scholarly journals Characteristics and Origin of Methane Adsorption Capacity of Marine, Transitional, and Lacustrine Shales in Sichuan Basin, China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xianglu Tang ◽  
Wei Wu ◽  
Guanghai Zhong ◽  
Zhenxue Jiang ◽  
Shijie He ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Content ◽  
Adsorption Capacity ◽  
Clay Minerals ◽  
Shale Gas ◽  
Sichuan Basin ◽  
Thermal Evolution ◽  
Methane Adsorption ◽  
Isothermal Adsorption ◽  
Xujiahe Formation

Adsorbed gas is an important component of shale gas. The methane adsorption capacity of shale determines the composition of shale gas. In this study, the methane adsorption capacity of marine, transitional, and lacustrine shales in the Sichuan Basin was analyzed through its isothermal adsorption, mineral composition, water content, etc. The results show that the methane adsorption capacity of marine (Qiongzhusi Formation and Longmaxi Formation), transitional (Longtan Formation), and lacustrine (Xujiahe Formation and Ziliujing Formation) shales is significantly different. The Longtan Formation has the strongest methane adsorption capacity. This is primarily related to its high organic matter and organic matter type III content. The methane adsorption capacity of the lacustrine shale was the weakest. This is primarily related to the low thermal evolution degree and the high content of water-bearing clay minerals. Smectite has the highest methane adsorption capacity of the clay minerals, due to its crystal structure. The water content has a significant effect on methane adsorption largely because water molecules occupy the adsorption site. Additionally, the temperature and pressure in a specific range significantly affect methane adsorption capacity.

scholarly journals Simulation of methane adsorption in diverse organic pores in shale reservoirs with multi-period geological evolution

2021 ◽  
Author(s):  
Shangbin Chen ◽  
Chu Zhang ◽  
Xueyuan Li ◽  
Yingkun Zhang ◽  
Xiaoqi Wang
Keyword(s):  
Organic Matter ◽  
Pore Size ◽  
Adsorption Capacity ◽  
Thermal Evolution ◽  
Methane Adsorption ◽  
Storage Site ◽  
Pressure Sensitivity ◽  
Adsorption Characteristics ◽  
Shale Reservoirs ◽  
Organic Pores

AbstractIn shale reservoirs, the organic pores with various structures formed during the thermal evolution of organic matter are the main storage site for adsorbed methane. However, in the process of thermal evolution, the adsorption characteristics of methane in multi type and multi-scale organic matter pores have not been sufficiently studied. In this study, the molecular simulation method was used to study the adsorption characteristics of methane based on the geological conditions of Longmaxi Formation shale reservoir in Sichuan Basin, China. The results show that the characteristics of pore structure will affect the methane adsorption characteristics. The adsorption capacity of slit-pores for methane is much higher than that of cylindrical pores. The groove space inside the pore will change the density distribution of methane molecules in the pore, greatly improve the adsorption capacity of the pore, and increase the pressure sensitivity of the adsorption process. Although the variation of methane adsorption characteristics of different shapes is not consistent with pore size, all pores have the strongest methane adsorption capacity when the pore size is about 2 nm. In addition, the changes of temperature and pressure during the thermal evolution are also important factors to control the methane adsorption characteristics. The pore adsorption capacity first increases and then decreases with the increase of pressure, and increases with the increase of temperature. In the early stage of thermal evolution, pore adsorption capacity is strong and pressure sensitivity is weak; while in the late stage, it is on the contrary.

scholarly journals Nanostructure Effect on Methane Adsorption Capacity of Shale with Type III Kerogen

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1690
Author(s):  
Yong Han ◽  
Yanming Zhu ◽  
Yu Liu ◽  
Yang Wang ◽  
Han Zhang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Adsorption Capacity ◽  
Clay Minerals ◽  
Co2 Adsorption ◽  
Methane Adsorption ◽  
Experimental Results ◽  
Type Iii ◽  
Positive Effects ◽  
Inorganic Matter ◽  
Injection Experiment

