gas hydrate - CCOP

Figure 5 shows the results of measured V p for the two cases where axial loading is 300 psig.
One is that with 100% water saturation, and the other is that with initial water saturation for
the hydrate formation. Although the size of the increase samples are different, measured V p at
100% and initial water saturation showed similar value around 1900m/sec and 750 m/sec
within ±4%, respectively. This indicates that the effect of grain size on V p of the samples
without gas hydrate may be negligible within the range of mean particle size used in this
study.
2000
1600
Vp(m/sec)
1200
100% Water saturation
Initial Sw with gas
800
Figure 5. Results of Vp measurements
of 4 samples without gas hydrate.
400
P wave velocity of the samples with gas hydrate
From now on, the whole measurements of V p have been carried out under 300 psig of uniaxial
loading applied. Calculated hydrate saturation may have error on it because we assumed no
volumetric change of gas during hydrate formation. The relationship between hydrate
saturation with Vp appears in Figure 6. Hydrate saturation (S h ) in x-axis means the
normalized volume to total pore volume of the samples. In this figure, the initial water
saturation when V p was measured may be different case by case. As expected, increasing
trend of V p with increase of hydrate saturation is manifest.
3000
2500
Hama#5
Hama#6
Hama#7
Hama#6
Vp(m/sec)
2000
1500
1000
Figure 6. Measured V p of 4 different
sediment samples.
500
0 0.2 0.4 0.6 0.8
Hydrate saturation(PV)
New Energy Resources in the CCOP Region - Gas Hydrates and Coalbed Methane 47