Journal of Marine Science and Engineering

Editorial

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3 pages, 168 KiB

Open AccessEditorial

Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration, and Development

by Liang Lei and Gaowei Hu

J. Mar. Sci. Eng. 2023, 11(2), 322; https://doi.org/10.3390/jmse11020322 - 02 Feb 2023

Cited by 1 | Viewed by 979

Abstract

Natural gas hydrate is critical for its tremendous potential to impact the energy supply field, accelerate global warming if methane reaches the atmosphere, and affect the safety of deep-sea oil and gas production [...] Full article

(This article belongs to the Special Issue Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration and Development)

Research

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15 pages, 4285 KiB

Open AccessArticle

Potential and Distribution of Natural Gas Hydrate Resources in the South China Sea

by Pibo Su, Lin Lin, Yaoyao Lv, Jinqiang Liang, Yunbao Sun, Wei Zhang, Huice He, Baiquan Yan, Zhanhuai Ji, Lifeng Wang, Feifei Wang and Mengya Cai

J. Mar. Sci. Eng. 2022, 10(10), 1364; https://doi.org/10.3390/jmse10101364 - 23 Sep 2022

Cited by 3 | Viewed by 1667

Abstract

The amount of natural gas contained in the world’s gas hydrate accumulations is enormous, but these estimates remain highly speculative. So far, it is still challenging to locate spatial distribution of marine gas hydrate and quantitatively characterize the evaluation parameters and systematic improvement [...] Read more.

The amount of natural gas contained in the world’s gas hydrate accumulations is enormous, but these estimates remain highly speculative. So far, it is still challenging to locate spatial distribution of marine gas hydrate and quantitatively characterize the evaluation parameters and systematic improvement of evaluation systems. Considering the systematic review of the key accumulation factors, such as heat flow, deposition rate and total organic carbon in the typical passive continental margin, the evaluation results of global marine gas hydrate resources were analyzed based on the characteristics of gas hydrate geology, geophysics and geochemistry anomalies in the South China Sea. We analyze the problems on the evaluation of marine gas hydrate resources, probing into the geological characteristics and distribution laws of marine gas hydrate resources in the South China Sea, and estimate the parameters for in-place resource evaluation, in which the volume method based on Monte Carlo probability was used to evaluate the gas hydrate potential resources in the South China Sea. The probability distribution ranges from 37.6 billion (with 90% probability) to 117.7 billion (with 10% probability) tons of oil equivalent, with an expected value of 74.4 billion tons of oil equivalent. The study results show that the gas hydrate resource density in the South China Sea is similar to that in the typical sea areas, and the estimated global resources are basically consistent with the assessment results at this stag; this shows that the South China Sea has great potential for gas hydrate resources. The research results can provide guidance for the evaluation of global climate change and the exploration and development of hydrate resources. Full article

(This article belongs to the Special Issue Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration and Development)

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14 pages, 4055 KiB

Open AccessArticle

Effect of Surfactants with Different Hydrophilic–Lipophilic Balance on the Cohesive Force between Cyclopentane Hydrate Particles

by Qingchao Fang, Xin Zhao, Sunbo Li, Zhengsong Qiu, Zhiyuan Wang and Qi Geng

J. Mar. Sci. Eng. 2022, 10(9), 1255; https://doi.org/10.3390/jmse10091255 - 06 Sep 2022

Cited by 8 | Viewed by 1996

Abstract

Effective control of the cohesive force between hydrate particles is the key to prevent their aggregation, which then causes pipeline blockage. The hydrophilic–lipophilic balance (HLB) value of surfactants was proposed as an important parameter for the evaluation and design of hydrate anti-agglomerants. A [...] Read more.

