As a new type of clean energy, natural gas hydrate is widely distributed in seabed strata. In order to find out the distribution of natural gas hydrate in Chinese sea area and reserves, drilling sampling needs to be obtained in the early stage. Based on the special physical-chemical properties of gas hydrate, pressure and temperature core sampler is needed to avoid gas-hydrate decomposition in sampling. Therefore one type of marine gas-hydrate pressure and temperature core sampler is developed. In order to solve the problem of low success rate of pressure holding during the fidelity sampling process, this drill tool adopts the ' plate valve-decoupling mechanism' to realize the bottom sealing of pressure-holding pipe by the reverse impact of the sampling barrel and then pressing the plate valve. This method greatly improves the reliability of plate valve sealing and increases the success rate of pressure holding. Through structural design, trial production, laboratory pressure test and offshore drilling test, the pressure-holding success rate of the temperature and pressure core sampler is 75%;
and core recovery rate is 72.14%.
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