How well can we predict permeability in sedimentary basins? Deriving and evaluating porosity–permeability equations for noncemented sand and clay mixtures
How well can we predict permeability in sedimentary basins? Deriving and evaluating porosity–permeability equations for noncemented sand and clay mixtures
复制标题
我们如何预测沉积盆地的渗透率？推导和评估非胶结砂和粘土混合物的孔隙度-渗透率方程？
DOI：
10.1111/gfl.12115
复制
发表时间：
2015
期刊：
影响因子：
1.7
通讯作者：
T. Gleeson
中科院分区：
文献类型：
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作者：
E. Luijendijk;T. Gleeson
在沉积盆地中，沉积物的渗透性是控制地下水流动以及与之相关的热量和溶质再分配的主要因素。虽然纯粘土和纯砂的孔隙度-渗透率关系已经在实验室规模上建立得相对较好，但天然沉积物的渗透率仍然高度不确定。在这里，我们量化以及现有的和新的孔隙度-渗透率方程可以解释非胶结硅质沉积物的渗透率。我们编制了纯砂和粉砂（n = 126），纯粘土（n = 148），天然砂，粉砂和粘土（n = 92）的混合物的粒度，粘土矿物学，孔隙度和渗透率数据。分别用Kozeny-Carman方程和经验幂律方程可以高置信度（R2 ≥ 0.9）预测纯砂和粘土的渗透率。天然沉积物的渗透率远高于实验二元混合物和理想填充模型的预测。渗透率可以中等置信度（R2 = 0.26 - 0.48）和0.6个数量级的平均误差预测为纯粘土和砂组分渗透率的几何平均值或算术平均值，几何平均值提供了渗透率变化的最佳测量。我们测试新的一组方程详细的测井和渗透率数据从三角洲沉积物在荷兰南部，表明渗透率可以预测的平均误差为0.7个数量级的粘土含量和孔隙度来自中子和密度日志。
The permeability of sediments is a major control on groundwater flow and the associated redistribution of heat and solutes in sedimentary basins. While porosity–permeability relationships of pure clays and pure sands have been relatively well established at the laboratory scale, the permeability of natural sediments remains highly uncertain. Here we quantify how well existing and new porosity–permeability equations can explain the permeability of noncemented siliciclastic sediments. We have compiled grain size, clay mineralogy, porosity, and permeability data on pure sand and silt (n = 126), pure clay (n = 148), and natural mixtures of sand, silt and clay (n = 92). The permeability of pure sand and clay can be predicted with high confidence (R2 ≥ 0.9) using the Kozeny–Carman equation and empirical power law equations, respectively. The permeability of natural sediments is much higher than predicted by experimental binary mixtures and ideal packing models. Permeability can be predicted with moderate confidence (R2 = 0.26– 0.48) and a mean error of 0.6 orders of magnitude as either the geometric mean or arithmetic mean of the permeability of the pure clay and sand components, with the geometric mean providing the best measure of the variability of permeability. We test the new set of equations on detailed well-log and permeability data from deltaic sediments in the southern Netherlands, showing that permeability can be predicted with a mean error of 0.7 orders of magnitude using clay content and porosity derived from neutron and density logs.