Startseite Analytical modeling of coupled flow and geomechanics for vertical fractured well in tight gas reservoirs
Artikel Open Access

Analytical modeling of coupled flow and geomechanics for vertical fractured well in tight gas reservoirs

  • Ruifei Wang , Xuhua Gao , Hongqing Song EMAIL logo und Xinchun Shang
Veröffentlicht/Copyright: 29. Dezember 2017

Abstract

The mathematical model of coupled flow and geomechanics for a vertical fractured well in tight gas reservoirs was established. The analytical modeling of unidirectional flow and radial flow was achieved by Laplace transforms and integral transforms. The results show that uncoupled flow would lead to an overestimate in performance of a vertical fractured well, especially in the later stage. The production rate decreases with elastic modulus because porosity and permeability decrease accordingly. Drawdown pressure should be optimized to lower the impact of coupled flow and geomechanics as a result of permeability decreasing. Production rate increases with fracture half-length significantly in the initial stage and becomes stable gradually. This study could provide a theoretical basis for effective development of tight gas reservoirs.

1 Introduction

Nowadays, the demand for energy has greatly increased and conventional reservoirs cannot satisfy this situation [1, 2]. The tight gas reservoir, as one of important unconventional reservoirs, has a wide distribution worldwide and many major oil companies pay more and more attention to developing it [3, 4].

Geomechanics has a huge impact on tight gas exploitation due to ultra-low porosity and permeability [5]. In the period of tight gas extraction, the porosity and permeability decrease somewhat with pressure depletion in the tight gas reservoir. Coupled flow and geomechanics should be involved in the numerical simulation for tight gas reservoir development [6, 7].

There are two research aspects on coupled flow and geomechanics. On the one hand, many researchers and reservoir engineers utilize modified porosity and permeability to form analytical formula for simulation and evaluation in different conditions [8, 9]. For example, Wei proposed a triple-porosity/dual-permeability model, which considered the effective stress, gas slippage and micropore shrinkage/swelling [10]. Zheng proposed a two-part Hooke’s model to consider the geomechanical effects [11]. Wang incorporated the effects of geomechanics into permeability by considering its impact on pore throats [12]. This approach makes it easy to understand reservoir variations, and is useful for industry application. On the other hand, the researchers focus on conductivity of fractures with numerical simulations using the finite volume method (FVM), finite element method (FEM) and Newton method (NM), which uses the linear part of Taylor’s formula to solve nonlinear problems [13, 14]. Ren et al. proposed an extended finite element method-embedded discrete fracture model (XFEM-EDFM) and a proppant model to analyze the influence of stress-dependent fracture permeability on cumulative production [15]. Wei Yu studied and evaluated the effect of geomechanics on the stress-dependent fracture conductivity using FEM [16]. However, numerical simulation is more complicated and timeconsuming compared to the theoretical method, and the simulation results are unreliable because of the uncertainty of input parameters [17, 18].

Due to the ultra-low porosity and permeability, fracturing technology was widely utilized for tight gas reservoir development to enlarge controlled volume and increase porosity and permeability. At present, the commonly used extraction of natural gas from tight reservoirs adopts the technology of the fractured well, which includes the vertical fractured well and the horizontal fractured well. Compared with horizontal well fractured technology, the vertical fractured technology is more economical [19, 20, 21, 22].

In this paper, a new mathematical model of coupled flow and geomechanics for a vertical fractured well in tight gas reservoirs was initially established. In addition, the analytical modeling of unidirectional flow and radial flow was achieved by Laplace transforms and integral transforms. Moreover, the calculated results were compared with actual production data from the Sulige gas reservoir in China to verify the model. Finally, the influences of elastic modulus and half fracture length to well performances were analyzed. This study could provide a theoretical basis for effective development of tight gas reservoirs.

2 Mathematical models

2.1 Physical description for vertical fractured well

The flow patterns of a controlled area in the tight gas reservoir can be categorized into unidirectional flow in the middle area and radial flow in the rest of the area [23]. The sketch of a vertical well for tight gas production is shown in Figure 1. For gas flow, the initial pressure and constant outer boundary are both pe. The pressure of the fracture connected with the well maintains pw.

Figure 1 Sketch of vertical well for tight gas production
Figure 1

Sketch of vertical well for tight gas production

2.2 Mathematical models with coupled flow and geomechanics

2.2.1 Equation of stress

According to the principle of effective stress [24], the effective stress of the formation can be expressed as:

σij=σijαBpδij,(1)

where σij is the solid stress, p is the fluid pressure, αB is Biot’s coefficient, and δij is defined as when i = j, δij = 1 and when ij, δij = 0.

