Estimating Permeability Using a Reservoir Quality Data-set Derived from Drill Cuttings: an Example from Pakistan

The studied Cretaceous gas field is located in Pakistan. As part of a greater integrated proof-of-concept and reservoir quality prediction project, part of this project’s scope was to demonstrate the validity of optically-derived permeability estimates from drill cuttings. The integration and interpretation of core, routine core analysis, petrology and drill cuttings data-sets has identified a set of ‘rules’ to constrain permeability estimates going forward and these are as follows: ≥80% total quartz coarse clay grain coating clay mean GS ≥ 0.3mm = ≥100 mD ≥ 80% total quartz coarse and/or fine clay ≥ 0.3mm mean GS = 10-100 mD 70-80% total quartz coarse and/or fine clay 8% = ≤ 1 mD Once constrained by either core-based testing and/or operator experience (microscopic analysis of core and cuttings (MACC) data provides a robust, rock-based data-set that can be used to accurately estimate permeability.