Comparative Analysis of Dual Continuum and Discrete Fracture Simulation Approaches to Model Fluid Flow in Naturally Fractured, Low-Permeability Reservoirs

2016 ◽  
Author(s):  
A. Kumar ◽  
D. Camilleri ◽  
M. Brewer
Keyword(s):  
Fluid Flow ◽  
Comparative Analysis ◽  
Low Permeability ◽  
Fracture Simulation ◽  
Discrete Fracture ◽  
Naturally Fractured ◽  
Model Fluid ◽  
Low Permeability Reservoirs

Research on Flow Units of Extra-Low Permeability Reservoirs in Fault Block Sheng554 of Shengping Oilfield

2013 ◽  
Vol 295-298 ◽  
pp. 3162-3165
Author(s):  
Lu Lu Zhou ◽  
Zi Nan Li ◽  
Jun Gang Liu ◽  
Yan Yun Zhang ◽  
Guang Qiang Shu
Keyword(s):  
Fluid Flow ◽  
Water Injection ◽  
Type A ◽  
Low Permeability ◽  
Type B ◽  
Flow Units ◽  
Fault Block ◽  
Remaining Oil ◽  
Type C ◽  
Low Permeability Reservoirs

Taking the example of the fourth member of the Lower Cretaceous Quantou formation reservoirs in fault block Sheng554 of Sanzhao sag, this article discusses the methodology of flow units in extra-low permeability reservoirs. The research on flow units in such reservoirs can be divided into two ranks, one is to determine the distribution of seepage barriers and inner connected sands， the other is to analyze the differentia of fluid flow in the inner connected sands so as to subdivide the flow units. The result shows that the pelitic barriers are rather developed in fault block Sheng554. Through the analysis of differentia of fluid flow, according to the value of flow zone index (FZI), the inner connected sands can be classified into three types of flow units, among which type A with FZI value greater than 1.0 has better permeable property and higher intensity of water injection, and the ability of permeability and water injection of type B with FZI value between 0.5 and 1.0 takes the second place, and type C is the worst flow unit with the worst permeable property and intensity of water injection with FZI value less than 0.5. Among the three types of flow units, type A poorly develops, while type B and type C develops well. The research on flow units can provide reliable geologic bases for forecasting the distribution of remaining oil in extra-low permeability reservoirs and for developing remaining oil in the study area.

A Dynamic Discrete Fracture Model for Simulation of Tight Low-Permeability Reservoirs

2014 ◽  
Author(s):  
Zhengdong Lei ◽  
Changbing Tian ◽  
Fang Wang ◽  
Wenhuan Wang ◽  
Huanhuan Peng ◽  
...  
Keyword(s):  
Fracture Model ◽  
Low Permeability ◽  
Discrete Fracture Model ◽  
Discrete Fracture ◽  
Low Permeability Reservoirs

scholarly journals Development of an Efficient Embedded Discrete Fracture Model for 3D Compositional Reservoir Simulation in Fractured Reservoirs

SPE Journal ◽  
2013 ◽  
Vol 19 (02) ◽  
pp. 289-303 ◽  
Author(s):  
Ali Moinfar ◽  
Abdoljalil Varavei ◽  
Kamy Sepehrnoori ◽  
Russell T. Johns
Keyword(s):  
Fluid Flow ◽  
Oil Recovery ◽  
Fractured Reservoirs ◽  
Naturally Fractured Reservoirs ◽  
Fracture Model ◽  
Continuum Models ◽  
Fine Grid ◽  
Discrete Fracture Model ◽  
Discrete Fracture ◽  
Naturally Fractured