The strain-displacement relation is expressed as:

εij=12(ui,j+uj,i),(2)

where ui is the component of the displacement in the i direction.

The constitutive relationship of stress and strain can be expressed as:

σij=Ev(1+v)(12v)εkkδij+E(1+v)εij,(3)

where E is the elastic modulus, and v is Poisson’s ratio.

Without the body force, the momentum balance equation can be expressed as:

σji,j=0.(4)

Substituting (1)-(3) into (4), the equation of stress in terms of displacement can be derived as:

E2(1+v)(12v)(u)+E2(1+v)2uαBp=0(5)

2.2.2 Equation of seepage

When gas transports in the porous media, gas and solid particles both have speed. The velocity of the gas can be given as:

vg=vr+vs,(6)

where Vs is the absolute velocity of solid particles, vg is the absolute velocity of gas; vr is the relative velocity of them, namely, the Darcy velocity. According to definitions, the velocities mentioned can be given as:

vs=wt,vr=kμp.(7)

The continuity equation of the solid can be given as:

(ρsvs)+(ρs(1φ))t=0,(8)

where ρs is the density of the formation and is considered as constant, so (8) can be simplified as:

vsφt=0.(9)

The continuity equation of gas can be given as:

(ρgvg)+(ρgφ)t=0,(10)

where ρgis the gas density. Substituting (6) and (9) into (10), the following formula can be derived:

(ρgvr)+2ρgvs+vsρg+φρgt=0.(11)

Since vs is too small relative to vr, and neglecting 2ρgvs+vsρg, then the equation of seepage field can be given as:

(ρgvr)+φρgt=0.(12)

2.2.3 Equations of parameters

Vs, Vb, and Vp are used to represent the volume of solid skeleton, the whole volume of the formation, and the pore volume, respectively. And ΔVs, ΔVb, and ΔVp represent their increment, respectively. θ is the volumetric strain. According to the definition, the porosity of the formation can be expressed as:

φ=Vp+ΔVpVb+ΔVb=1Vs+ΔVsVb+ΔVb=1Vs(1+ΔVs/Vs)Vb(1+ΔVb/Vb)=11φ01+θ(1+ΔVs/Vs)(13)

It is assumed that the deformation of the formation is just caused by the recombination of the incompressible solid particles, thus ΔVs = 0, (13) can be simplified as:

φ=θ+φ01+θ.(14)

The cubic relationship [24] between permeability and porosity can be expressed as:

k=k0(φφ0)3.(15)

Gas state equation can be given as:

ρg=TscZscρgscpscpTZ,(16)

where φ0 is the initial porosity; ko is the initial permeability; T is the temperature, and Z is the compressibility factor; Tsc, Zsc, and psc represent the temperature, compressibility factor, and pressure at standard state, respectively.

3 Analytical solution

To derive an analytical solution of this mathematical model, we need to obtain the relationship between displacement and pressure first. For planar radial flow, (5) can be written as:

E(1v)(1+v)(12v)(d2urdr2+1rdurdrurr2)=αBdpdr,(17)

where Ur is the axisymmetric radial displacement. For planar unidirectional flow, (5) can be written as:

E(1v)(1+v)(12v)d2uxdx2=αBdpdx,(18)

where Ux is the displacement in the x direction.

Integrating on both sides of (17) and (18), we then obtain:

E(1v)(1+v)(12v)(durdr+urr)=αB(p+c)(19a)
E(1v)(1+v)(12v)duxdx=αB(p+c).(19b)

Considering θ equals dudr+ur in planar radial flow, and equals duxdx in planar unidirectional flow, (19) can be unified as:

E(1v)(1+v)(12v)θ=αB(p+c).(20)

Since the outer boundary is fixed, namely, θ equals 0 when r = re, thus c = −pe and the following formula can be derived:

θ=αB(1+v)(12v)E(1v)(ppe).(21)

Define m = (p+μDk)2 and substitute (7) and (16) into (12), then define ct=μφkp and pseudo time ta=cti0tdtct, we can obtain

2m=ctimta,(22)

where cti is the value in the initial condition.

For planar radial flow, (22) can be written as:

2mr2+1rmr=ctimta.(23)

Now equation (23) has a certain solution:

m(r,ta)=c1Eictir24ta+c2,(24)

where Ei is the exponential integral function and Ei(−x) = xettdt.

