Banca de DEFESA: JANAILSON OLIVEIRA CAVALCANTI

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : JANAILSON OLIVEIRA CAVALCANTI
DATA : 15/10/2021
HORA: 08:00
LOCAL: videoconferência na plataforma RNP (sala PEI-UFBA)
TÍTULO:

ANALYSIS OF AVAILABILITY INDICATORS FOR MONITORING THE OPERATION OF PUMPS AND CRITICAL COMPRESSORS OF A NATURAL GAS PROCESSING UNIT.

PALAVRAS-CHAVES:

Q-Weibull distribution, Operational performance indicators, Bathtub curve, Nonmonotonous failure rate function, Failure and repair data modeling.

PÁGINAS: 144
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Produção
RESUMO:

The total natural gas processing capacity in Brazil at the end of 2020 reached 107.7 million m3/day, obtained from the nominal capacity of 15 natural gas processing units (NGPUs), headquartered in 9 states of the federation. NGPUs are made up of various equipment and systems, many called critical physical assets, whose operational performance is evaluated based on indicators of reliability, availability and maintainability. These indicators are also needed to design maintenance programs, meet customer requirements and operation and maintenance contracts. The general objective of this work is to evaluate the operational performance of four critical pieces of equipment in an NGPU (two compressors and two pumps), based on indicators of reliability, maintainability and availability. The performance of the compressors was evaluated using the reliability and failure rate curves, obtained through the q-Weibull, Weibull and exponential distributions adjusted to the times between failures. The performance of the pumps was evaluated using the reliability and failure rate curves, the mean time to repair and the stationary availability, obtained through the qWeibull, Weibull and exponential distributions, adjusted for the times between failures, and the distributions lognormal and exponential, adjusted for repair times. The parameters of the fitted models and probability graphs were obtained by linear regression (least squares method). Additional statistical measures such as the Akaike information criterion, mean squared error and mean absolute error were calculated to compare the goodness of fit of the models. The q-Weibull distribution best fits the failure data of three devices, describing times between failures in a unimodal curve format for two compressors and one pump. For these three devices, the q-Weibull distribution modeled a continuous failure rate function in unimodal format and with a single set of parameters. The unimodal curve has an advantage over the formats modeled by the Weibull and exponential distributions, as it simultaneously exhibits two different regions of failure rate (increasing and decreasing), making it possible to establish a distinct maintenance strategy for each region. The Weibull distribution fitted better to the times between failures of the other pump, describing a monotonous decreasing curve, the same failure rate function format reproduced by the q-Weibull distribution for this equipment. The exponential distribution was better suited to the repair times of the two NGPU pumps. Based on estimates of mean repair time and mean time between failures, it was found that a pump has greater maintainability and reliability, therefore, better operational availability. The graphic and numerical results obtained in this work can serve as a source of information on the reliability and maintainability characteristics of compressors and pumps installed in NGPU, helping professionals in the oil and natural gas industry in decisionmaking and in the preparation of maintenance programs. 

MEMBROS DA BANCA:
Externo à Instituição - EDILSON MACHADO DE ASSIS
Interna - 2574950 - KARLA PATRICIA SANTOS OLIVEIRA RODRIGUEZ ESQUERRE
Presidente - 1523793 - SILVIO ALEXANDRE BEISL VIEIRA DE MELO