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Learning from Experience: Incident Management Team Leader Training
Published in Schraagen Jan Maarten, Laura G. Militello, Tom Ormerod, Lipshitz Raanan, Naturalistic Decision Making and Macrocognition, 2017
Schraagen Jan Maarten, Laura G. Militello, Tom Ormerod, Lipshitz Raanan
At 3:59 a.m. on 21 May 2003, the 6,000-ft drilling riser suddenly parted at a depth of 3,200 feet sub-sea (see Figure 6.1). The drilling riser is a large-diameter pipe that connects the wellhead equipment on the seabed to the rig at the sea surface and which returns drilling chemical “mud” to the surface (see Figure 6.2a). Without the drilling riser, the chemical mud used for drilling purposes could spill and contaminate the seabed. The riser was under 2.1 million pounds of top tension and the parting produced not only a loud bang but everyone on board the drill ship felt the subsequent sudden jarring (Kirton, Wulf, and Henderson, 2004). Inspection by a Remote Operated Vehicle (ROV) showed that the drill pipe (which is internal to the drilling riser) was intact, and was actually supporting the broken riser. Wellhead equipment is the part of the oilwell where it reaches the surface (whether on land or sub-sea) and comprises valves and spools that contain the pressure and the oil within the well. The wellhead equipment on the seabed (see Figure 6.2b) functioned properly, preventing substantial leakage from the sub-sea reservoir into the Gulf.
Offshore Drilling
Published in Sukumar Laik, Offshore Petroleum Drilling and Production, 2018
A drilling riser is a conduit that provides a temporary extension of a subsea oil well to a surface drilling facility. Drilling risers are categorised into two types – (1) marine drilling riser and (2) tie-back drilling riser. Marine drilling risers are used by a floating vessel when the blowout preventer (BOP) is placed at the sea bottom and tie-back drilling risers are used with bottom supported units like jack-up platforms or compliant types like TLPs when the BOP is placed at the platform deck.
An improved coupled model for axial dynamic analysis of deepwater drilling risers under a soft hang-off mode
Published in Ships and Offshore Structures, 2023
Nan Zhang, Yuanjiang Chang, Lei Xu, Guoming Chen, Xiuquan Liu, Zhi Zhao, Weiguo Zhang, Yongguo Dai
The drilling riser system is critical and vulnerable offshore equipment during drilling operations (Wang et al. 2015; Mao et al. 2016; Meng et al. 2018; Chang et al. 2019; Chen et al. 2021a, 2021b; Liu et al. 2022). Normally, the drilling riser system connects the submarine wellhead system and the floating drilling platform to form a circulation path for the drilling fluid. However, the drilling riser should be disconnected from the BOPs and suspended on the platform to secure the drilling riser system and the wellhead in harsh environments, such as typhoons or storms (Mao et al. 2019; Li et al. 2021; Zhao et al. 2022; Zhang et al. 2023a, 2023b). Hang-off modes for the riser are divided into hard hang-off modes and soft hang-off modes according to the different upper boundary conditions of the riser, as shown in Figure 1(a,b) (Liu et al. 2018; Mao et al. 2020). In hard hang-off mode, the top end of the riser is connected to the platform directly and rigidly (Wu et al. 2014). While in soft hang-off mode, the top end of the riser is suspended on the platform through the tensioner.