壁面特性对凝析油析蜡聚集及黏壁过程影响的微观机理  

Micromechanism of the Effect of Wall Characteristics on Waxes Precipitation,Aggregation,and Adhesion in Condensates

作　　者：王志华[1] 刘晓宇 戚亚明 王聪 成庆林[1] WANG Zhihua;LIU Xiaoyu;QI Yaming;WANG Cong;CHENG Qinglin(Key Laboratory for Enhanced Oil&Gas Recovery of the Ministry of Education,Northeast Petroleum University,Daqing 163318,China;SINOPEC Maoming Petrochemical Company,Maoming 525099,China;Design Branch,Xinjiang Petroleum Engineering Co.,Ltd.,Karamay 834000,China)

机构地区：[1]东北石油大学提高油气采收率教育部重点实验室,黑龙江大庆163318 [2]中国石化茂名石化公司,广东茂名525099 [3]中油(新疆)石油工程有限公司设计分公司,新疆克拉玛依834000

出　　处：《石油学报（石油加工）》2024年第6期1635-1646,共12页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家自然科学基金项目(52074090);黑龙江省重点研发计划项目(JD22A004)资助。

摘　　要：利用分子动力学方法构建含蜡凝析油团簇在壁面上聚集黏附过程的模拟体系,揭示壁面材质及壁面粗糙特性等对其聚集黏附影响的微观机理。结果表明,含蜡凝析油在壁面上经历“团簇分解→分子脱离团簇向壁面扩散→油分子、蜡分子和沥青质分子在壁面上方聚集堆积→团簇在壁面上的铺展程度增加→在壁面上形成凝油层”的过程,团簇在不同材质壁面上均有不同程度的分解、扩散及在壁面附近聚集和黏附,团簇与玻璃钢壁面、718合金壁面、HP2-13Cr110合金壁面、BG140V合金壁面及普通钢管壁面间形成的接触角按顺序依次减小,在壁面上的铺展程度逐渐增强。尽管壁面形貌对团簇聚集与黏附的影响较小,但当进一步考虑粗糙特性时,团簇在壁面上的黏附程度与壁面表面积分数(壁面凸起部分宽度与整体壁面宽度的比值)及凹槽柱高度有关,表面积分数增大,接触角随之先增大后逐渐稳定,相应地,壁面对团簇的黏附性逐渐减弱;凹槽柱高度越大,团簇在壁面上的黏附程度越大,但模拟条件下在凹槽柱高度大于1.2 nm时会趋于稳定。A molecular dynamics method was used to construct a simulation system for the aggregation and adhesion of waxy condensate oil clusters on a wall,aiming to reveal the microscopic mechanism of the influence of wall material and wall roughness on the aggregation and adhesion.The result shows that the process that the waxy condensate oil undergoes on the wall can be demonstrated as cluster decomposition→molecular detachment from the cluster and diffusion towards the wall→aggregation and accumulation of oil,wax and asphaltene molecules above the wall→clusters increasing in spread on the wall→formation of a condensate layer on the wall.Waxy condensate clusters underwent varying degrees of decomposition and diffusion on the walls,and aggregation and adhesion near the walls of different materials.The contact angle formed between the materials such as fiberglass reinforced plastic surface,718 alloy surface,HP2-13Cr110 alloy surface,BG140V alloy surface and common steel pipe surface and the clusters decreased sequentially,and the degree of clusters spreading on the wall gradually increased.Although the influence of wall morphology on cluster aggregation and adhesion is relatively small,when further considering the roughness characteristics,the degree of cluster adhesion on the wall is related to the surface area fraction(i.e.,the ratio of the width of the raised part of the wall to the width of the entire wall surface)of the wall and the height of the groove column.As the surface area fraction increases,the contact angle increases first,and then tends to gradually stabilize.Correspondingly,the adhesion of the cluster on the wall is gradually weakened.The higher the height of the groove column,the greater the degree of cluster adhesion on the wall;however,under simulated conditions,cluster adhesion tends to stabilize when the height of the groove column is greater than 1.2 nm.

关 键 词：含蜡凝析油 聚集黏附 壁面材质 粗糙特性 分子动力学 

分 类 号：TE832[石油与天然气工程—油气储运工程]