摘要
为了得到原油管道检修过程中清管器推油换管作业出现的硫化氢质量浓度超标原因及其析出规律,通过分析管道检修典型作业流程,初步推断得到了硫化氢析出原因;并针对析出原因设计了缩比例试验,还原了清管作业过程,得到了原油中硫化氢在各个阶段的析出状况,根据试验结果确定了硫化氢析出原因,并得到了氮气流量对硫化氢质量浓度的影响规律。直管试验结果表明,直管推油过程中无论清管器卡阻与否,氮气放空基本不会出现硫化氢析出现象;弯管试验结果表明,产生高浓度硫化氢气体是由于清管器意外卡阻后,氮气穿过清管器直接与含硫原油接触,并且在地势高程差的作用下,对局部低点残留原油反复气提,导致放空时混合气体中硫化氢质量浓度超标。同时,对弯管试验数据进行分析表明,析出的硫化氢质量浓度受氮气对硫化氢的气提作用和稀释作用共同影响;在采取现场硫化氢质量浓度控制措施时,应根据实际管径及在输原油的硫化氢含量设计不同的注气流量。
The aim of this paper is to find the reason for the excessive concentration rate of the hydrogen sulfide appearing in the process of the pipeline maintenance. In this paper,the cause of hydrogen sulfide stripping has been preliminarily deduced by analyzing the typical operation process of pipeline maintenance.What is more,the scaling experiment has been laid out based on a specifically designed experimental device,the pigging process of which has been simulated to obtain the stripping mass concentration of the hydrogen sulfide in the crude oil at the various stages. The above mentioned experimental device is made up of a straight pipe and a U-shaped pipe with the simulated pig being pushed by the nitrogen. In the said process,3 conditions can be said to lead to high mass concentrations of the hydrogen sulfide.The reason for the hydrogen sulfide stripping can be determined in accordance with the experimental results,whose influential regularity for the nitrogen flow can be deduced on the mass concentration rate of the hydrogen sulfide. Therefore,the experiment of the straight pipe indicates that it wouldn’t be possible for the hydrogen sulfide stripping to take place in the nitrogen blowout,no matter whether the pig gets stuck or not. The experimental results of the U-shaped pipe also suggest that the hydrogen sulfide with high concentration can generate due to the direct contact of nitrogen with the crude oil through the pig accidental stuck when it was produced. Thus,in conclusion,on account of the elevation impact of the repeated gas stripping of the residual crude oil,the excessive concentration of the hydrogen sulfide may get diffused in the process of the gas mixture. At the same time,the experimental data analysis of U-shaped pipe tests also prove that the mass concentration of the hydrogen sulfide can be influenced by the gas stripping and dilution of the hydrogen sulfide by nitrogen. And,therefore,it is also of great need to lay out different injection flow rates in accordance with the actual pipe diameter and the actual hydrogen sulfide content in the crude oil so as to reduce the mass concentration of the hydrogen sulfide in the overall process of pigging operation.
作者
杨明
李龙冬
王晓波
郑登锋
万嵩
YANG Ming;LI Long-dong;WANG Xiao-bo;ZHENG Deng-feng;WAN Song(Petro China West Pipeline Company,Urumchi 830000,China;State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology,Beijing 100081,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2020年第3期987-993,共7页
Journal of Safety and Environment
关键词
安全工程
原油管道
清管作业
硫化氢
氮气气提
safety engineering
crude oil pipeline
pigging operation
hydrogen sulfide
nitrogen gas stripping
