The results, which can be displayed in two or three dimensions, can be interactively adjusted by modifying the stresses to investigate slip tendency and direction on each individual surface. Fault dilation tendency is computed from the three-dimensional stress state and the stress normal to a fault or extension fracture surface. Previously, these complex calculations were done manually for one fault orientation at a time. With 3DStress, calculations are made for all fault and fracture orientations and simultaneously displayed using stereographic projections, fault maps, and three-dimensional models of faults. A leaky trap is a naturally occurring potential gas or oil reservoir that may contain intersecting faults that channel the hydrocarbon away from the trap, resulting in little or no hydrocarbon accumulation.
Volcanic hazard analyses rely to a great extent on probabilistic techniques.
Ferrill explains that 3DStress provides a deterministic complement to these techniques by revealing the dilation tendencies of faults that could, under the right conditions, act as conduits for ascending magmas. The program can also be used to predict the effects of changing stress fields on existing faults in earthquake-prone areas. 3DStress provides a rapid means for evaluating dilation tendency in naturally fractured aquifers and can thus be used to predict groundwater flow direction and contaminant migration. 3DStress was developed under sponsorship of the U.S. Nuclear Regulatory Commission. Codevelopers are Ferrill and D. Brent Henderson of the Center for Nuclear Waste Regulatory Analyses, SwRI, and Dr. Alan Morris, associate professor at the University of Texas at San Antonio.