作　　者： (徐正建）; (刘洛夫）; (王铁冠）; (窦文超）; (宋兴沛）;

机构地区： 中国石油大学（北京）油气资源与工程国家重点实验室,北京102249 中国石油大学（北京）地球科学学院,北京102249

出　　处： 《矿物岩石地球化学通报》 2017年第4期637-649,共13页

摘　　要： 为探讨致密油成藏期次,结合成藏期烃源岩地层压力的估算,分析长7湖相致密油成藏动力,以鄂尔多斯盆地陇东地区上三叠统长7油层组致密油为例,通过有机地球化学与成藏动力学相结合的方法,结合区域地质资料,对所采集的样品进行储集层流体包裹体热动力学模拟和颗粒荧光定量分析(QGF与QGF-E),结果表明,研究区长7致密储集层发育5幕盐水包裹体与3幕烃类包裹体,代表连续一期三幕致密油成藏,成藏时间分别为142~139 Ma、128~122 Ma和114~106 Ma;PVT-sim模拟可得长7致密储集层烃类包裹体捕获压力为18.4~30.6 MPa,第1幕捕获压力为20.0 MPa左右,第2幕与第3幕捕获压力均大于25.0 MPa;早白垩世晚期,长7优质湖相烃源岩与致密储集层之间形成的源储压差为源储共生型致密油有效的成藏动力,成藏动力(源储压差)主要为3.6~27.8 MPa;第1幕致密油成藏动力为9.3 MPa,第2幕致密油成藏动力为14.9 MPa,第3幕致密油成藏动力为23.9 MPa。 Based on the thermodynamic simulations of fluid inclusions,the trapping temperatures and pressures of inclusions can be ascertained,and the characteristics of hydrocarbon accumulation dynamics can be analysed,combined with the formation pressure of source rocks during the main accumulation stage. This study focused on the tight oil of the Chang7 Member of Permian Triassic in the Longdong Area of the Ordos Basin. Through the methods of organic geochemistry and accumulation dynamics and the basis of collections and applications of the geological data in the study area,we make thermodynamic simulations on the fluid inclusions and analysis of quantitative grain fluorescence（ QGF and QGF-E） in the Chang 7 tight reservoir beds. We processed and analysed the data from the simulations and discussed the episodes and timing of tight oil accumulation. Lastly,the characters of the accumulation force of the Chang 7 tight oil reservoirs in the Longdong Area can be ascertained,combined with the formation pressure of source rocks during the main accumulation stage. The results show that five episodes of brine inclusions and three episodes of hydrocarbon inclusions were developed in the Chang 7 tight reservoir beds in the Longdong Area,indicating that three episodes of tight oil accumulation were developed in the Chang 7 tight reservoir beds. The accumulation timing is 142 - 139Ma,128 - 122Ma,and 114 - 106Ma.According to the PVT-simulations,the trapping pressure of hydrocarbon inclusions ranges from 18. 4MPa to 30. 6MPa.The 1^stepisode of trapping pressure was about 20. 0MPa,and the 2^ndand 3^rdepisodes of trapping pressures were over than25. 0MPa. In the late of the Early Cretaceous,the pressure differences between the source rocks and reservoir beds（ PDBSR） formed between the Chang 7high-quality source rocks and tight reservoir beds were the effective accumulation force of tight oil of para-genetic source-reservoir,which ranges from 3. 6MPa to 27. 8MPa. The 1stepisode of accumulation force of tight oil reservoirs was 9.

关 键 词： 流体包裹体 致密油 成藏动力 长 油层组 鄂尔多斯盆地