Characteristics of paleo-fluid and hydrocarbon charge history of Jurassic reservoir in Dibei gas field,Kuqa depression

Abstract

Petrography microthermometry of fluid inclusion, quantitative grain fluorescence (QGF) and quantitative grain fluorescence on extract(QGF-E) are used to study the paleo-fluid characteristics and hydrocarbon charging history of Jurassic reservoir in Dibei gas field, Kuqa depression, Tarim Basin.The results show that the Jurassic reservoirs in Dibei gas field develop inclusions with two stages:the first stage is liquid inclusion with yellow-green color, which indicats the filling of early oil;the second stage is gas-liquid inclusion with blue-white fluorescence color and gas inclusions with non-fluorescence color, which indicats that the late gas was charged.The homogenization temperature of inclusions indicats the two stages of hydrocarbon charging. QGF and QGF-E show that the oil in the Jurassic reservoir of the Dibei gas field may be a mixture of different origins or different maturity.Combined with the sedimentary history of Dibei gas field, it is suggested that the Dibei gas field has experienced two stages of oil and gas charging.The first is the filling of oil between 18~16 Ma.Gas charging period in the second stage is 5~3 Ma.Since the Xiyu period, the tectonic movement has been strong and the gas field accumulate at low parts.

Keywords

• dibei gas field
• jurassic reservoir
• fluid inclusion
• quantitative grain fluorescence
• hydrocarbon charge histoy
• characteristics of paleo-fluid