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Production performance analysis of fractured horizontal well in tight oil reservoir

Fig. 8 Log q/(Pi−Pwf) versus log time plot of simulated case 1

There main focuses of this study are in two aspects: (1) find out effective methods to estimate OOIPSRV for an individual MFHW in tight oil reservoir when there is only production data available and (2) study the relationship between productivity and fracturing network parameters (ω and λ) so as to

Analytical model for pressure and rate analysis of multi-fractured horizontal wells in tight gas reservoirs

Fig. 5 Transient pressure type curves of MFHW in tight gas reservoir

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

Effects of stress-dependent permeability on well performance of ultra-low permeability oil reservoir in China

Fig. 1 Permeability increment versus pore pressure or effective stress

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

Fig. 2 Structure of nanopores in organic material of shale formation. Reproduced with permission from (Zeng et al. 2017)

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

A numerical modeling framework is described that is able to calculate the coupled processes of fluid flow, geomechanics, and rock failure for application to general engineering problems related to reservoir stimulation, including 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

Fig. 21 3-D dynamic pressure depletion.

This result has been further compared with the help of MATLAB so as to obtain a complete pressure-derived model. The result shows the applicability of this in the real-life projects where it is difficult to model the fractures and obtain the flow rate with them in fractures and how to

A Comprehensive Prediction Model of Hydraulic Extended-Reach Limit Considering the Allowable Range of Drilling Fluid Flow Rate in Horizontal Drilling

Hydraulic extended-reach limit (HERL) model of horizontal extended-reach well (ERW) can predict the maximum measured depth (MMD) of the horizontal ERW. The HERL refers to the well’s MMD when drilling fluid cannot be normally circulated by drilling pump. Previous model analyzed the following two constraint conditions, drilling pump rated pressure and rated power. However, effects of the allowable range of drilling fluid flow rate (Qmin≤Q≤Qmax) were not considered. In this study, three cases of HERL model are proposed according to the relationship between allowable range of drilling fluid flow rate and rated flow rate of drilling pump (Qr). A horizontal ERW is analyzed to predict its HERL, especially its horizontal-section limit

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

In order to investigate the influence on shale gas well productivity caused by gas transport in nanometer-size pores, a mathematical model of multi-stage fractured horizontal wells in shale gas reservoirs is built, which considers the influence of viscous flow, Knudsen diffusion, surface diffusion, and adsorption layer thickness. A discrete-fracture model is used to simplify the fracture modeling, and a finite element method is applied to solve the model.

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 Lattice Boltzmann method can be used to study the flow field in the micropore spaces and then provides numerical solutions even in complex pore structure models. Understanding the transport characteristics and establishing a way to estimate potential gas flow is very important to guide shale gas reserve estimation and recovery schemes.

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

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

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

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

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 Duhamel’s theorem were used comprehensively to obtain the semianalytical solution.

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

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 and experimental measurements to probe the effect of fracture roughness on the properties of fluid flow in fractured rock. We develop a series of fracture models with various degrees of roughness characterized by fractal dimensions that are based on the Weierstrass– Mandelbrot fractal function. The Lattice Boltzmann Method (LBM), a discrete numerical algorithm, is employed for characterizing the complex unsteady non-Darcy flow through the single rough fractures and validated by experimental observations under the same conditions.

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

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 reservoir to investigate effect of matrix-wellbore flow, natural fracture porosity, and matrix porosity.

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

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