Ordovician carbonate fracture-cavity reservoirs identification and quantitative characterization in Tahe Oilfield

In Tahe Ordovician carbonate fracture-cavity reservoirs,21 fracture-cavity units were divided by integrating well-seismic data with static and dynamic methods.According to natural energy and the reserves scale,the fracture-cavity units were classified and evaluated.A 3D through-going model of cave reservoirs in Tahe Oilfield was built by integrating well-seismic data and sequential indicator co-simulation.The results show that the cave reservoir is the main reservoir in Tahe Oilfield.During drilling and logging,serious fluid loss,drilling tools unloading and drilling time reducing to the minimum are important indicators to a large cave.The beads-shaped reflection and high abnormal impedance are the typical seismic response characteristic of cave reservoirs.Based on this,the spread of caves between wells can be predicted qualitatively.Besides,the reflection energy bodies and high-accuracy coherence cube can quantitatively predict caves distribution between wells.