| Autor: |
Jaiswal, Vivek, Lifeng Feng, Saraswat, Rajil, Healy, Brian, Hørte, Torfinn, Sharma, Partha |
| Zdroj: |
Proceedings of the International Offshore & Polar Engineering Conference; 2016, p230-240, 11p |
| Abstrakt: |
This paper presents the findings of a numerical study on the evaluation of fatigue damage of a non-rigid locked wellhead due to wave loads. This study is consistent with the recommend practice (RP) DNVGLRP-0142, released in April of 2015. For the case study presented herein, a mobile offshore drilling unit (MODU) operated drilling riser system in relatively shallow water is selected. Two models are developed: (i) a fully coupled three-dimensional (3D) finite element (FE) model that includes the riser, the wellhead, the casing, the cement and the soil represented by P-y springs, and (ii) a global riser model that utilizes the decoupling method between the BOP and wellhead interface (wellhead datum). Note that the fully coupled model includes a local model of the wellhead system that can be analyzed separately to produce load-to-stress curves for use with the global riser model. Comparisons of fatigue results using three methods are presented: (a) hotspot stress taken directly from the fully coupled 3D model, (b) stress calculated using wellhead bending moment and load-to-stress curves, and (c) hotspot stress from the local wellhead model analyzed using synchronous time series of tension, bending moment and shear force at the wellhead datum, taken from the fully coupled analysis. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
