摘要
【目的】济阳坳陷大王庄地区石炭系太原组煤系地层分布广泛,煤系地层中的优质储层控制因素对油气勘探有重要影响,但是其储层特征及成因模式尚不明确。【方法】综合利用薄片鉴定、阴极发光、扫描电镜、流体包裹体、C-O同位素、原位激光剥蚀等技术方法,结合埋藏史和构造演化史研究,对济阳坳陷大王庄地区石炭系太原组煤系地层碎屑岩优质储层特征及成因模式进行了研究。【结果】济阳坳陷大王庄地区太原组煤系地层碎屑岩储层以岩屑质石英砂岩为主,优质储层储集空间以次生孔隙为主,主要为大气淡水以及有机酸溶蚀形成的填隙物溶蚀孔和长石溶蚀孔。胶结物为两期石英次生加大边和两期碳酸盐胶结物,以碳酸盐胶结物为主。两期石英加大边分别来源于石英颗粒的压溶作用和长石溶解供源。菱铁矿为同沉积—早成岩阶段由孔隙水沉淀形成的成岩碳酸盐岩,铁白云石主要与有机酸脱羧作用形成的CO_(2)有关。【结论】沉积相控制了现今优质储层岩相的分布位置,优质储层主要受控于晚期抬升的大气淡水淋滤作用以及埋藏有机酸溶蚀作用;受构造活动控制,优质储层与对接断层的距离较远,避免了脱羧作用产生的CO_(2)进一步沉淀形成铁白云石破坏储层物性。
[Objective]The coal-bearing strata of the Carboniferous Taiyuan Formation(C3t)are widely distributed in the Dawangzhuang area of the Jiyang Depression.The high-quality reservoir control factors in the coal-bearing stra⁃ta have an important impact on oil and gas exploration,but its reservoir characteristics and genetic model are still unclear.[Methods]Based on thin section identification,cathodoluminescence,scanning electron microscopy,fluid inclusion,C-O isotopes,in⁃situ laser ablation,and other technical methods,combined with burial history and tectonic evolution history,the characteristics and genetic model of high-quality clastic reservoirs in coal measures of the Carboniferous Taiyuan Formation in the Dawangzhuang area of Jiyang Depression were studied[.Results]The clastic reservoir of the Taiyuan Formation coal measure strata in the Dawangzhuang area of Jiyang Depression is dominated by lithic quartz sandstone,and the reservoir space of high-quality reservoir is dominated by secondary pores,which are primarily interstitial and feldspar dissolution pores formed by atmospheric fresh water and organic acid dissolu⁃tion.The cements are two phases of quartz overgrowth and two phases of carbonate cements,though they are mainly carbonate cements.The two phases of quartz overgrowth are derived from the pressure solution of quartz particles and the source of feldspar dissolution,respectively.The siderite is a diagenetic carbonate rock formed by precipitation of pore water in the synsedimentary-early diagenetic stage,and the ankerite is related to CO_(2) formed by decarboxylation of organic acid.[Conclusions]The sedimentary facies controls the distribution of lithofacies in high-quality reser⁃voirs.The high-quality reservoirs are controlled by the late uplift of atmospheric fresh water leaching and buried organic acid dissolution,as well as tectonic activity.The distance between the high-quality reservoirs and the docking faults should be large to avoid the further precipitation of CO_(2) produced by decarboxylation,which can form ankerite and destroy the reservoir properties.
作者
宋磊
王淑萍
赵妍菲
孙沛沛
盛凯
SONG Lei;WANG ShuPing;ZHAO YanFei;SUN PeiPei;SHENG Kai(School of Geosciences,China University of Petroleum(East China),Qingdao,Shandong 266580,China;Key Laboratory of Deep Oil&Gas in China University of Petroleum(East China),Qingdao,Shandong 266580,China;Oil Industry Training Center,China University of Petroleum(East China),Qingdao,Shandong 266580,China;College of Earth Sciences,Guilin University of Technology,Guilin,Guangxi 541006,China)
出处
《沉积学报》
北大核心
2025年第6期2114-2134,共21页
Acta Sedimentologica Sinica
基金
国家自然科学基金项目(42272165)。
关键词
太原组
煤系地层
优质储层
成因模式
大王庄地区
Taiyuan Formation
coal-bearing strata
high-quality reservoir
genetic model
Dawangzhuang area
