泌阳凹陷陆相页岩油气成藏条件

Accumulation conditions for continental shale oil and gas in the Biyang Depression

泌阳凹陷AS1井陆相页岩储层压裂后获得最高日产油4.68 m^3、天然气90 m^3,从而在我国东部陆相第三系断陷湖盆页岩油气领域取得了重要突破。页岩油与页岩气通常为共生关系,文章将重点应用地质实验、地质录井、测井等资料对泌阳凹陷深凹区AS1井井区的页岩分布特征、地化特征、储集特征及保存条件进行分析。研究表明AS1井2 450～2 510 m主力页岩段单层厚度大,分布范围广,有机碳含量较高,热演化程度镜质体反射率值一般在0.57%～0.72%,表明烃源岩处于成熟阶段和生烃高峰期。含油气页岩录井气测异常明显,测井曲线上具有"三高两低"的特征;页岩储集空间类型发育微孔隙、微裂缝,储集性能较好;储层石英等脆性矿物含量高,易于页岩油储层压裂改造。采用容积法对泌阳凹陷深凹区页岩油气资源量进行计算,得出泌阳凹陷页岩油气资源量5.4×10~8t,勘探潜力较大,勘探前景良好。

The AS1 Well in the continental shale reservoir in Biyang Depression reached a peak production of oil 4.68 m^3/d and gas 90 m^3/d after hydraulic fracturing stimulation,marking a major breakthrough in shale oil gas exploration and development in the Eogene continental faulted basins in eastern China.Oil in shale is often symbiotic with gas.The data gathered from geological experiments,well logging,etc.,are used to analyze shale distribution,organic geochemical features,reservoir characteristics and sealing conditions of AS1.Results show that major shale layers within the interval of 2450 -2510 m in well AS1 feature in great thickness and wide distribution of a single layer,high TOC and a R_o within 0.57%-0.72%,indicating that the source rocks are maturity and in peak hydrocarbon generation.R_o Gas logging of shale oil gas layers show abnormal results and the logging curve present special features of ＂3 high points and 2 low points＂.Shale layers contain well-developed micro-pores and fissures,which can be excellent reservoir space.The layers are also rich in brittle minerals like quarts,which is favorable for fracturing.After assessment by using the volumetric method,we believe that the Depression has great shale oil and gas exploration potential（about 0.54 billion tons of shale oil gas）.