四川盆地震旦系灯影组灰泥丘发育特征及储集意义  

Development and reservoir significance of mud mounds in Sinian Dengying Formation, Sichuan Basin

作　　者：李凌[1] 谭秀成[1,2] 曾伟[1] 周涛[1] 杨雨[3] 洪海涛[3] 罗冰[3] 边立曾[4] 

机构地区：[1]西南石油大学资源与环境学院 [2]油气藏地质及开发工程国家重点实验室 [3]中国石油西南油气田公司勘探开发研究院 [4]南京大学地球科学与工程学院

出　　处：《石油勘探与开发》2013年第6期666-673,共8页Petroleum Exploration and Development

基　　金："十二五"国家科技攻关重大专项项目(2011ZX05004-005-03);中国石油科技创新基金研究项目(2011D-5006-0105)

摘　　要：基于岩心及野外剖面观测,研究四川盆地震旦系灯影组灰泥丘发育特征及其储集意义。四川盆地灯影组普遍发育台内小型灰泥丘,发育规模不大,单个旋回厚度多小于2 m,但其发育频率很高,尤其在灯影组二段和四段频繁出现。构成灰泥丘的颗粒主要为与蓝菌群落建造有关的凝块石、藻叠层、核形石及粘结岩等,这些微生物粘结捕获灰泥,为灰泥丘建造的主体,相关的岩石类型主要有藻粘结凝块云岩、藻粘结骨架云岩以及与藻粘结凝块云岩共生的波状—柱状藻叠层云岩等。多期灰泥丘呈明显正地貌特征,发育大量格架构造、斑马状构造与层状晶洞构造;具有完整的丘基—丘核—丘坪、丘基—丘核—丘盖2种沉积演化模式,前者最为普遍。灰泥丘与储集层关系密切,丘核常发育规模不等的孔洞,为油气聚集提供了良好条件,丘滩复合体构成了四川盆地灯影组的主力勘探对象。Based on core and outcrop profile observation, the characteristics and reservoir significance in oil and gas accumulation of mud mounds in the Sinian Dengying Formation of the Sichuan Basin were studied. Small-scale mud mounds in platform are widespread in the Sinian Dengying Formation, Sichuan Basin, mostly less than 2 m thick per cycle, but high in occurrence frequency, especially in Member 2 and Member 4 of the Sinian Dengying Formation. Particles constituting the mud mounds are thrombolte, algal stromatolite, oncolite and bindstone, related to cyanobacteria biocoenosis buildup, which bind and capture lime mud for the mud mound construction, and the relevant rock types include algal bound clotted dolomitite, algal bound frame-dolomitite, and undulating-cylindrical algal stromatolite associated with clotted dolomitite. Multiphase mud mounds with positive relief have abundant frame structures, zebra structures and stromatactis. Two kinds of depositional models are mound base-core-flat and mound base-core-cap, the former is more common. The mud mounds are closely related to reservoirs. Different sizes of pores developed in the mud mound core provide space for oil and gas accumulation, so the mound-shoal complex is the main exploration target of the Sinian Dengying Formation.

关 键 词：灰泥丘 蓝藻菌 藻粘结凝块云岩 藻粘结骨架云岩 格架构造 震旦系灯影组 四川盆地 白云岩储集层 

分 类 号：TE122.1[石油与天然气工程—油气勘探]