Scaling analysis of deposition from turbidity currents

摘要

Many oil-bearing sedimentary deposits are formed by the settling of particles from turbidity currents. Modeling sedimentary processes that form these turbidites enables the calculation of properties such as extent, depth, porosity and permeability of hydrocarbon-bearing reservoirs. This paper estimates the extent and thickness of turbidites from the initial conditions of the turbidity flow. This is achieved by the application of scaling analysis of the partial differential equations that govern the dynamics of and deposition from turbidity currents. We apply the results of scaling analysis to five modern submarine fans. The predicted and actual values of the dimensions of the fan deposits match well. We then compare the derived results against tabulated sizes of ancient turbidites. The comparisons are good as long as we correctly identify the flow regimes in which the deposition took place. The good agreements observed in the two cases show that the estimates obtained using scaling analysis can provide useful first-guess values for the dimensions of the deposits.