Prediction of a fracture-cavern system in a carbonate reservoir: A case study from Tahe oil field, China

摘要

The carbonate reservoir in China's Tahe oil field is very heterogeneous with many caves and fractures that resulted from deposition, tectonic movements, diagenesis, and karstifi-cation. The reservoir spaces are mainly caves, pores, and fractures that resulted from karsti-fication and structural deformation over several geologic periods. The Lower Ordovician carbonate rock, the main target, is at a depth of more than 5000 m. Karst topography dominates near the basal surface, fractures and caverns within the weathering zone. Laterally, the reservoirs are controlled by paleokarst highlands, slope, and faults that originated in different tectonic periods.