Discrimination of effective from ineffective porosity in heterogeneous Cretaceous carbonates, Al Ghubar field, Oman

Morphometry of micrite particles in cretaceous microporous limestones of the Middle East: Influence on reservoir properties

“…The wide range of porosity types in limestones (Lucia, 1995;Smith et al, 2003;Lønøy, 2006;Ehrenberg et al, 2008;Hollis et al, 2010) implies a complex distribution of fluid flow properties, e.g. porosity, permeability, water saturation.…”

“…;Budd, 1989;Smith et al, 2003). In these limestones, inter-crystalline micropores (pore diameter < 10 mm as defined by Cantrell andHagerty, 1999 or Lønøy, 2006) occur in a lithified matrix composed essentially of microcrystalline calcite particles ('micrite', Folk, 1962).…”

“…These micropores display specific log responses (e.g. gamma ray, sonic, resistivity) and have a major influence on petrophysical properties and oil recovery because capillary forces are strong and irreducible water common (Pittman, 1971;Cantrell and Hagerty, 1999;Trabesli and Beg, 2000;Smith et al, 2003;Richard et al, 2007;Fournier and Borgomano, 2009;Maliva et al, 2009;Vincent et al, 2011). Because their comparatively low porosity and permeability make water/oil saturation/recovery difficult to predict and achieve (Kieke and Hartmann, 1974;Petricola et al, 2002;Ahr et al, 2005;Mallon and Swarbrick, 2008), microporous limestones have until now received less attention than coarser macroporous limestones.…”

Investigation of pore-type heterogeneity and its inherent genetic mechanisms in deeply buried carbonate reservoirs based on some analytical methods of rock physics

“…In contrast, well-connected pores may have lower resistivity, m and capillary pressure values. The separation between shallow and deep lateral resistivity curves can be used to distinguish effective and ineffective reservoirs (Lucia and Conti, 1987;Smith et al, 2003). However, different pore types in effective reservoirs may have a similar resistivity separation when the difference in porosity is sufficiently large.…”

Effects of the Permian–Triassic boundary on reservoir characteristics of the South Pars gas field, Persian Gulf

“…Homogeneous carbonate reservoirs may be prone to diagenetic overprints of their original, depositional fabric (Nurmi et al 1990;Mazzullo and Chilingarian 1992;Russell et al 2002;Smith et al 2003). Such heterogeneities may be magnified in horizons close to stratigraphic boundaries where textural variations are common.…”