Partially Decoupled Modeling of Hydraulic Fracturing Processes

Abstract

>SDE \/01)31Sum......,. A new method of partial decoupling of the problem of modeling a hydraulic fracture in a reservoir is described. This approach has significant advantages over previous methods with either fully coupled or completely uncoupled models. Better accuracy can be achieved in modeling the fracture propagation, and the new system is very efficient and versatile. Virtually any reservoir model can be used for predicting postfracture productivity. Examples of single-and multiphase applications for modeling fractured wells are discussed.

Numerical Modelling of Hydraulic Fracturing in Cohesionless Sand: Validation Against Laboratory Experiments

“…The discrete approach involves some computational disadvantages. For instance, fracturing increases the number of nodes and changes the topological connectivity of the mesh, which creates significant challenges for automating the approach (Suidan and Schnobrich 1973;Bažant and Oh 1983). Even though the smeared-fracture approach does not fully represent the physical nature of a crack, it is an alternative to the discrete-fracture method because it enables the simulation of fracture branching, fracture rotation, and multiple shear and tensile fractures in unpredetermined directions.…”

“…Modelling a fracture using a numerical method with the element size equal to the fracture thickness will result in a fine mesh because of the typically small aperture size compared with the model size, rendering engineering problems computationally impractical (Settari et al 1990;Weill and Latil 1992). It has been demonstrated that a fracture can be included in much larger elements, provided that an equivalent permeability of the element is determined from the average of the matrix permeability and the fracture conductivity (Settari et al 1990;Weill and Latil 1992;Ji 2008).…”

Evaluation of numerical schemes for capturing shock waves in modeling proppant transport in fractures

“…Settari et al (1990) were the first to propose the concept of partially decoupled fracture modeling. They linked a fracture simulator, a fluid flow simulator and a proppant simulator together and mapped the fracture geometry and proppant concentration in terms of permeability and porosity onto the reservoir simulator grids.…”

“…They linked a fracture simulator, a fluid flow simulator and a proppant simulator together and mapped the fracture geometry and proppant concentration in terms of permeability and porosity onto the reservoir simulator grids. To better capture the discontinuous front of proppants inside the fracture, Settari et al (1990) used a finer finite difference grid (finer than the grids used in the fracture and fluid flow modules) for solving the one-dimensional PDE of the proppant transport model. Later, several researchers used this approach in their numerical simulation of proppant transport.…”

“…Later, several researchers used this approach in their numerical simulation of proppant transport. Behr et al (2006), Shaoul et al (2007) and Miranda et al (2010) linked a commercial reservoir simulator to a commercial fracture and proppant simulator and used the same concept that Settari et al (1990) had used for frac pack analysis. Although the linking of proppant and fracture simulators was novel, the proppant transport in these works was not numerically modeled by solving the mass balance hyperbolic PDE.…”