论文部分内容阅读
通过分析渤海湾盆地东濮凹陷桥口—白庙地区古近系沙河街组天然气的组分、稳定碳同位素特征,对其天然气成因类型、成熟度和混源比例进行了研究,取得以下认识:桥口—白庙地区古近系沙河街组天然气成因复杂,有煤成气、油型气和混合气3种天然气类型;桥口地区烷烃气中甲烷含量明显低于白庙地区,而重烃气含量较高;白庙地区天然气成熟度普遍高于桥口地区,前者为成熟—高成熟阶段的烃源岩生成,后者为成熟早期—成熟阶段生成;桥口地区的桥14井、桥73井和桥76井为典型的油型气,主要来源于沙三段腐泥型有机质。白庙地区靠近兰聊断层的白3井和白8井,天然气为典型的煤成气,来源于石炭系—二叠系煤系地层。桥口地区的混合气以油型气为主,白庙地区的混合气则以煤成气为主。2个地区混合成因气具有多套烃源岩层位来源,石炭系—二叠系煤系、古近系腐泥型、腐殖型烃源岩均有贡献。
By analyzing the composition of natural gas in the Paleogene Shahejie Formation in the Qiaokou - Baimiao area of the Dongpu Depression in the Bohai Bay Basin and stabilizing the carbon isotope characteristics, the types of natural gas, the maturity and the ratio of mixed sources were studied, and the following findings were obtained: The Qiaokou-Baimiao area Paleogene Shahejie Formation is characterized by complex gas genera, including three gas types: coal gas, oil gas and gas mixture. The methane content in Qiaokou alkane gas is obviously lower than that in the Baimiao area, The gas content is relatively high; the maturity of natural gas in Baimiao area is generally higher than that in Qiaokou area, the former is the source rock of mature-high maturity stage and the latter is formed in mature early-maturity stage; Well 73 and Bridge 76 are typical oil-gas types, mainly derived from the sands of the sands. The Bai Miao area is close to the Bai 3 and Bai 8 wells of the Lan-Lia fault, with natural gas as a typical coal-derived gas, derived from the Carboniferous-Permian coal measures. Qiaokou gas mixture to the main oil-based gas, while the gas mixture in the White Temple area to coal-based gas. There are many sets of source rocks in the mixed gas source in the two areas, and the Carboniferous-Permian coal series, Paleogene sapropelic and humic hydrocarbon source rocks all contribute.