Experimental study on wax deposition of highly paraffinic oil in intermittent gas-oil flow in pipelines  

作　　者：Chuan-Shuo Wang Qian-Li Ma Xiao-Fang Lv Jie Zhang Yang Liu Shi-Dong Zhou 

机构地区：[1]Jiangsu Key Laboratory of Oil and Gas Storage and Transportation Technology,Changzhou University,Changzhou,213164,Jiangsu,PR China [2]Hade Oil and Gas Development Department,Tarim Oilfield Branch,Korla,841000,Xinjiang,PR China

出　　处：《Petroleum Science》2024年第3期2080-2088,共9页石油科学（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.52274061&52004039&51974037);China Postdoctoral Science Foundation(Grant No.2023T160717&2021M693908);CNPC Innovation Found(Grant No.2022DQ02-0501),Changzhou Applied Basic Research Program(Grant No.CJ20230030);The major project of universities affiliated with Jiangsu Province basic science(natural science)research(Grant No.21KJA440001);Jiangsu Qinglan Project,Changzhou Longcheng Talent Plan-Youth Science and Technology Talent Recruitment Project。

摘　　要：Oil-gas two phase wax deposition is a fairly common and open-ended question in flow assurance of multiphase transportation pipelines.This paper investigated the two main aspects of oil-gas two phase wax deposition layer:apparent thickness and crystal structure characteristics.A typical highly paraffinic oil in Bohai Sea,China,was used as the experimental material to investigate the wax deposition thickness in oil-gas two phase under the influence of different oil temperatures,superficial gas/liquid phase velocities and gas-oil ratios by using multiphase flow loop experimental device.Just as in the classical theory of wax molecular diffusion,it showed that wax deposition thickness of oil-gas two phase increased with increasing oil temperature.Analysis of the impact of different superficial phase velocities found that the actual liquid flow heat transfer and shear stripping was the gas phase dominant mechanisms determining wax deposit thickness.In addition,the crystal structure of the wax deposition layer was characterized with the help of small-angle X-ray scattering(SAXS)for different circumferential positions,flow rates and gas-oil ratios.The bottom deposition layer had a complex crystal structure and high hardness,which were subject to change over flow rate variations.Furthermore,the SAXS results provided evidence that the indirect effect of the actual liquid velocity modified by the gas phase was the main mechanism.Our study of the effect of gas phase on the wax deposition of oil-gas two phase will help shed light onto the mechanism by which this important process occurs.Our findings address a very urgent need in the field of wax deposition of highly paraffinic oil to understand the flow security of oilgas two phase that occurs easily in multiphase field pipelines.

关 键 词：Oil-gas two phase Highly paraffinic oil Wax deposition SAXS 

分 类 号：TE832[石油与天然气工程—油气储运工程]