Sedimentary Reservoir Characteristics and Reservoir Classification Evaluation of Benxi Formation in Well Da-Ning Area, Ordos Basin

Several sets of sandstones are developed in the Benxi Formation of Carboniferous in the Upper Paleozoic in the Ordos Basin, which are transitional facies of Marine and continental facies and have significant unconventional natural gas potential. In order to reveal the sedimentary reservoir characteristics of the Upper Carboniferous Benxi Formation in the southeastern Ordos Basin, this paper makes comprehensive use of drilling and logging data, combined with various experiments, and conducts an in-depth study on the sedimentary reservoir characteristics of the Benxi Formation in the study area. Think benxi formation development barrier—tidal flat sedimentary system, reservoir lithology is given priority with fine grained quartz sandstone and lithic quartz sandstone, corrosion hole as the main reservoir space, combined with the feature of reservoir petrology, pore types, pore structure characteristics, physical characteristics, thickness of sand body and sedimentary facies types such as evaluation parameters。 The Benxi Formation reservoirs in the study area are divided into class I high-quality reservoirs, class II medium reservoirs and class III poor reservoirs.