摘要
目前火山岩储层评价的主要依据是储集空间类型和孔渗参数,但储集空间类型与物性参数之间的关系尚不明确。为此,依据松辽盆地全取心井(营一D1井和营三D1井)开展营城组火山岩孔缝单元类型研究及其与孔渗参数关系的分析,取得如下主要认识。首先,研究区火山岩主要发育5种原生孔隙、3种次生孔隙、3种原生裂缝和3种次生裂缝;根据发育过程、分布排列特征的相似性,把储集空间归并为7种孔隙类和2种裂缝类;将上述孔隙类与裂缝类划分为7种组合类型,即7型孔缝单元,分别为1型离散气孔类-次生裂缝类组合型、2型定向气孔类-脱玻化类-次生裂缝类组合型、3型离散粒间孔类-溶蚀孔类组合型、4型离散粒间孔类-溶蚀孔类-原生裂缝类组合型、5型离散粒间孔类-溶蚀孔类-次生裂缝类组合型、6型定向粒间孔类-溶蚀孔类-次生裂缝类组合型和7型裂缝类组合型。其次,对比按孔隙单元拟合孔渗关系与按整体拟合孔渗关系的函数斜率,7型孔缝单元可划分为3组,即,略低于总体拟合函数(A组)的1型和2型孔缝单元,略高于总体拟合函数(B组)的3型、4型、5型和6型孔缝单元,远远高于总体拟合函数(C组)的7型孔缝单元。第三,除2型单元和7型单元之外的其他5型单元的储层物性较好;各型孔缝单元的孔喉分选系数随孔喉半径均值增大而增大,储层非均质性变强;多数孔缝单元具有复杂的岩性-岩相组合;孔缝单元分布与火山机构类型和相带关系密切。第四,依据孔缝单元的孔渗条件和孔渗相关拟合函数可知,应该依据孔缝单元进行储层评价分析,即使赋存于相同岩性的1型、2型单元也需要分别对待。
To evaluate volcanic reservoirs, only the parameters of porosity and permeability are now focused; while the void space, which is the controlling factor to influence the porosity and permeability, is ignored. It hampers the research of volcanic reservoirs. Types of pore-fracture units and their porosity and permeability are analyzed based on the cores of Yingcheng Formation in Early Cretaceous of well Y1D1 and well Y3D1 in Songliao basin. The main results are followings： 1）There are five kinds of primary pores, three kinds of secondary pores; three kinds of primary fractures, and three kinds of secondary fractures. The most pores and fractures have been reformed by compaction and dissolution. According to the formation process and distribution pattern, the reservoir spaces are assembled to seven kinds of pore-groups and two kinds of fracture-groups. On the basis of combined characteristics of pore groups and fracture groups, the volcanic reservoirs are divided into seven types of pore-fracture units as below： unit（1） assembling of scatter vesicles group （SVG） and secondary fracture group （SFG）, unit（2） assembling of directional vesicles group （DV）, devitrification pore group （DPG） and SFG, unit（3） assembling of scatter intergranular pores group （SIPG） and emposieu group（EG） , unit（4） assembling of SIPG, EG, and primary fracture group（PFG）, unit（5） assembling of SIPG, EG, and SFG, unit（6） assembling of directional intergranular pores group （DIPG）, EG, and SFG, and unit（7） assembling of PFG and SFG. 2）The porosity and permeability of the pore-fracture units have high value except unit（2） and unit（7）. There are three groups of slope of correlation function of pore-fracture units between porosity and permeability comparing to that of the total samples. Group A includes unit （1） and （2）, whose slope is smaller than the total＇s; Group B includes unit（3）,（4）,（5） and （6）, whose slope is bigger than the total＇s; Group C is unit （7）, whose slope is much bigger than the total＇s. 3） The pore throat sorting coefficient of pore-fracture units are positive correlation with pore throat average radius; this means that the heterogeneity of reservoir becomes stronger. Most pore-fracture units consist of complex lithology and lithofacies. The distribution characteristics of pore-fracture units are correlated to the types and facies belts of volcanic edifices. Based on the above, for reservoir evaluation, the pore-fracture units have also to be considered in addition to their parameters of porosity, permeability, and correlation function; although the units （1） and unit （2） bear in lava, they have distinct characteristics in porosity and permeability, and it is necessary to treat them individually.
出处
《吉林大学学报（地球科学版）》
EI
CAS
CSCD
北大核心
2016年第1期11-22,共12页
Journal of Jilin University：Earth Science Edition
基金
国家自然科学青年基金项目(41002038)
国家重点基础研究发展计划(973计划)(2012CB822002)~~
关键词
松辽盆地
营城组
火山岩
孔缝单元
储集空间
Songliao basin
Yingcheng Formation
volcanic rocks
pore-fracture units
void space
