Determination of Physical Property Lower Limits of Chang 6 Effective Reservoir in Tangjiaping Area, Ordos Basin

摘要

Arkose has been designated as the main reservoir of Chang 6 oil-bearing formation in Tangjiaping area and has a good development of residual inter-granular pores and dissolved pores. The porosity of Chang 6 reservoir mainly ranges from 5% to 12% and the average is 9.2%, while the permeability is mostly less than 1×10~(-3)μm~2 and the average is 0.85×10~(-3)μm~2, and belongs to typical tight reservoir. With integrated analysis of four methods, the physical property lower limits of Chang 6 tight reservoir have been determined: the porosity is 8%, permeability is 0.2×10~(-3)μm~2 and oil saturation is 42%, all of which can be used to calculate the reserves of tight reservoir.