gas hydrate - CCOP

Gas pr oduct i on r at e ml /min
300
250
200
150
100
50
0
0 20 40 60 80 100
Ti me
min
Figure 8. Gas production rate by
depressurization.
Cumul at i ve gas pr oduced ml
10000
8000
6000
4000
2000
0
0 20 40 60 80 100
Ti me
min
Figure 9. Accumulated gas by
depressurization.
Figures 10 and 11 plot the water production rate and cumulative water produced with time.
It can be revealed that:
1) The start time for water produced lags behind than that of the gas. This is due to the
fact that less free water exists in the experimental vessel after hydrate formation.
2) After certain time, there is a water rate peak before a rapid decrease.
3) The water produced keeps at a stable level until no water flows out. At this stage, the
water produced is mainly due to hydrate dissociation.
Wat er pr oduct i on r at e ml / mi n
3. 5
3
2. 5
2
1. 5
1
0. 5
0
0 20 40 60 80 100
Ti me
min
Figure 10. Water production rate by
depressurization.
40
Cumul at i ve wat er pr oduced
ml
30
20
10
0
0 20 40 60 80 100
Ti me
min
Figure 11. Accumulated water by
depressurization.
Figure 12 plots the temperature profile during the depressurization experiment. It can be
revealed that the environmental temperature keeps constant, however the temperature profiles
for other measuring points show similar trend, i.e., the temperature decreases first before
increasing. This suggests that hydrate dissociation is an endothermic process.
It can be concluded that depressurization is a good way for hydrate production in the current
experimental conditions.
72
New Energy Resources in the CCOP Region - Gas Hydrates and Coalbed Methane