ESP Run Life Increased by 230% Using a Small, Customized Device: The Next Step in Flow Assurance and Chemical Injection for ESP-Lifted Wells

Abstract

Carbonate scale is a mineral deposit transported by produced water, and its presence negatively affects well production and electrical submersible pump (ESP) performance. Instead of attempting to remediate it after it has already accumulated, a suitable and more-cost-effective process is to use a continuous inhibition treatment through an additional hardware installed in the ESP. An acid treatment can be suitable for certain types of scale, but acid treatments can cause damage to the tubing string and the ESP if not handled properly. A new hardware was developed and used in ESP applications by looking for inhibition in fouling fluids as soon as the fluid comes out of the reservoir and before considerable pressure or heat changes occur by increasing the contact time with the treatment and by looking for a faster homogenization between the reservoir fluid and the inhibitor treatment with a 360° tool injection. An analysis of historical data demonstrates a significant increase in ESP mean time between failure in wells dealing with fouling fluids where the tool, a tail pipe with a multipoint centralizer, was implemented. Additionally, a more-stable downhole parameter condition was reached. It was also observed that, depending on where the tool was placed, production improved by postponing the buildup of deposits at the reservoir face and mitigating skin damage. This hardware, which improves flow assurance, has been continuously improved, and each step will be covered. Additional information was retrieved during the analysis performed during teardown of the ESPs, and it has been possible to identify wells dealing with similar problems. Some wells were newly categorized as problematic, and several data suggest that the increase in water cut related to a waterflooding process could have changed the fluid properties. By understanding the specific cause of the ESP failure let us understand that there was a direct relationship to a lack of an effective chemical treatment, not related to the formulation or dosage of the chemical treatment, but because of the challenging well trajectory due the mechanical configuration or for uncertainties in the producing fluid properties. It was necessary to create alternative tools as new solutions to improve flow assurance. This project will provide an alternative solution that is cost effective and provides a tangible value to projects in which flow assurance and effective chemical treatment are effective when dealing with harsh fluid properties or the behavior of the fluid is unknown before ESP installation.