This study focuses on the nanostructure of shale samples with type III kerogen and its effect on methane adsorption capacity. The composition, pore size distribution, and methane adsorption capacities of 12 shale samples were analyzed by using the high-pressure mercury injection experiment, low-temperature N2/CO2 adsorption experiments, and the isothermal methane adsorption experiment. The results show that the total organic carbon (TOC) content of the 12 shale samples ranges from 0.70% to ~35.84%. In shales with type III kerogen, clay minerals and organic matter tend to be deposited simultaneously. When the TOC content is higher than 10%, the clay minerals in these shale samples contribute more than 70% of the total inorganic matter. The CO2 adsorption experimental results show that micropores in shales with type III kerogen are mainly formed in organic matter. However, mesopores and macropores are significantly affected by the contents of clay minerals and quartz. The methane isothermal capacity experimental results show that the Langmuir volume, indicating the maximum methane adsorption capacity, of all the shale samples is between 0.78 cm3/g and 9.26 cm3/g. Moreover, methane is mainly adsorbed in micropores and developed in organic matter, whereas the influence of mesopores and macropores on the methane adsorption capacity of shale with type III kerogen is small. At different stages, the influencing factors of methane adsorption capacity are different. When the TOC content is <1.4% or >4.5%, the methane adsorption capacity is positively correlated with the TOC content. When the TOC content is in the range of 1.4–4.5%, clay minerals have obviously positive effects on the methane adsorption capacity.

Effects of pore structure and wettability on methane adsorption capacity of mud rock: Insights from mixture of organic matter and clay minerals

Fuel ◽  
2019 ◽  
Vol 251 ◽  
pp. 551-561 ◽  
Author(s):  
Peng Luo ◽  
Ningning Zhong ◽  
Imran Khan ◽  
Xiaomei Wang ◽  
Huajin Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Pore Structure ◽  
Adsorption Capacity ◽  
Clay Minerals ◽  
Methane Adsorption

scholarly journals Micropore Characteristics and Geological Significance of Shale Reservoirs: Case Study of Fuling Shale Gas in Sichuan Basin, China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Liang Cheng ◽  
Fujia Guan ◽  
Dehua Liu ◽  
Wenxin Yang ◽  
Jing Sun
Keyword(s):  
Electron Microscopy ◽  
Organic Matter ◽  
Clay Minerals ◽  
Shale Gas ◽  
Sichuan Basin ◽  
Process Analysis ◽  
Gas Storage ◽  
Flow Process ◽  
Main Factors ◽  
Shale Reservoirs

Several techniques (such as scanning electron microscopy (SEM) and gas adsorption systems) have been used to study the pore features and structures of shale reservoirs. The available methods and techniques have restricted the specific research on micropores, and the morphology, genesis, volume, and main factors controlling pore characteristics are yet to be analyzed. Currently, there is no systematic understanding of the role that these spaces play in gas storage and flow. As such, our understanding of the spatial connectivity of pores and reserves of shale reservoirs is limited. In this study, the pores of the Fuling shale gas reservoir in the Sichuan Basin were systematically observed by SEM and transmission electron microscopy. Images of pores smaller than 2 nm were captured for the first time, and their morphology and genesis were analyzed by combining these images with the rock mineralogy theory. The pore size distribution characteristics of the reservoir were analyzed by the adsorption-mercury injection method and nuclear magnetic resonance, and the main factors controlling the distribution of different pore sizes were analyzed. The results show that large numbers of micropores were distributed between the mesopores and macropores in the shale reservoir, which mainly consisted intergranular pores, intermolecular pores, interlamellar pores of clay minerals, and organic matter skeleton pores. The development of pores smaller than 1 nm was mainly controlled by the clay mineral content, and the development of pores with a size of approximately 1-2 nm was related to the contents of clay minerals and organic matter. These pores could connect the macropores and mesopores well, which is important for gas storage and flow. In this paper, the types, distribution, and main controlling factors of micropores were studied, and our understanding of the reservoir space was improved from the nanometer level to the Angstrom level, which is important for gas storage and flow process analysis.

scholarly journals Clarifying the Effect of Clay Minerals on Methane Adsorption Capacity of Marine Shales in Sichuan Basin, China