Effective control of the cohesive force between hydrate particles is the key to prevent their aggregation, which then causes pipeline blockage. The hydrophilic–lipophilic balance (HLB) value of surfactants was proposed as an important parameter for the evaluation and design of hydrate anti-agglomerants. A microscopic manipulation method was used to measure the cohesive forces between cyclopentane hydrate particles in the presence of Tween and Span series surfactants with different HLB values; moreover, the measured cohesive force was compared with the results of calculations based on the liquid bridge force model. Combined with the surface morphology and wettability of the hydrate particles, we analyzed the mechanism by which surfactants with different HLB values influence the cohesion between hydrate particles. The results show that for both Tween (hydrophilic, HLB > 10) and Span (hydrophobic, HLB < 10) surfactants, the cohesive force between cyclopentane hydrate particles decreased with decreasing HLB. The experimental results were in good agreement with the results of calculations based on the liquid bridge force model. The cohesive force between hydrate particles increased with increasing concentration of Tween surfactants, while in the case of the Span series, the cohesive force decreased with increasing surfactant concentration. In the formation process of cyclopentane hydrate particles, the aggregation of low-HLB surfactant molecules at the oil–water or gas–water interface increases the surface roughness and hydrophobicity of the hydrate particles and inhibits the formation of liquid bridges between particles, thus reducing the cohesion between particles. Therefore, the hydrate aggregation and the associated blockage risks can be reduced. Full article

(This article belongs to the Special Issue Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration and Development)

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14 pages, 7035 KiB

Open AccessArticle

Effect of Hydrate Microscopic Distribution on Acoustic Characteristics during Hydrate Dissociation: An Insight from Combined Acoustic-CT Detection Study

by Qingtao Bu, Tongju Xing, Chengfeng Li, Jinhuan Zhao, Changling Liu, Zihao Wang, Wengao Zhao, Jiale Kang, Qingguo Meng and Gaowei Hu

J. Mar. Sci. Eng. 2022, 10(8), 1089; https://doi.org/10.3390/jmse10081089 - 09 Aug 2022

Cited by 8 | Viewed by 1364

Abstract

Geophysical detection techniques are important methods in marine gas hydrate exploration and monitoring, because the small-scale distribution of hydrates has a large impact on the wave velocity. The acoustic response characteristics of hydrate micro-distributions have strong significance for monitoring the hydrate dissociation process. [...] Read more.

Geophysical detection techniques are important methods in marine gas hydrate exploration and monitoring, because the small-scale distribution of hydrates has a large impact on the wave velocity. The acoustic response characteristics of hydrate micro-distributions have strong significance for monitoring the hydrate dissociation process. In this paper, experiments simulating the hydrate dissociation process were carried out in a self-developed experimental device combining X-ray computed tomography (X-CT) scanning and ultrasonic detection, which allowed the acoustic wave characteristics and X-CT scanning results to be simultaneously obtained during the hydrate dissociation process. This study found that the hydrate dissociation stage is divided into three stages. The hydrate begins to dissociate at spots where it comes into touch with sand particles early in the dissociation process. The main factor affecting the acoustic wave velocity of hydrates in this stage is changes in the microscopic distribution of hydrate. In the middle stage, a large amount of hydrate decomposes, and the main factor affecting the acoustic wave velocity of hydrate in this stage is the change in hydrate content. In the later stage of hydrate dissociation, the hydrate distribution pattern consists mainly of the pore-filling type, and the hydrate micro-distribution at this stage is the main factor affecting the acoustic wave velocity. This study will be of great significance for understanding the microscopic control mechanism of hydrate reservoir geophysical exploration. Full article

(This article belongs to the Special Issue Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration and Development)

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18 pages, 2802 KiB

Open AccessArticle

The Thermal Effect of Submarine Mud Volcano Fluid and Its Influence on the Occurrence of Gas Hydrates

by Zhifeng Wan, Junsheng Luo, Xiaolu Yang, Wei Zhang, Jinqiang Liang, Lihua Zuo and Yuefeng Sun

J. Mar. Sci. Eng. 2022, 10(6), 832; https://doi.org/10.3390/jmse10060832 - 19 Jun 2022

Cited by 6 | Viewed by 1788

Abstract

Mud volcanoes and other fluid seepage pathways usually transport sufficient gas for the formation of gas reservoirs and are beneficial to the accumulation of gas hydrate. On the other hand, the fluid thermal effects of mud volcanoes can constrain the occurrence of gas [...] Read more.

