江陵凹陷西南部梅槐桥富生烃洼陷及近源油气成藏  

Prolific Hydrocarbon Generating Depression and Near-Source Type Accumulation in the Southwest Area of Meihuaiqiao Depression of Jiangling Sag

作　　者：易积正[1,2] 何生[1] 刘琼[1] 耿锋[1] 

机构地区：[1]中国地质大学资源学院,武汉430074 [2]中国石油化工股份有限公司江汉油田分公司,湖北潜江433124

出　　处：《地质科技情报》2009年第1期57-62,共6页Geological Science and Technology Information

基　　金：中国石油化工股份有限公司中南分公司科研项目“江陵凹陷采穴-复兴场地区白垩系成藏主控因素与富集规律研究”(KT200503);国家自然科学基金重点项目(40739904-03)

摘　　要：江陵凹陷西南部已发现的油气藏紧邻梅槐桥富生烃洼陷分布,且油气储量主要集中在该洼陷生烃中心短轴方向两侧的谢凤桥、南岗、复兴场、采穴等断块和断鼻圈闭中。对梅槐桥富生烃洼陷内烃源岩发育特征及其洼陷内生烃差异性的研究表明:洼陷北部梅槐桥地区是烃源岩沉积时期的沉降中心,烃源岩发育,埋藏较深,生烃能力强,为该洼陷的生烃中心;而南部牛头岗地区烃源岩层厚度小,埋藏浅,生烃能力差。原油成熟度和油源对比研究表明,油气具有近距离运移近源成藏的特点;北部采穴断块、复I断块、谢凤桥断鼻和南岗断鼻油气藏中成熟度相对较高的原油主要来自北部梅槐桥地区;南部八宝断鼻油气藏中成熟度低的原油与牛头岗地区原地烃源岩具有亲缘关系;而偏南部丁家湖断鼻油气藏中的原油则为梅槐桥生烃中心成熟度较高的烃源岩和原地烃源岩的混合贡献的原油。因此,可认为梅槐桥生烃中心短轴方向的两侧为目前江陵凹陷西南部油气勘探最有利的地区。In the southwest of Jiangling Sag, the hydrocarbon pools discovered near Meiguiqiao prolific hydrocarbon generating depression and the oil production and reserves are mainly located in the entraps, such as Caixue, Fuxingchang, Xiefengqiao and Nangang, situated on both sides along the short-axis of hydrocarbon generating center of the depression. This paper studies the characteristics of source rocks and the hydrocarbon generating potentials of differential areas in Meiguiqiao hydrocarbon abundant generating depression. The northern area of the depression is identified as the subsidence center during the source rock depositional periods and as hydrocarbon generating center owing to thick and deeply buried source layer, and strong hydrocarbon generating ability compared to the southern area. The maturity of crude oils and oil-source correlation shows that the distance of petroleum secondary migration is quite short. The relative high maturity oils in the northern area, such as Caixue, Fuxingchang, Xiefengqiao, Nangang oil-fields, primarily migrated from the relative high maturity source rocks in the hydrocarbon generating center, while the relative low maturity oils in the Babao fault-nose structure in the southern margin of the depression mainly sourced from the local source rocks. The oils in the Dingjiahu fault-nose structure were mixed by relative high and low maturation hydrocarbons from oil generating center and local source rocks. It is suggested that the traps near the center of Meiguiqiao hydrocarbon generation should be the target for further oil exploration.

关 键 词：梅槐桥富生烃洼陷 油源对比 生物标志化合物 油气成藏 江陵凹陷 

分 类 号：TE122.11[石油与天然气工程—油气勘探]