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Parameter estimation from artificial tracer experiments
225A 924156 Correlation between permeability and deformatioual characteristics of the Shirahama sandstone and Inada granite Takahashi, M; Koide, H; Xue Zi-Qiu Proc 7tb ISRM International Congress on Rock Mechanics, Aachen, 16-20 September 1991 VI, P417-420. Publ Rotterdam; A A Balkema, 1991
Permeability and volume strains were measured for the two rock types under hydrostatic and deviatoric stress conditions. Permeability was obtained by a transient pulse method and was seen not to be a simple function of the difference between effective confining stress and internal fluid pressure. Anisotropic permeability was seen. For the sandstone and granite respectively, increases in permeability of x3 and x30 were seen for respective axial differential stresses of 80MPa and 300MPa over the value of isotropic stress. Changes in permeability with deformation can be accounted for by initial closing then dilatancy of pre-existing microfractures. 924157 Evaluation of hydraulic conductivities of a jointed rock mass by crosshole permeability test Aoki, K; Shiogama, Y; Tezuka, Y; Kobuchi, T; Matsumoto, K Proc 7th ISRM International Congress on Rock Mechanics, Aachen, 16-20 September 1991 VI, P423-426. Publ Rotterdam: A A Balkema, 1991
Hydraulic conductivity can be considered as a second rank symmetrical tensor. Crosshole permeability tests were carried out at two sites, one in granodiorite with RQD about 80% and relatively few joints, the other in heavily jointed rhyolite with RQD about 50%. Dimensions and direction of hydraulic conductivity and storativity were verified at the first site by BHTV scanning and observation of water inflows. At the second site, hydraulic properties were interpreted using crosshole tomography. 924158 Parameter estimation from artificial tracer experiments Maloszewski, P; Zuber, A Proc Conference on Calibration and Reliability in Groundwater Modelling, The Hague, 3-6 September 1990 P53-62. Publ Walling)Cord.• IAHS Press. 1990 (IAHS Publication No. 195)
Tracer experiments may yield a range of results, depending on the flow model and interpretation method used in analysis. Considerable errors in parameters may arise from unsuitable choice. This is illustrated for the case of tracer experiments in a granular formation (Quaternary sand) and in fissured chalk. In the fissured rock with a high matrix to fissure porosity ratio, dispersion is minimal, diffusion into the matrix being the main mechanism for longitudinal spread of solute.
using univariate statistical analysis to get smooth and unbiased transfer functions. The method is illustrated for hydraulic impedance tests in a highly permeable aquifer and constant head tests in low permeability fractured rock. 924160 Numerical studies of fluid flow through channels on fracture plane Kobayashi, A; Yamashita, R Proc International Conference on Mechanics of Jointed and Faulted Rock, Vienna, 18-20 April 1990 P613-620. Publ Rotterdam: A A Balkema, 1990
Fluid flow through a fracture whose aperture has been modelled stochastically is described. Gamma, exponential, and Iognormal probability density functions for channel aperture are used. Flow modelled by 2D finite element analysis using the distribution of permeabilities from these PDFs is compared to that seen in Stripa mine granites. Lognorrnal distribution with a large variance of channel aperture gives good approximation of real flow phenomena. Flow is mainly through preferred, large aperture channels. Real distribution of channel aperture may have a large variance. 924161 Flow predictions of a three dimensional conditioned discontinuum probabilistic flow model Sandford, T C; Dagher, H J; Shah, H J; Schonewald, I V Proc International Conference on Mechanics of Jointed and Faulted Rock, Vienna, 18-20 April 1990 P621-626. Publ Rotterdam: A A Balkema, 1990
A computer program is described which generates 3 dimensional fracture networks using a probabilistic statistical analysis which, after conditioning using pumping test data, can be used in simulation of fluid flow in rock masses. Results of flow to a well using patterns generated from subsurface information, with and without conditioning from the pumping test, are compared. 924162 Numerical model for fluid flow in the block interface network of three dimensional rock block system Xu Jixian; Cojean, R Proc International Conference on Mechanics of Jointed and Faulted Rock, Vienna, 18-20 April 1990 P627-633. Publ Rotterdam: A A Balkema, 1990
A model has been developed using the boundary element method to simulate and analyse in three dimensions fluid flow in a rock block. The three dimensional block system is generated using a program SIMBLOC which has the capability to handle convex or concave rock blocks intersected by finite or infinite fractures. The application of the model is demonstrated through a simple example of three orthogonal families of infinite fractures. Further developments and refinements are discussed.
