Understanding the spatial and temporal distribution of fluid flow in the subsurface is of funda- mental importance to the successful management of groundwater and hydrocarbon resources. The analysis is restricted to open mode fracture sets, usually recognized for important contributors…
Understanding the spatial and temporal distribution of fluid flow in the subsurface is of funda- mental importance to the successful management of groundwater and hydrocarbon resources. The analysis is restricted to open mode fracture sets, usually recognized for important contributors to permeability in the case of low porosity reservoirs. We investigated, on a mechanical basis, several field representations likely to oc- cur when jointing and fracture clustering take place. Clustering cannot be explained by effective horizontal tensional conditions resulting in fluid driven fractures, in view of the screening effect between very closely spaced fracture planes, even if we assume sub-critical propagating conditions. Systematic joints form at depth, as a result of tectonic compression in combination with high pore pressure. Unconfined effective con- ditions arise to produce low rock strength and brittle deformation and load parallel extension fractures are the rule.