摘要
贵州黔西南地区下石炭统打屋坝组是重要的含气页岩层系,也是近年来探索热点层系。该地区以垭都-紫云-罗甸断裂带为代表发育了多条断裂,构造条件十分复杂,是南方复杂构造区的典型代表,保存条件是该区页岩气富集的重要限制性因素。在野外地质调查及重点钻井解剖基础上,研究了黔西南下石炭统打屋坝组页岩矿物组成、有机地化特征、构造特征与断裂分布、含气性及其主控因素等,综合考虑岩性、断裂、盖层、有机质、矿物等对页岩含气的影响,提出了针对复杂构造区页岩气保存条件的评价方法,预测该地区页岩气发育有利区。结果表明:在研究区内,页岩矿物组成、有机质丰度和孔隙度等单因素与含气性相关性较弱,地质过程和多因素复合作用控制含气性,泥页岩与(泥)灰岩频繁叠置,构成“千层饼”式保存条件,有利于页岩气的保存;运用层次分析法和加权求和法对研究区保存条件进行定性半定量评价,评价结果显示紫云-罗甸及六枝-镇宁-关岭地区页岩保存条件相对较好。紫云、罗甸地区为Ⅰ类有利区,六盘水、六枝-镇宁-关岭地区为Ⅱ类有利区。
The Lower Carboniferous Dawuba Formation in southwest Guizhou is an important gas-bearing shale system and also a hot exploration area in recent years. There are many faults represented by the Yaziluo fault in this area, and the structure conditions are very complex, which is the representative of the complex structural area in south China. The preservation conditions are important limiting factors for shale gas enrichment in this area. On the basis of field geological survey and key drilling anatomy, the mineral composition, organic geochemical characteristics, structural characteristics and fault distribution, gas-bearing properties and main controlling factors of the Lower Carboniferous Dawuba shale in southwestern Guizhou were studied. The influence of lithology, faults, caprocks, organic matter, minerals, etc. on shale gas content is considered comprehensively, an evaluation method for shale gas preservation conditions in complex structural areas is proposed, and favorable areas for shale gas development in this area are predicted. The results show that: in the study area, single factors such as shale mineral composition, organic matter content, and porosity are weakly correlated with gas-bearing properties. Geological processes and multi-factor jointly control gas-bearing properties.(Mud) limestone is frequently superimposed, constituting a “thousand-layer cake” preservation condition, which is beneficial to the preservation of shale gas. Qualitative and semi-quantitative evaluation of the preservation conditions in the study area was carried out by using the analytic hierarchy process and the weighted sum method. The evaluation results showed that the preservation conditions of shale in the Ziyun and Luodian, Liuzhi, Zhenning and Guanling areas were relatively good. Ziyun and Luodian regions are class I favorable areas, while Liupanshui and Liuzhi, Zhenning and Guanling regions are Class II favorable areas.
作者
郑逢赞
苑坤
单俊峰
林拓
游铭心
牛嘉亮
梁宇涛
唐玄
ZHENG Fengzan;YUAN Kun;SHAN Junfeng;LIN Tuo;YOU Mingxin;NIU Jialiang;LIANG Yutao;TANG Xuan(School of Energy,China University of Geosciences,Beijing 100083,China;Oil and Gas Survey Center of China Geological Survey,Beijing 100083,China;Research Institute of Liaohe Oilfield,CNPC,Panjin,Liaoning 124010,China)
出处
《中国海上油气》
CAS
CSCD
北大核心
2022年第4期109-121,共13页
China Offshore Oil and Gas
基金
国家自然基金“中国南方寒武系页岩有机质、流体和孔隙演化耦合机制研究(编号:41730421)”“四川盆地及周缘龙潭组海陆过渡相页岩复杂有机质孔隙发育机制(编号:41972132)”
“十三五”国家科技重大专项课题“页岩气资源评价方法与勘查技术(编号:2017ZX05009-002)”
中国地质调查局“桂中—南盘江页岩气地质调查(编号:DD20190088)”部分研究成果。
关键词
页岩气
打屋坝组
保存条件
复杂构造区
垭紫罗断裂带
shale gas
Dawuba Formation
preservation conditions
complex structural area
Yaziluo fault zone
