2D-numerical analysis of hydraulic fracturing in heterogeneous geo-materials

Wang, Shanyong; Sun, Lijun; Au, A.S.K.; Yang, Tao; Tang, Chun’an

doi:10.1016/j.conbuildmat.2008.12.004

Cited by 75 publications

(36 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Distinct element code has been developed to study fracturing and later extended with pore fluid to study hydraulic fracturing (Al-Busaidi et al, 2005). Finally, finite element models are developed, which build on Biot's equations for poroelasticity, where the fractures are handled by changes in the permeability field (see for example Tang et al (1992); Wang et al (2009)). …”

Section: Introductionmentioning

confidence: 99%

Finite element modeling of hydraulic fracturing on a reservoir scale in 2D

Wangen

2011

Journal of Petroleum Science and Engineering

View full text Add to dashboard Cite

A finite element based procedure is suggested for the modelling of hydraulic fracturing of heterogeneous rocks on a macroscopic scale. The scheme is based on the Biot-equations for the rock, and a finite element representation for the fracture pressure, where the fracture volume appears as fracture porosity. The fracture and the rock are represented unified on the same regular finite element grid. The numerical solutions of pressure and displacement are verified against exact 1D results. The 1D model also shows how the tension forces that open the fracture decreases as the gradient of the pore pressure decreases. The fracture criterion is based on the "strength" of bonds in the finite element grid. It is shown how this criterion scales with the grid size. It is assumed that fracturing happens instantaneously and that the fluid volume in the fracture is the same after a fracture event. The pressure drop that follows a fracture event is computed with a procedure that preserves the fluid volume in the fracture. The hydraulic fracturing procedure is demonstrated on a homogeneous and an inhomogeneous rock when fluid is injected at a constant rate by a well at the centre of the grid. A case of a homogeneous rock shows that a symmetric fracture develops around the well, where one bond breaks in each fracture event. A heterogeneous case shows the intermittent nature of the fracture process, where several bonds break in each fracture event.

show abstract

Section: Introductionmentioning

confidence: 99%

Finite element modeling of hydraulic fracturing on a reservoir scale in 2D

Wangen

2011

Journal of Petroleum Science and Engineering

View full text Add to dashboard Cite

show abstract

“…The effect of microcrack generation on the permeability of saturated geomaterials has also been observed by and . More recently, the theory of the continuous damage of fracture mechanics has been applied by to solve problems related to hydraulic fracturing in heterogeneous geomaterials.…”

Section: Introductionmentioning

confidence: 92%

A high‐resolution local RBF collocation method for steady‐state poroelasticity and hydromechanical damage analysis

Stevens

Power

Polanco

et al. 2014

Num Anal Meth Geomechanics

View full text Add to dashboard Cite

International audiencen this work, we describe a meshless numerical method based on local collocation with RBFs for the solution of the poroelasticity equation. The RBF finite collocation approach forms a series of overlapping nodal stencils, over which an RBF collocation is performed. These local collocation systems enforce the governing PDE operator throughout their interior, with the intersystem communication occurring via the collocation of field variables at the stencil periphery. The method does not rely on a generalised finite differencing approach, whereby the governing partial differential operator is reconstructed at the global level to drive the solution of the PDE. Instead, the PDE governing and boundary operators are enforced directly within the local RBF collocation systems, and the sparse global assembly is formed by reconstructing the value of the field variables at the centrepoint of the local stencils. In this way, the solution of the PDE is driven entirely by the local RBF collocation, and the method more closely resembles the approach of the full-domain RBF collocation method. By formulating the problem in this fashion, high rates of convergence may be attained without the computational cost and numerical ill-conditioning issues that are associated with the full-domain RBF collocation approach. An analytical solution is formulated for a 2D poroelastic fluid injection scenario and is used to verify the proposed implementation of the method. Highly accurate solutions are produced, and convergence rates in excess of sixth order are observed for each field variable (i.e. pressure and displacement) and field-variable derivative (i.e. pressure gradients and stresses). The stress and displacement fields resulting from the solution of the poroelasticity equation are then used to describe the formation and propagation of microfractures and microfissures, which may form in the presence of large shear strain, in terms of a continuous damage variable which modifies the mechanical and hydraulic properties of the porous medium. The formation of such hydromechanical damage, and the resulting increase in hydraulic conductivity, is investigated for a pressurised injection into sandstone. Copyright © 2014 John Wiley & Sons, Lt

show abstract

“…The RFPA3D-flow code is based on the basic realistic failure process analysis model [44,45] and the flow-stress-damage model [46]. Its mechanism was described in detail in Tang et al [46] and Li et al [47], and its two-dimensional version has a number of applications in simulating hydraulic fracturing in heterogeneous rock masses [48][49][50].…”

Section: Numerical Modellingmentioning

confidence: 99%

Application of Dimensional Analysis to Project Laboratory Scale Numerical Modelling Prescribed Hydraulic Fracturing Results to Field Scales

et al. 2018

Energies

View full text Add to dashboard Cite

Abstract:Hydraulic fracturing has been applied in the cave mining industry with the purpose of re-creating an orebody rock mass condition that is suitable for caving. Prescribed hydraulic fracturing was proposed in a previous study as a supplement to the conventional hydraulic fracturing strategy. In this paper; dimensional analysis is used to project laboratory scale numerical modelling results to field scales in order to study the applicability of creating prescribed hydraulic fractures (PHFs) under field conditions. The results indicate that field scale PHFs are feasible if the stress shadows of the pre-located fractures are properly utilized. Water can be used to create the pre-located fractures that induce the local stress change in a low differential stress state; and the use of more proppants and a shorter pre-located fracture spacing lead to PHFs propagating more quickly towards the pre-located fractures. For field condition having high differential stresses, more viscous fluid must be used to create the pre-located fractures in order to enhance the stress shadows. In this case, a shorter pre-located fracture spacing does not necessarily result in the re-orientation of PHFs towards the pre-located fractures and may even lead to unsatisfactory pre-conditioning. A sufficiently high pre-located fracture net pressure to the differential stress ratio (close to 0.5) is the prerequisite for creating PHFs.

show abstract

2D-numerical analysis of hydraulic fracturing in heterogeneous geo-materials

Cited by 75 publications

References 26 publications

Finite element modeling of hydraulic fracturing on a reservoir scale in 2D

Finite element modeling of hydraulic fracturing on a reservoir scale in 2D

A high‐resolution local RBF collocation method for steady‐state poroelasticity and hydromechanical damage analysis

Application of Dimensional Analysis to Project Laboratory Scale Numerical Modelling Prescribed Hydraulic Fracturing Results to Field Scales

Contact Info

Product

Resources

About