scholarly journals Pore-Fractures of Coalbed Methane Reservoir Restricted by Coal Facies in Sangjiang-Muling Coal-Bearing Basins, Northeast China

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1196 ◽  
Author(s):  
Yuejian Lu ◽  
Dameng Liu ◽  
Yidong Cai ◽  
Qian Li ◽  
Qifeng Jia
Keyword(s):  
Coalbed Methane ◽  
Network Performance ◽  
Negative Relationship ◽  
Type I ◽  
Tissue Preservation ◽  
Groundwater Level Fluctuations ◽  
Delta Plain ◽  
Coalbed Methane Reservoir ◽  
Type C ◽  
Coal Facies

The pore-fractures network plays a key role in coalbed methane (CBM) accumulation and production, while the impacts of coal facies on the pore-fractures network performance are still poorly understood. In this work, the research on the pore-fracture occurrence of 38 collected coals from Sangjiang-Muling coal-bearing basins with multiple techniques, including mercury intrusion porosimetry (MIP), micro-organic quantitative analysis, and optic microscopy, and its variation controlling of coal face were studied. The MIP curves of 38 selected coals, indicating pore structures, were subdivided into three typical types, including type I of predominant micropores, type Ⅱ of predominant micropores and macropores with good connectivity, and type Ⅲ of predominant micropores and macropores with poor connectivity. For coal facies, three various coal facies were distinguished, including lake shore coastal wet forest swamp, the upper delta plain wet forest swamp, tidal flat wet forest swamp using Q-cluster analysis and tissue preservation index–gelification index (TPI-GI), and wood index–groundwater influence index (WI-GWI). The results show a positive relationship between tissue preservation index (TPI), wood index (WI), and mesopores (102 nm–103 nm), and a negative relationship between TPI, WI, and macropores/fractures. In addition, groundwater level fluctuations can control the development of type C and D fractures, and the frequency of type C and D fractures show an ascending trend with increasing groundwater index (GWI), which may be caused by the mineral hydration of the coal. Finally, from the perspective of the pore-fractures occurrence in CBM reservoirs, the wet forest swamp of upper delta plain is considered to be the optimization areas for Sangjiang-Muling coal-bearing basins by a comparative study of various coal facies.

Physical simulation of hydrodynamic conditions in high rank coalbed methane reservoir formation

2009 ◽  
Vol 19 (4) ◽  
pp. 435-440 ◽  
Author(s):  
Bo WANG ◽  
Bo JIANG ◽  
Lei LIU ◽  
Gui-qiang ZHENG ◽  
Yong QIN ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Physical Simulation ◽  
High Rank ◽  
Hydrodynamic Conditions ◽  
Coalbed Methane Reservoir

scholarly journals Influence of pressure, coal structure and permeability on CBM well productivity at various burial depths in South Yanchuan Block, China

2016 ◽  
Vol 20 (3) ◽  
pp. 1 ◽  
Author(s):  
Teng Li ◽  
Caifang Wu
Keyword(s):  
Effective Stress ◽  
Methane Production ◽  
Coalbed Methane ◽  
Gas Content ◽  
Burial Depth ◽  
Type I ◽  
Type Ii ◽  
Transformation Zone ◽  
Shallow Reservoir ◽  
Deep Reservoir

With a burial depth of 1000 m as the demarcation, the coal reservoir in South Yanchuan Block, China is divided into deep reservoir and shallow reservoir regions. A combination of coalbed methane well production data, well logging interpretation, coalbed methane numerical simulations and reservoir properties were used to research various production characteristics at different depths. The results indicate that coal thickness and gas content are not key factors that influence methane production. The shallow reservoir is located in a tension zone, while the deep reservoir is located in both a transformation zone and a compression zone. Although the reservoir and closure pressures increase with the burial depth, the pressures fluctuate in the deep reservoir, especially in the transformation zone. This fluctuation influences the opened degree of the fractures in the reservoir. The effective stress is lower in the deep reservoir than in the shallow reservoir, leading to higher permeability in the deep reservoir. This difference in effective stress is the key factor that influences the methane production. The combination of coal thickness and gas content also significantly influenced the methane production. Influenced by the reservoir and closure pressures, the Type III coal in the shallow reservoir is more developed, while the deep reservoir contained more developed Type I and Type II coal. The permeability increases exponentially with increasing thickness of Type I and Type II coal, which determines the high reservoir permeability in the deep reservoir. The development of Type III coal leads to the poor reservoir hydraulic fracturing effect. However, a reservoir with thick Type I and Type II coal can have a positive effect. Influencia de la presión, la estructura del carbón y su permeabilidad sobre la productividad de gas metano de carbón en profundidades de enterramiento del bloque Yanchuan Sur, ChinaResumenCon una profundidad de enterramiento de 1000 metros, el yacimiento de carbón del bloque Yanchuan Sur, en China, se divide en dos: el depósito profundo y el depósito superficial. Este trabajo combina los datos de la información de producción de gas metano asociado carbón, la interpretación de registros de pozo, las simulaciones numéricas de metano asociado a carbón y las propiedades del reservorio para encontrar las características de producción a diferentes profundidades. Los resultados indican que el espesor del carbón y el contenido de gas no son factores que alcancen a influir en la producción de metano. El depósito superficial se encuentra en una zona de tensión, mientras el depósito profundo está ubicado en una región tanto de transformación como de compresión. Aunque el reservorio y la presión de cierre se incrementan con la profundidad de enterramiento, las presiones fluctúan en el depósito profundo, especialmente en la zona de transformación. Esta fluctuación influye en el grado de apertura de las fracturas en el depósito. La tensión efectiva es más baja en el depósito profundo, lo que significa una mayor permeabilidad. La diferencia en la tensión efectiva es el factor clave que incide en la producción de metano. Afectado por las presiones de cierre y del yacimiento, el carbón tipo III en el depósito superficial está más desarrollado, mientras que el depósito profundo contiene carbón tipo I y tipo II más desarrollado. La permeabilidad se incrementa exponencialmente con el incremento del espesor en el carbón tipo I y tipo II, lo que determina la alta porosidad en el depósito profundo. El desarrollo de carbón tipo III lleva a un pobre efecto de la fractura hidráulica en el depósito. Sin embargo, un depósito con carbón tipo I y tipo II espeso podría tener un efecto positivo.

