摘要
鄂尔多斯盆地寒武系研究、勘探程度较低,明确其烃源岩地质特征与有利勘探方向、区带具有重要的理论、经济意义。研究表明,盆地本部寒武系残余厚度一般为0~200 m;沉积坳陷主要分布于盆地东北部、南部的局部地区,残余厚度一般为200~400 m;大陆裂谷主要发育于盆地西缘、南缘,残余厚度往往大于500 m。盆地本部烃源岩条件较差,寒武系泥质岩、泥质碳酸盐岩有机碳含量变化范围为0.08%~0.41%,个别样品可达1.18%,平均值为0.18%。盆地西缘、南缘与秦岭造山带局部地区寒武系烃源岩条件较好,其中盆地西缘有机碳含量变化范围为0.04%~0.56%,平均值为0.18%;盆地东缘有机碳含量变化范围为0.06%~0.58%,平均值为0.22%;盆地南缘有机碳含量变化范围较大,变化在0.03%~0.58%之间,个别样品可达1.94%,平均值为0.29%;秦岭造山带发育较好的烃源岩,有机碳含量变化范围为0.46~1.91%。寒武系烃源岩有机质类型主要为Ⅰ型,处于过成熟阶段,以生气为主。综合烃源岩地质条件,预测盆地古隆起周缘和南部是天然气勘探的有利区带。
For the Cambrian System in the Ordos Basin,the degree of research and exploration is relatively low.Therefore,it is of great theoretical and economic significance to study the geological characteristics and favorable exploration areas.It is shown that the residual thickness of Cambrian System in the Ordos Basin itself is generally 0~200 m,and the sedimentary depression is mainly distributed in the northeastern part of the Ordos Basin and some parts of the south,the thickness of the deposits is generally 200~400 m,while the continental rift is mainly developed in the west and south margin of the Ordos Basin,and the thickness of the deposits is usually greater than 500 m.It is also shown that the source rocks of the Ordos Basin itself are poor.The organic carbon content of Cambrian muddy rocks and muddy carbonate rocks ranges from 0.08%to 0.41%(0.18%on average)and the value of individual sample reaches 1.18%.The Cambrian source rock conditions in the western and southern margin of the basin and local areas of the Qinling orogenic belt are better.The range of organic carbon content in the western and eastern margin of the basin is 0.04%~0.56%and 0.06%~0.58%(0.22%on average),respectively,while the range of organic carbon content in the western and eastern margin of the basin is 0.04%~0.56%and 0.06%~0.58%(0.22%on average),respectively.The range of organic carbon content in the southern margin of the basin is large,ranging from 0.03%to 0.58%(0.29%on average),with the value of individual sample reaching 1.94%.In the southern margin of Qinling orogenic belt,the source rocks are well developed and the organic carbon content varies from 0.46%to 1.91%.The organic matter type of Cambrian source rocks is type I which is over mature stage and mainly generates natural gas.Based on the above analysis,it is predicted that the periphery of the palaeo-uplift and south of the Ordos Basin are favorable zones for natural gas exploration.
作者
欧阳征健
冯娟萍
姚韦卓
王琦
李文厚
Ouyang Zhengjian;Feng Juanping;Yao Weizhuo;Wang Qi;Li Wenhou(Bailie School of Petroleum Engineering,Lanzhou City University,Lanzhou 730070;College of Geology and Environment,Xi'an University of Science and Technology,Xi'an 710054;Geological Research Institute for Coal Green Mining,Xi'an 710054;Sulige Gas Field Branch of PetroChina Great Wall Drilling Engineering Co.LTD.,Panjin,Liaoning 124010;Department of Geology,Northwest University,Xi'an 710069)
出处
《地质科学》
CAS
CSCD
北大核心
2023年第4期1291-1308,共18页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
甘肃省高等学校创新基金项目(编号:2021B-284)
兰州城市学院博士科研基金项目(编号:LZCU-BS2019-03)资助。
关键词
鄂尔多斯盆地
寒武系
烃源岩地质特征
有利区带
Ordos Basin
Cambrian
Geological characteristics of source rocks
Favorable zone
