东海西湖凹陷中央反转构造带古近系花港组致密砂岩储集层裂缝发育特征与油气成藏关系  

Fracture development and hydrocarbon accumulation in tight sandstone reservoirs of the Paleogene Huagang Formation in the central reversal tectonic belt of the Xihu Sag,East China Sea

作　　者：周心怀 徐国盛[1] 崔恒远 张武 ZHOU Xinhuai;XU Guosheng;CUI Hengyuan;ZHANG Wu(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China;CNOOC China Limited,Shanghai Branch,Shanghai 200030,China)

机构地区：[1]油气藏地质及开发工程国家重点实验室(成都理工大学),成都610059 [2]中海石油(中国)有限公司上海分公司,上海200030

出　　处：《石油勘探与开发》2020年第3期462-475,共14页Petroleum Exploration and Development

基　　金：“十三五”国家科技重大专项“东海深层低渗-致密天然气勘探开发技术”(2016ZX05027,2016ZX05027-002-006)。

摘　　要：采用岩石薄片鉴定,阴极发光、常微量元素、流体包裹体、自生伊利石测年等测试技术,在岩心裂缝观察的基础上,结合裂缝微观特征及成像测井特征,对东海盆地西湖凹陷中央反转构造带花港组储集层裂缝发育期次进行了厘定,并确定裂缝发育期次与油气充注期次的匹配关系。研究区古近系花港组储集层发育成岩缝和构造缝,成岩缝发育于储集层成岩阶段,对油气运移与输导作用较小。构造缝根据受控构造运动及与油气充注关系可划分为3期:①喜马拉雅期龙井活动早期(距今12~13 Ma),构造应力仅使缝合线及泥质条带产生挠曲变形破裂,该期构造微裂缝延伸短、宽度窄、有效性差,对油气的运移与输导作用小;②喜马拉雅期龙井活动中晚期(距今9~12 Ma),构造运动使中央反转构造带构造缝发育,其规模大、延伸长、有效性好,同时与第1次油气大规模充注时间(距今9~12 Ma)相匹配,对油气运移、输导、聚集起重要作用;③喜马拉雅期冲绳活动至今(距今0~3 Ma),继承性发展构造缝,且与第2次天然气大规模充注时间(距今0~3 Ma)相匹配,为天然气的持续运移与输导创造了条件。证明西湖凹陷花港组储集层裂缝的发育可为油气的高效运移输导及聚集提供渗流储集空间和持续且有效的通道。By using thin section identification,cathodoluminescence,major and trace elements and fluid inclusion tests and authigenic illite dating,based on observation of core cracks,combined with the microscopic characteristics and imaging logging characteristics of fractures,the stages of the fractures in the Huagang Formation of the central reversal tectonic belt of the Xihu Sag in the East China Sea,and the matching relationship between the fracture development stages and the oil and gas charging stages are clarified.There are diagenetic fractures and tectonic fractures in the reservoirs of the Huagang Formation in the study area.The diagenetic fractures developed during the diagenetic stage of the reservoirs and have less effect on oil and gas migration and transport.The tectonic fractures are divided into three stages based on tectonic movements controlling the fractures and their relationships with hydrocarbon charging:The first stage of fractures was generated in the early stage of the Himalayan Movement–Longjing Movement(12–13 Ma ago),when the tectonic stress caused the sutures and shale strips to twist,deform,and break.Tectonic microfractures generated in this period had short extension,narrow width,and poor effectiveness,and had little effect on oil and gas migration and transport.The second stage of fractures came up during the middle-late period of Himalayan Movement–Longjing Movement(9–12 Ma ago),when tectonic movements caused the development of tectonic fractures in the central reversal tectonic belt,these fractures are of large scale,long extension,and good effectiveness,and matched with the first stage of large scale oil and gas charging(9–12 Ma ago),so they play an important role in oil and gas migration,transportation,and accumulation.The third stage of fractures were created from Himalayan Movement–Okinawa Trough movement to the present day(0–3 Ma ago),the fractures are tectonic ones developing successively;matching with the second stage(0–3 Ma ago)of large-scale oil and gas charging,the

关 键 词：自生伊利石 包裹体分析 裂缝特征 油气充注 古近系花港组 西湖凹陷 

分 类 号：TE122.2[石油与天然气工程—油气勘探]