Evolution of fractal pore structure in sedimentary rocks

Sedimentation and Sedimentary Rocks

Sedimentary rocks are one component of the modern threefold classification of rocks. They derive from the lithification of sediments, which are produced in basically two ways: by the mechanical deposition of grains derived from the alteration of other rocks (detrital or clastic rocks), or as chemical precipitates or grains formed organically or inorganically from an aqueous solution. The whole ...

Time-dependent Diffusion Coefficients in Sedimentary Rocks Predicted by a Fractal Capillary Model

Applying the pulsed field-gradient nuclear magnetic resonance (PFG-NMR) technique, timedependent self-diffusion coefficients, ) (∆ D 0 D , of water were measured in anhydrite cemented sandstones, in order to determine geometrical parameters of the pore space. As a first approach the Padé approximation, combining the short-time behaviour with the long-time asymptotic value of (where is the bulk ...

Groundwater in Sedimentary, Metamorphic and Volcanic Rocks

Triple oxygen isotope variations in sedimentary rocks

Relatively large (P0.2&) O anomalies in the geologic record have been used to recognize atmospheric processes such as photochemical reactions and to trace changes in the partial pressures of O2 and CO2 in Earth’s atmosphere through time. However, recent oxygen isotope measurements of terrestrial rocks, minerals and waters also reveal common, smaller (but statistically significant) deviations fr...

Elastic Properties of Sedimentary Anisotropic Rocks

In multidisciplinary studies carried out in the Budare Oil Field of the Great Oficina Oil Field, there was difficulty matching well log synthetic seismograms with 2D and 3D seismic data. In addition, the seismically determined depths of reservoir horizons are greater than the well sonic log depths. To examine this discrepancy we conducted an experimental study of dynamic elastic parameters of t...