B. Hagemann, J. Wegner, L. Ganzer
Clausthal University of Technology, Clausthal-Zellerfeld, Germany
In tight gas formations where the low matrix permeability prevents successful and economic production rates, hydraulic fracturing is required to produce a well at economic rates. As production from the well and its initial fracture declines, re-fracturing treatments are required to accelerate recovery. The orientation of the following hydraulic fracture depends on the actual stress-state of the ...
Application of the Focused Impedance Method (FIM) to Determine the Volume of an Object within a Volume Conductor
M. A. Kadir, S. P. Ahmed, G. D. Al Quaderi, R. Rahman, K. Siddique-e Rabbani
Department of Biomedical Physics & Technology, University of Dhaka, Dhaka, Bangladesh
Department of Physics, Jahangirnagar University, Savar, Dhaka, Bangladesh
Department of Physics, University of Dhaka, Dhaka, Bangladesh
Focused Impedance Method (FIM), a new technique of electrical impedance measurement having high sensitivity in the central region, can sense the change in transfer impedance of an object embedded at a shallow depth within a volume conductor of unchanging background conductivity, using electrodes at the surface. This paper presents a new method for measuring the volume of such an embedded object ...
T. Fong, M. Chui, and D. L. Freyberg
Department of Civil and Environmental Engineering, Stanford University, Stanford, CA, USA
Hydrological processes and components are intrinsically coupled, and thus must often be modeled as an integrated system. Unfortunately, although a few modeling codes are available, integrated hydrological modeling remains a challenge.The objective of this paper is to explore the feasibility of using COMSOL Multiphysics for integrated hydrological modeling; in particular, using the generic ...
Georg-August Universität Göttingen, Göttingen, Germany
Although there are porous media and subsurface flow modes available in a toolbox of COMSOL Multiphysics®, some common requirements in hydrogeological models can not be easily accessed in the graphical user interface. Most crucially, there is no distinction between confined and unconfined situations for permeable layers, so called aquifers. Using the Physics Builder for such distinctions aquifer ...
R. Caulk, J. McCartney, E. Ghazanfari
University of Vermont, Burlington, VT, USA
University of Colorado, Boulder, CO, USA
In this study, a model of in-situ geothermal energy piles was constructed using COMSOL Multiphysics® software. Geothermal energy piles serve two purposes, first to transfer building load into the subsurface, but also to extract thermal heat from surrounding soils. This is achieved using a heat pump coupled with embedded heat exchangers. As a result, a multiphysics problem is introduced - heat ...
Coupling Heat Transfer in Heat Pipe Arrays with Subsurface Porous Media Flow for Long Time Predictions of Solar Rechargeable Geothermal Systems
P. Oberdorfer, R. Hu, M. Azizur Rahman, E. Holzbecher, M. Sauter, P. Pärisch
Applied Geology, Geoscience Centre, University of Göttingen, Göttingen, Germany
Institute for Solar Energy Research Hameln/Emmerthal (ISFH), Emmerthal, Germany
An increased share of renewable energies is regarded as an integral part of a strategy towards a sustainable future. With regard to the heat supply sector this may be achieved using solar thermal collectors or heat pump systems with borehole heat exchangers. During the last years solar thermal and geothermal systems have generally been installed separately. Now, several proposals are discussed in ...
E. Holzbecher, P. Oberdorfer, F. Maier, and Y. Jin
Georg-August Universität Göttingen
Geothermal heat production from deep reservoirs (5000-7000 m) is currently examined, not only in Germany. Our reference set-up consists of two pipes within a single borehole: one for pumping. We examine a design, where a single borehole splits into two legs at a certain depth. The two legs are connected by highly permeable geological, natural or artificial strata in the deep subsurface. The ...
Finite Element Solution of Nonlinear Transient Rock Damage with Application in Geomechanics of Oil and Gas Reservoirs
S. Enayatpour, T. Patzek
The University of Texas at Austin, Austin, TX, USA
The increasing energy demand calls for advances in technology which translate into more accurate and complex simulations of physical problems. Understanding the rock damage is essential to understanding the geomechanics of hydrocarbon reservoirs. The fragile microstructure of some rocks makes it difficult to predict the propagation of fracture in these rocks, therefore a mathematical model is ...
E. Dagher, G. Su, T. S. Nguyen
Canadian Nuclear Safety Commission, Ottawa, ON, Canada
COMSOL® software was used to simulate the conductive heat transfer with phase change in the geological formations encompassed in permafrost surrounding a shallow thaw lake. The purpose of the simulation was to verify the adequacy of COMSOL to model such phenomena by comparing the COMSOL results to those obtained by another FEM model (Ling and Zhang, 2003). The graphical comparison of the ...
Department of Chemical Engineering, University of Arkansas, Fayetteville, AR, USA
During the hydraulic fracturing process, there can be possible re-activation of closed/sealed faults and natural fractures in the formation, which may lead to changes in the boundary conditions of the reservoir. While study models of shale gas formations have utilized the concept of a closed reservoir in order to optimize the production of gas in the well-bore, this assumption cannot be adopted ...