四川盆地西南部上二叠统峨眉山玄武岩成藏模式初探
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摘要
采用将周公山重点气藏解剖与区域地质分析相结合的方法,研究了四川盆地西南部上二叠统峨眉山玄武岩的特殊性、成藏的复杂性和多样性。分析认为:玄武岩在川、滇、黔广泛分布,研究区内其厚度为40~500m;玄武岩的多期溢流,造就其纵向上的多旋回性和各旋回顶部的溶蚀孔洞发育,发育的裂缝勾通孔洞构成了良好的渗流网络体系;气组分、同位素分析和亲缘对比研究结果认为,玄武岩天然气组成与震旦系和上三叠统气迥然有别,下二叠统是主烃源层,上二叠统相变为煤系地层区可能也有所贡献,燕山中晚期为生、排烃高峰期,也是玄武岩古油气藏的形成期,强烈的喜山运动使全区构造定型、油气重新调整并趋多样化。周公山—毡帽山区块应以寻找构造气藏为主,该区以东应着力于岩性气藏和构造—岩性复合型油气藏的勘探、研究工作。
The particularity of the Upper Permian Emeishan basalts and the complexity and variety of hydrocarbon accumulations in southwestern Sichuan Basin are studied through an analysis of the major gas reservoirs in the Zhougongshan area and regional geological study.It is believed that basalts are widely distributed in Sichuan,Yunnan and Guizhou provinces and are 40-500 m thick in the study area.Besides,the multistage overflow of basalts results in their vertical multicyclicity and the development of dissolution pores and cavities on the top of each cycle.The well-developed fractures interconnect the pores and cavities,forming favorable migration pathway networks.The following conclusions are also drawn through an analysis of gas components and isotopes and gas-source correlation.The components of gas in the basalts are distinctly different from that in the Sinian and Upper Triassic.The Lower Permian is the primary source rocks,while the Upper Permian may be the secondary source rocks in areas where facies change into coal measure strata.Hydrocarbon generation and expulsion peaked in the Middle-Late Yanshan when the basalt palaeo-reservoirs formed.The strong Himalayan Movement finalized the structural framework in the study area,and led to the readjustment and diversification of reservoirs.Structural gas reservoirs are the major targets of exploration in the Zhougongshan-Zhanmaoshan Block,while lithologic gas reservoirs and structural-lithologic composite gas reservoirs are the major targets in the areas to its east.
The particularity of the Upper Permian Emeishan basalts and the complexity and variety of hydrocarbon accumulations in southwestern Sichuan Basin are studied through an analysis of the major gas reservoirs in the Zhougongshan area and regional geological study.It is believed that basalts are widely distributed in Sichuan,Yunnan and Guizhou provinces and are 40-500 m thick in the study area.Besides,the multistage overflow of basalts results in their vertical multicyclicity and the development of dissolution pores and cavities on the top of each cycle.The well-developed fractures interconnect the pores and cavities,forming favorable migration pathway networks.The following conclusions are also drawn through an analysis of gas components and isotopes and gas-source correlation.The components of gas in the basalts are distinctly different from that in the Sinian and Upper Triassic.The Lower Permian is the primary source rocks,while the Upper Permian may be the secondary source rocks in areas where facies change into coal measure strata.Hydrocarbon generation and expulsion peaked in the Middle-Late Yanshan when the basalt palaeo-reservoirs formed.The strong Himalayan Movement finalized the structural framework in the study area,and led to the readjustment and diversification of reservoirs.Structural gas reservoirs are the major targets of exploration in the Zhougongshan-Zhanmaoshan Block,while lithologic gas reservoirs and structural-lithologic composite gas reservoirs are the major targets in the areas to its east.
引文
[1]刘成英,朱日祥.试论峨眉山玄武岩的地球动力学含义[J].地学前缘,2009,16(2):52-69.
[2]张云湘,骆耀南,杨崇喜.攀西裂谷[M].北京:地质出版社,1988.
[3]宋文海,庞家黎.四川盆地西南部上二叠统玄武岩含气性研究[J].天然气工业,1994,14(5):11-15.
[4]张若祥,王兴志,蓝大樵,等.川西南地区峨眉山玄武岩储层评价[J].天然气勘探与开发,2006,29(1):17-20.
[5]黄籍中,苟学敏.四川盆地二叠系玄武岩非常规气藏气源及勘探前景分析[J].天然气工业,1994,14(5):16-19.
[6]李厚民,毛景文,徐章宝,等.滇黔交界地区峨眉山玄武岩大火成岩区铜矿化蚀变特征[J].地球学报,2004,25(5):495-502.
[7]李厚民,毛景文,张长青,等.滇黔交界地区玄武岩铜矿中有机质的生物标志物特征及其地质意义[J].地质评论,2005,51(5):539-549.
[8]李厚民,毛景文,张冠,等.滇黔交界地区玄武岩铜矿蚀变分带和有机包裹体特征及其地质意义[J].地质学报,2006,80(7):1026-1034.
[2]张云湘,骆耀南,杨崇喜.攀西裂谷[M].北京:地质出版社,1988.
[3]宋文海,庞家黎.四川盆地西南部上二叠统玄武岩含气性研究[J].天然气工业,1994,14(5):11-15.
[4]张若祥,王兴志,蓝大樵,等.川西南地区峨眉山玄武岩储层评价[J].天然气勘探与开发,2006,29(1):17-20.
[5]黄籍中,苟学敏.四川盆地二叠系玄武岩非常规气藏气源及勘探前景分析[J].天然气工业,1994,14(5):16-19.
[6]李厚民,毛景文,徐章宝,等.滇黔交界地区峨眉山玄武岩大火成岩区铜矿化蚀变特征[J].地球学报,2004,25(5):495-502.
[7]李厚民,毛景文,张长青,等.滇黔交界地区玄武岩铜矿中有机质的生物标志物特征及其地质意义[J].地质评论,2005,51(5):539-549.
[8]李厚民,毛景文,张冠,等.滇黔交界地区玄武岩铜矿蚀变分带和有机包裹体特征及其地质意义[J].地质学报,2006,80(7):1026-1034.
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