Safety natural gas hydrate rotating pressure maintaining coring device

Abstract

The invention relates to a safe natural gas hydrate rotating pressure maintaining coring device, which comprises an outer pipe assembly and an inner pipe assembly arranged in the outer pipe assembly,wherein a drill bit is arranged at the bottom end of the outer pipe assembly; the inner pipe assembly comprises an inner pipe assembly a and an inner pipe assembly b; the inner pipe assembly b is arranged in the inner pipe assembly a and can move in the axial direction of the inner pipe assembly a; the inner pipe assembly a comprises a fishing spear head, an elastic clamping mechanism, a piston pipe, a middle pipe nipple, a sealing nipple, an accumulator connecting pipe, a middle pipe and a pressure maintaining ball valve overturning sealing mechanism which are sequentially connected from topto bottom; the inner pipe assembly b comprises a lifting device, a connection mechanism, a spring clip suspension mechanism, a single action mechanism, an adapter, a regulating connector, an accumulator connection pipe, a sealing mechanism, a thermostatic instrument, a core pipe connection nipple and a core pipe. The safe rotating pressure-maintaining sampling device can be suitable for quaternarysedimentary strata and bedrock, and is more reliable in application.

Description

technical field [0001] The invention relates to the technical field of drilling, in particular to a safe natural gas hydrate rotary pressure-maintaining coring device for natural gas hydration. Background technique [0002] Natural gas hydrate is an efficient and clean energy with rich resources, and it is the strategic commanding height of future global energy development. Natural gas hydrate occurs under the seabed of the deep-sea continental slope or buried in sediments in polar regions. Since natural gas hydrate needs to be kept in a stable In order to maintain stability and not decompose under pressure, it is necessary to use a pressure-holding method for collection. The shearing pin is used to trigger the core pipe to be pulled out from the pressure-holding ball valve and then the ball valve is closed. Because the shearing pin works unstable, it is sheared due to bumping and impact during the process of putting in the corer. Once the pin is sheared by the impact, it i...

AI Technical Summary

Problems solved by technology

Once the pin is cut off by the impact, it is easy to cause the inner tube assembly of the coring device to be disengaged early, and then the ball valve will be closed in advance, resulting in coring failure. Therefore, the coring device using the shear pin has poor reliability and poor safety.

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