OS4C-4：MODELING PARTICLE JAMMING AS A HYDRATE PLUGGING MECHANISM

Patrick G. LAFOND1, E. Dendy SLOAN1, Carolyn A. KOH1, David T. WU1,2, Amadeu K. SUM1*
1. Centre for Hydrate Research, Chemical & Biological Engineering Department, Colorado School of Mines, USA; 2. Chemistry Department, Colorado School of Mines, USA

    “Particle jamming” occurs when solids competitively flow through an opening.  If the particle size is similar to the opening size there is a chance for the particles to “clog” (or “jam”) the opening, whereby the solids arrange into a dome like shape of mutually stabilizing particles.  Gas and oil flowlines often operate in the hydrate stable region, and if the fluids are under-inhibited, hydrates may begin to form, deposit, and slough off of the pipe walls.  If the released deposits approach a restricted area (e.g., valve or deposit) there is a chance for the hydrates to jam the flowline.  Once a jam has formed, the particles may sinter and permanently plug the flowline resulting in a loss of production.  This work presents the construction of a 200 L flow loop to study the jamming of solids under fluid flow.  Measuring the particle concentration, fluid velocity, and time-to-jam, we have developed a comprehensive model to describe the jamming tendency of suspended particles.  The statistical model considers particle size, opening size, particle concentration, and fluid velocity.  With an appropriate jamming model, flow assurance engineers can mitigate jamming risks, and help avoid plugging of flowlines with hydrates.