924159 Evaluation of single borehole hydrotests in frequency domain by a univariate statistical method Marschall, P; Barczewski, B Proc Conference on Calibration and Reliability in Groundwater Modelling, The Hague, 3-6 September 1990 P63-73. Publ Wallingford." IAHS Press. 1990 (IAHS Publication No. 195)
924163 Simulation of non-isothermal block jointed systems Elsworth, D; Xiang, J Proc International Conference on Mechanics of Jointed and Faulted Rock, Vienna, 18-20 April 1990 P635-642. Publ Rotterdam: A A Balkema, 1990
Single borehole tests (slug, constant head, constant flow) are often used to determine local hydraulic parameters in porous or fractured media. A frequency domain approach to the analysis of such tests, using a transfer function independent of initial conditions (and hence of type of hydrotest), has been proposed. The reliability of the estimated transfer function can be improved by stacking several tests from a borehole and
A conceptual model representing permeability changes associated with block jointed rock masses as a result of fluid injection and non-isothermal flow is presented. An example model based on a hot dry rock reservoir containing a ubiquitous orthogonal fracture system is also presented. Illustrations of single well fluid injection and a typical simultaneous injectionwithdrawal stimulation are given. Development of the fluid
© 1992 Pergamon Press Ltd. Reproduction not permitted
Permeability and volume strains were measured for the two rock types under hydrostatic and deviatoric stress conditions. Permeability was obtained by a transient pulse method and was seen not to be a simple function of the difference between effective confining stress and internal fluid pressure. Anisotropic permeability was seen. For the sandstone and granite respectively, increases in permeability of x3 and x30 were seen for respective axial differential stresses of 80MPa and 300MPa over the value of isotropic stress. Changes in permeability with deformation can be accounted for by initial closing then dilatancy of pre-existing microfractures. 924157 Evaluation of hydraulic conductivities of a jointed rock mass by crosshole permeability test Aoki, K; Shiogama, Y; Tezuka, Y; Kobuchi, T; Matsumoto, K Proc 7th ISRM International Congress on Rock Mechanics, Aachen, 16-20 September 1991 VI, P423-426. Publ Rotterdam: A A Balkema, 1991
Hydraulic conductivity can be considered as a second rank symmetrical tensor. Crosshole permeability tests were carried out at two sites, one in granodiorite with RQD about 80% and relatively few joints, the other in heavily jointed rhyolite with RQD about 50%. Dimensions and direction of hydraulic conductivity and storativity were verified at the first site by BHTV scanning and observation of water inflows. At the second site, hydraulic properties were interpreted using crosshole tomography. 924158 Parameter estimation from artificial tracer experiments Maloszewski, P; Zuber, A Proc Conference on Calibration and Reliability in Groundwater Modelling, The Hague, 3-6 September 1990 P53-62. Publ Walling)Cord.• IAHS Press. 1990 (IAHS Publication No. 195)
Tracer experiments may yield a range of results, depending on the flow model and interpretation method used in analysis. Considerable errors in parameters may arise from unsuitable choice. This is illustrated for the case of tracer experiments in a granular formation (Quaternary sand) and in fissured chalk. In the fissured rock with a high matrix to fissure porosity ratio, dispersion is minimal, diffusion into the matrix being the main mechanism for longitudinal spread of solute.
using univariate statistical analysis to get smooth and unbiased transfer functions. The method is illustrated for hydraulic impedance tests in a highly permeable aquifer and constant head tests in low permeability fractured rock. 924160 Numerical studies of fluid flow through channels on fracture plane Kobayashi, A; Yamashita, R Proc International Conference on Mechanics of Jointed and Faulted Rock, Vienna, 18-20 April 1990 P613-620. Publ Rotterdam: A A Balkema, 1990
Fluid flow through a fracture whose aperture has been modelled stochastically is described. Gamma, exponential, and Iognormal probability density functions for channel aperture are used. Flow modelled by 2D finite element analysis using the distribution of permeabilities from these PDFs is compared to that seen in Stripa mine granites. Lognorrnal distribution with a large variance of channel aperture gives good approximation of real flow phenomena. Flow is mainly through preferred, large aperture channels. Real distribution of channel aperture may have a large variance. 924161 Flow predictions of a three dimensional conditioned discontinuum probabilistic flow model Sandford, T C; Dagher, H J; Shah, H J; Schonewald, I V Proc International Conference on Mechanics of Jointed and Faulted Rock, Vienna, 18-20 April 1990 P621-626. Publ Rotterdam: A A Balkema, 1990
A computer program is described which generates 3 dimensional fracture networks using a probabilistic statistical analysis which, after conditioning using pumping test data, can be used in simulation of fluid flow in rock masses. Results of flow to a well using patterns generated from subsurface information, with and without conditioning from the pumping test, are compared. 924162 Numerical model for fluid flow in the block interface network of three dimensional rock block system Xu Jixian; Cojean, R Proc International Conference on Mechanics of Jointed and Faulted Rock, Vienna, 18-20 April 1990 P627-633. Publ Rotterdam: A A Balkema, 1990
A model has been developed using the boundary element method to simulate and analyse in three dimensions fluid flow in a rock block. The three dimensional block system is generated using a program SIMBLOC which has the capability to handle convex or concave rock blocks intersected by finite or infinite fractures. The application of the model is demonstrated through a simple example of three orthogonal families of infinite fractures. Further developments and refinements are discussed.
924159 Evaluation of single borehole hydrotests in frequency domain by a univariate statistical method Marschall, P; Barczewski, B Proc Conference on Calibration and Reliability in Groundwater Modelling, The Hague, 3-6 September 1990 P63-73. Publ Wallingford." IAHS Press. 1990 (IAHS Publication No. 195)
924163 Simulation of non-isothermal block jointed systems Elsworth, D; Xiang, J Proc International Conference on Mechanics of Jointed and Faulted Rock, Vienna, 18-20 April 1990 P635-642. Publ Rotterdam: A A Balkema, 1990
Single borehole tests (slug, constant head, constant flow) are often used to determine local hydraulic parameters in porous or fractured media. A frequency domain approach to the analysis of such tests, using a transfer function independent of initial conditions (and hence of type of hydrotest), has been proposed. The reliability of the estimated transfer function can be improved by stacking several tests from a borehole and
A conceptual model representing permeability changes associated with block jointed rock masses as a result of fluid injection and non-isothermal flow is presented. An example model based on a hot dry rock reservoir containing a ubiquitous orthogonal fracture system is also presented. Illustrations of single well fluid injection and a typical simultaneous injectionwithdrawal stimulation are given. Development of the fluid
© 1992 Pergamon Press Ltd. Reproduction not permitted