High Pressure Control in Synthetic Experimental System of Gas Hydrates Simulation

The simulating experiment of gas hydrates often lasts a long time, has a high pressure (usually equal or more than 38 bar) and has many steps. A high-pressure console was developed to lighten labor intensity and guarantee experiment safety in the Synthetic Experimental System of Gas Hydrates Simulation (SESGHS). Gas inlet/outlet, cell pressure test and overpressure protection are all managed on the console. The overpressure protection module included a gas-control valve NV1-20-6M-ATC, a solenoid valve VP542, a relay OMRON/ G2R-1, a multi-function card PCI-1711, a pressure sensor and the corresponding software. The acquired pressure data was judged whether to surpass the alarm value, if so, alarm would be send out. And if over the unloading value, number 1 will be send to the channel connecting PCI-1711 card and the relay, then relay is switched on to make electromagnetic valve open and let low pressure gas enter so that the gas-control valve can release high pressure automatically. The whole pressure-control module was operated successfully in the experiments of gas hydrates formation, drilling fluids tests and mini-drilling simulation. It worked steadily, operated conveniently and had high sensitivity for overpressure protection, which largely enhanced the safety of the experiments.