Impact of surface roughness,surface charge,and temperature on sandstone wettability alteration by nanoparticles  

作　　者：Bingjun Zhang Kaustubh Rane Mohammad Piri Lamia Goual 

机构地区：[1]Lam Research Corporation,11361 SW Leveton Dr.,Tualatin,OR,97062,USA [2]Champion X Chemical Technologies,11177 S.Stadium Dr.,Sugarland,TX,77478,USA [3]Center of Innovation for Flow through Porous Media,Dept.4311,University of Wyoming,1000 E.University Avenue,Laramie,WY,82071,USA [4]Department of Energy and Petroleum Engineering,Dept.3295,University of Wyoming,1000 E.University Avenue,Laramie,WY,82071,USA

出　　处：《Petroleum Science》2023年第5期2852-2863,共12页石油科学（英文版）

基　　金：the financial support from Baker Hughes Company and the U.S.National Science Foundation(NSF CAREER Award 1351296).

摘　　要：The wettability of rocks affects the balance between capillary and viscous forces during multiphase flow through porous media,which in turn determines the fluid displacement process governing the recovery of oil from subsurface formations.In this work,the mechanism of wettability reversal of aged synthetic sandstones by metal oxide nanoparticles(SiO_(2) and Al_(2)O_(3))was investigated with particular focus on the impact of surface roughness,zeta potential,and temperature.The synthetic surfaces were prepared from powders of Berea sandstone with known grain size ranges and their average roughness and roughness ratio were obtained from the 3D surface reconstruction of their microscope images.Each surface was subsequently aged in Permian crude oil to alter its wettability.For surfaces with larger grain sizes and lower surface roughness ratios,the lower capillary pressure allowed stronger oil/surface interactions,leading to enhanced oil-wetness.The wettability alteration effects of nanoparticles were then examined through real-time top view imaging and dynamic front view contact angle experiments.The negatively charged SiO_(2) nanoparticles rapidly reversed the sandstone wettability,indicating their potential applicability as wettability alteration agents.By contrast,the positively charged Al_(2)O_(3) counterpart caused no wettability reversal.The mechanism of wettability alteration was further studied by microscale interaction analyses and nanoscale transmission electron microscopy.Because nanoparticles were only a few nanometers large,the microscale roughness had a negligible effect on the wettability reversal.Instead,the combined effect of van der Waals dispersion forces and surface-charge-induced electrostatic forces were recognized as the two key factors affecting the wettability of sandstone particles.Such interactions may be curbed at elevated temperatures due to a decrease in the zeta potential and colloidal stability of the particles.

关 键 词：WETTABILITY SANDSTONE Surface roughness NANOPARTICLE MICROSCOPE Enhanced oil recovery Contact angle Zeta potential 

分 类 号：TE357.46[石油与天然气工程—油气田开发工程]