Discussion on the relationship between iron content and corrosion rate in production fluid of oil wells

Abstract

To provide an economical and practical technique for the application of on-line corrosion monitoring technology in oil production system, in this paper, the iron content was measured by a water quality multi-parameter tester and corrosion rate was determined by the weight loss method. Then, the quantitative relationship between the iron ion and corrosion rate could be found. On this foundation, in order to correctly describe the corrosion in the wellbore of oil wells, according to SY/T0026-1999 water corrosion test method standards, a mathematical relational expression between iron ion content and corrosion rate in oil wells production fluid was established. In order to verify the reliability of relational expression, the iron content in the produced fluid of 17 wells corrosion conditions before and after adding medicine were measured on the spot. Then, the relational expression entered the field application. The results show that there was the positive correlation between the iron ion and corrosion rate. The error of the calculated corrosion rate of 17 wells in the field was less than 26% compared with the measured corrosion rate. The mathematical relational expression had good effect in J45-62 well. It could reflect the corrosion trend of well bore. Thus, through the internet+ technology, the on-line monitoring system for remote corrosion could be established, and corrosion trend of wellbore pipelines could be predicted with the help of nerve net algorithm.