Summary Many naturally fractured reservoirs around the world have depleted significantly, and improved-oil-recovery (IOR) processes are necessary for further development. Hence, the modeling of fractured reservoirs has received increased attention recently. Accurate modeling and simulation of naturally fractured reservoirs (NFRs) is still challenging because of permeability anisotropies and contrasts. Nonphysical abstractions inherent in conventional dual-porosity and dual-permeability models make them inadequate for solving different fluid-flow problems in fractured reservoirs. Also, recent technologies for discrete fracture modeling may suffer from large simulation run times, and the industry has not used such approaches widely, even though they give more-accurate representations of fractured reservoirs than dual-continuum models. We developed an embedded discrete fracture model (DFM) for an in-house compositional reservoir simulator that borrows the dual-medium concept from conventional dual-continuum models and also incorporates the effect of each fracture explicitly. The model is compatible with existing finite-difference reservoir simulators. In contrast to dual-continuum models, fractures have arbitrary orientations and can be oblique or vertical, honoring the complexity of a typical NFR. The accuracy of the embedded DFM is confirmed by comparing the results with the fine-grid, explicit-fracture simulations for a case study including orthogonal fractures and a case with a nonaligned fracture. We also perform a grid-sensitivity study to show the convergence of the method as the grid is refined. Our simulations indicate that to achieve accurate results, the embedded discrete fracture model may only require moderate mesh refinement around the fractures and hence offers a computationally efficient approach. Furthermore, examples of waterflooding, gas injection, and primary depletion are presented to demonstrate the performance and applicability of the developed method for simulating fluid flow in NFRs.

scholarly journals Effect of brine-CO2 fracture flow on velocity and electrical resistivity of naturally fractured tight sandstones

Geophysics ◽  
2018 ◽  
Vol 83 (1) ◽  
pp. WA37-WA48 ◽  
Author(s):  
Mohammad Nooraiepour ◽  
Bahman Bohloli ◽  
Joonsang Park ◽  
Guillaume Sauvin ◽  
Elin Skurtveit ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Fluid Flow ◽  
P Wave ◽  
Low Permeability ◽  
Fracture Flow ◽  
Fracture Permeability ◽  
Geophysical Monitoring ◽  
Primary Fluid ◽  
Naturally Fractured ◽  
Matrix Flow

Fracture networks inside geologic [Formula: see text] storage reservoirs can serve as the primary fluid flow conduit, particularly in low-permeability formations. Although some experiments focus on the geophysical properties of brine- and [Formula: see text]-saturated rocks during matrix flow, geophysical monitoring of fracture flow when [Formula: see text] displaces brine inside the fracture seems to be overlooked. We have conducted laboratory geophysical monitoring of fluid flow in a naturally fractured tight sandstone during brine and liquid [Formula: see text] injection. For the experiment, the low-porosity, low-permeability, naturally fractured core sample from the Triassic De Geerdalen Formation was acquired from the Longyearbyen [Formula: see text] storage pilot at Svalbard, Norway. Stress dependence, hysteresis, and the influence of fluid-rock interactions on fracture permeability were investigated. The results suggest that in addition to stress level and pore pressure, mobility and fluid type can affect fracture permeability during loading and unloading cycles. Moreover, the fluid-rock interaction may impact volumetric strain and consequently fracture permeability through swelling and dry out during water and [Formula: see text] injection, respectively. Acoustic velocity and electrical resistivity were measured continuously in the axial direction and three radial levels. Geophysical monitoring of fracture flow revealed that the axial P-wave velocity and axial electrical resistivity are more sensitive to saturation change than the axial S-wave, radial P-wave, and radial resistivity measurements when [Formula: see text] was displacing brine, and the matrix flow was negligible. The marginal decreases of acoustic velocity (maximum 1.6% for axial [Formula: see text]) compared with the 11% increase in axial electrical resistivity suggest that in the case of dominant fracture flow within the fractured tight reservoirs, the use of electrical resistivity methods have a clear advantage compared with seismic methods to monitor [Formula: see text] plume. The knowledge learned from such experiments can be useful for monitoring geologic [Formula: see text] storage in which the primary fluid flow conduit is the fracture network.

Sign in / Sign up

Export Citation Format

Share Document