ANALYSIS OF INTERFERON-I SIGNALING ACTIVITY IN CHILDREN WITH SYSTEMIC LUPUS ERYTHEMATOSUS: RESULTS OF A PILOT PROSPECTIVE STUDY

2021 ◽  
Vol 100 (3) ◽  
pp. 77-88
Author(s):  
R.K. Raupov ◽  
◽  
E.N. Suspitsyn ◽  
E.M. Kalashnikova ◽  
R.C. Mulkidzhan ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Lupus Erythematosus ◽  
Age Of Onset ◽  
Negative Relationship ◽  
Clinical Manifestations ◽  
Type I ◽  
Systemic Lupus ◽  
Cold Urticaria ◽  
Pediatric Department ◽  
Interferon System

The interferon system (IFN) is a group of signaling molecules with antiviral, antitumor and antiproliferative effects. The most studied signaling pathway is mediated by IFN type I. Mutations of IFN-I-regulated genes are involved in the pathogenesis of systemic lupus erythematosus (SLE). Interferon index (IFN-I-index) – a quantitative indicator of the level of expression of IFN-Iregulated genes – is used to assess the activity of the interferon system. Objective of the study: to assess the level of the IFN-I index in children with SLE, as well as to compare the clinical and laboratory characteristics of patients with high and normal levels of the IFN-I-index. Materials and methods of research: 40 patients (girls – 83%, boys – 17%) under 18 years of age with SLE diagnosed in accordance to the SLICC 2012 criteria were included in a multicenter prospective open uncontrolled nonrandomized continuous study. The age of the patients was 15,2 (12,5 ; 16,7) years. All of them underwent examination and treatment in the Pediatric department № 3 at the clinic of the St. Petersburg State Pediatric Medical University and in the Pediatric department of the Almazov National Medical Research Center. The IFN-I index was determined by real-time PCR with a quantitative assessment of the expression of 5 genes induced by IFN-α and β. Results: aggravated family history of rheumatic diseases was noted in 8 patients: SLE – in 3 (8%), rheumatoid arthritis – in 3 (8%), cold urticaria – in 2 (5%). The average age of onset of the disease is 12 years. The most common clinical manifestations were lesions of the skin, joints, mucous membranes, central nervous system, kidney and fever. 31 patients (78%) had an increased IFN-I index. All cases of kidney failure were observed only in patients with a high IFN index (36% vs 0%, p=0,036). Patients with increased IFN-I-index had statistically significant increased levels of antinuclear (87% vs 56%, p=0,043) and rheumatoid factors (36% vs 0%, p=0,036), higher ECLAM index values (3,0 vs 1.0, p=0,048), ferritin levels (p=0,0008) and, as a consequence, the need for more intensive immunosuppressive therapy (using rituximab and cyclophosphamide) compared with patients with normal IFN-Iindex. A positive statistically significant correlation of the IFN-I index with male sex (r=0,41, p=0,008), nephritis (r=0,35, p=0,026), livedoid rash (r=0,38, p=0,017 ), Raynaud's phenomenon (r=0,37, p=0,018), high antinuclear factor (r=0,82, p=0,001), rheumatoid factor (r=0,654, p=0,011), antibodies to Sm antigen (r=0,57, p=0,034), as well as a negative relationship with anemia (r=–0,67, p=0,009). Conclusion: IFN-I-index can be considered as a surrogate biomarker of activity and prognosis of SLE. Further research is required to validate its diagnostic role.

Geological and Gas-Content Features of Coalbed Methane System in Qinshui Basin, Shanxi

2012 ◽  
Vol 170-173 ◽  
pp. 1187-1191
Author(s):  
Ya Hui Jia ◽  
Xiao Ping Xie ◽  
Ai Li Lu
Keyword(s):  
Coalbed Methane ◽  
Gas Content ◽  
Structural Deformation ◽  
Shanxi Province ◽  
Qinshui Basin ◽  
The North ◽  
North Part ◽  
Coalbed Methane Reservoir ◽  
High Yields

Colabed methane system is a natural system that consists of coal seams, coalbed methane in them and surrounding rocks. As an unconventional natural gas, reservoir and conservation of coalbed methane are different from those of conventional hydrocarbon. The Qinshui Basin, covering an area about 30,000sq.km in southeastern Shanxi Province, has abundant coalbed methane resources in the carboniferous Taiyuan formation and permian Shanxi formation, with an in-situ methane resource 3.3×1012 m3.In this study, the structural deformation and tectonic evolution of coalbed methane system in Qinshui basin were reported. Relationships between structural deformation and the formation of coalbed methane reservoir in Qinshui Basin were also discussed. The results show that Yangquan-Shouyang area in the north part of the basin and Tunliu-Xiangyuan area in the east are favorable for formation coalbed methane system. In contrast, Jincheng-Qinshui area in the south part of basin and the Qinyuan area in the middle of basin are favorable for both the formation of coalbed methane reservoirs and high yields as well.

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