State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing, 102249, China.
Beijing Key Laboratory of Optical Detection Technology for Oil and Gas, China University of Petroleum, Beijing, 102249, China.
Sci Rep. 2016 Dec 15;6:39306. doi: 10.1038/srep39306.
Current geological extraction theory and techniques are very limited to adequately characterize the unconventional oil-gas reservoirs because of the considerable complexity of the geological structures. Optical measurement has the advantages of non-interference with the earth magnetic fields, and is often useful in detecting various physical properties. One key parameter that can be detected using optical methods is the dielectric permittivity, which reflects the mineral and organic properties. Here we reported an oblique-incidence reflectivity difference (OIRD) technique that is sensitive to the dielectric and surface properties and can be applied to characterization of reservoir rocks, such as shale and sandstone core samples extracted from subsurface. The layered distribution of the dielectric properties in shales and the uniform distribution in sandstones are clearly identified using the OIRD signals. In shales, the micro-cracks and particle orientation result in directional changes of the dielectric and surface properties, and thus, the isotropy and anisotropy of the rock can be characterized by OIRD. As the dielectric and surface properties are closely related to the hydrocarbon-bearing features in oil-gas reservoirs, we believe that the precise measurement carried with OIRD can help in improving the recovery efficiency in well-drilling process.
当前的地质开采理论和技术由于地质结构的复杂性，很难充分描述非常规油气藏。光学测量具有不干扰地磁场的优点，常用于检测各种物理特性。光学方法可以检测到的一个关键参数是介电常数，它反映了矿物和有机性质。在这里，我们报告了一种斜入射反射率差（OIRD）技术，该技术对介电常数和表面性质敏感，可应用于储层岩石的特征描述，例如从地下提取的页岩和砂岩岩心样品。OIRD 信号清楚地识别出页岩中的介电性能分层分布和砂岩中的均匀分布。在页岩中，微裂缝和颗粒取向导致介电常数和表面性质的方向变化，因此可以通过 OIRD 来描述岩石的各向同性和各向异性。由于介电常数和表面性质与油气藏的含烃特征密切相关，我们相信 OIRD 的精确测量有助于提高钻井过程中的采收率。
