下扬子黄桥地区二叠系栖霞组成藏条件分析

Analysis of reservoir forming conditions of Permian Qixia formation in Huangqiao block of lower Yangtze area

碳酸盐岩储层是近年来油气勘探的热点,上扬子地区在碳酸盐岩储层中发现了一系列大型气田,在二叠系栖霞组碳酸盐岩储层中也有重要的发现。下扬子黄桥地区多口井在栖霞组钻遇了灰岩溶蚀滩储层,见到了良好的油气显示,为了明确下一步的勘探方向,利用岩石热解、有机碳测试、有机显微组分镜检、气相色谱—质谱等手段对岩心样品进行分析测试,对栖霞组油藏的油源、储层控制因素及成藏类型进行了研究,结果表明:下扬子黄桥地区栖霞组油藏的油源主要来自于自身高成熟烃源岩;栖霞组在黄桥地区为生物滩沉积,影响储层后期改造的主要因素为垂直渗流造成的溶蚀作用,溶蚀影响的深度范围在500 m以内;油藏的区域性盖层为浦口组泥岩和含膏泥岩;油藏类型为挤压期—伸展期混合成藏。

Carbonate reservoir is the hot spot of the oil and gas exploration in recent years. A series of oilfields occur in carbonate reservoir of upper Yangtze block and Permian Qixia formation. The limestone erosion reservoir of Permian Qixia formation has been found in Huangqiao area of lower Yangtze area, which has good oil and gas storage. In order to define the direction of the further ex- ploration, the core samples were analyzed and tested by the technical measures of rock pyrolysis, determination of organic carbon, organic maceral microscopy, gas chromatography and mass spectrum of gas phase. Furthermore, the researches of oil source, reser- voir controlling factors and types of reservoir forming were conducted. The results show that the oil source of Permian Qixia forma- tion in Huangqiao block of lower Yangtze area mainly comes from highly mature source rock, and Qixia formation has organic bank deposition, in addition, the main factor affecting reservoir later reconstruction is denudation, which influence area is within 500 me- ters. Regional capping formation is consist of mudstone and gypsum mudstone of pukou formation. Its reservoir type is mixed reser- voir forming of compression period and extension period.