Uncertainty Evaluation in Measure Results of Rock Permeability

This paper introduced the measure methods model and principles of Permeability in the ECK- II; the uncertainty source for the measure results was analyzed in detail. Combined with the test and calibration works; the mathematical model was established; considering each uncertainty component which affected the measure results of rock permeability. The standard samples of cores; A38(length:2.495cm;diameter:2.456cm);was taken for example. The uncertainty of measure results was carried out by type A and B estimation; the relative uncertainty of the method was calculated. Through reasonable evaluated the components of uncertainty which including causing uncertainty by pressure changing; temperature changing; stability of the measure instruments and vernier caliper reading error. The uncertainty from stability of the measure instruments was detailedly analyzed by the line graph. By evaluating uncertainty of rock permeability in measure results; we find that the biggest influence on total standard uncertainty is the core size; so in the work the operator's experimental skills should be paid great attention to.