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

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.

[1]  N. Wu,et al.  Coupled thermal-hydrodynamic-mechanical–chemical numerical simulation for gas production from hydrate-bearing sediments based on hybrid finite volume and finite element method , 2022, Computers and Geotechnics.

[2]  Hua-lin Liao,et al.  3d Numerical Simulation on Drilling Fluid Invasion into Natural Gas Hydrate Reservoirs , 2021, SSRN Electronic Journal.

[3]  Yongchen Song,et al.  Consolidation deformation of hydrate-bearing sediments: A pore-scale computed tomography investigation , 2021 .

[4]  Xiaosen Li,et al.  Recent Advances on Natural Gas Hydrate Exploration and Development in the South China Sea , 2021 .

[5]  Yanlong Li,et al.  Characterization and development of marine natural gas hydrate reservoirs in clayey-silt sediments: A review and discussion , 2021 .

[6]  D. Gao,et al.  Optimization and analysis of gravel packing parameters in horizontal wells for natural gas hydrate production , 2021 .

[7]  D. Gao,et al.  Hydrate-induced clogging of sand-control screen and its implication on hydrate production operation , 2020 .

[8]  A. Tang,et al.  An experimental investigation on methane hydrate morphologies and pore habits in sandy sediment using synchrotron X-ray computed tomography , 2020, Marine and Petroleum Geology.

[9]  Yanlong Li,et al.  2-D electrical resistivity tomography assessment of hydrate formation in sandy sediments , 2020 .

[10]  Yuxuan Xia,et al.  ADVANCES IN MULTIPHASE SEEPAGE CHARACTERISTICS OF NATURAL GAS HYDRATE SEDIMENTS 1) , 2020 .

[11]  Praveen Linga,et al.  Methane hydrates: A future clean energy resource , 2019, Chinese Journal of Chemical Engineering.

[12]  Timothy J Kneafsey,et al.  Pore habit of methane hydrate and its evolution in sediment matrix – Laboratory visualization with phase-contrast micro-CT , 2019, Marine and Petroleum Geology.

[13]  Chengfeng Li,et al.  Acoustic characteristics and micro-distribution prediction during hydrate dissociation in sediments from the South China Sea , 2019, Journal of Natural Gas Science and Engineering.

[14]  Hailong Lu,et al.  The first offshore natural gas hydrate production test in South China Sea , 2018 .

[15]  Chengfeng Li,et al.  Experimental study on 2-D acoustic characteristics and hydrate distribution in sand , 2017 .

[16]  Xiangyun Hu,et al.  Electrical conductivity models in saturated porous media: A review , 2017 .

[17]  A. Best,et al.  The elastic wave velocity response of methane gas hydrate formation in vertical gas migration systems , 2017 .

[18]  Chengfeng Li,et al.  Influence of foraminifera on formation and occurrence characteristics of natural gas hydrates in fine-grained sediments from Shenhu area, South China Sea , 2016, Science China Earth Sciences.

[19]  W. Liang,et al.  Micro-CT analysis of structural characteristics of natural gas hydrate in porous media during decomposition , 2016 .

[20]  Praveen Linga,et al.  Review of natural gas hydrates as an energy resource: Prospects and challenges ☆ , 2016 .

[21]  F. Liu,et al.  A bond contact model for methane hydrate‐bearing sediments with interparticle cementation , 2014 .

[22]  William F. Waite,et al.  Methane gas hydrate effect on sediment acoustic and strength properties , 2007 .

[23]  G. Narsilio,et al.  Instrumented pressure testing chamber for characterizing sediment cores recovered at in situ hydrostatic pressure , 2006 .

[24]  William F. Waite,et al.  Physical properties and rock physics models of sediment containing natural and laboratory-formed methane gas hydrate , 2004 .