论四川盆地奥陶系天然气勘探
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摘要
四川盆地奥陶系的天然气勘探一直未取得较好成效。为此,分析了奥陶系2组烃源岩(灯影组、九老洞组)的生油气条件:①灯影组具有生油条件,唯其时代久远,埋藏一般较深,有机质已演化到过成熟阶段(Ro>2%),所生成的石油皆已裂解为天然气;②九老洞组烃源岩生气强度十分可观,以成都、乐山、自贡与资阳地区为最丰,生气强度为20×108~230×108m3/km2。通过储层物性、缝洞分析(古岩溶缝、洞穴的发育分布,古岩溶的演化,裂缝作用)及盖层条件分析,结合该区雅安—龙女寺古隆起、天井山古隆起、泸州古隆起与油气的生成关系分析结果,认为在奥陶系找气仍有较好前景,并提出了勘探建议:盆地中、西部的弧形地带,即从广元经南充、华蓥山—乐山,以及加里东期形成的泸州古隆起和威远巨型穹隆背斜构造,皆是奥陶系下一步勘探的有利区块。
No significant gas discoveries have ever been made in the Ordovician of the Sichuan Basin.As the Lower Ordovician is more adjacent to the underlying source rocks and has well-developed reservoirs,exploration has extended correspondingly to the Early Ordovician sedimentary facies,including clastic facies,carbonate platform facies changing upward to clastic facies,and shallow carbonate platform ramp facies.The hydrocarbon generation conditions of two source rocks in the Ordovician are studied.The first is the Dengying Formation.It had oil-generation conditions.However,it is old in age and deep in burial depth.The organic matters are over-mature (Ro>2%) and the oil generated has been cracked into gas.The second is the Jiulaodong Formation.It has quite good gas-generation intensity,especially in Chengdu,Leshan,Zigong and Ziyang,where the gas-generation intensity is up to 20-230 ×108m3/km2.Based on the analysis of petrophysical properties of the reservoirs,development of fractures and cavities,sealing conditions,as well as the relationship between hydrocarbon generation and plaeohighs such as Ya'an-Longnǘsi,Tianjinshan and Luzhou,it is believed that gas exploration in the Ordovician is prospective and several potential exploration areas are identified,including the arcuate zones in the central and western parts of the basin,as well as the Caledonian Luzhou paleohigh and the huge Weiyuan dome anticline.
No significant gas discoveries have ever been made in the Ordovician of the Sichuan Basin.As the Lower Ordovician is more adjacent to the underlying source rocks and has well-developed reservoirs,exploration has extended correspondingly to the Early Ordovician sedimentary facies,including clastic facies,carbonate platform facies changing upward to clastic facies,and shallow carbonate platform ramp facies.The hydrocarbon generation conditions of two source rocks in the Ordovician are studied.The first is the Dengying Formation.It had oil-generation conditions.However,it is old in age and deep in burial depth.The organic matters are over-mature (Ro>2%) and the oil generated has been cracked into gas.The second is the Jiulaodong Formation.It has quite good gas-generation intensity,especially in Chengdu,Leshan,Zigong and Ziyang,where the gas-generation intensity is up to 20-230 ×108m3/km2.Based on the analysis of petrophysical properties of the reservoirs,development of fractures and cavities,sealing conditions,as well as the relationship between hydrocarbon generation and plaeohighs such as Ya'an-Longnǘsi,Tianjinshan and Luzhou,it is believed that gas exploration in the Ordovician is prospective and several potential exploration areas are identified,including the arcuate zones in the central and western parts of the basin,as well as the Caledonian Luzhou paleohigh and the huge Weiyuan dome anticline.
引文
[1]中国科学院南京地质古生物研究所.西南地区地层古生物手册[M].北京:科学出版社,1974:23-30.
[2]张文堂.中国的奥陶系——全国地层会议学术报告汇编[M].北京:科学出版社,1962:58-66.
[3]中南地区区域地层表编写组.中南地区区域地层表[M].北京:地质出版社,1974:104-142.
[4]张声瑜,唐创基.四川盆地灯影组区域地质条件及油气远景[J].天然气工业,1986,6(1):3-9.
[5]西北大学地质系石油地质教研室.石油地质学[M].北京:地质出版社,1979.
[6]陈作全.石油地质学简明教程[M].北京地质出版社,1987:36.
[7]赵文智,邹才能,冯志强,等.松辽盆地深层火山岩气藏地质特征及评价技术[J].石油勘探与开发,2008,35(2):129-142.
[8]计德华,岳宏.川西南震旦系油气勘探前景的探讨[J].天然气工业,1986,6(1):10-14.
[9]王世谦,陈盛吉,陈宗清,等.四川盆地油气资源评价[R].成都:四川石油管理局,2002.
[10]宋文海.对四川盆地加里东期古隆起的新认识[J].天然气工业,1987,7(3):6-11.
[11]刘宝-.沉积岩石学[M].北京:地质出版社,1980:224.
[12]陈宗清.四川盆地中二叠统茅口组天然气勘探[J].中国石油勘探,2007,12(5):1-11.
[13]陈宗清.川东石炭系潮坪沉积区地层划分对比与找气意义[J].地质学报,1985,59(2):87-96.
[14]地质部第五普查大队.贵州及邻区地层古生物手册[R].贵州:地质部,1962.
[15]石油工业部四川石油会战指挥部.四川盆地石油勘探综合数据手册[G].成都:石油工业部四川石油会战指挥部,1966。
[2]张文堂.中国的奥陶系——全国地层会议学术报告汇编[M].北京:科学出版社,1962:58-66.
[3]中南地区区域地层表编写组.中南地区区域地层表[M].北京:地质出版社,1974:104-142.
[4]张声瑜,唐创基.四川盆地灯影组区域地质条件及油气远景[J].天然气工业,1986,6(1):3-9.
[5]西北大学地质系石油地质教研室.石油地质学[M].北京:地质出版社,1979.
[6]陈作全.石油地质学简明教程[M].北京地质出版社,1987:36.
[7]赵文智,邹才能,冯志强,等.松辽盆地深层火山岩气藏地质特征及评价技术[J].石油勘探与开发,2008,35(2):129-142.
[8]计德华,岳宏.川西南震旦系油气勘探前景的探讨[J].天然气工业,1986,6(1):10-14.
[9]王世谦,陈盛吉,陈宗清,等.四川盆地油气资源评价[R].成都:四川石油管理局,2002.
[10]宋文海.对四川盆地加里东期古隆起的新认识[J].天然气工业,1987,7(3):6-11.
[11]刘宝-.沉积岩石学[M].北京:地质出版社,1980:224.
[12]陈宗清.四川盆地中二叠统茅口组天然气勘探[J].中国石油勘探,2007,12(5):1-11.
[13]陈宗清.川东石炭系潮坪沉积区地层划分对比与找气意义[J].地质学报,1985,59(2):87-96.
[14]地质部第五普查大队.贵州及邻区地层古生物手册[R].贵州:地质部,1962.
[15]石油工业部四川石油会战指挥部.四川盆地石油勘探综合数据手册[G].成都:石油工业部四川石油会战指挥部,1966。
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