Pressure loading histories and clay fraction effects on the static and dynamic elastic properties of sand-clay synthetic sediments

摘要

Investigations of the elastic mechanical characteristics of loosely compacted mixed sand-clay samples are essential for the characterization of shallow seafloor sedimentary reservoirs. Here, we used a series of sand-clay mixtures (0-100% clay by weight) to investigate the effects of pressure load histories (2-50 MPa) and clay fraction on porosity, P-wave velocity, S-wave velocity, and static modulus. The results indicated that, under pressure load cycles, the sand-clay mixture samples exhibited high permanent compaction, and porosity decreased rapidly with increasing clay content. However, porosity changed differently in response to pressure load as compared to pressure unload. Correspondingly, P-wave velocities differed significantly between pressure load and unload.