Fracture orientation, trace length, termination mode, spacing and other surface and shape data have been collected, using scanline and areal mapping techniques, on approximately 1600 fractures from surface outcrops of the Monterey Formation in western Santa Barbara county. Trace lengths for each cluster or set of fractures appear to follow a log-normal distribution with mean values that vary by up to a factor of five between clusters in the same area and rock type. Spacing values also appeared to follow a log-normal distribution. However, mean spacing values differ only by a factor of up to two between clusters in the same rock mass. Correcting the raw data for censoring and truncation produced a significant change in the distribution statistics.
These fracture statistics have been used to create both 2-D and 3-D stochastic fracture network models that have been analyzed using discrete fracture flow codes to determine the effects of fracture geometry on reservoir permeability. Comparison is made to other work in which fracture geometry and hydraulic data have been integrated, using 3-D discrete codes, in order to provide 3-D reservoir properties that have compatible flow and transport properties.