A case study of the Samotlor field to analyze corrosive damage of casing strings in production wells

Abstract

   The principal prerequisites for this study include a reduction in the number of operating oil wells at the Samotlor Field due to the corrosive destruction of production strings, which has resulted in a loss of oil recoveries during workovers and well integrity restoration efforts. The volume of such destruction over the past five years of field development has exceeded one thousand wells.   The main focus of the study is to identify all the influencing factors that catalyze the wear of the production string metal, as well as to develop methods for protecting wells, taking into account the identified source of the causes.   The tasks set in this article are solved by applying statistical analysis, geological analysis, and field analysis of well data. The data pertaining to the production history were collated and validated, while the statistical training sample was constructed in Microsoft Excel. The geological and field analysis of well data was conducted using the RN-KIN software package. The corrosion rate was simulated in Microsoft Excel using the VBA programming language. The study represents a comprehensive analysis of the production well stock, which has enabled the root causes of the emergence and development of corrosion processes to be identified. The laboratory studies resulted in numerical corrosion rates and a mathematical model that permits the consideration of the identified factors in order to assess the risks and corrosion rates in the wells. The practical relevance of the study lies in the methods developed and introduced to protect production strings from corrosion and erosion effects in the production well stock.