南华北盆地倪丘集凹陷油气显示特征及找油意义

CHARACTERISTICS AND SIGNIFICANCES OF HYDROCARBON SHOWS IN THE NIQIUJI SAG, THE SOUTHERN NORTH CHINA BASIN

全裕科 柳广弟 丁文龙

Quan Yuke Liu Guangdi Ding Wenlong

中国石油大学, 北京 102249 2. 中国海洋石油股份有限公司, 北京 100010 3. 中国地质大学, 北京 100083

China University of Petroleum, Beijing 102249, China 2. China National Offshore Oil Co. , Beijing 100010, China 3. China University of Geoscience, Beijing 100083, China

南华北盆地倪丘集凹陷共施工了16口油气探井,有7口探井见油气显示,其中位于大王庄构造上的南12井试获工业油流,累计产油32.26m3.对凹陷内油气显示进行统计和分析,得出如下规律:油显示主要集中在下第三系双浮组;储集岩类型主要为中砂岩和细砂岩;油和气显示的深度分别集中在1 000~2 000m和3 000~4 000m;原油具有典型的煤成油特征;遭受过生物降解和水洗作用等次生变化.研究结果还表明,该凹陷存在至少一次煤成油气的生成、运移和聚集过程,并初步指出了在该凹陷的找油方向,即除了寻找原生煤成油油藏外,还要注意寻找次生油藏;上白垩统残留地层是凹陷内古生界源岩产生的油气向新生界圈闭运移聚集的遮隔层,为成藏的不利因素.

There are 16 exploration wells drilled in the Niqiuji Sag,the Southern North China Basin and 7wells of them have obtained hydrocarbon shows.The Well Nan 12 located in Dawangzhuang structure is an industrial discovery well with producing commercial crude oil of 32.26 m3s in well testing.In this article,statistics of the oil and gas shows was made and the conclusions have obtained as follows: the oil and gas shows occur mainly in Shuangfu Formation in Paleogene,the predominant reservoir rocks are medium-grained and fine-grained sandstones,oil shows occur mainly in the depths of 1 000 to 2 000 meters and gas shows occur mainly in the depths of 3 000 to 4 000 meters,the crude oil is characteristic of coal-derived oil and has undergone biodegradation and water-washing.The above conclusions suggest that there is at least one epoch of petroleum formation,migration and accumulation in Niqiuji depression.The preliminary conclusions for exploration orientation include that both primary and secondary pool are the exploration targets,the Upper Cretaceous is a disadvantageous factor for petroleum accumulation because it may be a barrier of vertical petroleum migration from the source rocks in CarboniferousPermain to the reservoirs in the Paleogene.

https://doi.org/10.11781/sysydz200604370