In-situ gas hydrate hydrate saturation estimated from various well logs at the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

2011 ◽  
Vol 28 (2) ◽  
pp. 439-449 ◽  
Author(s):  
M.W. Lee ◽  
T.S. Collett
Keyword(s):  
Gas Hydrate ◽  
Well Logs ◽  
North Slope ◽  
Hydrate Saturation

Experimental Study on Dynamic Elastic Properties of Gas Hydrate Bearing Sediments

2012 ◽  
Vol 446-449 ◽  
pp. 1396-1399
Author(s):  
Ling Dong Li ◽  
Yuan Fang Cheng ◽  
Xiao Jie Sun
Keyword(s):  
Elastic Properties ◽  
Gas Hydrates ◽  
Gas Hydrate ◽  
Hot Spot ◽  
Confining Pressure ◽  
Measuring System ◽  
Fundamental Parameters ◽  
Hydrate Saturation ◽  
Hydrate Bearing Sediments

As a kind of emerging energy with massive reserves, natural gas hydrates are becoming the hot spot of global research. The elastic properties of gas hydrate bearing sediments (HBS) are the fundamental parameters for gas hydrates exploration and resource evaluations. As the original coring in HBS is difficult and expensive, experimental method is important to study the problem. An acoustic wave in-situ measuring system for HBS was developed. Using the in-situ method, hydrate bearing rock samples of different hydrate saturation were synthesized, of which the supersonic wave measurement was carried out under different confining pressure. According to the elasticity theory, the dynamic elastic parameters were obtained using the measured ultrasonic wave velocity. The results show that compressional and shear waves increase with the confining pressure and hydrate saturation increasing, and so the dynamic elastic modulus is.

scholarly journals Research on the Estimate of Gas Hydrate Saturation Based on LSTM Recurrent Neural Network

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6536
Author(s):  
Chuanhui Li ◽  
Xuewei Liu
Keyword(s):  
Neural Network ◽  
Deep Learning ◽  
Recurrent Neural Network ◽  
Gas Hydrate ◽  
Short Term Memory ◽  
Chloride Concentration ◽  
Well Logs ◽  
Good Prediction ◽  
Learning Technology ◽  
Hydrate Saturation

Gas hydrate saturation is an important index for evaluating gas hydrate reservoirs, and well logs are an effective method for estimating gas hydrate saturation. To use well logs better to estimate gas hydrate saturation, and to establish the deep internal connections and laws of the data, we propose a method of using deep learning technology to estimate gas hydrate saturation from well logs. Considering that well logs have sequential characteristics, we used the long short-term memory (LSTM) recurrent neural network to predict the gas hydrate saturation from the well logs of two sites in the Shenhu area, South China Sea. By constructing an LSTM recurrent layer and two fully connected layers at one site, we used resistivity and acoustic velocity logs that were sensitive to gas hydrate as input. We used the gas hydrate saturation calculated by the chloride concentration of the pore water as output to train the LSTM network. We achieved a good training result. Applying the trained LSTM recurrent neural network to another site in the same area achieved good prediction of gas hydrate saturation, showing the unique advantages of deep learning technology in gas hydrate saturation estimation.

scholarly journals Quantifying in-situ gas hydrates at active seep sites in the eastern Black Sea using pressure coring technique

2011 ◽  
Vol 8 (3) ◽  
pp. 4529-4558 ◽  
Author(s):  
K. Heeschen ◽  
M. Haeckel ◽  
I. Klaucke ◽  
M. K. Ivanov ◽  
G. Bohrmann
Keyword(s):  
Black Sea ◽  
Gas Hydrate ◽  
Pore Volume ◽  
Sediment Cores ◽  
Stability Boundary ◽  
Hydrate Formation ◽  
Gas Hydrate Formation ◽  
Hydrate Saturation ◽  
Gas Volume

Abstract. In the eastern Black Sea, we determined methane (CH4) concentrations, gas hydrate volumes and their vertical distribution from combined gas and chloride (Cl−) measurements within pressurized sediment cores. The total gas volume collected from the cores corresponds to concentrations of 1.2–1.4 mol of methane per kg porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 15–18% of pore volume and amongst the highest values detected in shallow seep sediments. At the central seep site, a high-resolution Cl− profile resolves the upper gas hydrate stability boundary and a continuous layer of hydrates in a sediment column of 120 cm thickness. Including this information, a more precise gas hydrate saturation of 22–24% pore volume can be calculated. This is higher in comparison to a saturation calculated from the Cl− profile alone, resulting in 14.4%. The likely explanation is an active gas hydrate formation from CH4 gas ebullition. The hydrocarbons at Batumi Seep are of shallow biogenic origin (CH4 > 99.6%), at Pechori Mound they originate from deeper thermocatalytic processes as indicated by the lower ratios of C1 to C2–C3 and the presence of C5.

