Study and application of GWY194-70BB heat and pressure preservation coring tool

The GW194-70BB heat and pressure preservation coring tool is developed specifically for exploring gas hydrate and improving the recovery rate of gas hydrate samples. This tool has realized insulation and pressure keeping of core samples, surveying of massive amount of data, and solved problems such as volatilization of gas hydrate sample due to being unable to preserve core pressure and temperature by conventional tools and incomplete survey data. The tool achieved satisfactory performance in the test of conventional wells: 93% pressure keeping rate, 80% insulation rate, and 2-2.5 ℃ temperature variation rate per hour. Field tests show that this tool can meet the requirement of drilling and sampling of gas hydrate in terms of insulation and pressure keeping and is of great significance to recovering the gas hydrate samples and improving the effect of gas hydrate exploration and development.