Hydrate Blockage Assessment in a Pilot-Scale Subsea Jumper

completethermodynamic hydrate inhibition at the pressure and temperature conditions used in this trial. Our unique flowloop facility offers new insight toward hydrate formation in complex subsea jumper-likegeometries. Our findings may assist operators in controlling the extent of hydrate formation and depositionin jumper geometries, by optimizing the MEG injection and subsequently supporting lower-CAPEX tiebackdevelopment concepts.,In subsea production operations, wellhead jumpers are one of the subsea facilities more liable to theformation of hydrate blockages during restart operations. To manage hydrate formation and optimizethe amount of thermodynamic hydrate inhibitors (e.g. mono-ethylene glycol; MEG) injected, a newly-constructed jumper-like facility (the HyJump flowloop) has been developed in Perth, to simulate shut-downand restart operations over a range of superficial gas velocities. The test section of the flowloop has a unique geometry to mimic subsea jumpers, with three low pointsand two high points standing 13′ 2″ tall. The test section is fitted with twelve pressure and temperaturesensors spread regularly, a MEG sensor, a valve to simulate the wellhead choke, and a viewing window. Ineach test, the jumper low points were loaded with aqueous solutions of MEG (0 to 30 wt%) and pressurizedwith domestic Perth natural gas at a pressure of 1200 psig and pipeline temperature ranging from 41°F to25.8°F (+5 to-4°C). The extent of hydrate restrictions or blockages was evaluated through the dynamic pressure drop behaviorobserved throughout the flowloop. A closer assessment of the pressure drop trace during gas restartsuggests that the severity of the hydrate restriction decreases as the MEG content is increased above 10wt%. Further, our preliminary experimental results illustrate that severe hydrate deposition in the jumpercould be completely avoided by injecting MEG at concentrations above 20 wt%. This corresponds to anapproximately 50% reduction in MEG content, where ≈38 wt% MEG dosage was required.