Characterization of sub-seismic resolution structural diagenetic heterogeneities in porous sandstones: Combining ground-penetrating radar profiles with geomechanical and petrophysical in situ measurements (Northern Apennines, Italy)

Structural control on fluid flow and shallow diagenesis: insights from calcite cementation along deformation bands in porous sandstones

“…5a, b). The presence of pore-filling cement would increase the strength of the sandstone (Del Sole et al, 2020), preventing rotation and sliding of particles, and increase rock cohesion (Bernabé et al, 1992) and grain contact area, thus yielding a uniform contact stress distribution and higher stiffness (Dvorkin et al, 1991). Extensive cement, then, would inhibit DB development.…”

“…Structural and diagenetic processes commonly affect the petrophysical properties and reservoir quality in these rocks. The importance of the interaction between deformation and structures, fluid flow, and diagenetic processes has been emphasized only during the last 2 decades (e.g., see the recently coined term structural diagenesis; Laubach et al, 2010;Mozley and Goodwin, 1995;Eichhubl et al, 2009;Balsamo et al, 2012;Philit et al, 2015;Antonellini et al, 2017Antonellini et al, , 2020Del Sole et al, 2020). If deformation influences diagenesis and vice versa, a feedback can eventually develop between these two processes.…”

“…Early diagenesis influences the mechanical properties of rocks (Antonellini et al, 2020) and, in turn, their mechanical stratigraphy (Laubach et al, 2009;La Bruna et al, 2020). "Structural and diagenetic heterogeneities" (referred to as SDHs from now on) can determine the textural characteristics (e.g., grain L. Del Sole et al: Structural control on fluid flow and shallow diagenesis size, grain shape, relative proportion of grains, and matrix material) as well as the petrophysical and mechanical properties of the rock volume hosting them Aydin, 2000;Faulkner et al, 2010;Bense et al, 2013;Pei et al, 2015;Del Sole et al, 2020). Cement precipitation in granular porous siliciclastic rocks leads to porosity loss, reduction in permeability (Tenthorey et al, 1998;Morad et al, 2010), and, in turn, overall reservoir quality deterioration (Ehrenberg, 1990;Morad et al, 2010).…”

“…Carbonate cement is commonly concentrated within a few specific horizons or nodules with various shapes and arrangements (Kantorowicz et al, 1987;Bjørkum and Walderhaug, 1990;Mozley and Davis, 1996), making porosity and permeability prediction more challenging (Davis et al, 2006;Morad et al, 2010). Furthermore, cement increases the mechanical strength of the host rock (Dvorkin et al, 1991;Bernabé et al, 1992;Boutt et al, 2014), influencing fault-zone architecture and potential fault reactivation (Dewhurst and Jones, 2003;Flodin et al, 2003;Wilson et al, 2006;Williams et al, 2016;Philit et al, 2019;Pizzati et al, 2019).…”

“…Cement has been found in association with DBs. Localization of cement along these structural features may significantly enhance porosity and permeability reduction caused by mechanical crushing and reorganization of grains, thus increasing their sealing or buffering potential (Edwards et al, 1993;Leveille et al, 1997;Fisher and Knipe, 1998;Parnell et al, 2004;Del Sole et al, 2020). The occurrence, distribution, and petrophysical properties of cement along DBs therefore need to be properly characterized and implemented into reservoir quality modeling to predict porosity, permeability, and their heterogeneity (e.g., Morad et al, 2010).…”