Acoustic laboratory measurements during the formation of a THF-hydrate in unconsolidated porous media

Compressional and shear wave experiments are performed for a tetrahydrofura n (THF) hydrate/sand mixture. The THF cell allows for simultaneous measurem ent of the temperature gradient as well as reflected compressional (P) and shear (S) wave velocities as a function of time and temperature. Results fr om these early experiments illustrate the evolution of a multiphase system where THF hydrates form in pore bodies and only affect the bulk properties of the sediment. As temperature is decreased, remaining fluid water in the pores freezes and welds the grains affecting the shear strength of the sedi ment.