In-situ stress and coal bed methane potential in Western Canada

2006 ◽  
Vol 54 (3) ◽  
pp. 197-220 ◽  
Author(s):  
J.S. Bell
2013 ◽  
Vol 756-759 ◽  
pp. 4758-4762
Author(s):  
Xing Peng Jing

In Order to Achieve Accurate Quantitative Results of Parameters for Reservoir Pressure of Coal-Bed Methane, Neural Network Prediction Analytic Method is Adopted to Predict the Reservoir Pressure of Coal-Bed Methane. the Main Controlling Factors such as Conformation Stress, Buried Depth, in-Situ Stress and Permeability are Investigated. Mathematical Models of Neural Network of Reservoir Pressure of Coal-Bed Methane of Mathematical Analysis and System Architecture are Established; Taking the Qinshui Basin Coal Seam as Example to Forecast and use Reservoir Pressure of Coal-Bed Methane. Projections Show that: the use of Neural Network Prediction of Reservoir Pressure of Coal-Bed Methane is Feasible; Neural Network Method Makes up a Mathematical Point of Linear and Regularity in Order to Solve the Non-Linear Complex Relationship between the Input and Output Parameter Variables.


2018 ◽  
Vol 6 (2) ◽  
pp. T271-T281 ◽  
Author(s):  
Shuai Yin ◽  
Airong Li ◽  
Qiang Jia ◽  
Wenlong Ding ◽  
Yanxia Li

In situ stress has an important influence on coal reservoir permeability, fracturing, and production capacity. In this paper, fracturing testing, imaging logging, and 3D finite-element simulation were used to study the current in situ stress field of a coal reservoir with a high coal rank. The results indicated that the horizontal stress field within the coal reservoir is controlled by the burial depth, folding, and faulting. The [Formula: see text] and [Formula: see text] values within the coal reservoir are 1–2.5 MPa higher than those within the clastic rocks of the roof and floor. The [Formula: see text]–[Formula: see text] values of the coal reservoir are generally between 2 and 6 MPa and increase with burial depth. When the [Formula: see text]–[Formula: see text] value is less than 5 MPa, production from a single well is high, but when the [Formula: see text]–[Formula: see text] value is greater than 5 MPa, production from a single well is low. In addition, the accumulated water production is high when the [Formula: see text]–[Formula: see text] value is greater than 5 MPa, demonstrating that a higher [Formula: see text]–[Formula: see text] value allows the hydraulic fractures to more easily penetrate the roof and floor of the coal seam. In coal-bed methane development regions with high [Formula: see text]–[Formula: see text] values, repeated fracturing using the small-scale plug removal method — which is a fracturing method that uses a small volume of liquid, small displacement, and low sand concentration — is suggested.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Zhengrong Chen ◽  
Tengfei Sun

In order to evaluate the productivity effects of coal-bed methane well fracturing, the relationship between the five factors of horizontal in situ stress difference is analyzed: fracturing friction, net pressure, fracture morphology, fracturing curve shape, and fracturing effect, taking the coal-bed methane wells in the Qinshui Basin as the research target. The results show that the smaller the horizontal in situ stress difference, the larger the fracture stimulation volume; the smaller the fracturing friction and the net pressure, the higher the productivity of the coal-bed methane well; the greater the proportion of coal-bed methane wells with complex fractures in the form of fracturing fractures, the greater the productivity; the fractures formed by descending and mixed fracture curves are ideal, and the effect after fracturing is better. Based on support vector machine for the above five factors, a fracturing effect classification and evaluation model is established using the fractured wells in the target block as training samples, and the effect prediction of nearby coal-bed methane wells is performed. The results show that the prediction results are in excellent agreement, comparing the prediction classification results of support vector machine with the average daily gas production. This theoretical method realizes the classification of the complex effects of coal-bed methane fracturing and provides a theoretical basis for the design of coal-bed methane well production stimulation and effect prediction.


2008 ◽  
Vol 74 (8) ◽  
pp. 2424-2432 ◽  
Author(s):  
Dariusz Strąpoć ◽  
Flynn W. Picardal ◽  
Courtney Turich ◽  
Irene Schaperdoth ◽  
Jennifer L. Macalady ◽  
...  

ABSTRACT A series of molecular and geochemical studies were performed to study microbial, coal bed methane formation in the eastern Illinois Basin. Results suggest that organic matter is biodegraded to simple molecules, such as H2 and CO2, which fuel methanogenesis and the generation of large coal bed methane reserves. Small-subunit rRNA analysis of both the in situ microbial community and highly purified, methanogenic enrichments indicated that Methanocorpusculum is the dominant genus. Additionally, we characterized this methanogenic microorganism using scanning electron microscopy and distribution of intact polar cell membrane lipids. Phylogenetic studies of coal water samples helped us develop a model of methanogenic biodegradation of macromolecular coal and coal-derived oil by a complex microbial community. Based on enrichments, phylogenetic analyses, and calculated free energies at in situ subsurface conditions for relevant metabolisms (H2-utilizing methanogenesis, acetoclastic methanogenesis, and homoacetogenesis), H2-utilizing methanogenesis appears to be the dominant terminal process of biodegradation of coal organic matter at this location.


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