Differences in ordovician oil and gas reservoir formation in the Tahe area and surrounding regions

The Tarim Basin has developed multi-stage and multi-source hydrocarbon generation and accumulation characteristics due to the influence of multi-stage tectonic movements.Hydrocarbon accumulation conditions vary significantly across different structural belts.This study applies fluid inclusion analysis to explore the accumulation periods in the Tahe area and the reasons for the differences among blocks.The results reveal variations in the fluorescence color and maturity of hydrocarbon inclusions.The Ordovician crude oil maturity is generally high in the south and west and low in the north and east, while the density of crude oil is the opposite.The Ordovician hydrocarbons demonstrate multi-stage accumulation with mixed charging characteristics, displaying temporal variations in charging periods.Generally, there are four stages of the Tahe oil and gas charging identified: late Caledonian, late Hercynian, middle and late Yanshanian, late Himalayan.Differences in hydrocarbon accumulation are primarily controlled by regional tectonic factors.Variations in tectonic evolution control the differences in the stages and timings of hydrocarbon accumulation.In particular, multi-stage tectonic activities are fundamental factors that control the complex distribution of oil and gas.