Well Logging Evaluation for Three-Phase Zone with Gas Hydrate in the Shenhu Area, South China Sea

doi:10.19657/j.geoscience.1000-8527.2021.167

Abstract

Abstract:

During depressurization for the production test of natural gas hydrate, the free gas in the three-phase zone (gas hydrate, free gas, and water) was exploited first, which improves the depressurization efficiency and enhances the gas hydrate dissociation. Therefore, well-logging evaluation for three-phase zone with the core calibration logging method in Shenhu area (South China Sea) is important for the reserve calculation of gas hydrate bodies and subsequent industrial production. Compared with those in the gas hydrate layer, both the density and neutron porosity decrease, and the compressional wave speed drops dramatically in the three-phase zone. However, the shear modulus is still above the background and the chloridion concentration of core porewater falls below that in the free gas layer. Consequently, the three-phase zone can be identified. The density and hydrogen index of gas hydrate are close to those of water, thus the density and neutron porosity are only affected by the free gas, when the lithologies and physical properties are similar. We found that the reduction in density and neutron porosity are linearly correlated with core analysis gas saturation in the three-phase zone. Thus, for the gas saturation estimation, the dual-parameter binary linear regression model, which comprises the density and neutron porosity, was developed. Based on the water saturation and gas saturation achieved from the Indonesian formula and the dual-parameter free gas calculation model, respectively, the gas hydrate saturation was calcula-ted. The estimated gas hydrate saturation in the three-phase zone are in good agreement with the gas hydrate saturation derived from the chloridion content of core porewater, indicating that well-logging evaluation method for three-phase zone is reliable.

Key words: three-phase zone with gas hydrate, chloridion content of core porewater, density, neutron porosity, shear modulus, Indonesian formula, dual-parameter free gas calculation model

CLC Number:

XIE Yingfeng, LU Jing’an, KUANG Zenggui, KANG Dongju, WANG Tong, CAI Huimin. Well Logging Evaluation for Three-Phase Zone with Gas Hydrate in the Shenhu Area, South China Sea[J]. Geoscience, 2022, 36(01): 182-192.

Figures/Tables 9

Fig.1 Geological map and the natural gas hydrate drillholes in the Shenhu area, South China Sea

Fig.2 Correlation plot between the formation factor and porosity in the water-saturated layer

Fig.3 Correlation plot between the resistivity increase factor and core analysis water saturation

Fig.4 Correlation plot between core analysis gas saturation and reduction in density or in neutron porosity in the three-phase zone

Table 1 Parameters for coefficients of the dual-parameters calculation model (density and neutron porosity with binary linear regression method)

序号(i)	x₁_i(ΔTNPH)	x₂_i(ΔRHON)	y_i(S_g)	$x 1 i 2$	$x 2 i 2$	$y i 2$	x₁_ix₂_i	x₁_iy_i	x₂_iy_i
1	0.206 4	0.099 2	0.228 6	0.042 6	0.009 8	0.052 3	0.020 5	0.047 2	0.022 7
2	0.205 9	0.103 0	0.205 2	0.042 4	0.010 6	0.042 1	0.021 2	0.042 3	0.021 1
3	0.199 4	0.120 7	0.207 4	0.039 7	0.014 6	0.043 0	0.024 1	0.041 3	0.025 0
4	0.198 6	0.122 6	0.205 8	0.039 4	0.015 0	0.042 4	0.024 3	0.040 9	0.025 2
5	0.196 1	0.117 5	0.182 0	0.038 5	0.013 8	0.033 1	0.023 0	0.035 7	0.021 4
6	0.199 0	0.118 7	0.201 2	0.039 6	0.014 1	0.040 5	0.023 6	0.040 0	0.023 9
7	0.217 7	0.113 9	0.227 0	0.047 4	0.013 0	0.051 5	0.024 8	0.049 4	0.025 9
8	0.219 7	0.111 8	0.239 0	0.048 3	0.012 5	0.057 1	0.024 6	0.052 5	0.026 7
9	0.214 4	0.130 9	0.233 1	0.046 0	0.017 1	0.054 3	0.028 1	0.050 0	0.030 5
10	0.211 8	0.134 2	0.236 3	0.044 8	0.018 0	0.055 8	0.028 4	0.050 0	0.031 7
11	0.200 0	0.119 1	0.249 5	0.040 0	0.014 2	0.062 3	0.023 8	0.049 9	0.029 7
12	0.199 8	0.120 2	0.238 0	0.039 9	0.014 4	0.056 6	0.024 0	0.047 5	0.028 6
13	0.154 1	0.180 0	0.243 7	0.023 7	0.032 4	0.059 4	0.027 7	0.037 6	0.043 9
14	0.142 1	0.193 3	0.225 6	0.020 2	0.037 3	0.050 9	0.027 5	0.032 1	0.043 6
15	0.169 9	0.050 7	0.145 7	0.028 8	0.002 6	0.021 2	0.008 6	0.024 7	0.007 4
16	0.170 7	0.049 1	0.151 7	0.029 1	0.002 4	0.023 0	0.008 4	0.025 9	0.007 4
17	0.158 6	0.049 0	0.134 6	0.025 2	0.002 4	0.018 1	0.007 8	0.021 3	0.006 6
18	0.151 8	0.049 7	0.099 0	0.023 1	0.002 5	0.009 8	0.007 5	0.015 0	0.004 9
19	0.055 4	0.025 7	0.017 0	0.003 1	0.000 7	0.000 3	0.001 4	0.000 9	0.000 4
20	0.066 4	0.025 4	0.018 2	0.004 4	0.000 6	0.000 3	0.001 7	0.001 2	0.000 5
21	0.075 2	0.031 3	0.020 8	0.005 7	0.001 0	0.000 4	0.002 4	0.001 6	0.000 7
∑	3.613 0	2.065 8	3.709 5	0.671 9	0.249 0	0.774 6	0.383 4	0.707 2	0.427 8

