oa Defining Critical Capillary Entry Pressures in Heterogeneous Mudstones – A Multi-scale Stochastic Approach

We demonstrate a new methodology to define and upscale the Critical Capillary Entry Pressure (CEPc) of heterogeneous mudstones on a centimeter to meter scale. Two elements are involved: (a) quantification of CEPc of mudstones as a function of lithology and (b) definition of the texture or architecture of mudstone sequences, in particular the vertical connectivity of lithologies with the lowest and highest CEPc values. Since the CEPc values of coarse-grained muds can be two orders of magnitude greater than those of fine-grained mudstones, mudstone texture plays a key role in defining meter-scale CEPc. CEPc (and thus seal capacity) on a meter (and higher) scale can be very different from measurements obtained on a sample scale.