For planar unidirectional flow, (22) can be written as:

2mx2=ctimta.(25)

With Laplace transforms, defineL[m(x, ta)] = M(x, s), and (25) can be transformed into:

2M(x,s)x2=cti(sM(x,s)pe2).(26)

The solution of (26) can be easily derived:

M(x,s)=c3ectisx+c4ectisx+pe2s,(27)

where c3 and c4 are constant, which satisfy the following equations: c3+c4+pe2s=0c4=pe2s(1ectisre)M(re,s)ectisreectisre

Then m(r, ta) can be derived with Laplace inverse transforms:

m(r,ta)=L1[M(x,s)].(28)

4 Results and discussion

4.1 Validation

According to the established mathematical model of coupled flow and geomechanics for vertical fractured well, the simulation was carried out to describe coupled phenomenon.

Basic parameters from one of the actual wells in Sulige tight gas reservoir in China were picked up for simulation as follows: reservoir thickness 20m; fracture halflength 50m; wellbore radius 0.1m; drainage radius 1000m; permeability 0.2mD; porosity 6.5%; pressure at boundary 20MPa; bottom hole and artificial fracture pressure 6Mpa; reservoir temperature 383K; temperature at standard state 293K; gas viscosity 0.01mPa·s; elastic modulus 3GPa; Poisson’s ratio 0.2; and Biot’s coefficient 0.66.

Figure 2 is the comparison between simulation results and actual production data. The results show that the calculation results in terms of coupled flow and geomechanics have a good agreement with actual data from the Sulige gas reservoir in China and uncoupled flow would lead to overestimate the performance of the vertical fractured well especially in the later stage. This means that the present model and approximate analytical solution are more accurate than traditional approaches.

Figure 2 The comparison between simulation results and actual production data
Figure 2

The comparison between simulation results and actual production data

4.2 Elastic modulus

Figure 3 shows variations of porosity (a) and permeability (b) with different elastic modulus. Figure 4 shows variations in production rate and cumulative production with different elastic modulus. The results show that the production rate and cumulative production decrease with the decrease of elastic modulus. The elastic modulus has little effect on production rate after 3Gpa. When elastic modulus decreases, porosity and permeability decrease accordingly. So, the geomechanical effect should be taken into consideration for calculation and evaluation in tight gas reservoirs.

Figure 3 Variations of porosity (a) and permeability (b) with different elastic modulus
Figure 3

Variations of porosity (a) and permeability (b) with different elastic modulus

Figure 4 Variations of production rate and cumulative production with different elastic modulus
Figure 4

Variations of production rate and cumulative production with different elastic modulus

Figure 5 shows variations of permeability with different drawdown pressures. As shown, permeability decreases with drawdown pressure and the gap between the current permeability and the initial permeability becomes greater with the time. The drawdown pressure should be optimized to lower the impact of coupled flow and geomechanics.

Figure 5 Variations of permeability with different drawdown pressures
Figure 5

Variations of permeability with different drawdown pressures

4.3 Fracture half-length

The effect of the fracture half-length on production rate and cumulative production is studied considering the geomechanical effect (E = 3Gpa). Figure 6 shows production rate and cumulative production under different fracture half lengths. The results show that production rate increases with fracture half length. And the decline of production rate is fast in the initial stage, then it becomes stable gradually with the time.

Figure 6 Production rate and cumulative production under different fracture half lengths
Figure 6

Production rate and cumulative production under different fracture half lengths

5 Conclusion

We proposed the mathematical model of coupled flow and geomechanics for vertical fractured well in tight gas reservoirs. The analytical modeling of unidirectional flow and radial flow was achieved by Laplace transforms and integral transforms. The influences of elastic modulus and half fracture length to well performances were figured out.

The calculated results have a good agreement with actual production data from the Sulige gas reservoir in China, verifying the models. An uncoupled flow would lead to an overestimate in the performance of a vertical fractured well especially in the later stage. The production rate decreases with elastic modulus because porosity and permeability decreases accordingly. The geomechanical effect should be taken into consideration for calculation and evaluation in tight gas reservoirs. Drawdown pressure should be optimized to lower the impact of coupled flow and geomechanics as a result of permeability decrease. Production rate increases with fracture half-length significantly in the initial stage and becomes stable gradually. This study could a provide theoretical basis for effective development of tight gas reservoirs.

