在此基础上,结合利用斯通利波振幅和相位计算渗透率的方法,通过模拟退火算法实现地层渗透率的反演。反演结果表明:渗透率基值越大,反演结果越可靠;用斯通利波反演的渗透率曲线与岩心和常规曲线反映的储层性质以及砂泥岩剖面吻合好,其结果能满足现场工程的应用。

Influence factors of Stoneley wave and permeability inversion of formation

The influence factors of Stoneley wave were researched based on the theory of porous media acoustics.The effect of different factors on the phase velocity and attenuation of Stoneley wave was analysed systematically.After the sensitivity analysis using forward modeling,a method of borehole fluid calibration was proposed.Through a new derivation of the transfer matrix of Stoneley wave forward simulation under different borehole diameter conditions,the transfer matrix was established as a function of logging interval length.On this basis,combining with the permeability calculation methods through the amplitude and phase of Stoneley wave,the permeability of formation was calculated with the simulated annealing algorithm.It can be seen that the larger permeability,the more reliable the results.The results agree well with the core data,the conventional data and the mudstone profile,and can meet the requirements of field application.