Influence of a Paleosedimentary Environment on Shale Oil Enrichment: A Case Study on the Shahejie Formation of Raoyang Sag, Bohai Bay Basin, China

The characteristics of paleosedimentary environments are great significance for the enrichment organic matter (OM) and hydrocarbons in lacustrine shale. This study analyzed mineralogy, well logging data, geochemical parameters (total carbon pyrolyzed hydrocarbon), inorganic (major trace elements), multiple proxies based on parameters. These were used to reconstruct environment lower 1st Member Shahejie Formation (Es 1 L ) reveal OM shale oil mechanisms establish a model. (Fe 2 O 3 +Al )/(CaO + MgO), Sr/Ba, Rb/Sr, Cu/Al, Th/U indicate that Es Raoyang Sag was deposited paleoenvironment dominated by arid paleoclimate, reducing conditions, saltwater. Paleoclimate, clastic influx intensity, preservation paleoproductivity, paleosalinity all affect abundance. accumulation mainly controlled high primary productivity surface water due algal blooms moderate salinities, which achieved using stratified columns with low oxygen conditions bottom water. As main valuable sites storage, carbonate mineral depositions enrichment. dominant lithofacies enrichment, carbonate-rich calcareous under drier strong salinity paleoenvironment. Additionally, profile sweet spot determined through combination lithofacies, logging, data.