Abstract
The goal of this work is to show what things generate more temperature than the simulation of downhole conditions, and how to mitigate them by, for example, selecting the appropriate ESP position, considering the production rates vs. zones, and the right materials for the production tubing in order to reduce motor operating temperature and increase run life.
This study recovers information from different sources, history data of 15 years of running electric submersible pumps in the field, detailed data over three years from three different electric submersible pump suppliers, and more than 80 tear down analysis.
Starting 2013, twenty-five (25) electric submersible pumps were run with high temperature down-hole sensors–the interpretation of that information was one of the keys to success. In three cases the setting depth of the equipment was changed to test the theory.
All the wells are in secondary recovery projects, so the injection rate and selective zone are very important to take into account.
Today there is no software that exists that can simulate, with accuracy, the real dynamic temperature of the ESP above or between zones.
Several flow simulations were run to prove the hypothesis, considering different flow rates and pump intake pressure.
The position of the ESP related to production zone, flow rate, and submergence will determine the dynamic temperature of the motor.
The use of special isolation tubing (VIT – Vacuum Insulated Tubing, for example) is one way to reduce the ESP temperature in the deeper and higher temperature wells.
The study of the temperature profile in a pump between zones is not a common situation in the oil industry, there is no literature that explores this kind of down-hole situation.
Today, there is no sizing/design software prepared to predict the temperatures in these types of installations. This paper will show the considerations required to do it properly.
