Hydrate prevention method during deep well drilling period

Abstract

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.

Description

technical field [0001] The invention belongs to the technical field of drilling engineering of resources such as oil and natural gas, and in particular relates to a method for preventing and controlling hydrates during deepwater well drilling. Background technique [0002] In deepwater drilling, the formation of hydrates may bring great harm to operations and cause serious economic losses. In the process of offshore drilling, hydrates may cause blockage of choke lines, kill lines, risers, and blowout preventers. If the treatment method is unreasonable, it may increase operation time and cost; severe cases may also lead to drilling failure. Even wellbore scrapped. [0003] During the drilling process, there are many uncertain factors in the gas invasion process, especially the measurement lag and inaccuracy of the gas invasion volume are high. After gas invasion, hydrate may be formed in the hydrate stable zone during the upward movement of gas, but hydrate accumulation can...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to avoid the deficiencies in the prior art and provide a method for preventing and controlling hydrates during deepwater well drilling, so as to solve the problem that hydrates are easily formed in deepwater drilling

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