Banca de DEFESA: RHUAN COSTA SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : RHUAN COSTA SOUZA
DATE: 29/03/2022
TIME: 09:00
LOCAL: on-line
TITLE:

EXPERIMENTAL AND COMPUTATIONAL EVALUATION OF THE ROTARY CAGE SYSTEM USED IN THE CORROSION OF API X65 STEEL IN MEDIUMS CONTAINING CO2 AND H2S

KEY WORDS:

Flow accelerated corrosion, Rotating cage, CFD simulations, Sweet and sour corrosion, API X65 carbon steel.

PAGES: 260
BIG AREA: Ciências Exatas e da Terra
AREA: Física
SUMMARY:

Steel pipes in the oil and gas industry are constantly exposed to corrosive environments, where three factors that negatively affect the integrity of these pipelines stand out. The presence of carbon dioxide (CO2) (sweet corrosion), the presence of hydrogen sulfide (H2S) (sour corrosion), and internal flow, causing the phenomena known as flow accelerated corrosion. Therefore, it is necessary to study the relationship between these three factors that, in most practical cases, occur simultaneously. The turbulent flow, generates shear stresses in the walls of the ducts, increases the mass transport of contaminant species, from the aggressive environment towards the metal surface, favoring corrosive processes. In addition, fluid dynamics can hinder the addition of a protective film in the material, whether from products or corrosion inhibitors. The ASTM G170 standard, initially proposed in 2001, defines techniques for the study of these systems in the laboratory, including the rotating cage (GR). Currently, the combination of CFD computer simulations and tests in autoclaves with GR have been used. The standardized GR model has its proven efficiency and is widely used. However, it is known the need for an improvement in the experimental device and an update in the mathematical equation provided by the standard, seeking to reduce the great conservatism embedded in the values of corrosion rate obtained. The present work seeks to propose improvements in the standard rotational cage model (GRP) (ASTM G170 and G184), testing geometric modifications in a computational (CFD) and experimental study with API X65 steel in environments containing CO2/H2S. The study was divided into an initial stage to know the responses with the standard cage and the fluid dynamics inside the autoclave used. And then two new models were proposed (Opened Rotating Cage - GRV and 8-hole Rotating Cage - GR8), simulated and experimentally evaluated, as well as the behavior of API X65 steel in environments containing CO2/H2S. In general, both GRV and GR8 showed significant improvements in relation to GRP. The CFD results show that the gain in uniformity in the distribution of stresses was similar for the 2 modified models. However, GR8 presented superior results, in addition to a more regular formation of corrosion products in laboratory tests. These results were decisive for the 8-hole rotating cage (GR8) to be selected in this study as the best proposed modification.

BANKING MEMBERS:
Presidente - 1525125 - ALYSSON HELTON SANTOS BUENO
Externa ao Programa - 1720111 - ANDREIA MALACARNE
Externo ao Programa - 1987545 - GUILLERMO VILALTA ALONSO
Externa ao Programa - 435086 - HONORIA DE FATIMA GORGULHO
Externo à Instituição - JOSE ANTONIO DA CUNHA PONCIANO GOMES - UFRJ
Externo à Instituição - LOURIVAL JORGE MENDES NETO - UNIFEI