Estimation of gas hydrate saturation in Ulleung Basin using seismic attributes and well logs

2013 ◽  
Author(s):  
Taekju Jeong ◽  
Joongmoo Byun ◽  
Hyungwook Choi ◽  
Dong-Geun Yoo
Keyword(s):  
Gas Hydrate ◽  
Seismic Attributes ◽  
Well Logs ◽  
Ulleung Basin ◽  
Hydrate Saturation

scholarly journals Quantifying in-situ gas hydrates at active seep sites in the eastern Black Sea using pressure coring technique

2011 ◽  
Vol 8 (12) ◽  
pp. 3555-3565 ◽  
Author(s):  
K. U. Heeschen ◽  
M. Haeckel ◽  
I. Klaucke ◽  
M. K. Ivanov ◽  
G. Bohrmann
Keyword(s):  
Black Sea ◽  
Gas Hydrate ◽  
Pore Volume ◽  
Sediment Cores ◽  
Hydrate Formation ◽  
Gas Hydrate Formation ◽  
Hydrate Saturation ◽  
Gas Volume ◽  
Quantifying In

Abstract. In the eastern Black Sea, we determined methane (CH4) concentrations, gas hydrate volumes, and their vertical distribution from combined gas and chloride (Cl−) measurements within pressurized sediment cores. The total gas volume collected from the cores corresponded to concentrations of 1.2–1.4 mol CH4 kg−1 porewater at in-situ pressure, which is equivalent to a gas hydrate saturation of 15–18% of pore volume and amongst the highest values detected in shallow seep sediments. At the central seep site, a high-resolution Cl− profile resolved the upper boundary of gas hydrate occurrence and a continuous layer of hydrates in a sediment column of 120 cm thickness. Including this information, a more precise gas hydrate saturation of 22–24% pore volume could be calculated. This volume was higher in comparison to a saturation calculated from the Cl− profile alone, resulting in only 14.4%. The likely explanation is an active gas hydrate formation from CH4 gas ebullition. The hydrocarbons at Batumi Seep are of shallow biogenic origin (CH4 > 99.6%), at Pechori Mound they originate from deeper thermocatalytic processes as indicated by the lower ratios of C1 to C2–C3 and the presence of C5.

In Situ Measurement of Electrical Resistivity of Ocean Sediments Containing Gas Hydrates

2013 ◽  
Vol 432 ◽  
pp. 104-108 ◽  
Author(s):  
Yu Feng Chen ◽  
De Qing Liang ◽  
Neng You Wu
Keyword(s):  
Electrical Resistivity ◽  
Gas Hydrate ◽  
Hydrate Formation ◽  
Pore Fluid ◽  
Natural Gas Hydrate ◽  
Resistivity Index ◽  
Ocean Sediment ◽  
Hydrate Saturation ◽  
Water Saturated

An understanding of the physical properties of hydrate-bearing sediment is necessary for interpretation of geophysical data collected in field settings. We have conducted a laboratory experiment to measure the electrical property of initially water saturated sediment containing natural gas hydrate. When gas hydrate was formed from pore fluid in ocean sediment, bulk sediment resistivity was significantly increased. The resistivity of the sediment was largely changed below 20% hydrate saturation. With the increasing hydrate saturation, the resistivity of sediment was increased and the resistivity of pore fluid was decrease. In the final process of hydrate formation, the resistivity depression was found mainly due to the transition of gas hydrate morphology. The electrical resistivity of hydrate specimens varied from 1.930 Ohm.m to 3.950 Ohm.m for saturation ranging from 0% to 52.68%. Besides, the dependence of the resistivity index versus hydrate saturation is inconsistent with Archies law. The results of our studies have important implications for quantitative laboratory and field calibration of geophysical measurements within gas hydratebearing intervals.

GAS HYDRATE SATURATION ESTIMATED FROM ACOUSTIC IMPEDANCE IN THE ANDAMAN SEA, INDIA

2014 ◽  
Vol 33 (2) ◽  
pp. 163-168
Author(s):  
Xiujuan WANG ◽  
Jiliang WANG ◽  
Wei LI ◽  
Nittala Satyavani ◽  
Kalachand Sain
Keyword(s):  
Gas Hydrate ◽  
Acoustic Impedance ◽  
Andaman Sea ◽  
Hydrate Saturation
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