摘要
运用压汞、扫描电镜和低温氮吸附技术,研究鄂尔多斯盆地长7段致密油储层微观孔隙结构特征,获得储层毛细管压力曲线和低温氮吸附曲线,进而得到储层喉道类型、不同类型孔隙分布、孔隙特征与物性的相关关系等。研究结果表明:研究区储层孔隙度平均值为7.94%,克氏渗透率均值为0.033 m D,属于低孔、致密储层;研究区储层的毛管压力曲线从形态差异分为三类,Ⅰ类曲线储层宏孔最为发育,占全部空隙的80%,喉道以微细喉类型为主,微喉控制孔隙的退汞量占总退汞量13%;Ⅱ类曲线储层孔隙发育较差,喉道以细喉发育为主,微喉控制孔隙的退汞量占总退汞量25%;Ⅲ类曲线储层介孔最为发育,约占全部空隙的50%,喉道类型较为复杂,细喉、微细喉道和微喉均有发育,微喉控制孔隙的退汞量占总退汞量的46%;储层渗透性与储层比表面和孔喉比等特征参数呈负相关,且该储层微裂缝发育较差。
The throat type,different type pore size distribution,pore characteristics and poroperm characteristics correlation are studied in order to investigate the microscopic pore structure of tight oil in Erdos basin. A series of experimental methods,including mercury intrusion,scanning electron microscopic and low-temperature nitrogen absorption,are applied to obtain the mercury capillary-pressure curve and low-temperature nitrogen adsorption isothermal curves. The results show that： this reservoir porosity mean value is 7. 94%,the klinkenberg permeability mean 0. 033 m D,belongs to the low porosity,low permeability reservoir; Basically,capillary pressure curve can be classified into 3 classes according to the morphological differences,reservoir macro-pore whichⅠcurve reflects developed most,according for the total gap 80%,most of the pore throat diameter less than 0. 2 μm. In all mercury ejection volume,ejection volume of less than 0. 2 micron throat control gap account for 13%; reservoir pore volume which II curve reflects the smallest,most of the pore throat diameter is 0. 2 ~ 0. 5 μm,In all mercury ejection volume,ejection volume of less than 0. 2 micron throat control gap account for 25%; reservoir mesoporous which III curve reflects developed most,accounting for all air gap around 50%,The throat type is complex,the pore throat diameter is 0. 007 ~ 0. 42 μm. In all mercury ejection volume,ejection volume of less than 0. 2 micron throat control gap account for 46%; reservoir permeability was negatively correlated with the reservoir characteristic parameters such as the pore throat ratio and surface,and the micro fracture is poor.
出处
《科学技术与工程》
北大核心
2015年第29期124-130,共7页
Science Technology and Engineering
基金
国家科技重大专项(2011ZX05013-005)资助
关键词
孔隙结构
致密油
氮吸附
高压压汞
退汞效率
鄂尔多斯盆地
pore structure tight oil nitrogen adsorption high pressure mercury mercury withdrawal efficiency Erdos Basin
