The invention discloses a
hydrate prevention method during a deep
well drilling period. The
hydrate prevention method during the deep
well drilling period includes the steps that S1, preparatory workis carried out, specifically, a
high concentration hydrate inhibitor is injected into a
choke and kill manifold, and an inhibitor is mixed in
drilling fluid in a mud pit; S2, actual drilling operationis carried out, specifically, all columns are subjected to reaming operation for two times and sufficient circulation, and a centrifugal
machine and a
booster pump maintain opening condition; S3, vertical columns are connected, specifically, 4-5m3 of the
high concentration hydrate inhibitor replaces the
choke and kill manifold to enter a circulation
system and further supplements the
high concentration hydrate inhibitor of the
choke and kill manifold; S4, full circulation is carried out, specifically, a moving drilling tool circulates for at least one circle when drilling to one of predetermined distances; and S5, the drilling tool is pulled out of the well, specifically, the drilling tool is fully circulated before the drilling tool is pulled out of the well, inhibitive
drilling fluid ispumped in the well to prevent the
drilling fluid below mud surface from forming the hydrate, a
charge pump maintains the opening condition to prevent a shaft above the mud surface from forming the hydrate, the drilling tool is pulled out of the well when higher concentration inhibitive drilling fluid is filled the shaft below the mud surface, and next operation is continued. The hydrate prevention method during the deep
well drilling period can solve the problem that the hydrate is prone to be formed in the
deep water drilling process.