纳米颗粒改变碳酸盐岩凝析气藏储层润湿性评价  

Evaluation of the Wettability of Carbonate Rock Condensate Gas Reservoirs Modified by Nanoparticles

作　　者：高哲[1] 杨国平[1] 彭磊[1] 乐露[1] 付国民[2] 石磊[1] 付江龙[1] 贺涛[1] Gao Zhe;Yang Guoping;Peng Lei;Le Lu;Fu Guomin;Shi Lei;Fu Jianglong;He Tao(PetroChina Changqing Oilfield Company,Xi′an,Shaanxi 710018,China;Chang′an University,Xi′an,Shaanxi 710054,China)

机构地区：[1]中国石油长庆油田分公司,陕西西安710018 [2]长安大学,陕西西安710054

出　　处：《特种油气藏》2024年第2期143-151,共9页Special Oil & Gas Reservoirs

基　　金：国家自然科学基金“中国非常规油气储层特征、分类及地质模型建立”(41390451);国家科技重大专项“鄂尔多斯盆地大型低渗透岩性地层油气藏开发示范工程”(2016ZX05050)。

摘　　要：为了改变凝析气藏近井储层润湿性,有效解除凝析气反凝析伤害,采用X射线衍射、低温N 2吸附和扫描电子显微镜观测等方法,对氟化SiO 2纳米颗粒结构特征进行了研究,评价了不同矿物含量碳酸盐岩岩心对氟化SiO 2纳米颗粒的吸附程度;通过开展接触角测定、自发渗吸、岩心驱替单相和两相渗流实验,研究了纳米颗粒吸附前后岩石润湿性、自发渗吸效率、单相渗流压差、油气两相相对渗透率曲线以及凝析油采收率的变化。结果显示:氟化SiO 2纳米颗粒形状近似均匀球体,平均颗粒粒径为30.34 nm,平均孔径为20.00 nm;氟化SiO 2纳米颗粒在碳酸盐岩表面的吸附量随孔隙度的增大而增加,但在低渗透岩心中,吸附量和润湿接触角的变化幅度还随方解石含量的增加而增大;纳米颗粒吸附后岩石的油气两相共渗区变宽,等渗点向左上方移动,最大油气相对渗透率均大幅增加,束缚水饱和度和残余油饱和度明显降低;氟化SiO 2纳米颗粒能在约10 min内吸附在岩石表面,将强亲油、强亲水的液体润湿型岩石转变为中间(气体)润湿型,降低孔隙中毛管压力和凝析油渗流阻力,提高气、油两相的相对渗透率,达到解堵提产增效的效果。该研究结果具有极大的现场应用推广价值。In order to change the wettability of near-well reservoirs in condensate gas reservoirs and effectively relieve condensate gas retrograde condensation damage,the structural characteristics of fluorinated SiO 2 nanoparticles were investigated by using X-ray diffraction,low-temperature N 2 adsorption,and scanning electron microscope observation to evaluate the adsorption degree of fluorinated SiO 2 nanoparticles on carbonate rock cores with different mineral contents;and the changes in the wettability of the rocks,the efficiency of spontaneous permeation,the pressure difference of the single-phase seepage,the oil-gas phase relative permeability curves,and the changes in the condensate recovery before and after the adsorption of the nanoparticles were investigated by carrying out the contact angle measurements,the spontaneous permeation,and the single-phase and two-phase seepage experiments for the core displacement.The results show that The shape of fluorinated SiO 2 nanoparticles is similar to a uniform sphere,the average particle size is 30.34 nm,and the average pore size is 20.00 nm;the adsorption amount of fluorinated SiO 2 nanoparticles on the surface of carbonate rock increases with the increase of porosity,but in the low-permeability rock cores,the change of adsorption amount and the wetting contact angle increases with the increase of calcite content;the oil and gas two-phase co-seepage zone of the rock after nanoparticle adsorption,the oil-gas two-phase co-seepage zone of the rock widens,the isotropic point moves to the upper left,the maximum oil-gas relative permeability increases greatly,and the irreducible water saturation and remaining oil saturation decrease significantly;the fluorinated SiO 2 nanoparticles can be adsorbed on the surface of the rock in about 10 min,transforming the liquid-wetted rock,which is strongly oleophilic and hydrophilic,into an intermediate(gas)-wetted rock,lowering the capillary pressure in pores and the resistance to the seepage of condensate,and raising the relative permeab

关 键 词：碳酸盐岩 纳米颗粒 含氟基团 反凝析 润湿性 接触角 

分 类 号：TE348[石油与天然气工程—油气田开发工程]