| Under action of the vertical load generated by large-sized BOP and casings, and the horizontal load generated by the current force acting on the long riser, deepwater drilling subsea wellhead stability becomes a problem. Aiming at this problem, based on the extensive investigation of deepwater drilling wellhead stability relevant research situation and force analysis, wellhead mechanical model has been built and solved. Then the model is applied to analyze the wellhead stability of well JDZ-2-1 in West Africa, the results show that both the vertical bearing capacity and lateral stability of JDZ-2-1 wellhead can meet the operation requirements. By comparing the analysis results under different drilling vessel drift, current velocity, riser top tension ratio, drilling fluid density, riser buoyancy ratio, formation parameters and other different operating conditions, the influencing factors are summarized, then specific recommendations have been proposed for preventing destabilization of deepwater drilling wellhead. Then based on this, considered the wellhead selection influence factors and combined with fuzzy math theory, deepwater drilling wellhead equipment selection method is established, and then the method is applied to select the wellhead equipment of well JDZ-2-1.
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