Characteristics of fluid inclusions and accumulation process in the second Member of Dengying Formation of the Sinian in central Sichuan paleo-uplift
The accumulation process of Sinian Dengying reservoir in central Sichuan Paleo-uplift is complicated,and it is difficult to recover the filling period and evolutionary history of reservoir accumulation fluid.Predecessors have different views on the evolution process of paleo-oil reservoir accumulation in this area,which restricts the understanding of the accumulation law of deep marine oil and gas reservoir.This study takes the Penglai-Zhongjiang area on the northern slope of central Sichuan paleo-uplift as an example,and comprehensively analyzes the fluid inclusions in the area through microscopic petrographic observation,hydrocarbon inclusion abundance measurement,laser Raman spectroscopy analysis,homogenization temperature and salinity determination.The results show that there are three stages of fluid inclusions developed in the second Member of Dengying Formation of the Sinian in the Zhongjiang area of Penglai.In the early and middle stages,asphalt inclusions are mainly distributed in the calcite filled with pores in the early stage and in the dolomite and quartz near the carbonaceous asphalt in the middle stage.In the late stage,fluid inclusions are mainly gaseous hydrocarbon inclusions,with a few gas-liquid hydrocarbon inclusions and liquid hydrocarbon inclusions which distribute in the most recently formed healing fractures in quartz and calcite.The abundance EGOI of late gaseous hydrocarbon inclusions in the study area is more than 3％,which is an oil-bearing layer.The homogenization temperature and salinity tests show that the homogenization temperature of inclusions in the study area is continuously distributed from 80.6 ℃ to 231.4℃,and peaks appear in three sections,and the salinity ranges mainly from 8％to 20％.The analysis of reservoir accumulation process shows that there are three stages of accumulation in the study area.The first stage of paleo-oil reservoir was formed in the Late Silurian,the second stage of paleo-oil reservoir was formed in the Middle Triassic to Late Triassic,and the third stage of paleo-oil reservoir was formed by crude oil cracking from the Jurassic to Early Cretaceous;From the late Cretaceous to the present,the paleo-gas reservoir has been formed gradually through the adjustment period.
万方数据
维普
