琼东南盆地陵水凹陷S2井区梅山组物源

Provenance analysis of Meishan Formation in the Well S2 region of Lingshui Sag,Qiongdongnan Basin,China

探讨琼东南盆地陵水凹陷2号断裂带北部S2井区物源特征。通过搜集整理凹陷及周缘的6口井21个储层样品,利用岩石矿物学、重矿物分析、地球化学特征开展物源性质、母岩风化、成熟度分析,结合构造特征开展油气成藏特征分析。结果表明:S2井区物源主要来自海南岛西部,东北部物源对该区影响范围有限,具明显混源特征;沉积过程为石英质母岩经强烈风化、搬运再沉淀作用,砂岩成熟度中等,其重力流影响范围有限,只对凹陷东部沉积起到一定控制作用。S2井区具有一定的油气勘探前景,主要以断块圈闭、岩性圈闭和地层圈闭为勘探目标。

By using the methods of petromineralogy,heavy mineral analysis and geochemistry,the provenance properties,parent rock weathering and maturity of 21 reservoir samples from 6 wells in Lingshui Sag and its surrounding areas of Qiongdongnan Basin are analyzed.Through structural characteristic synthesis,the characteristics of oil and gas accumulation are analyzed in order to explore the provenance characteristics of Well S2 area in the north of No.2 fault zone of Lingshui Sag,Qiongdongnan Basin.The results show that the provenance of Well S2 is mainly from the west of Hainan Island.Although the influence of the northeast provenance on this area is limited,the provenance of Well S2 has obvious mixed provenance characteristics.The sedimentary process is that the quartz parent rock in the source area underwent intense weathering and denudation,and the detritus was transported to the sag area and deposited.The sandstone formed by this process has a moderate degree of maturity and gravity flows had a limited range of influence on diagenetic processes,it only played a certain role in controlling the deposition in the eastern part of the depression.It is considered that the Well S2 area has certain oil and gas exploration prospect,in which fault block trap,lithologic trap and stratigraphic trap are the main exploration targets.