摘要
以松辽盆地南部长岭凹陷白垩系青山口组一段富有机质页岩为例,基于岩石矿物、岩心薄片、测试分析、测井数据及钻井地质等多种资料分析,对大型坳陷陆源碎屑湖盆细粒沉积体系的岩性岩相、储集物性和页岩油富集模式进行研究。结果表明,半深湖—深湖区高有机质丰度薄片状页岩相相较于中有机质丰度块状泥岩相具有更好的生烃潜力,发育的页理缝在超压背景下提供了有效储集空间;三角洲外前缘周期性变迁的沉积背景和发育的底流搬运沉积形成了纹层状页岩相发育区,中有机质丰度纹层状页岩相相较于低有机质丰度纹层状页岩相具有相对较好的生烃潜力,生成的石油微运移至砂质纹层富集。其中,具有超低渗透块状泥岩相作为顶底板封隔层、保存条件好、压力系数高、高有机质丰度薄片状页岩相发育的特定相序和区带是“页理型”页岩油富集的条件;处于生油窗并具有微距排烃条件、中有机质丰度纹层状页岩相发育的特定相序和区带是“纹层型”页岩油富集的条件,且具有致密油-“纹层型”页岩油连片分布的特征。
The lithology,lithofacies,reservoir properties and shale oil enrichment model of the fine-grained sedimentary system in a lake basin with terrigenous clastics of large depression are studied taking the organic-rich shale in the first member of Cretaceous Qingshankou Formation(shortened as Qing 1 Member)in the Changling Sag,southern Songliao Basin as an example.A comprehensive analysis of mineralogy,thin section,test,log and drilling geologic data shows that thin-layered shale with high TOC content of semi-deep lake to deep lake facies has higher hydrocarbon generation potential than the massive mudstone facies with medium TOC content,and has bedding-parallel fractures acting as effective reservoir space under over pressure.The sedimentary environments changing periodically and the undercurrent transport deposits in the outer delta front give rise to laminated shale area.The laminated shale with medium TOC content has higher hydrocarbon generation potential than the laminated shale with low TOC content,and the generated oil migrates a short distance to the sandy laminae to retain and accumulate in situ.Ultra-low permeability massive mudstone facies as the top and bottom seals,good preservation conditions,high pressure coefficient,and thin-layered shale facies with high TOC are the conditions for“lamellation type”shale oil enrichment in some sequences and zones.The sequence and zone with laminated shale of medium TOC content in oil window and with micro-migration of expelled hydrocarbon are the condition for the enrichment of"lamination type"shale oil.The tight oil and“lamination type”shale oil are in contiguous distribution.
作者
柳波
孙嘉慧
张永清
贺君玲
付晓飞
杨亮
邢济麟
赵小青
LIU Bo;SUN Jiahui;ZHANG Yongqing;HE Junling;FU Xiaofei;YANG Liang;XING Jilin;ZHAO Xiaoqing(Key Laboratory of Continental Shale Hydrocarbon Accumulation and Efficient Development,Ministry of Education,Northeast Petroleum University,Daqing 163318,China;PetroChina Jilin Oilfield Company,China National Petroleum Corporation,Songyuan 138000,China)
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2021年第3期521-535,共15页
Petroleum Exploration and Development
基金
国家自然科学基金“陆相页岩油储层孔隙结构非均质性成因及其对烃类赋存相态的影响”项目(41972156)。
关键词
页岩岩相
纹层缝
层理缝
白垩系青山口组
松辽盆地
长岭凹陷
页岩油
有机质丰度
shale lithofacies
lamina fracture
bedding fracture
Cretaceous Qingshankou Formation
Songliao Basin
Changling sag
shale oil
organic abundance
