塔中地区ZG5-7井区横波速度的预测

纵、横波速度是储层岩性、物性和流体识别的重要参数，而实际生产中往往缺乏横波速度资料，因此，开展横波速度预测已成为岩石物理研究的重要内容。目前横波预测中普遍使用的是Greenberg-Castagna经验公式，但其在塔里木盆地塔中地区ZG5-7井区应用效果不佳。针对上述问题，充分利用已钻井的纵波速度、地层密度、泥质含量、孔隙度、含水饱和度等常规测井资料以及岩石骨架和流体的各种弹性参数，构建了流体置换的Xu-White模型，用来求取横波速度。该区６口井的横波曲线拟合的实验结果表明：Xu-White模型预测的横波速度与实测横波速度高低趋势一致，其相关系数最高达到0.970 9，完全能满足横波弹性反演和油气预测的需要。结论认为，Xu-White模型不仅适用于碎屑岩储层的横波速度预测，同样在碳酸盐岩的横波速度预测中也能取得良好的应用效果。

Prediction of S wave velocity in the wellblock ZG5 7, middle Tarim Basin

The P and S wave velocity is one of the most important parameters in characterizing the lithogical and petrophysical properties of reservoirs and identifying the fluids in reservoirs. However, there is a lack of such data on the S wave velocity in actual production. That is why the forecast of S wave velocity has become the main content in rock's petrophysical studies. At present, the Greenberg Castagna empirical formula is commonly used in the S wave forecasting, but achieved bad results in the wellblock ZG5-7, Middle Tarim Basin. In view of this, making full use of regular logging data including the P wave, formation density, mud content, porosity, and water saturation, etc. and all kinds of elastic parameters of rock skeleton and fluids, the fluid substitution Xu White modeling is built for the calculation of S wave velocity, The S wave curve fitting results from the 6 wells in the wellblock ZG5-7 demonstrate that the forecasted S wave velocity by use of the Xu White modeling agrees well with the actual measurement with the correlation R up to 0.9709, which can completely meet the need of elastic S wave inversion and hydrocarbon forecasting. This model can be adopted in the S wave velocity forecasting of clastic and carbonate rock reservoirs.