Pore pressure prediction in orthotropic medium based on rock physics modeling of shale gas
Pore pressure prediction in orthotropic medium based on rock physics modeling of shale gas
复制标题
基于页岩气岩石物理模型的正交各向异性介质孔隙压力预测
DOI：
10.1016/j.jngse.2019.103091
复制
发表时间：
2020-02
影响因子：
--
通讯作者：
Zong Z
中科院分区：
文献类型：
--
作者：
Lei T;Yin Xingyao;Zong Z
孔隙压力预测对于降低钻井成本和勘探碳氢化合物至关重要。目前的地震孔隙压力预测方法主要是先建立垂直有效应力与物理参数（速度、电阻率或孔隙度）之间的关系，然后根据已知的有效应力理论预测孔隙压力。常用的伊顿公式需要估算正常压实趋势（NCT），而NCT不能测量，只能推断。然而，传统的NCT曲线虽然能够描述正常的趋势，但相对粗糙，限制了孔隙压力预测的准确性。在这项研究中，正交各向异性（OA）介质中的页岩岩石物理模型的设计等效的NCT。在正常孔隙压力段，模型和实测纵波速度吻合较好，但在异常孔隙压力段，两者存在差异。利用该模型预测孔隙水压力，与实测孔隙水压力的对比表明，该模型的预测精度得到了提高。然后基于OA介质的反射率近似，从方位地震资料中反演纵波速度，并利用模拟的纵波速度预测研究区的孔隙压力（目的层为四川盆地某页岩气田）。预测结果与超压生烃机理特征一致，表明岩石物理模拟在孔隙压力预测中的有效性。
Pore pressure prediction is critical to reducing drilling costs and exploring hydrocarbons. Current seismic approaches for pore pressure prediction mainly initially establish the relation between vertical effective stress and physical parameters (velocity, resistivity or porosity), and then predict pore pressures with the known effective stress theory. The commonly used Eaton's equation requires the estimation of normal compaction trend (NCT), which cannot be measured but only be inferred. However, the conventional NCT is a curve which is able to describe the normal trend but is relatively rough, limiting the accuracy of pore pressure prediction. In this study, the shale rock physics modeling in orthotropic (OA) medium is designed to equate the NCT. The modeled and the measured P-wave velocity match well in normal pore pressure segments, but they differ in abnormal pore pressure segments. The modeled NCT is utilized to predict pore pressures, and the comparison with the measured pore pressures proves that the accuracy can be improved. Then P-wave velocity is inverted from azimuthal seismic data based on the reflectivity approximation of OA medium, and the pore pressure of the research area is predicted using the modeled P-wave velocity (the target play is a shale gas field in Sichuan basin of China). The prediction result is consistent with the characteristics of overpressure mechanism of hydrocarbon generation, indicating the effectiveness of rock physics modeling in pore pressure prediction.
登录
查看更多内容
影响因子：
12.1
作者：
Jincai Zhang
通讯作者：
Jincai Zhang
影响因子：
--
作者：
Jingzhou Zhao;Jun Li;Zeyang Xu
通讯作者：
Zeyang Xu
影响因子：
3.5
作者：
L. Vernik;C. Landis
通讯作者：
L. Vernik;C. Landis
影响因子：
--
作者：
B. Das;R. Chatterjee
通讯作者：
B. Das;R. Chatterjee
影响因子：
2.6
作者：
Z. Zong;Xingyao Yin;Guo-chen Wu
通讯作者：
Z. Zong;Xingyao Yin;Guo-chen Wu