Acknowledgement

We gratefully acknowledge the PetroChina Innovation Foundation under Grant No. 2015D-5006-0106, the National Nature Science Foundations of China under Grant 51404024 and 51104119 for financial support. We also express gratitude to researchers of the Sulige Gas field for their cooperation.

References

[1] Clarkson C.R., Jensen J.L., Chipperfield S., Unconventional gas reservoir evaluation: What do we have to consider?, J. Nat. Gas Sci. Eng., 2012, 8(9), 9-33.10.1016/j.jngse.2012.01.001Suche in Google Scholar

[2] Zou C., Yang Z., Zhang G., Hou L., Zhu R., Tao S., Yuan X., Dong D., Wang Y., Guo Q., Conventional and unconventional petroleum “orderly accumulation”: Concept and practical significance, Petrol. Explor. Dev+, 2014, 41(1), 14-30.10.1016/S1876-3804(14)60002-1Suche in Google Scholar

[3] Jia C., Zhang Y., Zhao X., Prospects of and challenges to natural gas industry development in China, Nat. Gas Ind., 2014, 1(1), 1-13.10.1016/j.ngib.2014.10.001Suche in Google Scholar

[4] Yilmaz K., Umul B., Davis J., Nilson G., Tight gas development in the Mezardere Formation, Thrace Basin Turkey, J. Nat. Gas Sci. Eng., 2016, 33, 551-561.10.1016/j.jngse.2016.05.049Suche in Google Scholar

[5] Dou H., Zhang H., Yao S., Zhu D., Sun T., Shiying M.A., Wang X., Measurement and evaluation of the stress sensitivity in tight reservoirs, Petrol. Explor. Dev+, 2016, 43(6), 1116-1123.10.1016/S1876-3804(16)30130-6Suche in Google Scholar

[6] Yuan B., Wood D.A., Yu W., Stimulation and hydraulic fracturing technology in natural gas reservoirs: Theory and case studies (2012–2015), J. Nat. Gas Sci. Eng., 2015, 26(March), 1414-1421.10.1016/j.jngse.2015.09.001Suche in Google Scholar

[7] Kim T.H., Park K., Choi J., Lee K.S., Integrated reservoir flow and geomechanical model to generate type curves for pressure transient responses in shale gas reservoirs, 2015.10.1016/j.petrol.2016.06.001Suche in Google Scholar

[8] Tutuncu A.N., Bui B.T., A coupled geomechanics and fluid flow model for induced seismicity prediction in oil and gas operations and geothermal applications, J. Nat. Gas Sci. Eng., 2015, 29, 110-124.10.1016/j.jngse.2015.12.039Suche in Google Scholar

[9] Gao H., Li H.A., Pore structure characterization, permeability evaluation and enhanced gas recovery techniques of tight gas sandstones, J. Nat. Gas Sci. Eng., 2016, 28, 536-547.10.1016/j.jngse.2015.12.018Suche in Google Scholar

[10] Wei Z., Zhang D., Coupled fluid-flow and geomechanics for triple-porosity/dual-permeability modeling of coalbed methane recovery, Int. J. Rock Mech. Min., 2010, 47(8), 1242-1253.10.1016/j.ijrmms.2010.08.020Suche in Google Scholar

[11] Zheng J., Ju Y., Liu H.H., Zheng L., Wang M., Numerical prediction of the decline of the shale gas production rate with considering the geomechanical effects based on the two-part Hooke’s model, Fuel, 2016, 185, 362-369.10.1016/j.fuel.2016.07.112Suche in Google Scholar

[12] Wang H., Marongiu-Porcu M., Impact of shale gas apparent permeability on production: combined effects of non-Darcy flow/gas slippage, desorption, and geomechanics (SPE-173196-PA), Spe Reserv. Eval. Eng., 2015, 18(4), 495-507.10.2118/173196-PASuche in Google Scholar

[13] Kim J., Moridis G.J., Development of the T+M coupled flow-geomechanical simulator to describe fracture propagation and coupled flow-thermal-geomechanical processes in tight/shale gas systems, Comput. Geosci-Uk., 2013, 60, 184-198.10.1016/j.cageo.2013.04.023Suche in Google Scholar

[14] Han J., Wang J.Y., Puri V., A fully coupled geomechanics and fluid flow model for proppant pack failure and fracture conductivity damage analysis, J. Nat. Gas Sci. Eng., 2016, 31, 546-554.10.2118/168617-MSSuche in Google Scholar