Mud volcanoes and other fluid seepage pathways usually transport sufficient gas for the formation of gas reservoirs and are beneficial to the accumulation of gas hydrate. On the other hand, the fluid thermal effects of mud volcanoes can constrain the occurrence of gas hydrates. Current field measurements indicate that fluid thermal anomalies impact the distribution of gas hydrates associated with mud volcanoes. However, due to the lack of quantitative analysis of the mud volcano fluid flow and thermal evolution, it is difficult to effectively reveal the occurrence of gas hydrates in mud volcano development areas and estimate their resource potential. This study took the Håkon Mosby Mud Volcano (HMMV) in the southwestern Barents Sea as the research object and comprehensively used seismic, well logging, drilling and heat flow survey data, combining the principles and methods of fluid dynamics and thermodynamics to study the fluid flow and heat transfer of a mud volcanic pathway. The space framework of the mud volcanic fluid temperature field thermal structure was established, the influence of the HMMV fluid thermal effect on gas hydrate occurrence was analyzed and the distribution and resource potential of gas hydrates in mud volcano development areas were revealed from the perspective of thermodynamics. This study provides a thermodynamic theoretical basis for gas hydrate accumulation research, exploration and exploitation under a fluid seepage tectonic environment. Full article

(This article belongs to the Special Issue Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration and Development)

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13 pages, 7508 KiB

Open AccessArticle

Analysis of the Mechanical Properties of the Reconstituted Hydrate-Bearing Clayey-Silt Samples from the South China Sea

by Lin Dong, Hualin Liao, Yanlong Li, Qingguo Meng, Gaowei Hu, Jintang Wang and Nengyou Wu

J. Mar. Sci. Eng. 2022, 10(6), 831; https://doi.org/10.3390/jmse10060831 - 19 Jun 2022

Cited by 14 | Viewed by 1827

Abstract

Mechanical properties of hydrate-bearing sediments (HBS) are crucial for evaluating drilling- and production-induced geo-hazards. However, investigations on mechanical behaviors of clayey-silt samples containing hydrate are insufficient due to low efficiency in preparing reconstituted hydrate-bearing samples. Herein, we carried out a series of triaxial [...] Read more.

Mechanical properties of hydrate-bearing sediments (HBS) are crucial for evaluating drilling- and production-induced geo-hazards. However, investigations on mechanical behaviors of clayey-silt samples containing hydrate are insufficient due to low efficiency in preparing reconstituted hydrate-bearing samples. Herein, we carried out a series of triaxial shear tests to analyze the deformation behaviors of reconstituted clayey-silt samples containing tetrahydrofuran (THF) hydrate. The sediments were taken from the Shenhu Area, northern South China Sea. The failure mechanisms during shearing are discussed based on micro-to-macro analyses. The results imply that the stress-strain curves show obvious strain-hardening under triaxial shearing, which can be divided into elastic deformation stage, transitional stage, and plastic deformation stage. Besides, the results reveal that cohesion strengthens from 0.09 MPa to 1.28 MPa when hydrate saturation increases from 15% to 60%. Moreover, calculation models are proposed to evaluate failure strengths and Young’s modulus. Establishing empirical formula based on experimental data can quickly determine the strength parameters with knowing the hydrate saturation and stress state of clayey-silt sediments containing hydrate. It is urgent in field operations and numerical simulation to use reliable empirical models. Full article

(This article belongs to the Special Issue Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration and Development)

