Geological conditions and enrichment factors of the Lucaogou Formation diamictite tight oil in Santanghu Basin, Xinjiang

The Lucaogou Formation in Santanghu Basin of Xinjiang is a set of lacustrine deposit, which is typical diamictite, mainly composed of detrital material of terrigenous origin, dust fall, carbonate rock in variable roportions.It has special geological formation conditions for tight oil, and unravelling its enrichment factors is critical for the further evaluation of the tight oil distribution and the favorable exploration area.In order to find out its enrichment factors, we make a comprehensive analysis of its geological background and main controlling factors in reservoir forming.The results indicate that deposited in saline sedimentation background, the deposits in the Lucaogou Formation in Santanghu Basin are dominated by shallow- semi-deep lacustrine facies, with dark fine-grained depostions.It has excellent oil-generating conditions.The distribution area of high-quality source rocks with organic matter abundance greater than 2% and thickness greater than 100 m exceeds 1200 km².Under the influence of volcanism, fault-crack and dissolution, favorable reservoir is widely developed.The condition of source rock-reservoir integration and intimate contaction in the Lucaogou Formation provides a good foundation for massive tight oil accumulation.The enrichment of tight oil in the Lucaogou Formation is mainly controlled by the quality of source rock, the quality of reservoir, source-reservoir assemblage and overpressure.