Stochastic modeling of coal fracture network by direct use of micro-computed tomography images

Abstract Characterization of coalbed methane reservoirs is a challenging task because of complex petrophysical properties of coal. Coal cleat system has a key role in permeability of gas through coalbed. Previous computational methods for characterization and modeling in coal formations do not account for the actual complexities in cleat systems as they commonly rely on simple statistical properties for describing the fractures. In this study, unlike the previous methods that try to extract some of the spatial statistical properties, the 2D/3D micro computed tomography images are used directly without any simplifications and assumptions. The generated models are compared to discrete fracture networks as one of the widely-used method for the modeling of such complex systems of coal cleats. Results show that the utilized algorithm produces visually satisfactory realizations of both coal matrix and cleat system. To quantify such similarities, autocorrelation functions, connectivity (with two distinct indices), average fracture length and orientation are computed. Moreover, permeabilities and porosities of the reconstructed samples are calculated and compared with the original sample. It is demonstrated that the proposed reconstruction method reproduces samples with similar statistical and petrophysical properties, but with different patterns of both coal porous region and fracture system. Finally, the proposed method and the DFN realizations are also compared extensively. The results of this study can be used for characterization of coal samples with any degree of complexity and heterogeneity by producing several realistic stochastic models. Consequently, petrophysical properties and their corresponding uncertainties can be evaluated more accurately.

[1]  Pejman Tahmasebi,et al.  Pore-scale simulation of flow of CO2 and brine in reconstructed and actual 3D rock cores , 2017 .

[2]  C. Özgen Karacan,et al.  Coal mine methane: A review of capture and utilization practices with benefits to mining safety and to greenhouse gas reduction , 2011 .

[3]  Peyman Mostaghimi,et al.  Digital rock analysis for accurate prediction of fractured media permeability , 2017 .

[4]  Tony F. Chan,et al.  Active contours without edges , 2001, IEEE Trans. Image Process..

[5]  Qian Fang,et al.  Relevance of computational rock physics , 2011 .

[6]  Pengcheng Fu,et al.  Proceedings, Thirty-eighth Workshop on Geothermal Reservoir Engineering Application of a Dual-continuum Model for Simulation of Fluid Flow and Heat Transfer in Fractured Geothermal Reservoirs , 2022 .

[7]  Pejman Tahmasebi,et al.  Image‐based modeling of granular porous media , 2017 .

[8]  J. Tukey,et al.  An algorithm for the machine calculation of complex Fourier series , 1965 .

[9]  Mark A. Knackstedt,et al.  3D porosity and mineralogy characterization in tight gas sandstones , 2010 .

[10]  Doug Stead,et al.  Numerical investigation of the scale effect and anisotropy in the strength and deformability of coal , 2014 .

[11]  Yanbin Yao,et al.  Non-destructive characterization of coal samples from China using microfocus X-ray computed tomography , 2009 .

[12]  S. Laubach,et al.  Regional Coal Fracture Patterns And Coalbed Methane Development , 1991 .

[13]  J. Olson,et al.  Characteristics and origins of coal cleat: A review , 1998 .

[14]  R. Ketcham,et al.  Three-dimensional measurement of fractures in heterogeneous materials using high-resolution X-ray computed tomography , 2010 .

[15]  Peyman Mostaghimi,et al.  Porosity and permeability characterization of coal: A micro-computed tomography study , 2016 .

[16]  F. Ting.  Origin and Spacing of Cleats in Coal Beds , 1977 .

[17]  Kamy Sepehrnoori,et al.  Development of a Coupled Dual Continuum and Discrete Fracture Model for the Simulation of Unconventional Reservoirs , 2013, ANSS 2013.

[18]  Pejman Tahmasebi,et al.  MS-CCSIM: Accelerating pattern-based geostatistical simulation of categorical variables using a multi-scale search in Fourier space , 2014, Comput. Geosci..

[19]  J. Serra.  Introduction to mathematical morphology , 1986 .

[20]  Xiao Lu,et al.  Cleat-scale characterisation of coal: An overview , 2017 .

