英买力地区中生界—新生界油气藏石油包裹体特征及成藏期次

The properties of petroleum inclusions and stages of hydrocarbon accumulation in Mesozoic-Cenozoic reservoirs in Yingmaili area of Tabei uplift,Tarim Basin

明确油气的成藏期次及成藏演化历史是当前英买力地区中生界—新生界油气藏勘探亟待解决的关键问题。利用石油包裹体岩相学、微束荧光光谱和显微测温技术,对英买力地区中生界—新生界石油包裹体特征和油气成藏期次开展了详细研究。结果表明：样品中主要观察到发蓝色、蓝白色、亮黄色、弱黄色荧光的石油包裹体;荧光光谱的主峰波长主要集中在470-490nm和510-540nm,分别指示近蓝白色和近黄色2种荧光的石油包裹体组合。其中,近黄色石油包裹体的红绿商Q在0.48-0.65,色度指数CIE-X和CIE-Y值在0.345-0.360和0.358-0.375,对应盐水包裹体的均一温度主峰值在80-90℃;近蓝白色石油包裹体的红绿商Q在0.20-0.51,色度指数CIE-X和CIE-Y值在0.302-0.333和0.325-0.352,对应盐水包裹体的均一温度主峰值在120-130℃。结合埋藏史、热演化史模拟结果,明确了英买力地区中生界—新生界油气藏具有2期成藏过程：第1期在8-5 Ma,以形成常规油藏为主,成熟度相对较低,石油包裹体发近黄色荧光;第2期在3 Ma以来,以形成凝析油气藏为主,成熟度较高,石油包裹体发近蓝白色荧光。

To clarify the stages and evolution process of hydrocarbon accumulation is presently the key issue of exploring Mesozoic-Cenozoic reservoirs in Yingmaili area of Tabei uplift,Tarim Basin.A detailed study was carried out to determine the properties of petroleum inclusions and the stages of hydrocarbon accumulation in Mesozoic-Cenozoic reservoirs using rock samples from typical wells,through a combination of microscopic examination,micro-beam fluorescence spectroscopy,and micro-thermometric technique.Results showed that petroleum inclusions in reservoirs rocks mainly emitted blue,blue-white,bright yellow,and weak yellow fluorescence.Peak wavelengths of the fluorescence spectra were mainly distributed in the ranges of 470-490 nm and 510-540 nm,corresponding to blue-white and yellow fluorescence,respectively.Of these,petroleum inclusions emitting yellow fluorescence had the red-green quotient of 0.48-0.65 and the chromaticity of 0.345-0.360（CIE-X）and 0.358-0.375（CIE-Y）,whereas the corresponding brine inclusions had the main peak of homogeneous temperatures at 80-90°C.Differently,petroleum inclusions emitting bluewhite fluorescence had the red-green quotient of 0.20-0.51,CIE-X of 0.302-0.333,and CIE-Yof 0.325-0.352,whereas the corresponding brine inclusions had the main peak of homogeneous temperatures at 120-130℃.Combined with simulation analysis of burial history and thermal evolution history,two-stage hydrocarbon accumulation was identified in Mesozoic-Cenozoic reservoirs in Yingmaili area：in the first stage（8-5 Ma）,mainly normal reservoirs were formed with relatively low maturity and petroleum inclusions emitting yellow fluorescence;and in the second stage（since 3 Ma）,mainly condensate reservoirs were formed with relatively high maturity and petroleum inclusions emitting blue-white fluorescence.