山东兖州煤矿区侏罗纪红层孔隙测试及其影响因素分析

在山东兖州煤矿区,侏罗纪红层含有较为丰富的地下水,赋水空间以孔隙为主。综合利用宏观岩芯观察和微观形态分析对红层的孔隙类型进行了较为详细地论述,主要有粒间溶蚀扩大孔隙、粒间缩小孔隙、胶结物溶蚀孔、粒内孔隙和晶间孔隙。指出岩石颗粒组分、颗粒分选磨圆程度、胶结方式及胶结程度等是影响红层中孔隙发育的主要因素,对照扫描电子显微镜(SEM)观察和压汞试验曲线对它们的影响方式和程度作了详细的论述。通过对比具近似孔隙率岩样的压汞测试结果,认为相同孔隙率的岩样可具有不同的孔隙结构形态,结构形态对赋水性能具有决定作用,孔隙结构形态的差异决定了红层储水空间内在结构特征的不同。

Pore Structure Test of Jurassic Red-Bed in Yanzhou Mining Area, Shandong Province, and Its Affecting Factors

Jurassic continental red beds in Yanzhou mining area, Shangdong Province, contains abundant underground water, in which pore is the main water-bearing space. Combining micro-appearance observation with hydrargyrum-pressure experiments, pore types of red beds, micro-structure features and affecting factors of pore structures have been systematically studied. Main pore types of the red beds, such as interparticle soluble enlarged pore, contracted interparticle pore, gelatinous materials soluble pore, interparticle pore, and inter-crystal pore have been described in detail. Based on the data from 93 rock samples, the porosity of red bed varies from 0.58% to 23.97%, and the average pore diameter varies from 2.3 um to 46.8um. Results show that different rock types have different micro-structures. The rock samples with same pore quantity may have absolutely different pore structures. The water-bearing ability of the rocks can be controlled by their pore structures.