New unconventional wells have been a huge challenge for ESPs in the Permian Basin due to horizontal wells with high-formation GORs or GLRs. The pumped fluid can cause issues such as gas interference, gas locking, short run life, low production, poor energy efficiency, increased failure rates, shutdowns, so forth. A major problem is gas presence around the ESPs, because it causes the motor to rapidly overheat since the gas is incapable of adequately cooling.
In short term, the presence of gas in the flow reduces the pump efficiency and in severe conditions leads to gas lock in the impeller which could damage the equipment. In the long term, the motor life is shortened as a function of the temperature increase. In general, for every 18F of operating temperature increase, the life of the insulation material is reduced by 50% and leading the motor material to be severely affected. The gas handling capacity of standard ESPs is very low, and the efficiency of the traditional rotary gas separator might not be as expected that is why a new and innovative downhole gas separator has been introduced in recent applications to combat the gas slug's problems.
The new gas mitigation technology consists of a shrouded ESP with a double stage of gas separation connected at the bottom of the shroud that act as intake and was designed to break the gas slugs and avoid gas entrance into ESPs by forcing free gas to go around the shroud and produce through the casing. The fluid is now forced to pass through an additional gas separator (New Gas Mitigation Technology), which helps on gas mitigation as well as lower motor temperature
This paper summarizes different case studies in wells located in the Permian Basin that had reported frequent shutdowns due to gas lock and high motor temperature. All the pump parameters are analyzed before and after the installation to conclude on optimization; in these wells, an increase on production was observed, and better performance of the pump. Other results observed were the reduction of the shutdowns and no gas mode with stable condition along with significantly breaking the drawdown barrier of the 700 psi (ESP PIP). This success was noted on most of our wells where the lowest of them operated at 290 psi (ESP PIP). Additionally, some operational and analytics guides are provided to understand how to identify and control the gas problem in ESPs.