摘要
黔南坳陷区域寒武系牛蹄塘组页岩分布广泛,层厚较大,富集有机质,处于成熟阶段,页岩气勘探和开发潜力较好,因此查明不同地区富有机质页岩层段有利区地质条件及其地球化学特征已成为页岩气勘探的关键问题。文章利用沉积学、有机岩石学和地球化学等综合手段,绘制丹寨有利区分布图,重点探讨了研究区有利区地质条件及优质烃源岩的生烃潜力和时空分布。结果表明:丹寨地区有利区显示该区牛蹄塘组页岩主体沉积环境为深水陆棚至深水盆地;富有机质页岩厚度为60~200 m,整体呈现出由西北向东南逐渐增厚的趋势;总有机碳含量主要介于4.5%~6.0%,有机质成熟度则主要在2.5%~2.7%之间,且从东北向西南方向逐渐降低,构造活动对地层保存条件和页岩气富集程度产生了重要影响;揭示黔南丹寨地区寒武系牛蹄塘组页岩地质条件较好,具有进一步深入开展页岩气调查勘探的潜力。
The Qiannan depression is located on the southwestern edge of the Yangtze block and is an important area of shale gas resources in South China.In recent years,significant progress has been made in shale gas exploration in this region.The shale in Cambrian Niutitang formation of the Qiannan depression is widely distributed,characterized by thick layers and abundant organic matter.Shale is developed in the mature stage and possesses significant potential for shale gas exploration and development.Although some progress has been made in the studies on shale in the Qiannan region,there is still a relative lack of in-depth research on the geological conditions,soluble organic matter,and reservoir formation mechanisms of the favorable zones.By measuring and collecting samples from typical profiles and survey wells of shale gas,this study systematically analyzed the geological conditions and organic geochemical characteristics of the favorable zones in Danzhai of the Qiannan depression.It also explored the distribution and development patterns of high-quality hydrocarbon source rocks in the Cambrian Niutitang formation.The results indicate that the Cambrian Niutitang formation in Danzhai is abundant in organic shale with a thickness of about 60 meters to 200 meters,showing an overall trend of gradually thickening from northwest to southeast.The total organic carbon content(TOC)of the Niutitang formation mainly ranges from 4.5%to 6.0%,while the organic matter maturity(Ro)predominantly varies from 2.5%to 2.7%,gradually decreasing from the northeast to the southwest.The mineral composition of shale in the Niutitang formation primarily consists of quartz,followed by clay minerals,and a small amount of carbonate minerals.The types of shale reservoir spaces include organic pores,inorganic pores,and microfractures,among which inorganic pores primarily consists of intergranular pores,intragranular pores,dissolution pores,etc.The shale matrix typically exhibits low porosity and permeability,categorizing the study area as a low po
作者
刘浩杰
张庆玉
巴俊杰
季少聪
聂国权
李振
LIU Haojie;ZHANG Qingyu;BA Junjie;JI Shaocong;NIE Guoquan;LI Zhen(China Geological Survey,Beijing 100037,China;Institute of Karst Geology,CAGS/Key Laboratory of Karst Dynamics,MNR&GZAR/International Research Center on Karst under the Auspices of UNESCO,Guilin,Guangxi 541004,China)
出处
《中国岩溶》
CAS
CSCD
北大核心
2024年第5期1196-1209,共14页
Carsologica Sinica
基金
中国地质调查项目(DD20221658)
广西重点研发基金(桂科AB23026062)
地科院重点基金(JKYZD202331,JKYQN202366)。
关键词
黔南坳陷
牛蹄塘组
黑色页岩
有机地球化学
储层特征
页岩气有利区
Qiannan depression
Niutitang formation
black shale
organic geochemistry
reservoir characteristics
favorable zone of shale gas