Table 1 Parameters for coefficients of the dual-parameters calculation model (density and neutron porosity with binary linear regression method)

序号(i)	x₁_i(ΔTNPH)	x₂_i(ΔRHON)	y_i(S_g)	$x 1 i 2$	$x 2 i 2$	$y i 2$	x₁_ix₂_i	x₁_iy_i	x₂_iy_i
1	0.206 4	0.099 2	0.228 6	0.042 6	0.009 8	0.052 3	0.020 5	0.047 2	0.022 7
2	0.205 9	0.103 0	0.205 2	0.042 4	0.010 6	0.042 1	0.021 2	0.042 3	0.021 1
3	0.199 4	0.120 7	0.207 4	0.039 7	0.014 6	0.043 0	0.024 1	0.041 3	0.025 0
4	0.198 6	0.122 6	0.205 8	0.039 4	0.015 0	0.042 4	0.024 3	0.040 9	0.025 2
5	0.196 1	0.117 5	0.182 0	0.038 5	0.013 8	0.033 1	0.023 0	0.035 7	0.021 4
6	0.199 0	0.118 7	0.201 2	0.039 6	0.014 1	0.040 5	0.023 6	0.040 0	0.023 9
7	0.217 7	0.113 9	0.227 0	0.047 4	0.013 0	0.051 5	0.024 8	0.049 4	0.025 9
8	0.219 7	0.111 8	0.239 0	0.048 3	0.012 5	0.057 1	0.024 6	0.052 5	0.026 7
9	0.214 4	0.130 9	0.233 1	0.046 0	0.017 1	0.054 3	0.028 1	0.050 0	0.030 5
10	0.211 8	0.134 2	0.236 3	0.044 8	0.018 0	0.055 8	0.028 4	0.050 0	0.031 7
11	0.200 0	0.119 1	0.249 5	0.040 0	0.014 2	0.062 3	0.023 8	0.049 9	0.029 7
12	0.199 8	0.120 2	0.238 0	0.039 9	0.014 4	0.056 6	0.024 0	0.047 5	0.028 6
13	0.154 1	0.180 0	0.243 7	0.023 7	0.032 4	0.059 4	0.027 7	0.037 6	0.043 9
14	0.142 1	0.193 3	0.225 6	0.020 2	0.037 3	0.050 9	0.027 5	0.032 1	0.043 6
15	0.169 9	0.050 7	0.145 7	0.028 8	0.002 6	0.021 2	0.008 6	0.024 7	0.007 4
16	0.170 7	0.049 1	0.151 7	0.029 1	0.002 4	0.023 0	0.008 4	0.025 9	0.007 4
17	0.158 6	0.049 0	0.134 6	0.025 2	0.002 4	0.018 1	0.007 8	0.021 3	0.006 6
18	0.151 8	0.049 7	0.099 0	0.023 1	0.002 5	0.009 8	0.007 5	0.015 0	0.004 9
19	0.055 4	0.025 7	0.017 0	0.003 1	0.000 7	0.000 3	0.001 4	0.000 9	0.000 4
20	0.066 4	0.025 4	0.018 2	0.004 4	0.000 6	0.000 3	0.001 7	0.001 2	0.000 5
21	0.075 2	0.031 3	0.020 8	0.005 7	0.001 0	0.000 4	0.002 4	0.001 6	0.000 7
∑	3.613 0	2.065 8	3.709 5	0.671 9	0.249 0	0.774 6	0.383 4	0.707 2	0.427 8

