gas hydrate - CCOP

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The dissociation zone created by the hydrate channels is also active, but hydrate lensing (Moridis et al., 2005b) leads to increasing S H , thus reducing the aperture of the “wormholes”. Compared to Stages I and II, RRR is lower in Stage III and has a downward trend because (a) the total area of dissociation is reduced after the occlusion of the bottom interface, (b) the remaining dissociating regions are more distant from the well, and (c) the cross-sectional area of the hydrate channels decreases. The onset of Stage IV is marked by another precipitous drop in the RRR value to levels below 0.1. This indicates a dramatic reduction in dissociation activity and is caused by occlusion of the upper interface, or through closure of the hydrate channels (Moridis et al., 2005b). In Figure 1a and 1b we observe that Q R attains high levels early, and it increases with time in Stage I and II. At the end of Phase II (t = 6.2 years), Q R = 0.533 ST m 3 /s and replenishes about 65% of Q P . Even with the decline in Q R in Stage III, RRR averages about 40%. Comparison of the cumulative volume of CH 4 released from dissociation (V R ) to V P leads to the VRR shown in Figure 1c, which confirms the hydrate potential as a promising gas source. At the end of the 10-year production period, VRR = 0.42, i.e., 42% of the total gas produced volume (1.08x10 8 ST m 3 ) has been replenished from dissociation. The corresponding water production is limited (Moridis et al., 2005b). These results indicate the technical feasibility of depressurization to readily produce large amounts of gas at high rates using conventional technology. Figure 2 shows the distribution of S H over time. Figure 2b reveals the expansion of the cylindrical interface radially from the wellbore during Stage I. The upper interface becomes evident after t = 4 years, i.e., at the beginning of Stage II (Figure 2c). The emergence of the banded S H distribution of the hydrate channels is also obvious, which becomes more pronounced with time as they advance into the hydrate body. The hydrate channels are evident at t = 4 years. These “wormhole-like” structures appear to permeate a large portion of the main hydrate body during Stage III (t = 6 years, Figure 2e) and an even larger one in Stage IV (Figure 2f, t = 10 years). Case 2: Gas Production from Class 1G Deposits The system configuration, geometry, and properties in this case are similar to those in the Class 1W case, from which it differs in that in the HBL, S H = 0.7 and S G = 0.3. The (a) volumetric rate of depressurization-induced CH 4 release from the hydrate, (b) the production rate at the well, and (c) the corresponding RRR appear in Figure 3a (Moridis et al., 2005b). This figure shows that dissociation from hydrates in Class 1G deposits is a continuous process that does not have the stages identified in Class 1W deposits (Figure 1). The hydrate contribution to production increases monotonically with time, and RRR = 0.75 at the end of the 30-year production period. Comparison of V R and V P leads to the VRR in Figure 2b, which rises rapidly early, increases continuously with time, and shows that 54% of the produced volume at the end of the 30-year production period has been replenished from hydrate dissociation. By that time, 4.13x10 8 ST m 3 have been released from dissociation. These results further confirm the technical feasibility of depressurization to produce large amounts of gas from hydrates at high rates using conventional technology. The attractiveness of Class 1G deposits is further enhanced by low water production (Moridis et al., 2005b). Case 3: Gas Production from a Class 2 Deposit The geometry of the Class 2 deposit discussed here is as in Case 1, from which it differs in that the zone underneath the HBL is water-saturated. Fluids are produced through a single well at the center of the reservoir at a constant rate of Q = 9.48 kg/s (5000 BPD). The producing interval extends from the top of the HBL to 7 m below its base. 56 New Energy Resources in the CCOP Region - Gas Hydrates and Coalbed Methane
Figure 2. Evolution of the hydrate saturation distribution during depressurization-induced gas production from a Class 1W hydrate deposit (Moridis et al., 2005b). (a) (b) Figure 3. (a) Evolution of Q R (A), Q P (B), and the corresponding RRR (C) from a Class 1G hydrate deposit; (b) evolution of V R (A), V P (B) and the corresponding VRR (C). Figure 4a shows the evolution of (a) the rate Q R of CH 4 release from hydrate dissociation into the reservoir, and (b) the rate Q P of CH 4 production at the well. In Class 2 hydrate deposits, Q R > Q P because of the need for gas to accumulate until S G exceeds the irreducible S irG before flowing to the well. Because of the very low compressibility of water, the depressurization effect is immediate, and leads to the release of large volumes of CH 4 . Figure 4a shows two stages, separated by a 30-day period of warm water injection to eliminate the secondary New Energy Resources in the CCOP Region - Gas Hydrates and Coalbed Methane 57
Page 2 and 3:
Coordinating Committee for Geoscien
Page 4 and 5:
Thematic Session on New Energy Reso
Page 6 and 7: CONTENTS Page OPENING REMARKS……
Page 8 and 9: OPENING REMARKS by Chen Shik Pei Di
Page 10 and 11: WELCOME ADDRESS by Tai-Sup Lee Pres
Page 12 and 13: WELCOME ADDRESS by Keun-Pil Park Di
Page 14 and 15: CONGRATULATORY ADDRESS by David Pri
Page 16 and 17: PART I GAS HYDRATE: EXPLORATION, RE
Page 18 and 19: Partial differential equations for
Page 20 and 21: RESULTS AND DISCUSSION In the follo
Page 22 and 23: REFERENCES Berner R. A. (1980) Earl
Page 24 and 25: features of the seabed than those o
Page 26 and 27: secure the stability of the solutio
Page 28 and 29: trends depending on the following f
Page 30 and 31: Organic carbon in sediments is of i
Page 32 and 33: Sedimentological and Geochemical As
Page 34 and 35: Figure 3. Sedimentation rate of the
Page 36 and 37: Marine Gas Hydrate off W. Canada an
Page 38 and 39: Several methods for computing the Q
Page 40 and 41: 0.035 0.03 Amplitude 0.025 0.02 0.0
Page 42 and 43: 60 50 Amplitude 40 30 20 10 0 0 50
Page 44 and 45: REFERENCES Dallimore, S.R. and T.S.