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6836
Author(s):  
Hongyan Wang ◽  
Shangwen Zhou ◽  
Jiehui Zhang ◽  
Ziqi Feng ◽  
Pengfei Jiao ◽  
...  
Keyword(s):  
Water Absorption ◽  
Adsorption Capacity ◽  
Clay Minerals ◽  
Mineral Composition ◽  
Sichuan Basin ◽  
Gas Adsorption ◽  
Methane Adsorption ◽  
Pore Characteristics ◽  
Surface Areas ◽  
Marine Shale

The effect of clay minerals on the methane adsorption capacity of shales is a basic issue that needs to be clarified and is of great significance for understanding the adsorption characteristics and mechanisms of shale gas. In this study, a variety of experimental methods, including XRD, LTNA, HPMA experiments, were conducted on 82 marine shale samples from the Wufeng–Longmaxi Formation of 10 evaluation wells in the southern Sichuan Basin of China. The controlling factors of adsorption capacities were determined through a correlation analysis with pore characteristics and mineral composition. In terms of mineral composition, organic matter (OM) is the most key methane adsorbent in marine shale, and clay minerals have little effect on methane adsorption. The ultra-low adsorption capacity of illite and chlorite and the hydrophilicity and water absorption ability of clay minerals are the main reasons for their limited effect on gas adsorption in marine shales. From the perspective of the pore structure, the micropore and mesopore specific surface areas (SSAs) control the methane adsorption capacity of marine shales, which are mainly provided by OM. Clay minerals have no relationship with SSAs, regardless of mesopores or micropores. In the competitive adsorption process of OM and clay minerals, OM has an absolute advantage. Clay minerals become carriers for water absorption, due to their interlayer polarity and water wettability. Based on the analysis of a large number of experimental datasets, this study clarified the key problem of whether clay minerals in marine shales control methane adsorption.

Accumulated Conditions of Shale Gas in the Middle-Low Palaeozoic, Yangtze Platform, China

2012 ◽  
Vol 524-527 ◽  
pp. 122-125 ◽  
Author(s):  
Hai Yan Hu ◽  
Zhen Duo He ◽  
Bao Cai Chen
Keyword(s):  
Organic Matter ◽  
Source Rock ◽  
Shale Gas ◽  
Sichuan Basin ◽  
Thermal Evolution ◽  
Vitrinite Reflectance ◽  
Michigan Basin ◽  
Longmaxi Formation ◽  
San Juan Basin ◽  
Maturity Degree

Shale gas is an important unconventional natural gas resource. There is probably abundant shale gas resource in the Longmaxi Formation of the lower Silurian, Sichuan Basin, West China. Longmaxi Formation is high quality source rock, its TOC(total organic carbon) up to the most vulue 6.5 percent; the Formation more than 1percent TOC is up to 105 meters. Because of high maturity, it cannot identify the kerogen type by element Carbon and Hydron ratio, rather than carbon isotopic value. The isotopic carbon values of Kerogens are more than 29.67 permillage, which showed One Type Kerogen. In the Longmaxi Formation, source rock is up to post maturity and lack of vitrinite, so vitrinite reflectance cannot measure the source maturity. It can measure bitumen reflectance, then calculate relevant vitrinite reflectance (Ro) by bitumen reflectance to identify the organic matter thermal evolution degree. The result showed the maturity degree of organic matter equal to more than 3 percent vitrinite reflectance (Ro), which showed the source rock yielded rich thermogenic gas during the geological thermal evolution. The source rock of Longmaxi Formation has some silt partly composed of quartz mineral, up to 40 percent, which is beneficial to gas reservoir. So, it has available shale gas developed elements because of rich organic matter, high thermal maturity degree, good pool. The geological analogy method is used to assess the resource potential. Sichuan Basin has drastically similar to Michigan Basin and San Juan Basin in basin type, seal conditions, reservoir states, source rock, matched condition and so on. So they are selected as standard basin. Sixteen parameters are used to appraise the shale gas pool geological conditions. Compared with Michigan Basin and San Juan Basin by analogy method, Longmaxi Formation shale gas potential is 0.06-0.36 billion cubic meter per square kilometer.

scholarly journals Effect of organic maturity on shale gas genesis and pores development: A case study on marine shale in the upper Yangtze region, South China

