Using Homogenization Temperature and Trapping Pressure of Fluid Inclusion to Doubly Constraint on Hydrocarbon Charging Times: As an Example of the Ordovician in Yubei Slope, Tarim Basin

Abstract

Although the method of homogenization temperature (Th) of fluid inclusion projecting on burial history diagram with thermal curve to obtain hydrocarbon charging times has been widely and effectively used, some uncertainty arises on the multi-cycle superimposed basins, in which one Th can appear at two or more than two depths. For the purpose of reducing the multiple solutions, two parameters of Th and trapping pressure (Pt) have been utilized to doubly constrain the times of hydrocarbon charging. When the Ths of oil inclusion and its coeval aqueous inclusion, gas to liquid ratio of oil inclusion and chemical components of oil inclusion are known, the trapping pressure of the oil inclusion can be thermodynamically modeled by the software VTflinc. As well known, Tarim basin is a typical multi-cycle superimposed basin. 63 fluid inclusion samples of the Ordovician from 11 wells in Yubei area were systematically measured. And the burial history diagrams with thermal curves for each well were established. After the Th of aqueous inclusion and the Pt of its coeval oil inclusion were projected doubly on burial history diagram for each well, the hydrocarbon charging time would be determined. Then, we put all the charging times on the same geological age axis, two events of hydrocarbon charging occurred: the first event took place from 272.2Ma to 257.5Ma (during the Late Hercynian), indicated by yellow and blue-green fluorescent oil inclusions; the secondary event from 13.1Ma to 9.9Ma (during the Late Himalaya), indicated by yellow and yellow-green fluorescent oil inclusions.

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