Page 46 and 47: Frequency % 20 16 12 8 HAMA #5, MV=
Page 48 and 49: Figure 3. Experimental procedures f
Page 50 and 51: Figure 7 shows two cases of the com
Page 52 and 53: Seismic Characteristics of Gas Hydr
Page 54 and 55: Purpose The purpose of this paper i
Page 58 and 59: hydrate that forms near the wellbor
Page 60 and 61: dissociation, composite thermal con
Page 62 and 63: Figure 9. The Advanced Light Source
Page 64 and 65: Experimental Studies and Developmen
Page 66 and 67: Natural gas hydrate exploitation an
Page 68 and 69: Natural gas Free gas layer Figure 5
Page 70 and 71: Figure 7. One-dimensional developme
Page 72 and 73: Temper at ur e 2 1 0 -1 -2 -3 -4
Page 74 and 75: From the above discussion, the heat
Page 76 and 77: INTRODUCTION Clathrate hydrates are
Page 78 and 79: MATHEMATICAL MODEL The mathematical
Page 80 and 81: Where the hydrate-aqueous radius of
Page 82 and 83: REFERENCES Brooks, R.H., and A.T. C
Page 84 and 85: 86 New Energy Resources in the CCOP
Page 86 and 87: In this paper, an overview of the M
Page 88 and 89: The brief tasks in the Phase I are:
Page 90 and 91: In "Development of the dissociation
Page 92 and 93: Figure 5. Preparation equipment. AN
Page 94 and 95: Other recent research subjects in t
Page 96 and 97: same crystalline structure directly
Page 98 and 99: Another important aspect of the pre
Page 100 and 101: a + CO 2 CH 4 C 2 H 6 b CH 4 in sII
Page 102 and 103: REFERENCES Collett, T.S. and Kuuskr
Page 104 and 105: Figure 1. Physiographic and crust m
Page 106 and 107:
Figure 3. Seismic profile showing s
Page 108 and 109:
Figure 7. Distribution of echo char
Page 110 and 111:
Figure 10. Seismic profile and its
Page 112 and 113:
In the early stage of back-arc open
Page 114 and 115:
PART II COALBED METHANE (CBM)
Page 116 and 117:
Supply and demand infrastructure of
Page 118 and 119:
Amisan, Jogyeri, Baegunsa, and Seon
Page 120 and 121:
PROPERTIES OF ANTHRACITE The coals
Page 122 and 123:
Table 4. Average chemical compositi
Page 124 and 125:
CONCLUSIONS 1. Most of the coals em
Page 126 and 127:
INTRODUCTION Coal (total reserves 2
Page 128 and 129:
ีีีีีีีีี ั ิ
Page 130 and 131:
RESULTS By Government: The outcomes
Page 132 and 133:
The gas composition (12 samples ana
Page 134 and 135:
Table 4. Coal Depth Interval Hole N
Page 136 and 137:
The results of studies made on 11 c
Page 138 and 139:
CONCLUSION CBM is still hoped to be
Page 140 and 141:
The Government of Indonesia through
Page 142 and 143:
The Berau basin is a major coal pro
Page 144 and 145:
PP: CBM - 1 Rambutan (GOI Sponsor)
Page 146 and 147:
Overview of Project for CO 2 Seques
Page 148 and 149:
The organic geochemistry research g
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3.5 25 3.0 20 Ar(%) C O 2(%) 2.5 2
Page 152 and 153:
20 8 10 0 6 δ13C of CO2(‰) -10 -
Page 154 and 155:
Figure 1. Index map of Akabira Coal
Page 156:
ORIGIN OF AKABIRA CBM In Akabira mi
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