Begell House Inc.
Journal of Porous Media
JPM
1091-028X
19
7
2016
ON NONEXISTENCE OF OSCILLATORY MOTIONS IN MAGNETOTHERMOHALINE CONVECTION IN POROUS MEDIUM
567-581
Jyoti
Prakash
Department of Mathematics and Statistics, Himachal Pradesh University, Summer Hill,
Shimla-171005, India
Sanjay Kumar
Gupta
Department of Mathematics, Himachal Pradesh University, Summer Hill, Shimla 171005, India
The present paper deals with the linear stability analysis of thermohaline convection in porous medium in the presence of a uniform vertical magnetic field and provides a classification of the neutral or unstable magnetothermohaline convection configuration of the Veronis type into two classes, namely, the bottom-heavy class and the top-heavy class, and then strikes a distinction between them by means of a characterization theorem which disallows the existence of oscillatory motions of neutral or growing amplitude in the former class whenever the thermohaline number is less than a critical value. It is further established that this result is uniformly valid for the quite general nature of the bounding surfaces. A similar characterization theorem is also proved for magnetothermohaline convection of the Stern type.
PERFORMANCE ANALYSIS MODEL FOR MULTISTAGE FRACTURING HORIZONTAL WELL IN SHALE GAS RESERVOIR BASED ON COUPLED MECHANISMS
583-601
Ya
Deng
Petro China Research Institute of Petroleum Exploration and Development, Beijing 100083,
China
Rui
Guo
PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083, China
Rongrong
Jin
PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083, China
Zhongyuan
Tian
PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083, China
Cong
Xiao
College of Petroleum Engineering, China University of Petroleum, Beijing 102249, China
Mingjin
Liu
School of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, China
Xiaowei
Sun
PetroChina Research Institute of Petroleum Exploration and Development, Beijing 100083, China
Not only can multistage fracturing horizontal well technology activate the natural fracture system defined as stimulated reservoir volume (SRV) but it can also connect the remaining region similarly defined as unstimulated reservoir volume (USRV). In this article, a new performance analysis model for multifractured horizontal wells considering coupled mechanisms, including desorption, viscous flow, stress sensitivity, and dual-depletion mechanisms, is established, originally based on the assumption that the SRV zone and USRV zone are simplified, respectively, as cubic triple-porosity and slab dual-porosity media. Different flow regimes can be identified using related type curves. The whole flow process can be divided into eight regimes: linear flow in SRV, bilinear flow, pseudo-elliptic flow, dual interporosity flow, transition flow, linear flow in USRV, pseudo-interporosity flow, and boundary-dominated flow. The stress sensitivity has a negative influence on the whole production period. The less the value of Langmuir volume and the larger the value of Langmuir pressure, the more late the interporosity flow and boundary-dominated flow occur. It is concluded that the USRV zone enhances production and cannot be ignored when the reservoir properties reach certain values. Numerical simulation and two real field cases are selected to validate the proposed new model and show promising application.
TWO-DIMENSIONAL PLANE STRAIN PROBLEM OF A GENERALIZED THERMOVISCOELASTIC SOLID WITH VOIDS UNDER THE INFLUENCE OF GRAVITY
603-616
Neelam
Hooda
Department of Mathematics, Guru Jambheshwar University of Science and Technology, Hisar-125001, Haryana, India
Sunita
Deswal
Guru Jambheshwar University of Science and Technology
In this work, a two-dimensional problem for a homogeneous, isotropic, thermally conducting viscoelastic half-space with voids and gravity field is solved. The surface of the half-space is taken to be traction free, and the temperature on it is specified. The formulation is applied under the purview of generalized thermoelasticity based on Green−Lindsay theory. Expressions for displacement components, stresses, temperature field, and change in volume fraction field are obtained for an isothermal boundary subjected to mechanical and thermal loads using a normal mode analysis technique. Effects of void, viscosity, and gravity on the field variables are shown graphically. Some particular cases of special interest have been deduced from the present investigation.
STEFAN BLOWING, NAVIER SLIP, AND RADIATION EFFECTS ON THERMO-SOLUTAL CONVECTION FROM A SPINNING CONE IN AN ANISOTROPIC POROUS MEDIUM
617-633
Mohammed Jashim
Uddin
School of Mathematical Sciences, Universiti Sains Malaysia, Penang 11800, Malaysia; Department of Mathematics, American International University-Bangladesh, Banani, Dhaka 1213, Bangladesh
O. Anwar
Bég
Fluid Mechanics, Nanosystems and Propulsion, Aeronautical and Mechanical Engineering,
School of Computing, Science and Engineering, Newton Building, University of Salford,
Manchester M54WT, United Kingdom
Tasveer A.
