Relative permeability,hysteresis and I-Sw measurements on a carbonate prospect

摘要

We present SCAL measurements on a high porosity Middle East carbonate reservoir.The cores are aged with crude,and relative permeability is measured using an X-ray steady state,a γ-ray steady state and the centrifuge technique.In the steady state we measured the primary imbibition and secondary drainage relative permeability curves of oil and water.Both resistivity and oil/water saturation can be measured along the core on different places,allowing the quantification of capillary end effects and its impact on resistivity.In the centrifuge we measured the imbibition oil relative permeability curve.The main points of interest are: 1.Reconciling reservoir initial water saturation as obtained from logs and SCAL 2.Wettability and relative permeability of aged samples;3.Comparing I-Sw measurements from the continuous injection technique with resistivity measurements done in the X-ray steady state.4.Hysteresis in relative permeability and I-Sw between the imbibition and secondary drainage curves.We will show that the hysteresis in relative permeability is typical for a mixed-wet sample.After aging the samples I-Sw results show marginal hysteresis.For these mixedwet samples we measured a high saturation exponent(n = 3)compared to n=2.2 measured in the continuous injection method on water-wet samples taken from the same formation.