Fig.5 Chloridion anomaly and logging curves for well GMGS3/5-SH17

Fig.6 Element capture energy spectrum results of well GMGS3/5-SH17

Fig.7 Integrated logging interpretation results of well GMGS3/5-SH17

Fig.8 Integrated logging interpretation results of well GMGS6-SH02

References 39

[1]	SLOAN E D. Fundamental principles and applications of natural gas hydrates[J]. Nature, 2003, 426: 353-363. DOI URL
[2]	GILLES G, GOLDBERG D, MELTSER A. Characterization of in situ elastic properties of gas hydrate-bearing sediments on the Blake Ridge[J]. Journal of Geophysical Research, 1999, 104 (8):17781-17795. DOI URL
[3]	LEE M W, COLLETT T S. Gas hydrate and free gas saturations estimated from velocity logs on Hydrate Ridge, offshore Oregon, USA[J]. Proceedings of the Ocean Drilling Program Scientific Results, 2006, 204:1-25.
[4]	MILKOV A V, DICKENS G R, CLAYPOOL G E, et al. Co-existence of gas hydrate, free gas, and brine within the regional gas hydrate stability zone at Hydrate Ridge (Oregon margin): evidence from prolonged degassing of a pressurized core[J]. Earth and Planet Science Letters, 2004, 222: 829-843. DOI URL
[5]	KANG Dongju, LU Jing’an, ZHANG Zijian, et al. Fine-grained gas hydrate reservoir properties estimated from well logs and lab measurements at the Shenhu gas hydrate production test site, the northern slope of the South China sea[J]. Marine and Petroleum Geology, 2020, 122:1-5.
[6]	QIN Xuwen, LU Jing’an, LU Hailong, et al. Coexistence of natural gas hydrate, free gas and water in the gas hydrate system in the Shenhu Area, South China Sea[J]. China Geology, 2020, 3(2):210-220.
[7]	QIAN Jin, WANG Xiujuan, COLLETT T S, et al. Downhole log evidence for the coexistence of structure II gas hydrate and free gas below the bottom simulating reflector in the South China Sea[J]. Marine and Petroleum Geology, 2018, 98:662-674. DOI URL
[8]	LEE M W. Elastic velocities of partially gas-saturated unconsolidated sediments[J]. Marine and Petroleum Geology, 2004, 21(6):641-650. DOI URL
[9]	孙建孟, 罗红, 焦滔, 等. 天然气水合物储层参数测井评价综述[J]. 地球物理学进展, 2018, 33(2):715-723.
[10]	钟广法, 张迪, 赵峦啸. 大洋钻探天然气水合物储层测井评价研究进展[J]. 天然气工业, 2020, 40(8):25-44.
[11]	LI Jinfa, YE Jianliang, QIN Xuwen, et al. The first offshore natural gas hydrate production test in South China Sea[J]. China Geology, 2018, 1(1):5-16. DOI URL
[12]	YE Jianliang, QIN Xuwen, XIE Wenwei, et al. The second natural gas hydrate production test in the South China Sea[J]. China Geology, 2020, 3(2):197-209.
[13]	张伟, 梁金强, 陆敬安, 等. 中国南海北部神狐海域高饱和度天然气水合物成藏特征及机制[J]. 石油勘探与开发, 2017, 44(5):1-11.
[14]	杨承志, 罗坤文, 梁金强, 等. 南海北部神狐海域浅层深水沉积体对天然气水合物成藏的控制[J]. 天然气工业, 2020, 40(8):68-76.
[15]	何家雄, 陈胜红, 马文宏, 等. 南海东北部珠江口盆地成生演化与油气运聚成藏规律[J]. 中国地质, 2012, 39(1):106-118.
[16]	龚跃华, 杨胜雄, 王宏斌, 等. 南海北部神狐海域天然气水合物成藏特征[J]. 现代地质, 2009, 23(2):210-216.
