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Dynamic safety risk analysis of offshore drilling


Abimbola, M and Khan, FI and Khakzad, N, Dynamic safety risk analysis of offshore drilling, Journal of Loss Prevention in the Process Industries, 30, (1) pp. 74-85. ISSN 0950-4230 (2014) [Refereed Article]

Copyright Statement

Copyright 2014 Elsevier Ltd. All rights reserved.

DOI: doi:10.1016/j.jlp.2014.05.002


The exploration and production of oil and gas involve the drilling of wells using either one or a combination of three drilling techniques based on drilling fluid density: conventional overbalanced drilling, managed pressure drilling and underbalanced drilling. The conventional overbalanced drilling involves drilling of wells with mud which exerts higher hydrostatic bottom-hole pressure than the formation pore pressure. Unlike the conventional overbalanced drilling, underbalanced drilling involves designing the hydrostatic pressure of the drilling fluid to be lower than the pore pressure of the formation being drilled. During circulation, the equivalent circulating density is used to determine the bottom-hole pressure conditions. Due to lower hydrostatic pressure, underbalanced drilling portends higher safety risk than its alternatives of conventional overbalanced drilling and managed pressure drilling. The safety risk includes frequent kicks from the well and subsequent blowout with potential threat to human, equipments and the environment. Safety assessment and efficient control of well is critical to ensure a safe drilling operation. Traditionally, safety assessment is done using static failure probabilities of drilling components which failed to represent a specific case. However, in this present study, a dynamic safety assessment approach for is presented. This approach is based on Bow-tie analysis and real time barriers failure probability assessment of offshore drilling operations involving subsurface Blowout Preventer. The Bow-tie model is used to represent the potential accident scenarios, their causes and the associated consequences. Real time predictive models for the failure probabilities of key barriers are developed and used in conducting dynamic risk assessment of the drilling operations. Using real time observed data, potential accident probabilities and associated risks are updated and used for safety assessment. This methodology can be integrated into a real time risk monitoring device for field application during drilling operations.

Item Details

Item Type:Refereed Article
Keywords:blowout, bow-tie approach, drilling techniques, dynamic risk assessment, kick, predictive probabilistic model, blowouts, drilling fluids, drilling platforms, hydrostatic pressure, pore pressure, probability, risk assessment, safety engineering, kick
Research Division:Engineering
Research Group:Engineering practice and education
Research Field:Risk engineering
Objective Division:Energy
Objective Group:Mining and extraction of energy resources
Objective Field:Oil and gas extraction
UTAS Author:Khan, FI (Professor Faisal Khan)
ID Code:120735
Year Published:2014
Web of Science® Times Cited:139
Deposited By:NC Maritime Engineering and Hydrodynamics
Deposited On:2017-08-30
Last Modified:2017-10-25

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