[15] Ren G., Jiang J., Younis R.M., A fully coupled XFEM-EDFM model for multiphase flow and geomechanics in fractured tight gas reservoirs, Procedia Comput. Sci., 2016, 80, 1404-1415.10.1016/j.procs.2016.05.449Suche in Google Scholar

[16] Yu W., Sepehrnoori K., Simulation of gas desorption and geomechanics effects for unconventional gas reservoirs, Fuel, 2014, 116(1), 455-464.10.2118/165377-MSSuche in Google Scholar

[17] Yang D., Moridis G.J., Blasingame T.A., A fully coupled multiphase flow and geomechanics solver for highly heterogeneous porous media, J. Comput. Appl. Math., 2014, 270(270), 417-432.10.1016/j.cam.2013.12.029Suche in Google Scholar

[18] Ostojic J., Rezaee R., Bahrami H., Production performance of hydraulic fractures in tight gas sands, a numerical simulation approach, J. Petrol. Sci. Eng., 2012, 88–89(2), 75-81.10.1016/j.petrol.2011.11.002Suche in Google Scholar

[19] Soliman M.Y., Daal J., East L., Fracturing unconventional formations to enhance productivity, J. Nat. Gas Sci. Eng., 2012, 8(8), 52-67.10.1016/j.jngse.2012.01.007Suche in Google Scholar

[20] Wang H., Liao X., Lu N., Cai Z., Liao C., Dou X., A study on development effect of horizontal well with SRV in unconventional tight oil reservoir, J. Energy Inst., 2014, 87(2), 114-120.10.1016/j.joei.2014.03.015Suche in Google Scholar

[21] Lu D., Du X., Xu C., Analytical solutions to principle of effective stress, Chinese J. Geotec. Eng., 2013, 35, 146-151.Suche in Google Scholar

[22] Chen Z., Liao X., Zhao X., Zhu L., Liu H., Performance of multiple fractured horizontal wells with consideration of pressure drop within wellbore, J. Petrol. Sci. Eng., 2016, 146, 677-693.10.1016/j.petrol.2016.07.009Suche in Google Scholar

[23] Song H., Yu M., Zhu W., Wu P., Yu L., Wang Y., Killough J., Numerical investigation of gas flow rate in shale gas reservoirs with nanoporous media, Int. J. Heat Mass Tran., 2015, 80(4), 626-635.10.1016/j.ijheatmasstransfer.2014.09.039Suche in Google Scholar

[24] Liu J., Wang J., Chen Z., Wang S., Elsworth D., Jiang Y., Impact of transition from local swelling to macro swelling on the evolution of coal permeability, Int. J. Coal Geol., 2011, 88(1), 31-40.10.1016/j.coal.2011.07.008Suche in Google Scholar

Received: 2016-10-21
Accepted: 2017-9-20
Published Online: 2017-12-29

© 2017 R. Wang et al.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Artikel in diesem Heft

