Abstract
Electric submersible pumps (ESPs) are considered to be a very cost effective artificial lift method by industry standards, particularly in water supply wells (WSWs). In four WSWs, ESP performance had experienced a number of premature failures, which resulted in short average run lives of less than 1 ½ years, high operating costs, and unsustainable water supply required for injection pressure support and field development. To ensure that future ESP application in these wells is successful and improve run life, a multidisciplinary team was formed and conducted a comprehensive review to identify the causes of previous ESP failures and recommend methods to improve current practices based on all gathered engineering data; including, dismantle results of pulled ESP units, well and reservoir data, completion strategy, ESP equipment design, commissioning, and data monitoring.
The analysis indicated that the failures were primarily the results of corrosion and solids, and lack of close monitoring of ESP performance review, which prevented rectification of the problems in a timely manner. Secondary problems were also identified, such as tight wellhead clearance that damaged wellhead penetrators during installation, failure of tubing internal coating, and insufficient wellbore cleanout before making up ESPs during workovers, etc.
This engineering approach has successfully helped to increase confidence in, and reliability of, ESP operations, optimization, sustained field production levels, and reduced capital and operating costs due to improved pump run life.
This paper reviews the performance of ESP systems in WSWs and the challenges faced during the past 4 years of operation. Also, it covers installations, commissioning, dismantle inspection failure analysis (DIFA) results, operation philosophy, optimization methodology, average ESP run life, and ESP technical improvements.
