东营凹陷王家岗地区孔店组油气运移模式

Hydrocarbon migration model in Kongdian Formation of Wangjiagang area, Dongying Depression

巩建强 杨怀宇 王文彬 陈涛

中国石化胜利油田分公司勘探开发研究院，山东 东营 257000

Exploration and Development Research Institute, Shengli Oilfield Company, SINOPEC, Dongying 257000, China

古近系孔店组是东营凹陷南部斜坡带重要的勘探方向和储量接替层系之一。通过生物标志化合物和饱和烃气相色谱分析，将南部斜坡带东段的王家岗地区孔店组与凹陷内烃源岩进行油源对比。结果表明，孔店组的油气来源主要为孔二段烃源岩，具有典型的自生自储型成藏特征。流体包裹体荧光特征分析显示，王家岗地区油气充注期次至少分为2期：早期成熟度相对较低，但生烃量大、油气运移距离远；晚期充注原油成熟度高，但生烃量小、油气运移距离近。文中利用地球化学参数，对油气运移路径进行了示踪分析。结果显示：孔二段油源沿王46井北断层垂向运移至孔店组，之后沿“砂体￣断层”呈阶梯状向南部斜坡带侧向运移聚集成藏；其次为沿不整合面运移，但油气沿不整合面运移距离短且规模较小。王家岗地区孔店组红层的油气运移模式为东营凹陷南部斜坡带油气勘探评价提供了指导。

The Paleogene Kongdian Formation is one of the important exploration directions and reserve replacement strata in the south slope of Dongying Depression. By means of biomarker compounds and saturated hydrocarbon gas chromatographic analysis, the Kongdian Formation in the Wangjiagang area in the east of the south slope are compared with the source rocks in the depression. The results show that the hydrocarbon in the Kongdian Formation is mainly from the source rock in the 2nd member of Kongdian Formation, which showing typical self-generation and self-storage hydrocarbon accumulation characteristics. The fluorescence characteristics of fluid inclusions are analyzed, which shows the oil and gas charging period in Wangjiahe area is divided into at least two periods. The oil maturity in early period is relatively low, but the hydrocarbon generation is large and migration distance is long, while the late charging oil has a high maturity, but the hydrocarbon generation is few and migration distance is short. According to geochemical parameters, the oil and gas migration paths are analyzed. The result shows that the oil source of the 2nd member migrated vertically along the north fault of well Wang 46 to the Kongdian Formation, then the oil and gas migrated and accumulated laterally along the "sand-fault" to the south slope in a step-like pattern and accumulated into reservoirs, and followed by the migration along the unconformity, but migration along the unconformity has short distance and small scale. The oil and gas migration and accumulation model of the red beds of Kongdian Formation in Wangjiagang area is summarized, which provides ideas for oil and gas exploration and evaluation in south slope of Dongying Depression.

10.6056/dkyqt202203007