  1. Regular Articles
  2. Analysis of a New Fractional Model for Damped Bergers’ Equation
  3. Regular Articles
  4. Optimal homotopy perturbation method for nonlinear differential equations governing MHD Jeffery-Hamel flow with heat transfer problem
  5. Regular Articles
  6. Semi- analytic numerical method for solution of time-space fractional heat and wave type equations with variable coefficients
  7. Regular Articles
  8. Investigation of a curve using Frenet frame in the lightlike cone
  9. Regular Articles
  10. Construction of complex networks from time series based on the cross correlation interval
  11. Regular Articles
  12. Nonlinear Schrödinger approach to European option pricing
  13. Regular Articles
  14. A modified cubic B-spline differential quadrature method for three-dimensional non-linear diffusion equations
  15. Regular Articles
  16. A new miniaturized negative-index meta-atom for tri-band applications
  17. Regular Articles
  18. Seismic stability of the survey areas of potential sites for the deep geological repository of the spent nuclear fuel
  19. Regular Articles
  20. Distributed containment control of heterogeneous fractional-order multi-agent systems with communication delays
  21. Regular Articles
  22. Sensitivity analysis and economic optimization studies of inverted five-spot gas cycling in gas condensate reservoir
  23. Regular Articles
  24. Quantum mechanics with geometric constraints of Friedmann type
  25. Regular Articles
  26. Modeling and Simulation for an 8 kW Three-Phase Grid-Connected Photo-Voltaic Power System
  27. Regular Articles
  28. Application of the optimal homotopy asymptotic method to nonlinear Bingham fluid dampers
  29. Regular Articles
  30. Analysis of Drude model using fractional derivatives without singular kernels
  31. Regular Articles
  32. An unsteady MHD Maxwell nanofluid flow with convective boundary conditions using spectral local linearization method
  33. Regular Articles
  34. New analytical solutions for conformable fractional PDEs arising in mathematical physics by exp-function method
  35. Regular Articles
  36. Quantum mechanical calculation of electron spin
  37. Regular Articles
  38. CO2 capture by polymeric membranes composed of hyper-branched polymers with dense poly(oxyethylene) comb and poly(amidoamine)
  39. Regular Articles
  40. Chain on a cone
  41. Regular Articles
  42. Multi-task feature learning by using trace norm regularization
  43. Regular Articles
  44. Superluminal tunneling of a relativistic half-integer spin particle through a potential barrier
  45. Regular Articles
  46. Neutrosophic triplet normed space
  47. Regular Articles
  48. Lie algebraic discussion for affinity based information diffusion in social networks
  49. Regular Articles
  50. Radiation dose and cancer risk estimates in helical CT for pulmonary tuberculosis infections
  51. Regular Articles
  52. A comparison study of steady-state vibrations with single fractional-order and distributed-order derivatives
  53. Regular Articles
  54. Some new remarks on MHD Jeffery-Hamel fluid flow problem
  55. Regular Articles
  56. Numerical investigation of magnetohydrodynamic slip flow of power-law nanofluid with temperature dependent viscosity and thermal conductivity over a permeable surface
  57. Regular Articles
  58. Charge conservation in a gravitational field in the scalar ether theory
  59. Regular Articles
  60. Measurement problem and local hidden variables with entangled photons
  61. Regular Articles
  62. Compression of hyper-spectral images using an accelerated nonnegative tensor decomposition
  63. Regular Articles
  64. Fabrication and application of coaxial polyvinyl alcohol/chitosan nanofiber membranes
  65. Regular Articles
  66. Calculating degree-based topological indices of dominating David derived networks
  67. Regular Articles
  68. The structure and conductivity of polyelectrolyte based on MEH-PPV and potassium iodide (KI) for dye-sensitized solar cells
  69. Regular Articles
  70. Chiral symmetry restoration and the critical end point in QCD
  71. Regular Articles
  72. Numerical solution for fractional Bratu’s initial value problem
  73. Regular Articles
  74. Structure and optical properties of TiO2 thin films deposited by ALD method
  75. Regular Articles
  76. Quadruple multi-wavelength conversion for access network scalability based on cross-phase modulation in an SOA-MZI
  77. Regular Articles
  78. Application of ANNs approach for wave-like and heat-like equations
  79. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  80. Study on node importance evaluation of the high-speed passenger traffic complex network based on the Structural Hole Theory
  81. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  82. A mathematical/physics model to measure the role of information and communication technology in some economies: the Chinese case
  83. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  84. Numerical modeling of the thermoelectric cooler with a complementary equation for heat circulation in air gaps
  85. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  86. On the libration collinear points in the restricted three – body problem
  87. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  88. Research on Critical Nodes Algorithm in Social Complex Networks
  89. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  90. A simulation based research on chance constrained programming in robust facility location problem
  91. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  92. A mathematical/physics carbon emission reduction strategy for building supply chain network based on carbon tax policy
  93. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  94. Mathematical analysis of the impact mechanism of information platform on agro-product supply chain and agro-product competitiveness
  95. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  96. A real negative selection algorithm with evolutionary preference for anomaly detection
  97. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  98. A privacy-preserving parallel and homomorphic encryption scheme
  99. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  100. Random walk-based similarity measure method for patterns in complex object
  101. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  102. A Mathematical Study of Accessibility and Cohesion Degree in a High-Speed Rail Station Connected to an Urban Bus Transport Network
  103. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  104. Design and Simulation of the Integrated Navigation System based on Extended Kalman Filter
  105. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  106. Oil exploration oriented multi-sensor image fusion algorithm
  107. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  108. Analysis of Product Distribution Strategy in Digital Publishing Industry Based on Game-Theory
