The effects of reservoir natural enviorenments, oil biodegradation and thermal recovery process on the endogenous prokaryotic communities in crude oils

While numerous studies have focused on environmental samples linked to crude oil, direct studies on microbial communities within crude oil are rare. This study investigates the chemical compositions and microbial communities of crude oils from Henan, Bamianhe, and Jianghan oilfields using gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS), and 16S rRNA gene amplicon sequencing. The prokaryotes in the crude oils of Henan oilfield were mainly composed of Lentimicrobium and Tepidiphilus, the prokaryotes in the crude oils from Bamianhe oilfield were mainly Klebsiella, Marinobacter, and the prokaryotes and fungi in the crude oils of Jianghan were mainly Flexistipes, Halanaerobium, and Sulfurimonas.