2020 ◽  
Vol 12 (1) ◽  
pp. 1617-1629
Author(s):  
Kun Zhang ◽  
Jun Peng ◽  
Xin Wang ◽  
Zhenxue Jiang ◽  
Yan Song ◽  
...  
Keyword(s):  
Organic Matter ◽  
Shale Gas ◽  
Sichuan Basin ◽  
Storage Capacity ◽  
Thermal Evolution ◽  
Marine Shale ◽  
The Sichuan Basin ◽  
The Impact ◽  
And Storage ◽  
Cracking Gas

AbstractThe marine shale in southern China has undergone complex tectonic evolution with a high thermal evolution degree. Excessive thermal evolution brings certain risks to shale gas exploration and development. With the advancement of experimental methods, the evolution process of shale reservoirs can be better understood from the micro-nanoscale. This work takes the Ordovician-Silurian Wufeng and the first member of Longmaxi Formation in the Sichuan Basin and Lower Cambrian Niutitang Formation in Outer Margin of the Sichuan Basin to study the impact of maturity upon the genesis of shale gas and development features of the reservoir. A series of geochemical research methods, including TOC, gas component and gas isotope, were adopted to study the impact of different thermal evolution stages of organic matter upon the genesis of shale gas. The nanoscale micro-imaging technique, such as FIB-SEM and FIB-HIM, was used to analyze the development of OM-hosted pores. As shown from the results, when Ro = 1.2–3.5%, the marine shale gas is dominated by methane and other hydrocarbon gases, since the mixture of cracking gas from liquid hydrocarbons and kerogen-cracking gas cause the carbon isotope reversal. Besides, the pyrobitumen pores characterized by the strong connectivity and storage capacity were primarily developed. When Ro > 3.5%, the organic matter is at the graphitization stage. The shale gas is mainly composed of nitrogen at this stage. The nitrogen is originated from the atmosphere and the thermal evolution process, and the OM-hosted pores (pyrobitumen and kerogen pores) characterized by the bad connectivity and storage capacity are developed. Finally, the main component of shale gas, the genesis of shale gas and the pattern of OM-hosted pores under different thermal evolution stages of organic matter are summarized, which provide technical support for the exploration and development of shale gas.

scholarly journals Adsorption Characteristics and Controlling Factors of CH4 on Coal-Measure Shale, Hedong Coalfield

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 63
Author(s):  
Weidong Xie ◽  
Meng Wang ◽  
Hongyue Duan
Keyword(s):  
Organic Matter ◽  
Adsorption Capacity ◽  
Mineral Composition ◽  
Shale Gas ◽  
Total Content ◽  
Coal Measure ◽  
Gas Reservoirs ◽  
Quartz Content ◽  
Adsorption Characteristics ◽  
Adsorbed Gas

Adsorbed gas is one of the crucial occurrences in shale gas reservoirs; thus, it is of great significance to ascertain the adsorption capacity of shale and the adsorption characteristics of CH4. In this investigation, the Taiyuan–Shanxi Formations’ coal-measure shale gas reservoir of the Carboniferous–Permian era in the Hedong Coalfield was treated as the research target. Our results exhibit that the shale samples were characterized by a high total organic carbon (TOC) and over to high-over maturity, with an average TOC of 2.45% and average Ro of 2.59%. The mineral composition was dominated by clay (62% on average) and quartz (22.45% on average), and clay was mainly composed of kaolinite and illite. The Langmuir model showed a perfect fitting degree to the experimental data: VL was in the range of 0.01 cm3/g to 0.77 cm3/g and PL was in the range of 0.23–8.58 MPa. In addition, the fitting degree depicted a linear negative correlation versus TOC, while mineral composition did not exhibit a significant effect on the fitting degree, which was caused by the complex pore structure of organic matter, and the applicability of the monolayer adsorption theory was lower than that of CH4 adsorption on the mineral’s pore surface. An apparent linear positive correlation of VL versus the TOC value was recorded; furthermore, the normalized VL increased with the growth of the total content of clay mineral (TCCM), decreased with the growth of the total content of brittle mineral (TCBM), while there was no obvious correlation of normalized VL versus kaolinite, illite and quartz content. The huge amount of micropores and complex internal structure led to organic matter possessing a strong adsorption capacity for CH4, and clay minerals also promoted adsorption due to the development of interlayer pores and intergranular pores.

Sign in / Sign up

Export Citation Format

Share Document