Theory of compaction bands in porous rock

Abstract

Abstract. Compaction bands are narrow planar zones of localized purely compressive (without shear) deformation that form perpendicular to the most compressive principal stress. Such bands have been observed in high porosity rocks in the laboratory and in the field. Because compaction presumably decreases permeability, these bands can act as barriers to flow within reservoirs. Reexamination of the results of Rudnicki and Rice (J. Mech. Phys. Solids, 1975) for shear localization, with corrections by Perrin and Leblond (J. Appl. Mech., 1993), reveals that they admit solutions for compaction bands in a range of parameters that is representative of porous rock. Solutions for compaction bands are possible when the inelastic volume deformation is compactive and is associated with a "cap" on the yield surface. The expression for the critical hardening modulus (related to the slope of the shear stress vs. shear strain curve at constant mean stress) at which compaction bands are predicted to form differs from that for shear localization. For parameters representative of porous rock, axisymmetric compression is the most favorable deviatoric stress state for formation of compaction bands. Comparison of conditions for shear localization and compaction band formation suggests that either may occur depending on the stress path and magnitude of the confining stress.

Deformation bands in sandstone: a review

“…Early stages of shear band formation may also involve a component of dilation, and, although rare, dilational shear bands have been observed in experiments and in the field Bésuelle 2001;Borja & Aydin 2004;Okubo & Schultz 2005). Pure compaction bands have been described in experiments and theory (Olsson 1999;Olsson & Holcomb 2000;Issen & Rudnicki 2001;Wong et al 2001;Baud et al 2004) and have been recognized in the field (Hill 1989;Mollema & Antonellini 1996;Sternlof et al 2005). They are favoured in high-porosity (20-30%) coarse sand and sandstone (Mollema & Antonellini 1996) and have been reported to occur in the contractional (leading) quadrants of faults (e.g.…”

Compaction bands and induced permeability reduction in Tuffeau de Maastricht calcarenite

“…To date, most of the modeling efforts for the prediction of compaction bands have focused on two invariant constitutive descriptions of the homogeneous deformation. Rudnicki and Rice [25], Olsson [20] and Issen and Rudnicki [11,12] adopted a simple constitutive framework whereby the yield envelope and inelastic volumetric change can be characterized by the pressure sensitivity parameter and the dilatancy factor, respectively. Their results are roughly consistent with the conditions under which compaction bands form.…”

Compaction Localization in Porous Sandstone: Implications for Reservoir Mechanics

“…He derived what is now known to be an overly restrictive set of values of constitutive properties for the appearance of compaction bands in axisymmetric compression. New work on the theoretical foundations of compaction band formation has extended the space of constitutive parameters over which the bands can form (Issen andRudnicki, 2000, 2001;Rudnicki, 2001). Besuelle (2001) draws attention to the fact that the theory actually predicts that the orientation of deformation bands can vary smoothly from parallel, through oblique, to perpendicular to the maximum compression direction.…”