北部湾盆地福山凹陷花东—白莲北部地区流三段砂岩储层致密成因  

Origin Mechanism of Tightness from the Third Members of Liushagang Formation Sandstone Reservoir in the Northern Huadong-Bailian Area,Fushan Sag,Northern Bay Basin

作　　者：熊绍云[1] 黄羚[1] 程刚[2] 徐政语[1] 李昌[1] 

机构地区：[1]杭州地质研究院,杭州310023 [2]中国石油天然气股份有限公司南方石油勘探开发有限公司,广州510240

出　　处：《地质学报》2013年第10期1624-1633,共10页Acta Geologica Sinica

基　　金：中国石油天然气股份有限公司科技管理部项目(编号2011D-0707)"成熟探区油气分布规律与精细勘探技术研究"资助的成果

摘　　要：花东一北莲地区为福山凹陷重要产油区，流三段为花东北莲地区目前重要产层，其储层岩性以砂砾岩、含砾细砂岩及细砂岩为主，主要为岩屑砂岩、长石岩屑砂岩，岩石学上表现为高成分成熟度、高结构成熟度及较高胶结物含量的“三高”特征，孔隙度为8．41％～12．14％，渗透率为0．224×10^2。～3．472×10μm3，属于中低孔特低一超低渗储层。研究表明机械压实作用是本区砂岩储层致密的主要因素，成岩中期A阶段的溶解作用对储层物性有一定改善作用，由于长期处于封闭的成岩环境，长石和岩屑溶解不彻底，自生高岭石的形成有效改善了储层物性，但其含量少，并与伊／蒙混层、伊利石、绿泥石共生充填孔隙，因此对储层物性改造有限。沿流体通道或孔隙沉淀的伊／蒙混层、伊利石、绿泥石、碳酸盐以及石英Ⅱ级次生加大是储层进一步致密的重要因素。Fushan Sag is in the Beibuwan Basin is enriched in hydrocarbon. The third member of Liushagang Formation is currently an important reservoir in the northern part of the Huadong-Beilian area. Its reservior lithology contains sandy conglomerate, gravel sandstone and fine sandstone,which consist mainly of lithic sandstone and feldspar lithic sandstone. In petrology, the sandstones are characterized by high composional maturity, high textural maturity and higher cement. Sandstone reservoirs from the third members of Liushagang Formation,which porosity is 8.41-12.14 and permeability is 0. 224 X 10 ^3m2 3. 472 X l0^3 /m2 , belong to the medium-low porosity and ultra low permeability reservoir. Study demonstrates that mechanical compaction is main cause of tight sandstone reservoir, dissolution in medium diagenesis ＂A＂ improved reservoir property. Due to the enclosed diagenetic enviroment, feldspar and debris were not dissoluted completely. Authigenic kaolinite, although low content, can improve reservoir physics effectively,and fill pores along with illite/smectite mixed layer, illite and chlorite. Thus their effect on the reservoir is limited. Precipitation of illite/smectite mixed layer, illite, chlorite, carbonate and phase 11 quautz along the fluid channel or pores are the important fators to the tightness of reservoir.

关 键 词：福山凹陷 流三段 砂岩储层 致密成因 北部湾 

分 类 号：P618.13[天文地球—矿床学]