A testing procedure and analysis method is proposed that gives compaction and compressibility data that are independent of test duration for unconsolidated sands. Compaction data on unconsolidated sand material (including several Gulf of Mexico reservoirs) using this method are presented. Tests on twin plugs give essentially the same stress-strain data for test durations from 1 day to three months. This occurs because of a fundamental time-scaling property of these unconsolidated materials. The creep behavior is modeled using a fractional power law dependence with time, which represents the Voigt material model having an extremely broad distribution of relaxation times. This analysis indicates that the characteristic relaxation times of these materials are measured in decades or longer. ‘Creep equilibrated’ tests are therefore impractical and not relevant to a reservoir that will be depleted in one or two decades. Analysis of the power law creep parameters indicates the creep behavior is consistent at higher stresses among the materials tested. The creep parameters scale with stress and provide a means of decoupling the time-dependent behavior from the stress-strain behavior.

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