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17 pages, 3985 KiB

Open AccessArticle

A Novel Wellbore-Wall Heating Method without External Energy Injection for Natural Gas Hydrate Production—A Heat Transfer Device

by Hongyu Ye, Xuezhen Wu, Gaoqiang Guo, Dayong Li and Yujing Jiang

J. Mar. Sci. Eng. 2022, 10(6), 799; https://doi.org/10.3390/jmse10060799 - 10 Jun 2022

Cited by 8 | Viewed by 1731

Abstract

Natural gas hydrate (NGH) dissociation is a heat-absorbing process, and the cooling around the wellhead is more pronounced during depressurization production. Low temperature will cause NGH regeneration or ice formation, blocking gas flow paths and reducing extraction efficiency. In this study, a novel [...] Read more.

Natural gas hydrate (NGH) dissociation is a heat-absorbing process, and the cooling around the wellhead is more pronounced during depressurization production. Low temperature will cause NGH regeneration or ice formation, blocking gas flow paths and reducing extraction efficiency. In this study, a novel heat transfer device (HTD) was innovatively proposed to alleviate this problem. Theoretical analysis and numerical simulations were used to research the methodological principles, applicable conditions, and expected benefits of the HTD. Results show that the HTD utilizes the characteristics of the geothermal gradient to rapidly transfer energy from the lower reservoir to the wellbore wall, which in turn raises the temperature and prevents the ice and NGH regeneration causing the blockage from adhering to the wellbore wall. The heat transfer radius, the length of the endothermic section, and the operating temperature difference make a tremendous difference in the heat transfer efficiency of the HTD. The HTD may be more suitable for Class 1 reservoir conditions and help to improve gas production under the depressurization method in the Shenhu sea of the South China Sea. The device can achieve continuous self-heat transfer without external energy injection to significantly reduce costs, which provides a new idea for marine NGH production. Full article

(This article belongs to the Special Issue Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration and Development)

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15 pages, 10743 KiB

Open AccessArticle

Microcosmic Characteristics of Hydrate Formation and Decomposition in the Different Particle Size Sediments Captured by Cryo-SEM

by Jingsheng Lu, Decai Lin, Dongliang Li, Deqing Liang, Long Wen, Siting Wu, Yiqun Zhang, Yong He, Lingli Shi and Youming Xiong

J. Mar. Sci. Eng. 2022, 10(6), 769; https://doi.org/10.3390/jmse10060769 - 01 Jun 2022

Cited by 4 | Viewed by 1508

Abstract

Sand production and sand control studies in non-diagenetic reservoirs are the weak point in the conventional petroleum industry. However, natural gas hydrate (NGH) mainly exists in non-diagenetic strata, and sand production occurs during exploitation, which restricts the safe and sustainable production of NGH. [...] Read more.

Sand production and sand control studies in non-diagenetic reservoirs are the weak point in the conventional petroleum industry. However, natural gas hydrate (NGH) mainly exists in non-diagenetic strata, and sand production occurs during exploitation, which restricts the safe and sustainable production of NGH. To study the microcosmic characteristics of sand production, the hydrate decomposition behaviours in the sediments were captured by the Cryo-SEM method. The micromorphology of different particle sizes of sand samples containing NGH (the sand median diameter d50 is 150, 87, 55, 38, 24, and 13 µm) and the microcosmic processes of NGH decomposition were observed. Then, the microcosmic characteristics of sand production, during the decomposition process, were analysed. (1) The gas hydrate decomposition increases pore space and reduces reservoir strength; the expansion action of the decomposition of water and gas, the softening action of the decomposition of water, and the compression action by overlying stress (crustal stress) promoted sand production, deformation, and subsidence of the NGH reservoirs in the mining process. (2) The decomposition of NGH has a more significant impact on sediments with smaller particle sizes. (3) The particle size of NGH may be larger than the particle size of the mud in the reservoirs, and acting as “gravel” plays a particular role in sand control. Therefore, the particle size of NGH cannot be ignored in the design of sand control. (4) It has been revealed, and verified, that sputtering (splashing) is a unique process of sand production caused by NGH decomposition. In other words, the rapid expansion of the volume of the decomposed gas and water from NGH leads to the eruption and sputtering of hydrate particles, providing the driving force for sand migration, which is a different process of sand production than in conventional oil and gas. Full article