  109. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  110. Expanded Study on the accumulation effect of tourism under the constraint of structure
  111. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  112. Unstructured P2P Network Load Balance Strategy Based on Multilevel Partitioning of Hypergraph
  113. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  114. Research on the method of information system risk state estimation based on clustering particle filter
  115. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  116. Demand forecasting and information platform in tourism
  117. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  118. Physical-chemical properties studying of molecular structures via topological index calculating
  119. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  120. Local kernel nonparametric discriminant analysis for adaptive extraction of complex structures
  121. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  122. City traffic flow breakdown prediction based on fuzzy rough set
  123. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  124. Conservation laws for a strongly damped wave equation
  125. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  126. Blending type approximation by Stancu-Kantorovich operators based on Pólya-Eggenberger distribution
  127. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  128. Computing the Ediz eccentric connectivity index of discrete dynamic structures
  129. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  130. A discrete epidemic model for bovine Babesiosis disease and tick populations
  131. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  132. Study on maintaining formations during satellite formation flying based on SDRE and LQR
  133. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  134. Relationship between solitary pulmonary nodule lung cancer and CT image features based on gradual clustering
  135. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  136. A novel fast target tracking method for UAV aerial image
  137. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  138. Fuzzy comprehensive evaluation model of interuniversity collaborative learning based on network
  139. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  140. Conservation laws, classical symmetries and exact solutions of the generalized KdV-Burgers-Kuramoto equation
  141. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  142. After notes on self-similarity exponent for fractal structures
  143. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  144. Excitation probability and effective temperature in the stationary regime of conductivity for Coulomb Glasses
  145. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  146. Comparisons of feature extraction algorithm based on unmanned aerial vehicle image
  147. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  148. Research on identification method of heavy vehicle rollover based on hidden Markov model
  149. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  150. Classifying BCI signals from novice users with extreme learning machine
  151. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  152. Topics on data transmission problem in software definition network
  153. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  154. Statistical inferences with jointly type-II censored samples from two Pareto distributions
  155. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  156. Estimation for coefficient of variation of an extension of the exponential distribution under type-II censoring scheme
  157. Special issue on Nonlinear Dynamics in General and Dynamical Systems in particular
  158. Analysis on trust influencing factors and trust model from multiple perspectives of online Auction
  159. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  160. Coupling of two-phase flow in fractured-vuggy reservoir with filling medium
  161. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  162. Production decline type curves analysis of a finite conductivity fractured well in coalbed methane reservoirs
  163. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  164. Flow Characteristic and Heat Transfer for Non-Newtonian Nanofluid in Rectangular Microchannels with Teardrop Dimples/Protrusions
  165. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  166. The size prediction of potential inclusions embedded in the sub-surface of fused silica by damage morphology
  167. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  168. Research on carbonate reservoir interwell connectivity based on a modified diffusivity filter model
  169. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  170. The method of the spatial locating of macroscopic throats based-on the inversion of dynamic interwell connectivity
  171. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  172. Unsteady mixed convection flow through a permeable stretching flat surface with partial slip effects through MHD nanofluid using spectral relaxation method
  173. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  174. A volumetric ablation model of EPDM considering complex physicochemical process in porous structure of char layer
  175. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  176. Numerical simulation on ferrofluid flow in fractured porous media based on discrete-fracture model
  177. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  178. Macroscopic lattice Boltzmann model for heat and moisture transfer process with phase transformation in unsaturated porous media during freezing process
  179. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  180. Modelling of intermittent microwave convective drying: parameter sensitivity
  181. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  182. Simulating gas-water relative permeabilities for nanoscale porous media with interfacial effects
  183. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  184. Simulation of counter-current imbibition in water-wet fractured reservoirs based on discrete-fracture model
  185. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  186. Investigation effect of wettability and heterogeneity in water flooding and on microscopic residual oil distribution in tight sandstone cores with NMR technique
  187. Special Issue on Advances on Modelling of Flowing and Transport in Porous Media
  188. Analytical modeling of coupled flow and geomechanics for vertical fractured well in tight gas reservoirs
  189. Special Issue on Ever-New "Loopholes" in Bell’s Argument and Experimental Tests
  190. Special Issue: Ever New "Loopholes" in Bell’s Argument and Experimental Tests
  191. Special Issue on Ever-New "Loopholes" in Bell’s Argument and Experimental Tests
