Assessing exploration risk requires an analysis of a range of issues including trap, seal, charge then considering reservoir issues. When risking 3-way structures across-fault juxtaposition and/or membrane seal are key issues. Trap preservation related to fault reactivation may also need be assessed. Considerable work has been done by a number of workers (Vrolijk 2016) to calibrate membrane sealing. Most notably back calculating the pressure capacity of the Shale Gouge Ratio (SGR) algorithm, to allow forecasting of columns. Importantly, this back-fitting of SGR and seal capacity has been conducted on single "best" technical models with no direct modelling of uncertainty (Yielding 2002).