摘要
鄂尔多斯盆地陇东地区延长组7段(长7段)页岩油勘探取得重大突破,实践表明陕北地区长7段也发育丰富的页岩油,成为该盆地非常规石油勘探新的接替目标。通过对烃源岩品质、类型、储集层、隔夹层及源储配置关系等开展定量刻画,表明:①广泛分布的黑色页岩(TOC值为13.81%)、暗色泥岩(TOC值为3.74%),及与之互层共生的砂岩薄层,构成了页岩油形成的有利地质条件。②陕北地区长7段页岩油砂地比平均值为20.1%,单层砂体厚度平均值为3.8 m,长7段源内油藏为典型的页岩油,储集层甜点以“夹层型”为主,源储有效配置为页岩油的形成提供了保障。③地质工程一体化综合研究表明:有利储集层、隔夹层及裂缝的发育规模,共同控制了页岩油“甜点”分布规律和富集高产能力。在页岩油富集主控因素分析的基础上,建立了陕北地区长7段“甜点区”的评价标准,共评价甜点21个,为下一步勘探开发提供了重要依据。
A great breakthrough has been made in the exploration of shale oil in the 7th Member of Yanchang Formation(Chang 7 Member)in Longdong area of the Ordos Basin.The practice shows that there is rich shale oil in the Chang 7 Member in the northern Shaanxi area,which has become a new target for the unconventional oil exploration of the basin.In this paper,the quality,type,reservoir,interlayer and source-reservoir configuration of source rocks are quantitatively characterized.The results show that:(1)Black shale(TOC=13.81%)and dark mudstone(TOC=3.74%)are widely distributed,the thin layers of sandstone associated with them constitute favorable geological conditions for the formation of shale oil.(2)The mean ratio of shale oil-sand is 20.1%and the mean thickness of single sand body is 3.8 m in the Chang 7 Member of the northern Shaanxi area.The source reservoir of the Chang 7 Member is typical shale oil,and the reservoir dessert is mainly“sandwich type”,the effective allocation of source and reservoir provides guarantee for the formation of shale oil.(3)Comprehensive study of the integration of geological engineering shows that the favorable reservoir,interlayer and fracture scale control the distribution law of shale oil"sweet spot"and the high productivity.Based on the analysis of the main controlling factors of shale oil enrichment,the evaluation criteria of the“sweet spot area”of the Chang 7 Member in the northern Shaanxi area were established,with a total of 21“sweet spots”evaluated.
作者
马艳丽
辛红刚
马文忠
毛振华
周树勋
淡卫东
MA Yanli;XIN Honggang;MA Wenzhong;MAO Zhenhua;ZHOU Shuxun;DAN Weidong(Exploration and Development Research Institute of PetroChina Changqing Oilfield Company,Xi’an 710018,China;National Engineering Laboratory for Exploration and Development of Low Permeability Oil&Gas Fields,Xi’an 710018,China;Oilfield Department of Changqing Oilfield Company,Xi’an 710018,China)
出处
《天然气地球科学》
CAS
CSCD
北大核心
2021年第12期1822-1829,共8页
Natural Gas Geoscience
基金
中国石油天然气股份有限公司重大科技专项“鄂尔多斯盆地石油富集规律及勘探目标评价”(编号:2016E-0501)资助.
关键词
鄂尔多斯盆地
陕北地区
长7段页岩油
富集主控因素
甜点区
Ordos Basin
Northern Shaaxi area
Chang 7 Member shale oil
Main control factors of the enrichment
Sweet spot
