Fractal porosity and permeability were employed to describe the heterogeneous distribution of the complex fracture network. The stress sensitivity of fractures was also considered in the model. Pedrosa substitution and perturbation method were applied to eliminate the nonlinearity of the model. Analytical solutions in the Laplace domain were obtained using
Flow Mechanics
In Shale formations whit pores of nanometers sizes the interacting forces between the pore walls and the gas molecules are increasingly producing alterations in the flow behavior. As a result the flow classic theory doesn’t work appearing new transport mechanisms such as the Slip flow, transitional flow and Knudsen diffusion.
This category shows papers and researches explaining the new advances in understanding how the flow works in these nanopores and how we can model it.
Effects of stress-dependent permeability on well performance of ultra-low permeability oil reservoir in China
Several analytical simulations under the conditions of constant wellbore flowing pressure were performed to quantitatively assess the impact of stress sensitivity on single well performance. It is demonstrated that despite the stress-dependent permeability can have an adverse impact on production rate and recovery volume, it may be favorable for water
An analytical equation for oil transport in nanopores of oil shale considering viscosity distribution
Introduction Great pressure is laid on the energy supply with the rapid rising population (Lee 2011; Sun et al. 2017a, b, c, d, e, f, g, h, i, j; Sheikholeslami et al. 2018a, b, c). Besides, the rapid depletion of conventional petroleum and natural gas resources aggravates the seriousness of the
An embedded fracture modeling framework for simulation of hydraulic fracturing and shear stimulation
As fluid is exchanged between the two domains, conservation of mass is guaranteed through a coupling term that appears as a simple source term in the governing mass balance equations. In this manner, as new tensile fractures nucleate and propagate subject to mechanical effects, numerical complexities associated with the introduction
Modeling and simulation of gas flow behavior in shale reservoirs
A Comprehensive Prediction Model of Hydraulic Extended-Reach Limit Considering the Allowable Range of Drilling Fluid Flow Rate in Horizontal Drilling
Results show that when Qmin ≤Qr ≤Qmax (Case I), Lh depends both on horizontal-section limit based on rated pump pressure (Lh1 ) and horizontal-section limit based on rated pump power (Lh2 ); when Qmin < Q max < Qr (Case II), Lh is exclusively controlled by Lh1; while Lh is only determined by
Influence of gas transport mechanisms on the productivity of multi-stage fractured horizontal wells in shale gas reservoirs
The existence of an adsorption layer on the nanopore surfaces reduces the effective pore radius and the effective porosity, resulting in low production from fractured horizontal wells. With a decrease in the pore radius, considering the adsorption layer, the production reduction rate increases. When the pore radius is less than
Investigation of shale gas microflow with the Lattice Boltzmann method
The results show that net desorption, diffusion, and slip flow are very sensitive to the pore scale. Pore pressure also plays an important role in mass fluxes of gas. Temperature variations only cause small changes in mass fluxes. The Lattice Boltzmann method can be used to study the flow field
Study of Gas Flow Characteristics in Tight Porous Media with a Microscale Lattice Boltzmann Model
Abstract To investigate the gas flow characteristics in tight porous media, a microscale lattice Boltzmann (LB) model with the regularization procedure is firstly adopted to simulate gas flow in three-dimensional (3D) digital rocks. A shale digital rock and a sandstone digital rock are reconstructed to study the effects of pressure, temperature
Non-equilibrium dynamics of dense gas under tight confinement
Under ultra-tight confinement, the famous Knudsen minimum disappears, and the mass flow rate increases with Kn, and is larger than that predicted by the Boltzmann equation in the free-molecular flow regime; for a fixed Kn, the smaller L/σ is, the larger the mass flow rate. In the transitional flow regime,
Shale Gas Productivity Predicting Model and Analysis of Influence Factor
Abstract To know the dynamic characteristics of shale gas reservoirs’ production and to improve shale gas well production, it is very important to research on shale gas seepage mechanism and production evaluation. According to the shale gas seepage mechanism, adsorption and desorption characteristics, the diffusion mechanism and mass conservation theory in
Rate Transient Analysis for Multistage Fractured Horizontal Well in Tight Oil Reservoirs considering Stimulated Reservoir Volume
Abstract A mathematical model of multistage fractured horizontal well (MsFHW) considering stimulated reservoir volume (SRV) was presented for tight oil reservoirs. Both inner and outer regions were assumed as single porosity media but had different formation parameters. Laplace transformation method, point source function integration method, superposition principle, Stehfest numerical algorithm, and
Fractal model and Lattice Boltzmann Method for Characterization of Non-Darcy Flow in Rough Fractures
Abstract The irregular morphology of single rock fracture significantly influences subsurface fluid flow and gives rise to a complex and unsteady flow state that typically cannot be appropriately described using simple laws. Yet the fluid flow in rough fractures of underground rock is poorly understood. Here we present a numerical method
Effect of Matrix-Wellbore Flow and Porosity on Pressure Transient Response in Shale Formation Modeling by Dual Porosity and Dual Permeability System
Abstract A mathematical dual porosity and dual permeability numerical model based on perpendicular bisection (PEBI) grid is developed to describe gas flow behaviors in shale-gas reservoirs by incorporating slippage corrected permeability and adsorbed gas effect. Parametric studies are conducted for a horizontal well with multiple infinite conductivity hydraulic fractures in shale-gas
Numerical Simulation Research on Gas-Solid Two Phase Flow in Oil Shale Circulating Fluidized Bed
Numerical Simulation Research on Gas-Solid Two Phase Flow in Oil Shale Circulating Fluidized Bed Qing Wang1,Jun-tao Feng1,Bai-zhong Sun1,Yong-qing Qi2,Deng-feng Chen2,Jin-long Luo1 1.Northeast Dianli University, Jilin, Jilin Province, China-2. Daqing Oilfield Limited Company, Daqing City, Chin Abstract Oil shale circulating fluidized bed combustion technology is a new technology and it is the most economical and