Characteristics and main controls of shale oil reservoirs in Lucaogou Formation, Jimsar Sag, Junggar Basin

The characteristics and main controls of continental shale oil reservoirs in the Permian Lucaogou Formation in the Jimsar Sag of Junggar Basin were studied based on seismic, core and logging data. Oil was found in a large area in the Lucaogou Formation, mainly in micro and nano pore throats or bedding fractures in free or adsorbed states. There are two sweet spot layers separated by mudstones. The formation pressure and maturity of shale reservoirs gradually decrease from the sag area to the slope area, while the crude oil density gradually increases. The quality and maturity of source rocks controlled the distribution and properties of shale oil. The sedimentary microfacies controlled the distribution of shale oil. The lithology and physical properties of shale controlled the enrichment of shale oil. Hydrocarbon generation pressurization was the main driving force for shale oil accumulation.