Determination Of The Existence Of A Fractal-Law Distribution Throughout The Mereenie Field Fracture System
Geoscience Honours Degree, 2011
University of Adelaide
On the basis of results obtained from analysis of size and population fracture data collected over five orders of magnitude, the fracture system observed at the Mereenie Field, northwest Amadeus Basin, does not correspond to a power-law distribution and is therefore not indicative of a natural fractal.
Analysis of two data sets used to collate information on the number of fractures obtained for a given area were plotted against the respective size of the fractures on a log-log plot to assess whether a straight line curve, indicative of a power-law distribution could be obtained. This could then be used to create an idealised straight line curve between core and field scale fracture data, allowing for the prediction of fracture size or population values at any point along the line.
Collection of data aimed at determining the population and size of fractures at core and field scale, resulted in observation of fracture properties in both data sets. Core observations noted a lithology control on the size and population variations of small scale fractures. Where competent sandstones display evidence of extensive natural fracturing by brittle deformation while shales demonstrate stress accommodation via ductile deformation resulting in only minimal shale hosted natural fractures.
Field scale fracture observations noted the dominance of north-northwest trending type 2 fold related fractures at the surface of the field, accompanied by numerous less developed fracture sets including type 1 fold related fractures and a set of north-northwest trending fractures indicative of the presence of a regional fracture swarm across the Mereenie Anticline.