PERMEABILITY RESCALING AND NEAR-WELLBORE MODELING OF HETEROGENEITIES IN LOWER JURASSIC TIDAL-INFLUENCED TILJE FORMATION, HEIDRUN FIELD

摘要

The Lower Jurassic Tilje Formation constitutes an important reservoir in the Heidrun Field. Reservoir characterization of its strongly tide-influenced deposits is challenging due to the high degree of heterogeneity. This is especially true for the estimation of permeability data from different scales (core plug measurements, log data and well test data). On a well test scale, permeability is influenced by larger scale heterogeneities, such as lateral changes in depositional facies, dipping beds and faults. In this study, we demonstrate that the use of small and medium scale process-oriented geological models has the potential to reconcile conflicting data and give a consistent interpretation of both horizontal and vertical permeabilities. We illustrate how this advanced modeling technique can be used to evaluate anisotropic permeability in a thinly bedded, low net-to-gross reservoir. We present a case study for which stochastic near-wellbore models are built at the centimeter-to decimeter-scale for a 35m well interval in the lower Tilje formation. This makes it possible to rescale high resolution measurements (core plug and wireline log data) to the well test scale and compare uncertainties from the different data sets in a systematic manner. The model results are compared to well observations at the appropriate scale. The modeling technique successfully quantifies the effects of heterogeneity in this strongly tidal-influenced reservoir system.