Case Study: Enhanced Compression Pumps with Mixed Flow Stages for Unconventional Shale Plays

Abstract

Abstract The challenges of unconventional reservoirs have driven electric submersible pump (ESP) providers to continue making improvements to the mechanical design of the pump stages. These improvements enable covering wider operating flow ranges and maximizing production without the need to replace the artificial lift system with a different method such as gas lift or rod pumps. In 2016 and 2020, two new pump types were introduced as a solution for unconventional wells. This case study summarizes the results of the analysis of 52 ESPs installed with the new pump types in the Midland Basin from 2019 to 2021 for a leading operator in the basin. The operator's well test data showed a declining production averaging from 1,300 to 100 BFPD, with water cut from 40% to 99% and gas-oil ratios up to 9,000 SCF/STB. This paper presents the results of how the re-engineering of a standard mixed-flow stage becomes a solution to improve the performance of the ESPs when producing from unconventional shale plays where the downhole environment is extremely harsh. The re-engineering of the standard mixed-flow stage produced a stage characterized by high hydraulic performance and superior efficiency. The study's conclusions can also be applied to conventional shale plays with more benign conditions. To develop the new stages used in the two new pump types, an engineering team conducted an extensive study considering the available run life data and the results of the top failure modes of the ESPs when operating at low flow ranges in unconventional wells. The engineering team considered a stage design to optimize the operation in the low-flow-rate region by a better distribution of downthrust and stress management of the pump's internal components.