(This article belongs to the Special Issue Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration and Development)

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21 pages, 11394 KiB

Open AccessArticle

Comparative Analysis on the Evolution of Seepage Parameters in Methane Hydrate Production under Depressurization of Clayey Silt Reservoir and Sandy Reservoir

by Yaobin Li, Xin Xin, Tianfu Xu, Huixing Zhu, Haibin Wang, Qiang Chen and Bo Yang

J. Mar. Sci. Eng. 2022, 10(5), 653; https://doi.org/10.3390/jmse10050653 - 11 May 2022

Cited by 7 | Viewed by 1541

Abstract

Gas hydrates are likely to become an important strategic resource with commercial development prospects. It is therefore of great significance to realize the long-term and efficient production of methane hydrate reservoirs. Previous studies have shown that the lithological characteristics of hydrate reservoirs have [...] Read more.

Gas hydrates are likely to become an important strategic resource with commercial development prospects. It is therefore of great significance to realize the long-term and efficient production of methane hydrate reservoirs. Previous studies have shown that the lithological characteristics of hydrate reservoirs have a significant impact on reservoir productivity by influencing the evolution of seepage parameters in the process of hydrate production. The porosity (Φ) and initial hydrate saturation (SH) affect the amount of hydrate decomposition and pressure transfer, and also indirectly affect the reservoir temperature field. The permeability (k) directly affects the rate of pressure-drop transmission and methane gas discharge. Due to the differences in seepage parameters caused by different reservoir lithology, a sandy hydrate reservoir (SHR) in Japan and a clayey silt hydrate reservoir (CHR) in China were found to have different gas production rates and the spatial evolution characteristics of the temperature and pressure fields varied in gas hydrate production tests. Therefore, to ensure the long-term and efficient production of the CHR in China, two models were established for a comparative analysis based on a numerical simulation. The two models were depressurizing models of the CHR of the W11 drilling site in the Shenhu Sea area of the South China Sea and the SHR of the AT1 drilling site in the Eastern Nankai Trough of Japan. Both models considered the heterogeneity of seepage parameters, and the TOUGH+HYDARATE (T+H) code was used in subsequent calculations. Four key results were obtained: (a) The order of the significance levels of the lithological parameters on productivity was k > SH > Φ in the CHR and SH > k > Φ in the SHR. (b) The heat conduction and heat convection in the CHR were weaker than in the SHR, which made it difficult to recover the low-temperature area caused by hydrate decomposition. (c) The exploitation of a high k hydrate reservoir should be given priority when the other initial conditions were the same in both the CHR and SHR. (d) The exploitation of both the CHR and SHR should not only rely on the hydrate content or seepage capacity to determine the reservoir exploitation potential, but the combined effect of the two parameters should be fully considered. Full article

(This article belongs to the Special Issue Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration and Development)

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28 pages, 13976 KiB

Open AccessArticle

New Insight on the Stratigraphic-Diffusive Gas Hydrate System since the Pleistocene in the Dongsha Area of the Northeastern South China Sea

by Jinan Guan, Yian Liang, Shujia Wang, Lihua Wan, Shuanshi Fan, Pibo Su, Wei Zhang and Deqing Liang

J. Mar. Sci. Eng. 2022, 10(3), 434; https://doi.org/10.3390/jmse10030434 - 16 Mar 2022

Cited by 2 | Viewed by 2036

Abstract

The stratigraphic-diffusive type of gas hydrate system is formed by microbial methane produced in a shallow slope space when flowing laterally into hydrate stable zones and is worth studying for both energy supply and academic understanding. A deposition production model matching the vertical [...] Read more.