  192. The ultimate loophole in Bell’s theorem: The inequality is identically satisfied by data sets composed of ±1′s assuming merely that they exist
  193. Special Issue on Ever-New "Loopholes" in Bell’s Argument and Experimental Tests
  194. Erratum to: The ultimate loophole in Bell’s theorem: The inequality is identically satisfied by data sets composed of ±1′s assuming merely that they exist
  195. Special Issue on Ever-New "Loopholes" in Bell’s Argument and Experimental Tests
  196. Rhetoric, logic, and experiment in the quantum nonlocality debate
  197. Special Issue on Ever-New "Loopholes" in Bell’s Argument and Experimental Tests
  198. What If Quantum Theory Violates All Mathematics?
  199. Special Issue on Ever-New "Loopholes" in Bell’s Argument and Experimental Tests
  200. Relativity, anomalies and objectivity loophole in recent tests of local realism
  201. Special Issue on Ever-New "Loopholes" in Bell’s Argument and Experimental Tests
  202. The photon identification loophole in EPRB experiments: computer models with single-wing selection
  203. Special Issue on Ever-New "Loopholes" in Bell’s Argument and Experimental Tests
  204. Bohr against Bell: complementarity versus nonlocality
  205. Special Issue on Ever-New "Loopholes" in Bell’s Argument and Experimental Tests
  206. Is Einsteinian no-signalling violated in Bell tests?
  207. Special Issue on Ever-New "Loopholes" in Bell’s Argument and Experimental Tests
  208. Bell’s “Theorem”: loopholes vs. conceptual flaws
  209. Special Issue on Ever-New "Loopholes" in Bell’s Argument and Experimental Tests
  210. Nonrecurrence and Bell-like inequalities
  211. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  212. Three-dimensional computer models of electrospinning systems
  213. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  214. Electric field computation and measurements in the electroporation of inhomogeneous samples
  215. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  216. Modelling of magnetostriction of transformer magnetic core for vibration analysis
  217. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  218. Comparison of the fractional power motor with cores made of various magnetic materials
  219. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  220. Dynamics of the line-start reluctance motor with rotor made of SMC material
  221. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  222. Inhomogeneous dielectrics: conformal mapping and finite-element models
  223. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  224. Topology optimization of induction heating model using sequential linear programming based on move limit with adaptive relaxation
  225. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  226. Detection of inter-turn short-circuit at start-up of induction machine based on torque analysis
  227. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  228. Current superimposition variable flux reluctance motor with 8 salient poles
  229. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  230. Modelling axial vibration in windings of power transformers
  231. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  232. Field analysis & eddy current losses calculation in five-phase tubular actuator
  233. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  234. Hybrid excited claw pole generator with skewed and non-skewed permanent magnets
  235. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  236. Electromagnetic phenomena analysis in brushless DC motor with speed control using PWM method
  237. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  238. Field-circuit analysis and measurements of a single-phase self-excited induction generator
  239. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  240. A comparative analysis between classical and modified approach of description of the electrical machine windings by means of T0 method
  241. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  242. Field-based optimal-design of an electric motor: a new sensitivity formulation
  243. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  244. Application of the parametric proper generalized decomposition to the frequency-dependent calculation of the impedance of an AC line with rectangular conductors
  245. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  246. Virtual reality as a new trend in mechanical and electrical engineering education
  247. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  248. Holonomicity analysis of electromechanical systems
  249. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  250. An accurate reactive power control study in virtual flux droop control
  251. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  252. Localized probability of improvement for kriging based multi-objective optimization
  253. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  254. Research of influence of open-winding faults on properties of brushless permanent magnets motor
  255. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  256. Optimal design of the rotor geometry of line-start permanent magnet synchronous motor using the bat algorithm
  257. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  258. Model of depositing layer on cylindrical surface produced by induction-assisted laser cladding process
  259. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  260. Detection of inter-turn faults in transformer winding using the capacitor discharge method
  261. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  262. A novel hybrid genetic algorithm for optimal design of IPM machines for electric vehicle
  263. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  264. Lamination effects on a 3D model of the magnetic core of power transformers
  265. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  266. Detection of vertical disparity in three-dimensional visualizations
  267. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  268. Calculations of magnetic field in dynamo sheets taking into account their texture
  269. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  270. 3-dimensional computer model of electrospinning multicapillary unit used for electrostatic field analysis
  271. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  272. Optimization of wearable microwave antenna with simplified electromagnetic model of the human body
  273. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  274. Induction heating process of ferromagnetic filled carbon nanotubes based on 3-D model
  275. Special Issue: The 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering ISEF 2017
  276. Speed control of an induction motor by 6-switched 3-level inverter
Heruntergeladen am 11.9.2025 von https://www.degruyterbrill.com/document/doi/10.1515/phys-2017-0093/html
Button zum nach oben scrollen