A new kinetic model for authigenic quartz formation under overpressure

Abstract

To model the change of authigenic quartz content precisely in geological history, a new kinetic model combining time, temperature and pressure was established considering the retardation of overpressure to the formation of authigenic quartz on the basis of Walderhaug's kinetic model including time and temperature. The model was tested to be practically applicable in the Yinggehai Basin. The Cenozoic quartz sandstone in the central depression of the Yinggehai Basin was affected by overpressure during the formation of authigenic quartz. The overpressure inhibiting index was determined based on the measured pressure and authigenic quartz content. The model with overpressure inhibiting index can simulate the evolution of authigenic quarzt much better than Walderhaug's model. Overpressure sandstones with a pressure coefficient between 1.7 to 2.0 can cause the total amount of authigenic quartz to drop by 2.72% to 4.72%, which would result in high-quality reservoirs in deep overpressured formation. Key words: overpressure, authigenic quartz, overpressure inhibiting index, tight sandstone, kinetic model, high quality reservoir, Yinggehai Basin