Beg
Engineering Mechanics Associates, Manchester, M16, England, United Kingdom
Thermal radiation features in many high-temperature materials processing operations. To evaluate the influence of radiative flux on spin coating systems, we consider herein the thermo-solutal (coupled heat and mass transfer) in steady laminar boundary layer natural convection flow from a rotating permeable vertical cone to an anisotropic Darcian porous medium. Surface slip effects are also included in the model presented. The conservation equations are rendered into self-similar form and solved as an ordinary differential two-point boundary value problem with surface and free stream boundary conditions using MAPLE 17 software. The transport phenomena are observed to be controlled by 10 parameters, namely, primary and secondary Darcy numbers (Dax and Daθ), rotational (spin) parameter (NR), velocity slip parameter (a), suction/injection parameter (S), thermal slip parameter (b), mass slip parameter (c), buoyancy ratio parameter (N), and conduction-radiation parameter (Rc). Tangential velocity and temperature are observed to be enhanced with greater momentum slip, whereas swirl velocity and concentration are reduced. Increasing swirl Darcy number strongly accelerates both the tangential and swirl flow and also heats the regime, whereas it decreases concentrations. Conversely, a rise in tangential Darcy number accelerates only the tangential flow and decelerates swirl flow, simultaneously depressing temperatures and concentrations. Increasing thermal slip accelerates the swirl flow and boosts concentration but serves to retard the tangential flow and decrease temperatures. With higher radiation contribution (lower Rc values), temperatures are elevated and concentrations are reduced. Verification of the MAPLE 17 solutions is achieved using a Keller box finite difference method (Tables 1 and 2). A number of interesting features in the thermo-fluid and species diffusion characteristics are addressed.
NUMERICAL SIMULATION OF COUNTERCURRENT SPONTANEOUS IMBIBITION OF CARBONATED WATER IN POROUS MEDIA
635-647
Mohsen
Abbaszadeh
School of Chemical, Petroleum and Gas Engineering, Semnan University, Semnan, Iran
Masoud
Nasiri
School of Chemical, Petroleum, and Gas Engineering, Semnan University, Semnan, Iran
Masoud
Riazi
Enhanced Oil Recovery (EOR) Research Center, School of Chemical and Petroleum Engineering, Shiraz University, Shiraz, Iran
Spontaneous imbibition is known as one of the main recovery driving forces in naturally fractured reservoirs. In this study, a numerical model to investigate the impact of carbonated water on oil recovery during spontaneous countercurrent imbibition is presented. This model includes the dynamic modification of oil viscosity, oil swelling, wettability, and interfacial tension. The results show that the injection of carbonated (CO2-enriched) water can improve water spontaneous imbibition rates as the system goes toward a more water-wet condition. The tertiary process also becomes more efficient as the remaining oil viscosity decreases. The results show that using the same relative permeability and capillary pressure data for simulation of both water and carbonated water displacements yields the system more quickly reaching the residual oil saturation in the carbonated water case, however, with the same ultimate oil recovery compared to that of the water case.
FREE, FORCED, AND MIXED CONVECTION IN A DARCY−BRINKMAN POROUS MEDIUM ALONG A VERTICAL ISOTHERMAL PLATE
649-657
Asterios
Pantokratoras
School of Engineering, Democritus University of Thrace, 67100 Xanthi, Greece
The characteristics of the boundary layer flow past a plane surface adjacent to a saturated Darcy-Brinkman porous medium are investigated in this article. The flow is driven by an external free stream moving with constant velocity and a buoyant force due to temperature difference. The surface temperature and the ambient temperature are constant. The flow is nonsimilar and is investigated numerically by a finite volume method. The free convection and the forced convection flows are governed by two nondimensional parameters, that is, the Prandtl number and the axial distance along the plate (different for the two cases), whereas the mixed convection flow is governed by an extra nondimensional parameter, which is a modified Grashof number. The influence of these parameters on the results is investigated and the results are presented in tables and figures. The free and forced convection flows were related to the corresponding magnetohydrodynamic flows. It was found that the mixed convection always tends to the forced convection state where some analytical solutions exist.