Reservoir quality estimation using a new ternary diagram approach applied to carbonate formations in north-western Iraq

A new reservoir quality ternary plot (RQTP) of effective porosity, shale volume, and matrix is presented in this study. We show it to be a useful tool for first-order estimation the petrophysical zones classes each unit within reservoir. Subsequently, we combine RQTP results with permeability fracturing intensity data carbonate rocks provide better overall characterisation quality. The approach has been applied Butmah Formation, thick variable succession Liassic (Lower Jurassic) north-western Iraq. divides reservoirs into according to: (i) measure (ii) fraction shale, (iii) non-shale matrix. outcome applying model Formation indicates that best identified Unit 4, which consists fine medium dolomite rocks. These are not associated anhydrite cement or dissolved later due late dissolution, presenting as clean complex pore network heterogeneity. types were classified Rc2 Rc3 using Model. By contrast, worst qualities (Rc7) 1 composed cemented limestone shows low heterogeneity (predominantly uniform sizes), poor permeability.