Simulation analysis and experimental research of a sampling valve for the seafloor natural gas hydrates survey

Abstract

A hydraulically actuated sampling valve is developed for the sub-sea situ pore-water and bottom seawater sampler. A unique pressure compensation design for the valve core is adopted in the sampling valve, which makes the sampling valve open or closure reliably under high pressure. Based on the developed sampling valve, a fluid sampler is manufactured, which includes three collecting bottles, one equilibrium bottle, one negative pressure bottle, one sampling valve, and a set of control unit. The simulation model of the developed sampler is established for the whole sampling process using the AMESim, and the dynamic and static characteristics of the sampling valve, check valve in the collecting bottle, negative pressure bottle are obtained numerically. And then, the simulation tests of the sampling valve are conducted at the simulated high pressure tank of 45 MPa. The developed sampling valve and sampler have been applied on the sub-sea situ pore-water and bottom seawater sampling system and tested at the situ pore-water and bottom seawater, which could also be widely used in marine and offshore oil and gas environmental investigation. This research will lay the foundation for the development of undersea tools for nature gas hydrate survey.