[21]  Pejman Tahmasebi,et al.  Enhancing multiple‐point geostatistical modeling: 2. Iterative simulation and multiple distance function , 2016 .

[22]  M. Wheeler,et al.  Effective Flow Properties for Cells Containing Fractures of Arbitrary Geometry , 2016 .

[23]  N. Otsu.  A threshold selection method from gray level histograms , 1979 .

[24]  Pejman Tahmasebi,et al.  Conditional reconstruction: An alternative strategy in digital rock physics , 2016 .

[25]  Peyman Mostaghimi,et al.  Coal cleat reconstruction using micro-computed tomography imaging , 2016 .

[26]  Yanjie Liang,et al.  Rock fracture skeleton tracing by image processing and quantitative analysis by geometry features , 2016 .

[27]  Lanru Jing,et al.  A review of techniques, advances and outstanding issues in numerical modelling for rock mechanics and rock engineering , 2003 .

[28]  J. Crelling.  Separation and characterization of coal macerals: accomplishments and future possibilities , 1989 .

[29]  Lindi J. Quackenbush.  A Review of Techniques for Extracting Linear Features from Imagery , 2004 .

[30]  Pejman Tahmasebi,et al.  Stochastic shale permeability matching: Three-dimensional characterization and modeling , 2016 .

[31]  L. Connell,et al.  Modelling permeability for coal reservoirs: A review of analytical models and testing data , 2012 .

[32]  Pejman Tahmasebi,et al.  Multiscale study for stochastic characterization of shale samples , 2016 .

[33]  Influence of Coal Composition and Rank on Fracture Development in Fruitland Coal Gas Reservoirs of , 1991 .

[34]  Younes Fadakar Alghalandis,et al.  ADFNE: Open source software for discrete fracture network engineering, two and three dimensional applications , 2017, Comput. Geosci..

[35]  P. C. Robinson.  Connectivity of fracture systems-a percolation theory approach , 1983 .

[36]  Pejman Tahmasebi,et al.  Multiscale and multiresolution modeling of shales and their flow and morphological properties , 2015, Scientific Reports.

[37]  Christopher R. Clarkson,et al.  Variation in permeability with lithotype and maceral composition of Cretaceous coals of the Canadian Cordillera , 1997 .

[38]  Christoph H. Arns,et al.  Techniques in helical scanning, dynamic imaging and image segmentation for improved quantitative analysis with X-ray micro-CT , 2014 .

[39]  Yu-Shu Wu,et al.  On the Effective Continuum Method for Modeling MultiphaseFlow, Multicomponent Transport and Heat Transfer in FracturedRock , 2013 .

[40]  Pieter Botha,et al.  High-resolution three-dimensional imaging of coal using microfocus X-ray computed tomography, with special reference to modes of mineral occurrence , 2013 .

[41]  John C. Crelling,et al.  Applied coal petrology : the role of petrology in coal utilization , 2008 .

[42]  Christoph H. Arns,et al.  Developing a virtual materials laboratory , 2007 .

[43]  Geostatistical Simulation and Reconstruction of Porous Media , 2015 .

[44]  M. Blunt,et al.  Pore-scale imaging and modelling , 2013 .

[45]  Talal Yusaf,et al.  Coal seam gas and associated water: A review paper , 2013 .

[46]  Mark Whitty,et al.  Robotics, Vision and Control. Fundamental Algorithms in MATLAB , 2012 .

[47]  Emmanuel Ledoux,et al.  Modeling fracture flow with a stochastic discrete fracture network: Calibration and validation: 2. The transport model , 1990 .

[48]  P. Young,et al.  Time series analysis, forecasting and control , 1972, IEEE Transactions on Automatic Control.

[49]  Peyman Mostaghimi,et al.  Micro-CT image calibration to improve fracture aperture measurement , 2016 .

[50]  Adrian Sheppard,et al.  Techniques for image enhancement and segmentation of tomographic images of porous materials , 2004 .

[51]  Frank van Bergen,et al.  Determination of the cleat angle distribution of the RECOPOL coal seams, using CT-scans and image analysis on drilling cuttings and coal blocks , 2008 .

