Wireline log-cyclicity analysis as a tool for dating and correlating barren strata: an example from the Upper Rotliegend of The

Abstract: The stratigraphic subdivision and correlation of the Upper Rotliegend Group in The Netherlands offshore is difficult due to lack of biostratigraphic data. A regional study of 150 released wells and core data has revealed the preservation of five supersequences, 12 sequences and short-term cyclicities in the Upper Rotliegend deposits. They are interpreted to reflect long- and short-term climate changes, which controlled the deposition of Rotliegend sequences. The supersequences (second order) se v best for regional correlation and prediction of sand distribution. The sequences (third order) are best suited for detailed block- or field-scale correlation a d distribution of (un)favourable lithofacies. The short-term (higher order) cycles represent orbital-forcing (Milankovitch) cycles and are used as quantitative parameters in wireline log cyclicity analysis. This includes the calibration of sequence boundaries and maximum flooding surfaces, the determination f the absolute age, the estimation of the duration time and the net accumulation rate of the preserved rock succession, and the pattern recognition of the trend of net accumulation rate variations within the third-order sequence. The method has revealed a new possibility of dating and correlating strata such as the Upper Rotliegend. The Upper Rotliegend Group is a succession of barren siliciclastic and evaporitic red-bed sedi