Natural gas hydrate rotary pressure maintaining coring device

Abstract

The invention relates to a natural gas hydrate rotary pressure maintaining coring device which comprises an outer pipe assembly and an inner pipe assembly mounted in the outer pipe assembly, a drilling 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 mounted in the inner pipe assembly a and can move along to the axis direction of the inner pipe assembly a, the inner pipe assembly a comprises a fishing spearhead, an elastic card mechanism, a lengthening pipe, a middle pipe short joint, a short connector, a sealing short joint, a connecting pipe, a middle pipe and a pressure retaining ball valve overturning and sealing mechanism which are sequentially connected from top to bottom, and the inner pipe assembly b comprises a lifting device, an elastic card hanging mechanism, an elastic pin short joint, an single-acting mechanism, a transformation connector, an adjusting connector, a connecting pipe, a sealing mechanism, a connecting long pipe, a connecting long pipe short joint and a rock core pipe which are sequentially connected from top to bottom. According to the device, rotary pressure maintaining sampling is achieved, the device can adapt to quaternary sedimentary land layers and bed rock and wider in application range.

Description

technical field [0001] The invention relates to the technical field of drilling, in particular to a 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 Therefore, it is necessary to adopt a pressure-holding method for collection, and ordinary coring devices are generally not airtight and cannot maintain pressure. Such coring devices usually have unsatisfactory coring effects. In addition, the common coring device has a complex structure and many parts, which makes maintenance difficult and inconvenient, and has a short service life. Small range. Therefore, it is an urgent problem to be ...

AI Technical Summary

Problems solved by technology

[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 It cannot be decomposed under pressure, so it needs to be collected by maintaining pressure, and ordinary coring devices are generally not airtight and cannot maintain pressure. Such coring devices usually have unsatisfactory coring effects

In addition, the common coring device has a complex structure and many parts, which makes maintenance difficult and inconvenient, and has a short service life. small range

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