塔中地区中深5井寒武系油气成藏期次研究

Hydrocarbon Accumulation Period of Cambrian in Zhongshen 5 Well in Tazhong Area

塔里木盆地塔中地区中深5井在中下寒武统揭示了工业性油气显示。为厘定中深5井寒武系油气成藏期次,对溶孔充填方解石及微裂缝中检测到的大量与含烃(油、气)包裹体共生的盐水包裹体进行系统检测。基于紫外光、透射光显微镜下观察、均一温度测试、激光拉曼气体组分分析等技术手段,结合中深5井埋藏史-热史特征,对寒武系油气成藏期次开展研究。结果表明:塔中地区中深5井上寒武统阿瓦塔格组发育3期不同类型烃类包裹体,对应3期成藏过程;中深5井寒武系发育3期油气充注过程,第一期与第二期为加里东晚期原油充注过程,对应均一温度为90℃~110℃、130℃~140℃;第三期为喜山期天然气充注过程,对应均一温度为160℃。

Industrial oil and gas from the Middle and Lower Cambrian were found in Well ZS5 in the Tazhong area of the Tarim Basin. In order to determine the hydrocarbon accumulation period of the Cambrian in the Zhongshen 5 well, a large number of brine inclusions coexisting with hydrocarbon-containing (oil, gas) inclusions detected in the dissolved pores and micro-cracks were systematically tested. Based on the ultraviolet light, transmission light microscopy observation, homogenization temperature test, laser Raman gas composition analysis and other technical means, combined with the burial history of the Zhongshen 5 well, the research on the Cambrian oil and gas accumulation period was carried out. The results show that there are three different types of hydrocarbon inclusions in the Upper Cambrian Avatag Formation in the Zhongshen 5 well of the Tazhong area, corresponding to the three stages of accumulation process;there are three stages in the hydrocarbon filling process of the Cambrian development in the Zhongshen 5 well, the first and second stages are the filling process of crude oil in the Caledonian movement, and the corresponding homogenization temperature is 90℃-110℃ and 130℃-140℃;the third stage is the natural gas charging process happened during Himalayan movement, corresponding to the homogenization temperature of 160℃.