粗糙裂隙溶解过程反应性溶质运移特征

岩体裂隙中溶质运移受对流、扩散和水岩化学反应三种机制控制.分析了不同机制主导作用下,粗糙裂隙溶解过程中反应性溶质运移特征,并分析粗糙度的影响.研究结果显示,粗糙裂隙溶解过程存在4种类型,分别是均匀、非均匀、极度非均匀和均匀-非均匀溶解.其中对流占主导作用条件下,裂隙发生均匀溶解;化学反应占主导作用条件下,流体上游溶解速率高于下游.初始粗糙度对裂隙溶解过程也具有重要影响:初始粗糙度增大会使水岩化学反应速率增大,同时随着水岩反应的进行,裂隙溶解后粗糙度增大.

Characteristics of Reactive Solute Transport in the Dissolution Process of Rough Fractures

Solute transport in rock fractures is controlled by three mechanisms of convection, diffusion, and water-rock chemical reactions. The characteristics of reactive solute transport during the dissolution of rough fractures under the dominance of different mechanisms were analyzed, and the effect of roughness on solute transport was analyzed. The research results showed that there are four types of rough fractures dissolution processes, viz. uniform, non-uniform, extremely non-uniform, and uniform-non-uniform dissolution. In convection-dominated conditions, the fractures are dissolved uniformly, in chemical reactions dominated conditions, the dissolution rate at upstream of the fluid is higher than that at downstream. The initial roughness also has an important effect on the rough fractures dissolution process. Increasing the initial roughness will increase the water-rock chemical reaction rate, and at the same time, as the water-rock chemical reaction progresses, the fractures roughness will increase after the fractures are dissolved.