A study on well design and integrity for deepwater exploratory drilling in Brazilian Equatorial Margin.

• Autor(a) principal: Salazar Ruiz, Manuel Sebastian
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Biblioteca Digital de Teses e Dissertações da USP
• Texto Completo: http://www.teses.usp.br/teses/disponiveis/3/3134/tde-25092018-100849/
• topic: Assentamento de sapata; Barriers integrated set; Casing setting; Conjunto solidário de barreiras; Deepwater drilling; Janela operacional; Kick tolerance; Operating envelope; Perfuração; Petróleo; Poços; Well design; Well integrity

Drilling operations in deepwater (DW) or ultra-deepwater areas, even more in exploratory frontiers, have been increasingly challenging due to the operational complexities and limited available data about the subsurface conditions. In this sense, enhancing safety and minimizing the likelihood of losing well integrity and damage to the environment is a currently essential objective relating to offshore drilling activities. Hence, deepwater well designs should advance to safely meet the challenges related to the progression of well and water depths. The safe construction of these wells requires the application of suitable well design considerations that include well integrity approaches to reduce the risk of an unintended release of formation fluids (oil, gas or water) to the environment during the deepwater drilling operations, in other words a \"Blowout\" occurrence. In this study it is proposed two deepwater well architectural designs, limited to drilling stage, that safely accomplish the well targets and facing several deepwater well complexities, e.g. narrow operating envelopes. Thus, well logging and geological data of two actual pioneer wells drilled in deep and ultradeep water zones in Ceará Basin are used as a basis to construct and assess the drilling operating envelopes, to define the casing shoe depths and well barrier envelope. Furthermore, it is introduced the application of at least two independent Barrier Integrated Sets (BISs) to ensure the well integrity during the 4th phase drilling of the proposed well architectures, as it has recently been required in Brazil by the National Petroleum Agency (ANP) through \"Well Integrity Management System\" (SGIP for its acronym in Portuguese).