Device and method for identifying and cutting natural gas hydrate layer section in casing pipe on site

Abstract

The invention relates to the technical field of natural gas hydrate exploration, in particular to a device and method for identifying and cutting a natural gas hydrate interval in a casing pipe on site. The device comprises a temperature measuring unit and a cutting unit horizontally arranged with the temperature measuring unit. And the temperature measuring unit comprises a temperature measuring shell, a temperature measuring transparent cover, a movable temperature measuring mechanism, a temperature measuring pipe inlet, a temperature measuring pipe outlet and a sleeve transfer mechanism. The cutting unit comprises a cutting shell, a cutting transparent cover, a movable sleeve clamping and cutting mechanism, a cutting pipe inlet, a cutting pipe outlet and a carrying platform. According to the invention, the identification-acquisition integrated operation of the hydrate-containing layer in the casing pipe can be realized, the acquisition rate of the hydrate sample is improved, and the loss of the hydrate in the process of acquiring the hydrate from the casing pipe is reduced. In addition, the sampling accuracy is also improved through the constraint of the actual measurement temperature difference. And powder generated in operation can be controlled in the equipment for centralized treatment, so that dust pollution on a construction site is avoided.

Description

technical field [0001] The invention relates to the technical field of natural gas hydrate exploration, in particular to a device and method for on-site identification and cutting of natural gas hydrate intervals in a casing. Background technique [0002] Natural gas hydrate (hereinafter referred to as "hydrate") is considered to be a potential green and clean energy in the 21st century, and its commercial exploration and development technology has always been an important direction for governments to explore and develop. An important engineering node in its industrial process is to obtain samples of hydrates in the rock formations under the seabed in deep sea environments. The successful acquisition of the samples is an affirmation of the understanding of hydrate occurrence laws in the previous stage and a verification of the accuracy of the collected data. The trial production of hydrates in the engineering stage provides strong support for physical testing and scheme desi...

AI Technical Summary

Problems solved by technology

However, hydrates will decompose automatically when exposed to the air in field operations. The existing technology is inefficient in accurately identifying and cutting hydrate samples in the casing, resulting in a large loss of hydrate samples during the collection process, which affects follow-up work. Research and testing on the occurrence state of in-situ hydrate under the seabed

In addition, because there is no scale and other marks used to indicate the specific horizon in the casing, the accuracy of cutting the horizon is not high, which also causes the loss of hydrate samples

[0004] At present, there is no complete device and scheme to directly complete the above work. Therefore, it is urgent to design a device and method that can identify and cut the natural gas hydrate interval in the casing in an integrated manner.

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