Experimental study of sealing performance: Effects of particle size and particle‐packing state on threshold pressure of sintered compacts

摘要: Threshold pressure Pcth (kPa), a parameter controlling rock's sealing performance in cases of CO2 geological sequestration, was studied supercritical CO2-water system under conditions 1000 m depth (10 MPa and 40°C). With respect to correlation between another important permeability, k (mdarcy), the closest-packing structure spherical particles is defined theoretically as line having slope −0.5 on double logarithmic plot. This study found this by measuring capillary plate with known throat diameter Pcth = 377.7 k– 0.5. function directly applicable different salinity conditions, although it requires minor correction at some temperature conditions. As first step determining range variation rocks' from internal particle structures, we used sintered compacts uniform silica diameters 0.1–10 µm. Results show that measured values were scattered around line, difference packing state depending additives sintering temperatures. The change state, occurring independently resultant changes porosity, varied sensitively according Pcth. Therefore, inferred depend strongly local within rocks. Knudsen number estimated for indicated transmuted into noncontinuum k < 0.1 µdarcy structure. Future studies should consider whether concept situation.