Quantitative estimate of residual or palaeo-oil column height

A method to quantitatively estimate residual or palaeo-oil column heights is proposed using criteria based on the presence or absence of oil shows in a single heterogeneous reservoir rock sample. The residual or palaeo-oil column height below the sample is constrained through the determination of the displacement pressure of regions in the sample containing oil shows (Pd-o) and the displacement pressure for regions that are devoid of any evidence of oil shows (Pd-w). The height of the residual or palaeo-oil column below the sampling depth can then be estimated to be greater than the equivalent height corresponding to Pd-o, but less than the height corresponding to Pd-w. Three examples from two basins in China were investigated using the method to determine their residual and palaeo-oil column heights.