THE HYDRODYNAMICS OF A SUBSEA BLOWOUT

This paper considers the two-phase flow associated with a submerged ga s release. A new series of experimental observations is presented in w hich the axial velocity of the liquid phase, the gas concentrations wi thin the bubble plume, and the radial velocities near the water surfac e were measured within a laboratory environment. The results are compa red with the existing Gaussian formulations, and a new numerical appro ximation which is based upon a simplified k-epsilon turbulence model. This latter solution was originally developed in the context of a gas stirred metallurgical flow, but is shown to be equally applicable to t he description of an underwater blowout. Experimental data suggest tha t an empirically modified Gaussian solution cannot provide a consisten t description of both the axial velocities and the gas concentrations. In contrast, the numerical model provides a reasonable description of the entire flow field. In particular, the large radial velocities occ uring near the water surface are shown to be associated with a re-circ ulation of the liquid phase. It is a description of these velocities w hich is required to determine the stability of a surface vessel OT str ucture located in the vicinity of a subsea blowout.