Heterogeneous geological conditions and differential enrichment of medium and high maturity continental shale oil in China

HU Suyun,BAI Bin,TAO Shizhen,BIAN Congsheng,ZHANG Tianshu,CHEN Yanyan,LIANG Xiaowei,WANG Lan,ZHU Rukai,JIA Jinhua,PAN Zhejun,LI Siyang,LIU Yuxi

Table 1. Continental shale oil source rocks and reservoirs in Meso-Cenozoic lake basins of China

Water properties Basin Stratum Sedimentary facies Source rock characteristics Reservoir characteristics Lithology TOC/% S1/(mg•g-1) S2/(mg•g-1) Ro/% Organic matter type Thickness/m Favorable area/km2 Environment Paleoclimate Volcanic ash Sedimentary microfacies Lithology Thickness/m Porosity/% Permeability/10-3 μm2 Average pore-throat radius/μm Saline-brackish water Junggar Permian Lucaogou Fm. Salinized lake-delta Mudstone, dolomitic mudstone 2.0-14.0 0.01-3.00 0.06-110.00 0.50-1.60 Ⅱ 100-240 870 Anoxic bottom water environment Hot-warm climate Distributed in the whole sag Semi deep-deep lake Dolomitic siltstone and micritic dolomite 20-50 4-14 0.007 5-1.000 0.01-1.00 Freshwater-slightly saline water Songliao Daqing Cretaceous Qingshankou Fm. Deep lake- delta front Shale 1.8-4.5 1.00-10.00 5.80-37.60 0.75-1.67 I/II 200-600 2 225-5 520 Anoxic water body Warm and wet Developed locally Underwater distributary channel, beach bar, gravity flow, deep lake Siltstone-fine sandstone, shale 5-30 2-15 0.030-1.000 0.04-0.15 Jilin Cretaceous Qing-1 Member Semi deep lake Shale 1.0-2.5 0.04-3.00 0.70-14.00 0.70-1.00 I/II 60-300 2 200 Anoxic water body Warm and wet Freshwater Ordos Triassic Yanchang Fm. Semi deep - deep lake Shale and mudstone 0.6-32.0 0.20-7.10 0.30-46.10 0.70-1.30 I/II 20-100 30 000 Anoxic water body Warm Widely developed Underwater distributary channel, sandy debris flow, beach bar, gravity flow Siltstone-fine sandstone, muddy siltstone, medium- fine sandstone 2-10 3-13 Mainly 0.010-0.300 0.03-1.00