摘要
储层中流体古压力特征对刻画油气充注状态具有指示意义,流体包裹体PVTx热动力学模拟应用包裹体组分、均一温度和气液比,结合模拟软件可以恢复包裹体被捕获时的古流体压力,以塔里木盆地麦盖提斜坡玛南构造带鹰山组为例,首先应用激光共聚焦扫描显微镜测量油包裹体气液比,然后通过冷热台显微测温获得流体包裹体均一温度,最后通过荧光光谱仪,研究原油成熟度,综合划分了油气充注幕次并恢复了各幕次流体古压力,该应用有效区分了不同幕次流体古压力值。研究结果表明:玛南构造带鹰山组存在2期油气充注,第1期发生在海西中晚期,主要充注发橙色荧光的原油,其油包裹体均一温度范围43~59.2℃,伴生的同期盐水包裹体均一温度范围58.1~85.3℃,古流体压力为13.63~14.78 MPa,依据油包裹体荧光光谱参数判断该期原油为低成熟原油;第2期发生在喜山期晚期,主要充注发黄绿色、蓝绿色、蓝白色荧光颜色的原油,其油包裹体均一温度范围66~142.3℃,伴生的同期盐水包裹体均一温度范围95.4~189.2℃,古流体压力为20.09~33.52 Mpa,该期原油为中—高成熟度。研究结果有助于深化勘探区油气成藏规律的认识。
The reservoir paleo-pressure has implications to investigate the oil and gas charging events. This paleo-pressure can be restored by using PVTx thermal dynamics simulation of reservoir fluid inclusions based on components,homogenization temperatures and gas liquid ratio in combination with simulation software. A case study of the Ordovician Yanshan Formation in the Manan structural belt of the Maigaiti slope, Tarim Basin was conducted. First, the gas-liquid ratio of oil inclusion was measured by laser confocal scanning microscopy. Then, the fluid inclusion homogenization temperature was obtained by a heating/freezing system. Finally, the maturity of oil was studied by the fluorescence spectrometer. The oil and gas charging events and the pressure of each stage of fluid charging were recovered. The application of this methodology can effectively distinguish the paleo-pressure values of the different stages of fluid charging. Results show that there are two phases of oil and gas charging in the Yanshan Formation of the Manan structural belt. The first phase occurred in the middle and late Hercynian, mainly charging with orange fluorescent oil. The oil inclusions have a homogenization temperature range of 43~59.2℃, associated with the same period of aqueous inclusions, whose homogenization temperature ranges at58.1~85.3℃. The paleo-pressure of reservoir fluid was 13.63~14.78 MPa, and the crude oil was of low maturity according to the fluorescence parameters of oil inclusion. The second stage occurred in the late Himalayan period, mainly filled with yellow-green,blue-green, blue-white fluorescence color of crude oil. The oil inclusion homogenization temperature ranges at 66~142.3℃, associated with the same period of aqueous inclusion, whose homogenization temperature is of 95.4~189.2℃. The paleo-pressure of reservoir fluid is of 20.09~33.52 Mpa. The crude oil was of medium-high maturity. The results of this study can help to improve the understanding of hydrocarbon accumulation in the exploration area.
出处
《高校地质学报》
CAS
CSCD
北大核心
2017年第4期706-714,共9页
Geological Journal of China Universities
基金
国家重点基础研究发展项目"973"计划(2012CB214804)
西安石油大学青年科技创新基金项目(2014BS06)
陕西省教育厅重点实验室项目(16JS087)联合资助
关键词
流体包裹体
PVTx模拟
古压力
玛南构造带
fluid inclusion
PVTx simulation
paleo-pressure
Manan structural belt
