渤海湾盆地济阳坳陷潜山油气藏成藏期次和过程——来自储层流体包裹体的证据

Characteristics of reservoir fluid inclusions and hydrocarbon charging process in the Dawangzhuang buried hill zone of Jiyang Depression, Bohai Bay Basin

张芷晴 刘华 马立驰 刘景东 郭志扬

ZHANG Zhiqing LIU Hua MA Lichi LIU Jingdong GUO Zhiyang

中国石油大学(华东) 深层油气重点实验室, 山东 青岛 266580 中国石油大学(华东) 地球科学与技术学院, 山东 青岛 266580 中国石化 胜利油田分公司 勘探开发研究院, 山东 东营 257015

Key Laboratory of Deep Oil and Gas, China University of Petroleum(East China), Qingdao, Shandong 266580, China School of Geosciences, China University of Petroleum(East China), Qingdao, Shandong 266580, China Research Institute of Petroleum Exploration and Development, SINOPEC Shengli Oilfield Company, Dongying, Shandong 257015, China

渤海湾盆地济阳坳陷古生界潜山油气藏储量巨大，但成藏过程复杂，制约了油气勘探进程。为了探明其油气充注与调整改造过程，以大王庄潜山带为例，利用包裹体岩相学、显微测温及烃包裹体丰度分析等技术，对古生界油气成藏进行了研究。研究区古生界储层烃包裹体发育，奥陶系烃包裹体呈淡黄色、蓝绿色荧光，沿方解石脉及颗粒愈合缝分布，沥青包裹体与油质沥青仅在大古671油藏少量分布，均一温度主峰为80~90℃和100~110℃；石炭—二叠系储层烃包裹体呈蓝绿色荧光，赋存于石英颗粒微裂隙及次生加大边，均一温度主峰为100~110℃。结合烃源岩生排烃期可以得出，研究区古生界存在两期油气充注：第一期发生在东营组沉积晚期（27~25 Ma），为古生界小规模成藏，以奥陶系为主；第二期发生在馆陶组沉积末期—明化镇组沉积末期（5~2 Ma），为奥陶系和石炭—二叠系大规模成藏。大古671井区附近沥青包裹体的发育以及含烃包裹体有效网格（EGOI）显示古油水界面低于现今油水界面的现象，与明化镇组沉积末期（2 Ma）大1断层的活动有关，导致油气藏发生了局部调整，范围变小。

The Dawangzhuang buried hill zone is a typical representative of Paleozoic oil and gas exploration in the Jiyang Depression, Bohai Bay Basin, and has experienced a complicated accumulation process. Using petrographic observation, microthermometry and abundance of hydrocarbon inclusions, the Paleozoic hydrocarbon charging process in Dawangzhuang buried hill zone was discussed. The study shows that the Paleozoic reservoirs developed hydrocarbon inclusions in the study area. Ordovician hydrocarbon inclusions with pale yellow and blue-green fluorescence distributed along the calcite veins and particle healing joints. Asphalt inclusions and oleaginous are only distributed in Dagu 671 oil reservoir with a small scale. The main peaks of the homogenization temperature are from 80 ℃ to 90 ℃ and from 100 ℃ to 110 ℃; Carboniferous-Permian hydrocarbon inclusions with blue-green fluorescent distributed along the micro-cracks of quartz particles and secondary enlarged edges. The main peak of the homogenization temperature is from 100 ℃ to 110 ℃. Combining with the hydrocarbon generation and expulsion periods of source rocks, it can be concluded that there are two stages of hydrocarbon charging in the Paleozoic in the study area. The first stage of oil and gas charging occurred in the late Dongying period (27~25 Ma), which was a small-scale accumulation of Paleozoic, mainly in the Ordovician; the second stage of oil and gas charging occurred from the end of Guantao period to the end of Minghuazhen period (5~2 Ma), which was a large-scale accumulation of Ordovician and Carboniferous-Permian. The development of asphalt inclusions near the Dagu 671 well area and the fact shown by the Effective Grids containing Oil Inclusions (EGOI) that the ancient oil-water interface is lower than the current one are related to the activity of the Da 1 fault at the end of the Minghuazhen period (2 Ma), resulting in local adjustments and smaller scope of oil and gas reservoir.

国家自然科学基金创新研究群体项目 41821002;国家科技重大专项 2016ZX05006-003

https://doi.org/10.11781/sysydz202201129