Impacts of fracture network geometries on numerical simulation and performance prediction of enhanced geothermal systems

2021 ◽  
Author(s):  
Gang Liu ◽  
Chunwei Zhou ◽  
Zhenghua Rao ◽  
Shengming Liao
Keyword(s):  
Numerical Simulation ◽  
Performance Prediction ◽  
Fracture Network ◽  
Enhanced Geothermal Systems ◽  
Geothermal Systems ◽  
And Performance

scholarly journals Experimental and Numerical Evaluation of Hydraulic Fracturing under High Temperature and Embedded Fractures in Large Concrete Samples

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3171
Author(s):  
Liangliang Guo ◽  
Zihong Wang ◽  
Yanjun Zhang ◽  
Zhichao Wang ◽  
Haiyang Jiang
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Hydraulic Fracturing ◽  
Laboratory Test ◽  
High Temperatures ◽  
Large Scale ◽  
Hydraulic Fractures ◽  
Enhanced Geothermal Systems ◽  
Geothermal Systems ◽  
Fracture Density

In order to study the mechanism of hydraulic fracturing in enhanced geothermal systems, we analyzed the influence of high temperatures and embedded fractures on the initiation and propagation of hydraulic fractures using a laboratory test and numerical simulation. The analysis was conducted via large-scale true triaxial hydraulic fracturing tests with acoustic emission monitoring. Moreover, we discussed and established the elastic-plastic criterion of hydraulic fracturing initiation. The corresponding fracturing procedure was designed and embedded into the FLAC3D software. Then, a numerical simulation was conducted and compared with the laboratory test to verify the accuracy of the fracturing procedure. The influence of high temperatures on hydraulic fracturing presented the following features. First, multi-fractures were created, especially in the near-well region. Second, fracturing pressure, extension pressure, and fracture flow resistance became larger than those at room temperature. 3D acoustic fracturing emission results indicated that the influence of the spatial distribution pattern of embedded fractures on hydraulic fracturing direction was larger than that of triaxial stress. Furthermore, the fracturing and extension pressures decreased with the increase of embedded fracture density. For hydraulic fracturing in a high temperature reservoir, a plastic zone was generated near the borehole, and this zone increased as the injection pressure increased until the well wall failed.

Modeling fluid flow through complex fracture network in geological media by using hierarchical hydraulic properties

2020 ◽  
Author(s):  
Kyung Won Chang ◽  
Gungor Beskardes ◽  
Chester Weiss
Keyword(s):  
Fluid Flow ◽  
Surrounding Medium ◽  
Computational Cost ◽  
Energy Resource ◽  
Fracture Network ◽  
Fractured Media ◽  
Enhanced Geothermal Systems ◽  
Geothermal Systems ◽  
Hydraulic Stimulation ◽  
Complex Fracture

<p>Hydraulic stimulation is the process of initiating fractures in a target reservoir for subsurface energy resource management with applications in unconventional oil/gas and enhanced geothermal systems. The fracture characteristics (i.e., number, size and orientation with respect to the wellbore) determines the modified permeability field of the host rock and thus, numerical simulations of flow in fractured media are essential for estimating the anticipated change in reservoir productivity. However, numerical modeling of fluid flow in highly fractured media is challenging due to the explosive computational cost imposed by the explicit discretization of fractures at multiple length scales. A common strategy for mitigating this extreme cost is to crudely simplify the geometry of fracture network, thereby neglecting the important contributions made by all elements of the complex fracture system.</p><p>The proposed “Hierarchical Finite Element Method” (Hi-FEM; Weiss, Geophysics, 2017) reduces the comparatively insignificant dimensions of planar- and curvilinear-like features by translating them into integrated hydraulic conductivities, thus enabling cost-effective simulations with requisite solutions at material discontinuities without defining ad-hoc, heuristic, or empirically-estimated boundary conditions between fractures and the surrounding formation. By representing geometrical and geostatistical features of a given fracture network through the Hi-FEM computational framework, geometrically- and geomechanically-dependent fluid flow properly can now be modeled economically both within fractures as well as the surrounding medium, with a natural “physics-informed” coupling between the two.</p><p>SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.</p>

Integration of Distributing Energy System I: Modeling and Simulation

2012 ◽  
Vol 512-515 ◽  
pp. 1156-1162
Author(s):  
Jin Yang Wang ◽  
Guo Min Cui ◽  
Fu Yu Peng
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
Performance Prediction ◽  
System Modeling ◽  
Energy System ◽  
Primary Energy ◽  
Simulation System ◽  
Generation System ◽  
Micro Gas Turbine ◽  
And Performance

The heating, power and cooling distributing energy system is studied by numerical simulation. System modeling and performance prediction are studied on the tri-generation system based on micro gas turbine as primary energy utilizing equipment in part Ⅰ. The results show: The numerical simulation can replace pilotscale experiment of objective project in the aspects of design and performance prediction of distributing energy system.

scholarly journals Hydraulic Fracturing in Enhanced Geothermal Systems—Field, Tectonic and Rock Mechanics Conditions—A Review

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5725
Author(s):  
Rafał Moska ◽  
Krzysztof Labus ◽  
Piotr Kasza
Keyword(s):  
Hydraulic Fracturing ◽  
Fracture Network ◽  
Hydraulic Fractures ◽  
Enhanced Geothermal Systems ◽  
Seismic Velocities ◽  
Geothermal Systems ◽  
Principal Stresses ◽  
Pumping Rate ◽  
Work Related ◽  
Stimulation Method

Hydraulic fracturing (HF) is a well-known stimulation method used to increase production from conventional and unconventional hydrocarbon reservoirs. In recent years, HF has been widely used in Enhanced Geothermal Systems (EGS). HF in EGS is used to create a geothermal collector in impermeable or poor-permeable hot rocks (HDR) at a depth formation. Artificially created fracture network in the collector allows for force the flow of technological fluid in a loop between at least two wells (injector and producer). Fluid heats up in the collector, then is pumped to the surface. Thermal energy is used to drive turbines generating electricity. This paper is a compilation of selected data from 10 major world’s EGS projects and provides an overview of the basic elements needed to design HF. Authors were focused on two types of data: geological, i.e., stratigraphy, lithology, target zone deposition depth and temperature; geophysical, i.e., the tectonic regime at the site, magnitudes of the principal stresses, elastic parameters of rocks and the seismic velocities. For each of the EGS areas, the scope of work related to HF processes was briefly presented. The most important HF parameters are cited, i.e., fracturing pressure, pumping rate and used fracking fluids and proppants. In a few cases, the dimensions of the modeled or created hydraulic fractures are also provided. Additionally, the current state of the conceptual work of EGS projects in Poland is also briefly presented.

Sign in / Sign up

Export Citation Format

Share Document