Compaction Banding in High‐Porosity Carbonate Rocks: 1. Experimental Observations

Identifying the mechanisms that control formation of compaction bands is high interest in reservoir mechanics since these structures may drastically affect performance geosystems operations. Considering difficulty to identify carbonate samples tested laboratory, Digital Volume Correlation technique applied here and proves be a relevant method. X-Ray Computed Tomography (XRCT) images Saint-Maximin limestone centimetric are recorded before after several triaxial loading stages deformation maps built. A new postprocessing method based on analysis kinematics throughout observed localization proposed their type. Compaction identified at relatively high-confining pressures, while shear lower confinements. The brittle-ductile transitional regime reveals compactive bands, diffuse under hydrostatic loading. effect porosity heterogeneities strain explored by computing 3D from calibrated XRCT images. found dominantly lay inside high-porosity zones, can cross both high- low-porosity zones. band orientation controlled primarily confining pressure. Moreover, heterogeneity strongly affects volumetric behavior with dilatant zones contrast Finally, Scanning Electron Microscopy observations reveal calcite grain crushing dominant intergranular cement cracking occurs denser