四川类前陆盆地须家河组层序充填样式与油气分布规律  

Sequence Filling Patterns and Oil-Gas Distribution Rules of the Xujiahe Formation in the Sichuan Foreland-like Basin

作　　者：戴朝成[1] 郑荣才[1] 朱如凯[2] 高志勇[2] 翟文亮[1] 

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]中国石油勘探开发研究院油气储层重点实验室,北京100083

出　　处：《地质学报》2010年第12期1817-1828,共12页Acta Geologica Sinica

基　　金：国家重大专项“大型油气田及煤层气开发”(编号2008ZX05000-003-01)资助的成果

摘　　要：通过对四川类前陆盆地上三叠统须家河组地表剖面、钻井岩芯和测井资料的沉积相和层序分析,结合区域地质背景和油气地质特征,对须家河组沉积层序、充填样式和油气分布规律进行分析,将须家河组划分为两个超长期旋回层序(SLSC1和SLSC2),分别对应于"须下盆"和"须上盆"2个盆-山耦合次系统的成盆构造活动期,5个长期旋回层序(LSC1—LSC5),分别对应于5个区域性湖进—湖退沉积旋回。在此基础上,选择长期基准面上升和下降半旋回为等时地层单元编制全盆地地层等厚图和岩相古地理图,结果表明:须家河组二段和三段沉降-沉积中心位于川西坳陷,须四段开始向川东北方向迁移,须五段—须六段迁移至川东北坳陷;不同的沉积演化阶段和前缘坳陷具有不同的层序充填样式和油气分布规律;伴随"须下盆"和"须上盆"2个盆-山耦合次系统的沉降-沉积中心和优越的生、储、盖组合条件自川西坳陷向川东北坳陷迁移,油气藏分布也具有自南向北再折向北东方向迁移和围绕前陆隆起带发育的特点。This study analyzed the surface sections of the Xujiahe Formation of the upper Triassic in the Sichuan foreland-like basin,and the sedimentary facies and sequence of drilling cores and logging data.In combination with the regional geology and oil and gas geological characters,this study also focused on the sedimentary order of the Xujiahe Formation,filling patterns,and gas-oil distribution rule.Two super long-term sequence cycles （SLSC1,SLSC2）and 5long-term sequence cycles（LSC1—LSC5）were indentified,which correspond to the lower and upper Xujiahe Formation of the coupling process between basin and mountain,and 5regional lake transgression-lake regression sedimentary cycles,respectively. The stratigraphic isopach and lithofacies paleogeography maps of whole basin have been compiled based on the isochronous stratigraphic unit defined by the half cycle of long-term base level rising and falling.The results indicate that the subsidence and depocenter of members 2and 3of the Xujiahe Formation was located in the western Sichuan depression;member 4migrated to northeastern Sichuan;members 5and 6 to the northeastern Sichuan depression.Different sedimentary evolution stage and frontal depression are characterized by various filling patterns and oil and gas distribution rules.Accompanied by the depocenter of two basin-mountain coupling subsystem（low Xujiahe basin and upper Xujiahe basin）and the migration of the subsidence-depocenter of excellent source-reservoir-cap rock assemblage to the northeast from the western Sichuan depression,the oil and gas distribution are also characterized by the migration from south to north and to northeast and the development around foreland rise area.

关 键 词：四川类前陆盆地 上三叠统须家河组 盆-山耦合系统 充填样式 油气分布规律 

分 类 号：P618.13[天文地球—矿床学]