摘要
综合利用有机地球化学分析、全岩分析、场发射扫描电镜分析、CO_(2)和N_(2)吸附实验以及高压压汞实验等分析测试资料,结合区域构造及沉积演化特征,对松辽盆地梨树断陷下白垩统沙河子组页岩的分布特征、有机质发育特征、含气特征、储集层特征及保存条件进行综合分析,揭示陆相页岩气富集地质条件及资源潜力。梨树断陷下白垩统富含气的优质页岩主要发育在沙河子组二段下亚段,页岩发育厚度较大且分布稳定。页岩有机质含量较高,有机质类型以Ⅱ_(1)型和Ⅱ_(2)型为主,有机质热演化程度处于成熟到过成熟阶段。火山活动和咸化还原的水体环境有利于富有机质页岩的形成。页岩储集空间类型主要为黏土矿物晶间孔、有机质孔、碳酸盐矿物溶蚀孔和页理微裂缝,孔径主要分布在10~50 nm的介孔区间,微裂缝宽峰值为5~10μm。在沙二段下亚段含气页岩层上下分别沉积低位域和高位域块状泥岩,形成页岩气聚集保存过程的天然顶底板,由此控制页岩气的富集。基于以上认识,在松辽盆地梨树断陷部署实施了沙河子组第1口页岩气参数井,直井压裂测试获得日产7.6×10^(4) m^(3)高产页岩气流,实现了沙河子组陆相页岩气勘探重大突破,对松辽盆地及外围广泛分布的下白垩统陆相页岩气勘探具有借鉴意义。
Distribution characteristics,organic matter development characteristics,gas-bearing characteristics,reservoir characteristics and preservation conditions of the Shahezi Formation shale of Lower Cretaceous in the Lishu fault depression,Songliao Basin are analyzed using organic geochemical,whole rock,and SEM analysis data,and CO_(2) and N_(2) adsorption and high pressure mercury injection experiment data in combination with the tectonic and sedimentation evolution of the region to reveal the geological conditions for enrichment and resource potential of continental shale gas.The organic-rich shale in the Lower Cretaceous of the Lishu fault depression is mainly developed in the lower sub-member of the second member of Shahezi Formation(K1sh21),and is thick and stable in distribution.The shale has high TOC,mainly types Ⅱ_(1) and Ⅱ_(2) organic matter,and is in mature to over mature stage.The volcanic activity,salinization and reduction water environment are conducive to formation of the organic-rich shale.The shale reservoirs have mainly clay mineral intergranular pores,organic matter pores,carbonate mineral dissolution pores and foliated microfractures as storage space.The pores are in the mesopore range of 10-50 nm,and the microfractures are mostly 5-10μm wide.Massive argillaceous rocks of lowland and highstand domains are deposited above and below the gas-bearing shale separately in the lower sub-member of the K1sh21 Fm.,act as the natural roof and floor in the process of shale gas accumulation and preservation,and control the shale gas enrichment.Based on the above understandings,the first shale gas exploration well in Shahezi Formation was drilled in the Lishu fault depression of Songliao Basin.After fracturing,the well tested a daily gas production of 7.6×10^(4) m^(3),marking a breakthrough in continental shale gas exploration in Shahezi Formation of Lishu fault depression in Songliao Basin.The exploration practice has reference significance for the exploration of continental shale gas in Lower Cretaceous
作者
张君峰
徐兴友
白静
陈珊
刘卫彬
李耀华
ZHANG Junfeng;XU Xingyou;BAI Jing;CHEN Shan;LIU Weibin;LI Yaohua(Oil and Gas Survey,China Geological Survey,Beijing 100083,China;National Key Laboratory of Continental Shale Oil,Daqing 163002,China;Key Laboratory of Unconventional Oil and Gas,China Geological Survey,Beijing 100029,China)
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2022年第3期440-452,共13页
Petroleum Exploration and Development
基金
中国地质调查局项目“松辽盆地南部页岩油战略调查”(DD20190115)
中国地质调查局项目“大兴安岭西缘中生界油气战略选区调查”(DD20160202)。
关键词
陆相页岩气
页岩储集空间
有机质
含气性
勘探
白垩系
沙河子组
梨树断陷
松辽盆地
continental shale gas
shale reservoir space
organic matter
gas-bearing
exploration
Cretaceous
Shahezi Formation
Lishu fault depression
Songliao Basin
