Maceral Control on the Hydrocarbon Generation Potential of Lacustrine Shales: A Case Study of the Chang 7 Member of the Triassic Yanchang Formation, Ordos Basin, North China

Organic matter (OM) type critically controls the hydrocarbon generation potential and organic pore development in black shales. However, maceral variation lacustrine shales its control on are not yet well understood. In this study, 15 Chang 7 Member shale samples of Yanchang Formation, Ordos Basin, were investigated with petrography, Rock-Eval pyrolysis, a scanning electron microscope to study composition, potential, pores succession. The results show that studied oil window (Ro~0.70%). OM belongs Type I III kerogen, as demonstrated by pyrolysis. Macerals composed amorphous OM, alginite, sporinite, liptodetrinite, vitrinite, inertinite, solid bitumen. Amorphous alginite major hydrocarbon-generating macerals, their content determines Secondary observed due either low thermal maturity or dominance terrigenous OM. Maceral can affect reliability using Tmax indicator. This provides important insights into shales, calling for critical evaluation successions petrography.