准噶尔盆地吉木萨尔凹陷致密油储层纳米孔隙特征及其含油性

Nanopore Characteristics and Oil-Bearing Properties of Tight Oil Reservoirs in Jimsar Sag,Junggar Basin

纳米技术在非常规油气致密储层微观孔隙结构表征、油气赋存等研究中发挥着重要的作用.以准噶尔盆地东部吉木萨尔凹陷二叠系芦草沟组致密油储层为例,综合运用高压压汞分析、场发射扫描电镜及纳米CT扫描等纳米分析技术,对吉木萨尔凹陷芦草沟组致密油储层微纳米孔隙特征与结构进行研究,并结合宏微观特征分析了原油在孔隙中的赋存状态.结果表明:吉木萨尔凹陷二叠系芦草沟组储层为中低孔、特低渗储层,孔隙以微纳米级为主,类型多样,主要有粒间孔(隙)、粒间溶孔、晶间孔及微裂隙等,纳米孔隙是吉木萨尔凹陷二叠系芦草沟组致密油储层主要储集空间之一,纳米孔隙中普遍含油,且多以吸附状态存在,赋存在纳米孔隙中的油气,改变了微米级孔隙是油气储层唯一微观孔隙的传统认识,是未来石油工业的发展方向.

Nanotechnology plays an important role in the study of microscopic pore structure characterization and hydrocarbon accumulation in unconventional oil and gas tight reservoirs.This paper takes the tight oil reservoir of Permian Lucaogou Formation Jimsar sag in eastern Junggar basin as an example,comprehensively using high pressure mercury analysis,field emission scanning electron microscope（SEM）and nano CT scanning analysis technology to study micronano pore characteristics and structure of Lucaogou Formation tight oil reservoir in Jimsar sag.In addition,the occurrence state of crude in nanopores is analyzed combined with macro and micro characteristics.The results show that nanopore space is one of the main reservoir spaces in the Permian Lucaogou Formation tight oil reservoir in Jimsar sag of Junggar basin.On the whole,the main reservoir pore structure is micron and nano level,showing the characteristics of micron and nano pore throat.Nanopores are generally oil-bearing,and exist mostly in the adsorption state,which changes the traditiongal cognition that micron pore is the only microscopic pore in reservoir.It is the development direction of the future petroleum industry.