The stratigraphic-diffusive type of gas hydrate system is formed by microbial methane produced in a shallow slope space when flowing laterally into hydrate stable zones and is worth studying for both energy supply and academic understanding. A deposition production model matching the vertical and lateral seabed morphological characteristics was constructed to show the accumulation process, layer timing sequence, and reservoir quality of the stratigraphic-diffusive hydrate system in the Dongsha slope sediments since the Pleistocene. Six representative key system factors at three selected moments (1.5 Ma, 700 ka B.P., and at present) have been exhibited during debris is continuously accumulating. The coexistence of the hydrate decomposition in the lower part and the formation in the upper part, and the uneven distribution of hydrates within the slope sediment surface are explained clearly. By comparing four geological cases with diverse environments, it is shown that the diffusive hydrate system is likely to develop into moderate geological conditions. The most powerful carbon fixation ability in this system was quantified within the time range of 100−50 ka B.P. Finally, it was verified that residual methane would converge near the seafloor interface and then eventually overflow out of the seabed into the seawater. Full article

(This article belongs to the Special Issue Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration and Development)

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13 pages, 4708 KiB

Open AccessArticle

Pore-Scale Investigation of the Electrical Property and Saturation Exponent of Archie’s Law in Hydrate-Bearing Sediments

by Jinhuan Zhao, Changling Liu, Chengfeng Li, Yongchao Zhang, Qingtao Bu, Nengyou Wu, Yang Liu and Qiang Chen

J. Mar. Sci. Eng. 2022, 10(1), 111; https://doi.org/10.3390/jmse10010111 - 14 Jan 2022

Cited by 14 | Viewed by 1681

Abstract

Characterizing the electrical property of hydrate-bearing sediments is essential for hydrate reservoir identification and saturation evaluation. As the major contributor to electrical conductivity, pore water is a key factor in characterizing the electrical properties of hydrate-bearing sediments. The objective of this study is [...] Read more.

Characterizing the electrical property of hydrate-bearing sediments is essential for hydrate reservoir identification and saturation evaluation. As the major contributor to electrical conductivity, pore water is a key factor in characterizing the electrical properties of hydrate-bearing sediments. The objective of this study is to clarify the effect of hydrates on pore water and the relationship between pore water characteristics and the saturation exponent of Archie’s law in hydrate-bearing sediments. A combination of X-ray computed tomography and resistivity measurement technology is used to derive the three-dimensional spatial structure and resistivity of hydrate-bearing sediments simultaneously, which is helpful to characterize pore water and investigate the saturation exponent of Archie’s law at the micro-scale. The results show that the resistivity of hydrate-bearing sediments is controlled by changes in pore water distribution and connectivity caused by hydrate formation. With the increase of hydrate saturation, pore water connectivity decreases, but the average coordination number and tortuosity increase due to much smaller and more tortuous throats of pore water divided by hydrate particles. It is also found that the saturation exponent of Archie’s law is controlled by the distribution and connectivity of pore water. As the parameters of connected pore water (e.g., porosity, water saturation) decrease, the saturation exponent decreases. At a low hydrate-saturation stage, the saturation exponent of Archie’s law changes obviously due to the complicated pore structure of hydrate-bearing sediments. A new logarithmic relationship between the saturation exponent of Archie’s law and the tortuosity of pore water is proposed which helps to calculate field hydrate saturation using resistivity logging data. Full article

(This article belongs to the Special Issue Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration and Development)

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13 pages, 1780 KiB

Open AccessArticle

Active Methanotrophs and Their Response to Temperature in Marine Environments: An Experimental Study

by Jing Li, Xiaoqing Xu, Changling Liu, Nengyou Wu, Zhilei Sun, Xingliang He and Ye Chen

J. Mar. Sci. Eng. 2021, 9(11), 1261; https://doi.org/10.3390/jmse9111261 - 12 Nov 2021

Cited by 7 | Viewed by 1930

Abstract

Aerobic methane (CH₄) oxidation plays a significant role in marine CH₄ consumption. Temperature changes resulting from, for example, global warming, have been suggested to be able to influence methanotrophic communities and their CH₄ oxidation capacity. However, exact knowledge regarding [...] Read more.

