Solid fluidization is a current promising
method to explore hydrate
resources. The rheological properties of hydrate slurry are significant
to solid fluidization and prevent hydrate blockage during pipeline
transportation. To determine the impact of hydrate on the rheological
properties of mudflow, a rheological experiment was conducted on methane
hydrate slurry formed from a mudflow, which was prepared with marine
sediment sampled from South China Sea. It was found that both mudflow
and hydrate slurry exhibited viscoelastic fluid properties. The existence
of hydrate substantially increased the apparent viscosity of the mudflow,
and when the hydrate formed at a rapid rate, the apparent viscosity
rose rapidly. With different initial pressures, the amount of hydrate
formed in mudflow was different. A larger water conversion rate would
increase the viscosity of the hydrate slurry significantly. Meanwhile,
a yield stress measurement was conducted by stress sweep after hydrate
formation. When the water conversion fractions were 17.8%, 20.3%,
and 21.2%, the yield stresses of the hydrate slurry were 57.8, 465.2,
and over 10,000 Pa, respectively. In addition, a frequency test sweep
was conducted, and the results showed that the existence of hydrate
would significantly increase the elasticity of the slurry.