西南石油大学学报(自然科学版)

• 本期导读 • 上一篇    下一篇

超临界CO2 驱对储层物性影响的实验研究

张超,李兆敏,张东   

  1. 中国石油大学(华东)石油工程学院,山东青岛266580
  • 出版日期:2013-10-20 发布日期:2013-10-20
  • 基金资助:

    国家自然科学基金重点项目(51034007);国家科技支撑计划项目(2012BAC24B03)。

Experimental Research on the Influence of Supercritical CO2 Flooding on
Reservoir Physical Property

Zhang Chao, Li Zhaomin, Zhang Dong   

  1. School of Petroleum Engineering,China University of Petroleum(East China),Qingdao,Shandong 266580,China
  • Online:2013-10-20 Published:2013-10-20

摘要:

分析并研究了储层岩石经过N2、CO2 及SC–CO2(超临界CO2)驱替后注入气体对储层物性的影响,并利用X
射线衍射及扫描电镜技术对储层岩石进行矿物成分及微观结构分析。实验结果表明,CO2 注入储层后能够溶蚀岩石
中的矿物成分,使孔隙度变大,渗透率升高;由于溶解快、扩散快的特性,SC–CO2 在注入地层时,前期对储层物性的
改变十分明显;另外,脱落的黏土矿物发生运移又会堵塞岩石孔隙,导致岩石渗透性变差。通过X 射线衍射分析发现
CO2 所溶蚀的矿物成分为方解石、长石,通过扫描电镜观察岩石溶蚀前后的微观孔隙结构发现,溶蚀后样品疏松,次生
孔隙发育充分,连通性变好。

关键词: 超临界CO2, 溶蚀, 储层物性, 扫描电镜, X 射线衍射

Abstract:

The influence of injected gas on reservoir physical property was studied after reservoir rocks being flooded by
N2,CO2,and supercritical CO2. The mineral composition and microstructure of the reservoir rocks were also investigated
by applying X-ray diffractometer(XRD)and scanning electron microscopy(SEM). The results show that the injected CO2
can corrode the mineral compositions,make porosity and permeability increase. Supercritical CO2 will change the physical
property of the reservoir at the initial stage of the injection because of its rapid dissolution and fast diffusion. However,clay
minerals could plug rock pores,which result in the deterioration of the permeability. Calcite and feldspar could be corroded by
CO2 which was detectable by XRD,and the microstructure of the reservoir rocks were observed by SEM before and after the
corrosion. The corroded rocks became loose and had many secondary pores with better connectivity.

Key words: supercritical CO2, corrosion, reservoir physical property, scanning electron microscopy(SEM), X-ray diffraction