[52]  Pejman Tahmasebi,et al.  Reconstruction of nonstationary disordered materials and media: Watershed transform and cross-correlation function. , 2015, Physical review. E, Statistical, nonlinear, and soft matter physics.

[53]  C. Karacan,et al.  Fracture/cleat analysis of coals from Zonguldak Basin (northwestern Turkey) relative to the potential of coalbed methane production , 2000 .

[54]  Pejman Tahmasebi,et al.  A Hierarchical Sampling for Capturing Permeability Trend in Rock Physics , 2017, Transport in Porous Media.

[55]  Adler,et al.  Fractured Porous Media , 2012 .

[56]  R. Purl,et al.  Measurement of Coal Cleat Porosity and Relative Permeability Characteristics , 1991 .

[57]  Pejman Tahmasebi,et al.  Enhancing multiple‐point geostatistical modeling: 1. Graph theory and pattern adjustment , 2016 .

[58]  K. Koike,et al.  Identifying spatial heterogeneity of coal resource quality in a multilayer coal deposit by multivariate geostatistics , 2008 .

[59]  K. Elewaut,et al.  Application of X-ray computed tomography for analyzing cleat spacing and cleat aperture in coal samples , 2006 .

[60]  Peyman Mostaghimi,et al.  Rough-walled discrete fracture network modelling for coal characterisation , 2017 .

[61]  Pejman Tahmasebi,et al.  Geostatistical Simulation and Reconstruction of Porous Media by a Cross-Correlation Function and Integration of Hard and Soft Data , 2015, Transport in Porous Media.

[62]  Alan V. Oppenheim,et al.  Discrete-Time Signal Pro-cessing , 1989 .

[63]  L. J. Lorig,et al.  Application of discrete fracture networks in mining and civil geomechanics , 2015 .

[64]  Peter C. Lichtner,et al.  CRITIQUE OF DUAL CONTINUUM FORMULATIONS OF MULTICOMPONENT REACTIVE TRANSPORT IN FRACTURED POROUS MEDIA , 2000 .

[65]  M. Blunt,et al.  Modelling stress-dependent permeability in fractured rock including effects of propagating and bending fractures , 2013 .

[66]  Martin Vetterli,et al.  Fast Fourier transforms: a tutorial review and a state of the art , 1990 .

[67]  Gwilym M. Jenkins,et al.  Time series analysis, forecasting and control , 1971 .

[68]  M. Sahimi,et al.  Three-Dimensional Stochastic Characterization of Shale SEM Images , 2015, Transport in Porous Media.

[69]  T. N. Narasimhan,et al.  A PRACTICAL METHOD FOR MODELING FLUID AND HEAT FLOW IN FRACTURED POROUS MEDIA , 1985 .

[70]  H. Gundersen,et al.  Quantification of connectivity in cancellous bone, with special emphasis on 3-D reconstructions. , 1993, Bone.

[71]  Xiao Lu,et al.  Pore Scale Characterisation of Coal: An Unconventional Challenge , 2016 .

[72]  T. Moore,et al.  Coalbed methane: A review , 2012 .

[73]  Pejman Tahmasebi,et al.  Structural adjustment for accurate conditioning in large-scale subsurface systems , 2017 .

[74]  Veerle Cnudde,et al.  High-resolution X-ray computed tomography in geosciences: A review of the current technology and applications , 2013 .

[75]  Katsuaki Koike,et al.  Coal quality related to microfractures identified by CT image analysis , 2015 .

[76]  Christopher R. Clarkson,et al.  Variation in micropore capacity and size distribution with composition in bituminous coal of the Western Canadian Sedimentary Basin: Implications for coalbed methane potential , 1996 .

[77]  Peyman Mostaghimi,et al.  X-Ray Micro-Computed Tomography Imaging for Coal Characterization , 2015 .

[78]  Laurent Gicquel,et al.  Multiscale and Multiresolution Approaches in TurbulenceP. Sagaut, S. Deck, and M. Terracol, 2nd ed., Imperial College Press, London, 2013, 448 pp., 128 hardcover and 96 ebook. , 2015 .