02109nab a2200205 4500 20260520000224.0 260224s2009 xxu Natural fracture characterization in tight gas sandstones Integrating mechanics and diagenesis nov. 2009 17/06/2010 ; 17/06/2010 16 p. ; 1535-1550 Transcripción del resumen del autor. Accurate predictions of natural fracture flow attributes in sandstones require an understanding of the underlying mechanisms responsible for fracture growth and aperture preservation. Poroelastic stress calculations combined with fracture mechanics criteria show that it is possible to sustain opening-mode fracture growth with sublithostatic pore pressure without associated or preemptive shear failure. Crack-seal textures and fracture aperture to length ratios suggest that preserved fracture apertures reflect the loading state that caused propagation. This implies that, for quartz-rich sandstones, the synkinematic cement in the fractures and in the rock mass props fracture apertures open and reduces the possibility of aperture loss on unloading and relaxation. Fracture pattern development caused by subcritical fracture growth for a limited range of strain histories is demonstrated to result in widely disparate fracture pattern geometries. Substantial opening-mode growth can be generated by very small extensional strains (on the order of 10–4); consequently, fracture arrays are likely to form in the absence of larger scale structures. The effective permeabilities calculated for these low-strain fracture patterns are considerable. To replicate the lower permeabilities that typify tight gas sandstones requires the superimposition of systematic cement filling that preferentially plugs fracture tips and other narrower parts of the fracture pattern. 11 AAPG Bulletin 93 ARTICULO Olson, Jon E. 12292 Laubach, Stephen E. 42957 Lander, Robert H. 31913 171181 171181 0 0 0 0 239000 BAAB BAAB 2026-03-05 200046039 0 200046039 2026-03-05 15:13:33 2026-03-05 ARTICULO