Abstract:

Statistical analysis,probability cumulative curve of sandstone grain size,C-M plot and core observation show that the shallow reservoirs in Gaoshangpu oilfield are of fluvial depositional system.3-D visiualized models have been made for the sedimentary facies in a single well,section and plane,and the fluvial type can further be classified as alluvial fan braided channel.Based on the research of depositional system,3-D quantitative characterization of reservoir's porosity and permeability has been made by using well logging interpretation data(including porosity,permeability,shale content and oil-reservoir groups)and geostatistical modeling technology.Lastly,according to the evaluation parameters,including control factor of oil,facies association,reservoir-cap rock association and faults,3 major reservoir groups have been pointed out,and G75-G94-G29 and G3106-G30-G68-30 well blocks are determined to be the most favourable blocks.There are 14 layers evaluated to be the most favorable pay beds,including the 1st and 2nd layer in the 2nd submember and the 1st layer in the 3rd submember of the lower member of Minghuazhan Formation;and there are 15 layers evaluated to be relatively favorable pay beds,including the 3rd layers in the 2nd and 3rd submembers of the lower member of Minghuazhen Formation;while the other 15 layers are evaluated as unfavorable layers,including the 4th,5th and 6th layers in the 2nd submember of the lower member of Minghuazhen Formation.

Key words: Gaonan, sedimentary facies, reservoir modeling, comprehensive evaluation of reservoirs