Aerobic methane (CH₄) oxidation plays a significant role in marine CH₄ consumption. Temperature changes resulting from, for example, global warming, have been suggested to be able to influence methanotrophic communities and their CH₄ oxidation capacity. However, exact knowledge regarding temperature controls on marine aerobic methane oxidation is still missing. In this study, CH₄ consumption and the methanotrophic community structure were investigated by incubating sediments from shallow (Bohai Bay) and deep marine environments (East China Sea) at 4, 15, and 28 °C for up to 250 days. The results show that the abundance of the methanotrophic population, dominated by the family Methylococcaceae (type I methanotrophs), was significantly elevated after all incubations and that aerobic methane oxidation for both areas had a strong temperature sensitivity. A positive correlation between the CH₄ oxidation rate and temperature was witnessed in the Bohai Bay incubations, whereas for the East China Sea incubations, the optimum temperature was 15 °C. The systematic variations of pmoA OTUs between the Bohai Bay and East China Sea incubations indicated that the exact behaviors of CH₄ oxidation rates with temperature are related to the different methanotrophic community structures in shallow and deep seas. These results are of great significance for quantitatively evaluating the biodegradability of CH₄ in different marine environments. Full article

(This article belongs to the Special Issue Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration and Development)

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Review

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23 pages, 9249 KiB

Open AccessReview

Research Progress on Global Marine Gas Hydrate Resistivity Logging and Electrical Property Experiments

by Qiang Chen, Nengyou Wu, Changling Liu, Changchun Zou, Yang Liu, Jianye Sun, Yanlong Li and Gaowei Hu

J. Mar. Sci. Eng. 2022, 10(5), 645; https://doi.org/10.3390/jmse10050645 - 09 May 2022

Cited by 5 | Viewed by 2202

Abstract

Natural gas hydrate is widely spread in marine environments around the world. It has great energy potential due to its high methane gas content. High-precision exploration and evaluation of marine gas hydrate still face great challenges as it is affected by the complex [...] Read more.

Natural gas hydrate is widely spread in marine environments around the world. It has great energy potential due to its high methane gas content. High-precision exploration and evaluation of marine gas hydrate still face great challenges as it is affected by the complex reservoir control mechanisms and distribution characteristics. Resistivity is widely used in geophysical logging and theoretical research on gas hydrate-bearing reservoirs by utilizing the high sensitivity electrical response. In this paper, based on the examination of the global marine gas hydrate occurrences, resistivity logging results are summarized. Then the key remaining gas hydrate resistivity experimental concerns are reviewed. In summary, resistivity properties are a reliable means to derive the gas hydrate reservoir characteristics, despite the effect induced by the anisotropic properties of hydrate reservoirs and drilling technology. The overall resistivity change associated with the occurrence of pore filling gas hydrate in reservoirs are relatively small, and the specific value is affected by sediment lithology and hydrate saturation. On the other hand, fracture filling hydrate reservoirs have strong anisotropy, and massive hydrate occurrences (i.e., layers of gas hydrate with no sediment) section shows very high resistivity variation. Clay minerals are an important factor restricting the accurate estimation of gas hydrate saturations from in situ resistivity measurements. Many experimental studies have proposed the correction of Archie empirical formula, but widely representative models have not yet been developed. It is worth noting that more complex resistivity measurements may be able to provide additional electrical response information on various gas hydrate systems. Full article

(This article belongs to the Special Issue Marine Gas Hydrate: Geological Characterization, Resource Potential, Exploration and Development)

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