苏北盆地浅层天然气藏成藏条件探讨  

Trapping conditions of shallow gas accumulation in Subei Basin

作　　者：张冬玲[1] 鲍志东[1] 刘平兰[2] 

机构地区：[1]中国石油大学(北京)资源与信息学院 [2]中国石化江苏油田地质科学研究院

出　　处：《石油勘探与开发》2005年第2期46-49,共4页Petroleum Exploration and Development

摘　　要：苏北盆地深度小于1500m的浅层天然气资源丰富,已在新近系盐城组发现周庄气田和溪桥气田,在古近系阜宁组发现刘庄气田。苏北盆地浅层虽然仅局部地区的阜宁组生成未熟—低熟油,但储盖条件较好,且下伏层位烃源岩生成的天然气沿断层向上运移,在盐城组或部分地区阜宁组圈闭配置理想的条件下形成了气藏。苏北盆地天然气藏的发育受断裂、气源、生气强度和盖层等4个因素控制,其中断裂为主控因素。根据气源,可将气藏成因类型划分为3 种:生物气—低温热解气(刘庄气田);油田伴生气—凝析气(周庄气田);多源混合气(溪桥气田)。3 种成藏模式为:①刘庄气田为自生自储型生物气成藏模式;②周庄气田为下生上储型热解气成藏模式;③溪桥气田为有机气和幔源气混合成藏模式。图4Abundant gas resources are accumulated in the shallow strata above 1500m depth of Subei Basin. Zhouzhuang and Xiqiao gas field have been found in Yancheng Formation of Neogene. Liuzhuang gas field is in Funing Formation, Paleogene. The study shows that the immature to low mature hydrocarbon was generated in Funing Formation in Liuzhuang area. The hydrocarbon can migrate upwards along faults and accumulate in the traps of Yancheng Formation and favorable traps of Funing Formation. The gas reservoirs can be divided into biogas-low temperature pyrolysis reservoir such as the Liuzhuang gas field; gas-condensate reservoir such as the Zhouzhuang gas field; and multi-source mixed reservoir, as the Xiqiao gas field. Three gas reservoir formation models are set up: Liuzhuang self-generating and self-reserving primary biogenic gas reservoir; Zhouzhuang lower-generating and top-storing pyrolysis reservoir and Xiqiao mixed organic and mentle-sourced gas reservoir. The formations of gas fields are mainly controlled by source rock, fault, cap rock and the intensity of gas generation, and the key one is fault.

关 键 词：苏北盆地 浅层 天然气藏 成藏条件 控制因素 

分 类 号：TE122.3[石油与天然气工程—油气勘探]