Prince Sultan Institute for Environmental, Water and Desert Research, King Saud University, Riyadh, 11451, Saudi Arabia.
Geology Department, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt.
Sci Rep. 2019 Feb 26;9(1):2825. doi: 10.1038/s41598-019-39192-4.
The Umm er Radhuma (UER) Formation is a major karst aquifer in Saudi Arabia. This study investigated the hydraulic and petrophysical characteristics of the folded UER carbonate aquifer using integrated hydrological and geophysical logging datasets to understand its complex hydraulic setting as well as detect possible water flow. Petrophysical analysis showed that the UER aquifer has three zones with different lithologic and hydraulic properties. The upper zone attains the best properties with average values of 20%, >100 mD, 3.30 × 10-1.34 × 10 m/s, and 1.49 × 10-6.04 × 10 m/s, with respect to effective porosity, permeability, hydraulic conductivity and transmissivity. The gamma-ray logs indicate a good fracture system near the upper zone of the UER Formation. Pumping test measurements of transmissivity, hydraulic conductivity and storage coefficients were matched with those from geophysical logs and found to be within the expected range for confined and leaky aquifers. Hydrogeological properties were mapped to detect possible groundwater flow in relation to the dominant structure. The underground water of the folded UER aquifer was forced along meandering flow patterns from W-E to SW-NE through the anticlinal axes. The integrated approach can be further used to enhance local aquifer models and improve strategies for identifying the most productive zones in similar aquifer systems.
乌姆拉达玛（UER）地层是沙特阿拉伯的一个主要喀斯特含水层。本研究利用综合水文地球物理测井数据集调查了褶皱的 UER 碳酸盐含水层的水力和岩石物理特性，以了解其复杂的水力环境，并探测可能的水流。岩石物理分析表明，UER 含水层有三个具有不同岩性和水力性质的带。上带具有最佳性质，平均有效孔隙度为 20%，渗透率>100mD，水力传导率为 3.30×10-1.34×10m/s，渗透率为 1.49×10-6.04×10m/s。伽马射线测井表明 UER 地层上部附近有良好的断裂系统。传输率、水力传导率和储层系数的抽水测试测量值与地球物理测井值相匹配，并且在封闭和渗漏含水层的预期范围内。对水文地质性质进行了制图，以探测与主要构造有关的可能地下水流动。褶皱 UER 含水层的地下水沿曲折的流动模式从 W-E 向 SW-NE 被强制穿过背斜轴。综合方法可进一步用于增强局部含水层模型，并改进在类似含水层系统中识别最具生产力区域的策略。
