Vibrating type marine hydrate pressure maintaining sampler

Abstract

The invention discloses a vibrating type marine hydrate pressure maintaining sampler. The vibrating type marine hydrate pressure maintaining sampler consists of a positioning mechanism, a vibration coring mechanism, a hydraulic lifting mechanism, a flushing mechanism and a pressure maintaining mechanism. Gas hydrate exists stably in the high-pressure and low-temperature sea floor and frozen soil zone, and is sensitive to temperature and pressure changes; and non-pressure-maintaining hydrate sampling can cause hydrate decomposition. Marine hydrate generally exists in pores of shallow sedimentary sandstones at the bottom of the sea, is low in degree of consolidation, is loose and easy to be washed out, and is difficult for coring. Aiming at seabed argillaceous powder sand type hydrate, in-situ pressure maintaining coring of a hydrate layer is carried out in a mode of providing power by armored cables, coring with vibration, eliminating solid phase particles with cleaning liquid and maintaining pressure by a flap valve.

Description

technical field [0001] The invention relates to a vibrating marine hydrate pressure-holding sampler, which is especially suitable for in-situ fidelity sampling of hydrates in loose muddy silt deposits easily subject to erosion. Background technique [0002] Gas hydrate is a clathrate crystalline compound formed by water and gas under high pressure and low temperature environment. Marine gas hydrate has huge reserves, cleanness and high calorific value, and it is a promising potential energy source. Several countries have carried out detection research on marine hydrates. The existence of marine hydrates is mainly based on ① BSR pseudo-bottom reflection seismic zone, ② logging-while-drilling technology, and ③ seabed sediment sampling technology. Natural gas hydrate sampling is used as direct evidence of the existence of hydrates. The test of cores can also analyze the reasons for the formation of hydrates and evaluate the reserves of regional hydrates. Since the exploitation...

AI Technical Summary

Problems solved by technology

Marine hydrates often occur in the muddy silt sedimentary layer in the shallow ocean, and the reservoir is not completely consolidated. Under the action of flushing fluid, the core is difficult to form a columnar shape, and is easily washed away by the flushing fluid, resulting in incomplete core , formation information lost

[0004] (2) The success rate of pressure holding is low

Due to the complex seabed environment, the reliability of the mechanical structure of the sampler is reduced, and the solid phase particles have a greater impact on the pressure holding mechanism. The low success rate of pressure holding and low pressure retention rate are the main problems of pressure holding sampling at present.

Images