Analysis of risks associated with exploration well drilling in the Brazilian Equatorial Margin.

• Ano de defesa: 2019
• Autor(a) principal: Perez Venera, Alberto Mario
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Análise de risco; Brazilian Equatorial Margin; Drilling hazards; Exploration wells; Margem Equatorial Brasileira; Perfuração de poços; Poços exploratórios; Riscos na perfuração; Risk analysis
• Link de acesso: http://www.teses.usp.br/teses/disponiveis/3/3134/tde-19112019-092952/

Even though exploratory maritime activities in Brazil had begun in the early 1970s, the Brazilian Equatorial Margin (BEM) is still considered an exploratory frontier. Geological similarities with the Gulf of Guinea in Africa, where the Jubilee field was discovered, motivated the arrival of new international operating companies in Brazil giving to BEM a renewed commercial interest. Further tectonic, climatic and biotic evolution of this region continues being the object of several scientific studies. However, deepwater well drilling in an under-explored area is a challenging task due to all type of risks involved. A risk analysis is mandatory is to eliminate or reduce potential damage to people, environment or assets. Most of the drilling problems are derived from geological, metocean and human factors which resulted in significant delays on the drilling program or, in the worst cases, early well abandonment. The purpose of this work is to assess qualitatively the risks associated with exploratory well drilling in the Brazilian Equatorial Margin by collecting, synthesizing, and interpreting incident and occurrence data from offshore wells drilled off the coast of the state of Ceará. This research is divided into two parts. The first part includes the hazard identification based on the well folders and drilling reports of 14 exploratory wells obtained from ANP´s Exploration and Production Data Base. The second part of this research is a quantitative analysis to identify the frequency and severity of risk events. The frequency was obtained from the same well folders and drilling reports used to in the first part. To identify the severity, a questionnaire survey was sent to well engineering professionals in Brazil and abroad using the social networking services available. As a result, the events of highest risk for the operation was the lost circulation. The second highest risk place is shared between pipe sticking and wellbore instability. Discussions about risk mitigation of such risks identified in this research are included.