In the M Gasfield of Bohai Sea,there are two sets of gravels with different sedimentary types in the Paleogene Kongdian Formation,namely,residual/slope and alluvial,which have significant differences in clay minerals,mechanical properties,and pore structure,resulting in substantial differences in the lower limit of the gas saturation and the test productivity between the two sets of gravels.In addition,the resistivity curves are affected by the gravels and the low porosity and low permeability.The distinction between gas and non-gas layers is not apparent.The gas saturation obtained using the Archie equation often contradicts the test results,making it difficult to evaluate the reservoir quantitatively.Under the condition that the lower limit of gas saturation of two types of sandy conglomerate is determined by gas-water permeability experiments,based on the rock volume physical model of sandy conglomerate,a gas saturation model is constructed by using neutron and density logging response equations.After verifying the test productivity of three wells,compared with the Archie equation,the gas saturation calculated by the new model has more apparent differences between gas and non-gas layers,and the interpreted results are more consistent with the test productivity.
NETL
NSTL
维普
万方数据