[17]	何家雄, 卢振权, 张伟, 等. 南海北部珠江口盆地深水区天然气水合物成因类型及成矿成藏模式[J]. 现代地质, 2015, 29(5):1024-1034.
[18]	苏丕波, 梁金强, 沙志彬, 等. 神狐深水海域天然气水合物成藏的气源条件[J]. 西南石油大学学报(自然科学版), 2014, 36(2):1-8.
[19]	苏丕波, 梁金强, 张子健, 等. 神狐海域扩散型水合物在地震反射剖面上的“亮点”与“暗点”分析[J]. 地学前缘, 2017, 24(4): 51-56.
[20]	苏丕波, 梁金强, 张伟, 等. 南海北部神狐海域天然气水合物成藏系统[J]. 天然气工业, 2020, 40(8):77-89.
[21]	YANG Shengxiong, LIANG Jinqiang, LU Jing’an, et al. Petrophysical evaluation of gas hydrate in Shenhu area, China[M]//The 23rd Formation Evaluation Symposium of Japan. China:Japan Agency for Marine-Earth Science and Technology. Kyushu: Japan Kyushu University, 2017:1.
[22]	郭依群, 杨胜雄, 梁金强, 等. 南海北部神狐海域高饱和度天然气水合物分布特征[J]. 地学前缘, 2017, 24(4):24-31.
[23]	杨胜雄, 梁金强, 陆敬安, 等. 南海北部神狐海域天然气水合物成藏特征及主控因素新认识[J]. 地学前缘, 2017, 24(4):1-14.
[24]	COLLETT T S, LEE M W, ZYRIANOVA M V, et al. Gulf of Mexico Gas Hydrate Joint Industry Project Leg II: logging-while-drilling data acquisition and analysis[J]. Marine and Petroleum Geology, 2012, 34(1):41-61. DOI URL
[25]	宁伏龙, 刘力, 李实, 等. 天然气水合物储层测井评价及其影响因素[J]. 石油学报, 2013, 34(3):591-606.
[26]	楚泽涵, 黄隆基, 高杰, 等. 地球物理测井方法与原理(上册)[M]. 北京: 石油工业出版社, 2008.
[27]	DEGRANGE J M, GRIFFITHS R. Formation evaluation-while-drilling technology improves data delivery[J]. Journal of Petroleum Technology, 2013, 65(7):36-38.
[28]	康冬菊, 梁金强, 匡增桂, 等. 元素俘获能谱测井在神狐海域天然气水合物储层评价中的应用[J]. 天然气工业, 2018, 38(12):54-60.
[29]	张锋, 刘军涛, 冀秀文, 等. 地层元素测井技术最新进展及其应用[J]. 同位素, 2011, 24(增刊): 21-28.
[30]	康晓楠, 肖承文, 信毅, 等. 元素俘获测井在库车深层致密砂岩中的应用[J]. 测井技术, 2017, 41(3):331-335.
[31]	ARPS J J. The effect of temperature on the density and electrical resistivity of sodium chloride solutions[J]. Journal of Petroleum Technology, 1953, 5(10):17-20.
[32]	雍世和, 张超谟. 测井数据处理与综合解释[M]. 东营: 中国石油大学出版社, 2002.
[33]	ARCHIE G E. The electrical resistivity log as an aid in determining some reservoir characteristics[J]. Transactions of AIME, 1942, 146: 54-62. DOI URL
[34]	洪有密. 测井原理与综合解释[M]. 东营: 中国石油大学出版社, 2007.
[35]	PEARSON C F, HALLECK P M, MCGUIRE P L, et al. Natural gas hydrate deposits: a review of in situ properties[J]. The Journal of Physical Chemistry, 1983, 87(21):4180-4185. DOI URL
[36]	WANG X, WU S, LEE M, et al. Gas hydrate saturation from acoustic impedance and resistivity logs in the Shenhu area, South China Sea[J]. Marine and Petroleum Geology, 2011, 28(9):1625-1633. DOI URL
[37]	LEE M W, COLLETT T S. In-situ gas hydrate saturation estimated from various well logs at the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope[J]. Marine and Petroleum Geology, 2011, 28(2):439-449. DOI URL
[38]	MALINVERNO A, KASTNER M, TORRES M E, et al. Gas hydrate occurrence from pore water chlorinity and downhole logs in a transect across the northern Cascadia margin (Integrated Ocean Drilling Program Expedition 311)[J]. Journal of Geophysical Research, 2008, 113(8): B08103.
[39]	党世英. 运用二元线性回归计算晋华宫煤的发热量[J]. 煤质技术, 2019(2):55-57.