Multilevel Fracture Network Modeling of Naturally Fractured Reservoirs

Kazemi, Hossein; Atan, Safian; Al-Matrook, M.; Dreier, J.; Özkan, Erdal

doi:10.2118/93053-ms

Cited by 15 publications

(4 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our approach (Yetkin, 2007) for an isotropic reservoir reduces to the classical 9-point finite-difference (Smith, 1978) with the discretization error of O (Δx 6 ). Furthermore, in our 13-point discretization, we used a square reservoir with no-flow outer boundary conditions instead of an infinite reservoir used by Bagheri and Settari. Another method to account for the permeability tensor is constructing a 2-D octagonal perpendicular bisector (PEBI) grid from a conventional 2-D Cartesian grid (Kazemi, 1992, Chong et el., 2004, and Kazemi et al, 2005 as shown in Figs. 3 and 4.…”

Section: Background and Literature Reviewmentioning

confidence: 95%

See 1 more Smart Citation

A Simple Method to Account for Permeability Anisotropy in Reservoir Models and Multi-Well Pressure Interference Tests

Yetkin¹,

Ramírez

Kobaisi

et al. 2009

SPE Rocky Mountain Petroleum Technology Conference

Self Cite

View full text Add to dashboard Cite

Permeability anisotropy, via full permeability tensor, has not been accurately accounted for in reservoir models because of the implementation complexity. Specifically, numerical implementation of the off-diagonal components of the permeability tensor is inconvenient and cumbersome. This paper shows how directional permeability, calculated from a full permeability tensor, can be used as a simple replacement both in coding numerical models and in day-to-day engineering analysis. For the former, we have implemented the directional permeability for single-phase flow in a 9-point finite-difference formulation, which is easy to code. This formulation, however, is easily applicable to any control-volume formulation including the perpendicular bisector (PEBI) grid. The implementation of this technique has produced excellent numerical results in numerical simulation of multi-phase flow displacement. For routine engineering applications, we have also applied this technique to generate pressure responses for a four-well interference test in a highly anisotropic system. The analysis of the test results by conventional type-curve matching produced the correct reservoir geometric-average permeability and a very good approximation for the direction of the maximum permeability, which is a testimony to the credibility of the formulation. The use of this formulation should be very useful in determining major natural fracture trends in reservoirs undergoing water or gas injection, and in modeling fracture trends in other fractured reservoir situations, such as tight sands.

show abstract

Section: Background and Literature Reviewmentioning

confidence: 95%

“…Chong et al (2004) successfully used this grid to reduce grid orientation effects in a quarter of a five-spot homogeneous isotropic waterflood simulation. Kazemi, et al (2005) proposed this construction to account for permeability anisotropy in naturally fractured reservoirs.…”

Section: Background and Literature Reviewmentioning

confidence: 99%

A Simple Method to Account for Permeability Anisotropy in Reservoir Models and Multi-Well Pressure Interference Tests

Yetkin¹,

Ramírez

Kobaisi

et al. 2009

SPE Rocky Mountain Petroleum Technology Conference

Self Cite

View full text Add to dashboard Cite

show abstract

“…The DFN approach has widely been used in modelling fractures (e.g. [32,33,34,35,36]), which is appropriate for well scale modelling [37]. The fracture sub-sets have honoured detailed geological observations of the outcrop [9].…”

Section: Fracture Permeabilitymentioning

confidence: 99%

Fracture Conductivity Effect in DFN Modelling Using Carbonate Outcrop Data

Aljuboori,

Lee,

Elraies

et al. 2023

Unconventional Methods for Geoscience, Shale Gas and Petroleum in the 21st Century

View full text Add to dashboard Cite

Synthetic well testing is an important tool which can be utilised to understand the fractures’ influence on flow behaviour. Different fracture sets have been used to identify the well performance and the conductivity of the fracture network. Five models were built using outcrop fracture data sets with similar statistical properties, and their flow performances were analysed using the well-test response to evaluate the outcrop-related uncertainties. The results of the aforementioned scenarios have shown remarkable differences in the pressure responses related to the degrees of fracture conductivity in each fracture set. This variation in the pressure response indicates that the higher fracture density may not necessarily result in a higher fracture conductivity. The fracture conductivity effect was further investigated using a scenario of a producer completed in a matrix block trapped within fractures. The results have referred that the distance to the fracture and the fracture conductivity have a considerable influence on the dual-porosity signature, which may mask the radial flow response of the matrix in the derivative plot when the fractures are very close. The outcome of this work can be used to understand the outcrop-related uncertainties as a pre-work of a full field fracture modelling and to calibrate the fracture conductivity at the well vicinity to improve the history matching. The results can also help in well-test interpretations when a similar pattern of pressure response is obtained from real well-test data.

show abstract

“…The illustrated fracture pattern in Figure 2 (the red part), was imported into a geological modelling package and a fracture network was created deterministically in the model. The discrete fracture networks (DFN) approach was used, which is appropriate for well scale or sector modelling [5,6,26,27,28,29]. This work aims to investigate the effect of contact areas and fracture surface roughness on effective fracture permeability.…”

Section: D Simulation Modelsmentioning

confidence: 99%

The Impact of Contact Area and Fracture Surface Roughness on Fluid Flow in Fractured Reservoirs

Aljuboori,

Lee,

Elraies

et al. 2023

Unconventional Methods for Geoscience, Shale Gas and Petroleum in the 21st Century

View full text Add to dashboard Cite

The estimation of effective fracture permeability depends mainly on the geometry of the void space between the fracture surfaces. Sometimes, these void spaces are closed partially or totally for various reasons, which create a contact area between the fracture surfaces. These contact areas cause the fluid to follow a tortuous path around them, which reduces the permeability magnitude notably. In this study, a digitised fracture network of a carbonate formation has been used to investigate the impact of contact areas and variable aperture width on the effective fracture permeability by using a discrete fracture networks approach. Moreover, a statistical analysis of a fracture width was used to build a stochastic aperture distribution to evaluate the fluid flow behaviour. Where, the properties of the aperture histogram are the only required parameters for the aperture modelling, in addition to several advantages in the current workflow compared with the former modelling approaches. The results were represented by a correction curve plotted based on the 3D simulation results, which can be used to evaluate the reduction factor in fracture permeability by considering the impact of contact areas in fractures. Furthermore, it can also be utilised for the history-matching process by calibrating the fracture permeability, hence fluid flow behaviour at the well region or the reservoir scale.

show abstract

Multilevel Fracture Network Modeling of Naturally Fractured Reservoirs

Cited by 15 publications

References 11 publications

A Simple Method to Account for Permeability Anisotropy in Reservoir Models and Multi-Well Pressure Interference Tests

A Simple Method to Account for Permeability Anisotropy in Reservoir Models and Multi-Well Pressure Interference Tests

Fracture Conductivity Effect in DFN Modelling Using Carbonate Outcrop Data

The Impact of Contact Area and Fracture Surface Roughness on Fluid Flow in Fractured Reservoirs

Contact Info

Product

Resources

About