A cyclostratigraphic framework of the Upper Carboniferous Westoe and Cleaver formations in the southern North Sea Basin as a methodology for stratigraphic reservoir characterisation

Abstract Orbital driven climate control on sedimentation produces regional, stratigraphically repetitive characters and so cyclostratigraphic correlation can improve identify stratigraphic trends in borehole sections. This concept is commonly used to correlate marine lacustrine strata. However, the alluvial domain, its use more challenging because internal, local dynamics controlling may interfere with expression of cyclic forcing. Intervals low net-to-gross be important for successful application this domain as they tend better document regional changes. study applies climate-based concepts well correlations, characterise vertical sand distribution, potential reservoir targets a generally interval. Coarsening upward sedimentary repetitions (cyclothems) are identified correlated high certainty nineteen sections upper Carboniferous Westoe Cleaver formations Silverpit Basin. Local provide variability character cyclothems several types cyclothem classified. Correlation using recognised wireline logs done twice: once manually semi-automatically. The semi-automated based calculation deviation curves which depict changes that less dependent absolute values follow clearly. correlations composite stratigraphies analysed proportions curves. Both approaches yield similar results terms trends. detailed wells, manual at accounting any within system. same two zones higher ratios found both methods. These linked palaeoclimatic by long eccentricity proposed model has predictive value identifying sandstone occurrence. improves assessment distribution properties small (10–20 m thickness) large (100–200 stratigraphical scales.