Avaliação do desgaste do Par Casing-Hardbanding a partir de ensaios em escala reduzida

Abstract

In the drilling oil wells, the drill string tool joints (TJ) slides against the casing. In order to avoid excessive wear on the tool joints, anti-wear alloys called hardbandings (HB) are deposited on them. HBs are manufactured to exhibit high wear resistance aiming to protect the TJ. However, the TJ high wear resistance may lead to excessive wear on the inner casing well, causing loss of structural well reliability. To find a HB that shows both proper drill string protection against wear and low casing wear is therefore a challenge for the oil industry. In this work, the performance of five different used as HBs alloys was studied using a small-scale test simulating some of the conditions observed in the field. The wear behaviors in casing and in the HBs materials were considered, correlating the results with the different microstructures and the behavior of the wear rates obtained in the experimental tests. The results showed that HB alloys contained primary carbides, homogeneously distributed on their surface, had the lowest wear rates in both HB and casing. This is because the presence of the hard phases allowed a more uniform distribution of nominal contact pressure, without the formation of preferential abrasive flow channels, reducing abrasive wear.