If the hydrate crystals are clogging up the containment vessel,
then why don’t they clog up a production well?
Too much pressure, which breaks them down, although I understand they can cause some problems. In the containment device, although there is plenty of pressure from the ocean above (22,000 PSI in all directions), there is not the contained pressure which is present in a production line. The bottom is open and the contents are a mixture of sea water, oil and gas.