Hydrodynamic Characteristics of Hydrocarbon Accumulation in Paleogene Ziniquanzi Formation of Huoerguosi-Manasi-Tugulu Structural Belt, Southern Junggar Basin, China: Constrains From Fluid Inclusions

Abstract

The subsurface hydrodynamic field, namely fluid potential, is a fundamental controlling factor on hydrocarbon migration and accumulation. Reconstruction of paleo-fluid potential in hydrocarbon accumulation process is helpful to correctly understand oil-gas distribution. Using fluid inclusions trapped in diagenetic minerals formed in different oil-gas evolution stages to reconstruct paleo-fluid potential is a direct and reliable method, which has been widely used at present. Hydrocarbon accumulation process in the south of Junggar basin is one of the research focuses of hydrocarbon exploration for foreland basins in China. In this study, mainly based on data from systematic analysis of fluid inclusions (petrography, micro-fluorescence, micro-FTIR, and microthermometry), combining with the reconstruction of burial history and thermal history, the stages of hydrocarbon accumulation in Ziniquanzi Formation of Huoerguosi-Manasi-Tugulu Structural belt were determined. On this basis, the evolution of paleo-fluid potentials and the advantageous areas for hydrocarbon accumulation in Ziniquanzi Formation during different hydrocarbon accumulation periods were reconstructed by fluid inclusion data. The results show that the studied area experienced two periods of hydrocarbon accumulation processes, the first period mainly occurred in Middle-Late Miocene (about 14–9 Ma), while the second period mainly occurred in Middle-Late Pliocene (around 3.7–2.5 Ma). The distribution characteristics of paleo-fluid potentials during these two periods of hydrocarbon accumulation processes are significantly different. In the first period, Tugulu anticline area was in the lowest potential area, which became the favorable area for accumulation of oil generated from Cretaceous source rocks. In the second period, Manasi anticline area became the lowest potential area, in which the gas generated by coal measures source rocks in Middle-Lower Jurassic accumulated.

AAPG Datapages/Search and Discovery Article #90217 © 2015 International Conference & Exhibition, Melbourne, Australia, September 13-16, 2015