Characteristics and origin of lateral cyclic patterns in petrophysical, geochemical, and petrographic properties of dolomite: Miocene Seroe Domi Formation, Bonaire, Netherland Antilles.

摘要

Two ∼200 ft long lateral transects were drilled at 1-ft spacing across a dolomitization front in the Miocene Seroe Domi Formation in Bonaire, Netherland Antilles. All 287 recovered samples were analyzed for petrophysical, geochemical, and petrographic attributes. Variography of the resultant data sets show that dolomite porosity, permeability, and trace-element attributes contain three scales of lateral variability: ∼60% of the total variance at short lags (1-ft), short-scale correlation lengths of 10--36 ft, and long-range oscillatory patterns at 62 ft. In contrast, none of the variograms of limestone attributes show evidence for any patterns. Additionally, no dolomite petrographic feature appears to control lateral patterns. Lateral patterns in the dolomite must have formed by the process of dolomitization as the limestone contains not patterns to be inherited and this is the only geologic process that has affected the dolomites but not the limestones on the other side of the front.