摘要
Llanos盆地是南美洲重要的前陆盆地,从构造演化角度出发,利用Vail层序地层学原理搭建层序格架,研究了层序沉积充填;再利用储集物性、岩石组分、排驱压力等资料,分析了Carbonera组储盖组合条件。研究表明从中生代至今盆地及周缘地区的形成演化经历了4个阶段:裂谷-弧后裂谷(三叠纪-白垩纪)、早前陆盆地(古新世-早始新世)、前安第斯期前陆盆地(中始新世-早中新世)、安第斯期前陆盆地(中中新世-现今)。依据构造沉积演化及海平面变化特征,将中新生界划分为5个二级层序,其中Carbonera组划分为4个三级层序,每个三级层序由高位体系域(HST)和海侵体系域(TST)组成,缺失低位体系域。据地震相、砂地比和岩性资料编制Carbonera组高位体系域沉积相平面图,在图中识别出多个主河道,并认识到海平面变化呈上升趋势。Carbonera组砂泥旋回是有效的储盖组合,同时上覆Leon组是盆地内具良好封闭性的区域盖层。盆地中部和北部Carbonera组具有良好的储盖组合条件。
Llanos Basin is a foreland basin and it is an important in petroliferous basin of South America.In the research results,the sequence stratigraphy and reservoir-cap combinations need for further research.Taking the principle of sequence stratigraphy（P.R.Vail）and research results of structural evolution to study the sequence filling and use the data of physical-property,rock composition and replacement pressure to analyze reservoir-cap combinations for Carbonera Formation.From Mesozoic to present the tectonic evolution history of basin and its vicinity is divided into four stages：from rift basin to back-arc rift basin（Triassic to Cretaceous）,early foreland basin（Paleocene to Early Eocene）,early Andes stage foreland basin（Midterm Eocene to Early Miocene）,Andes stage foreland basin（Midterm Miocene to present）.We take tectonic evolution history and eustatic sea level change to divide the stratigraphic sequence.Mesozoic-Cenozoic have 5second-order sequences.Carbonera formations have 4third-order sequences,which all sequences have HST and TST without LST.We use seismic facies,sand-strata ratio and lithology to make HST planes of sedimentary facies.There are multiple channels and increasing sea level rise.Because of the sand-mud cycle,Carbonera Formation is favorable reservoir-cap combinations.And Leon Formation is excellent regional seal.The research and exploration prove that favorable reservoir-cap combinations of Carbonera Formation situated in the central and northern basin.
出处
《地质科技情报》
CAS
CSCD
北大核心
2015年第2期98-108,共11页
Geological Science and Technology Information
