Abstract

Some conditions present in unconventional wells, such as high abrasives content, high gas-liquid ratios, and high temperatures, are detrimental to the bearing systems of an electric submersible pump (ESP) because they decrease system run-life. A testing regimen was conducted using a slurry loop (a specially designed flow loop capable of handling fluid with high sand content) to examine the effects of fluid with high abrasives content on pump wear and using an industrial oven to examine temperature effects on bearings and bearing materials. Controlled variables during testing included bearing material, assembly methods, component features, build configurations, flow rate, and thrust loads. Testing produced statistics on the properties of industry-standard bearing materials and data on the performance of bearings and bushing retention in high abrasive and high temperature environments, resulting in the development of a model of bushing retention. Testing of modifications to the bearing systems resulted in a change in bearing materials and a patented (Nowitzki and Roberts 2016)high thermal expansion material (HTEM) bushing retention system that, respectively, increased bearing abrasive resistance sixfold and reduced the occurrence of bushing migration in high temperature environments from 90.3 to 10% of the population.

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