Mhpm Solution to Mhd Fluid Flow Through Porous Medium with an Exponentially Variable Permeability

This article involves the study and analysis of the fully developed flow of a magnetorheological fluid through a non-isotropic porous medium under the effect of an external, uniform, and transversal magnetic field. Permeability is taken as an exponential distribution function of the transverse direction. The Darcy-Brinkman-Lapwood-Lorentz equation for the fluid flow in porous media has been used and solved under non-slip boundary conditions by Modified Homotopy Perturbation Method and the results validated by the Numerical Shooting Method. Finally, the analysis of results is made of the influence on the velocity, volumetric flow, and wall shear stress.

Flow of a Fluid with Pressure-Dependent Viscosity through Variable Permeability Porous Layer

In this work, we consider flow of a fluid with pressure-dependent viscosity down an inclined porous plane with variable permeability that is incorporated in the pressure-dependent drag coefficient. We provide a solution to a recently developed flow model, and study the effects of flow and domain parameters (viscosity control parameter, permeability proportionality constant, and angle of inclination) on the flow characteristics. Suitability of a variable permeability model that considers permeability proportional to the flow velocity is investigated. Results show that large values of the permeability proportionality constant have little or no effects on flow characteristics.

New Analytical Approach to Operational Assessment of Fractured Well Productivity with Variable Permeability

Requirements of targeted optimization are imposed on the hydraulic fracturing operations carried out in the conditions of borderline economic efficiency of fields taking into account geological and technological features. Consequently, the development of new analytical tools foranalyzing and planning the productivity of fractured wells, taking into account the structuralfeatures of the productive reservoir and inhomogeneous distribution of the fracture conductivity, is becoming highly relevant. The paper proposes a new approach of assessing the vertical hydraulic fracture productivityin a rectangular reservoir in a pseudo-steady state, based on reservoir resistivity concept described in the papers of Meyer et al. However, there is a free parameter in the case of modeling the productivity of a hydraulic fracture by the concept. The parameter describes the distribution of the inflow along the plane of the fracture. This paper presents a systematic approach to determining of the parameter. The resulting model allows to conduct an assessment of the influence of various complications in the fracture on the productivity index. During the research a method of determining the free parameter was developed,it was based on the obtained dependence of the inflow distribution on the coordinate along the fracture of finite conductivity. The methodology allowed to refine existent analytical solution of the Meyer et al. model, which, in turn, allowed to assess the influence of different fracture damages in the hydraulic fracture on the productivity index of the well. The work includes the cases of the presence of fracture damages at the beginning and at the end of the fracture. A hydraulic fracture model was built for each of the types of damages, it was based on the developed method, and also the solution of dimensionless productivity ratio was received. The results of the obtained solution were confirmed by comparison with the numerical solutions of commercial simulators and analytical models available in the literature. The advantage of the methodology is the resulting formulas for well productivity are relatively simple, even for exotic cases ofvariable conductivity fractures. The approaches and algorithms described in the paper assume the calculation of the productivity of a hydraulic fracture with variable conductivity and the presence of other complicatingfactors.The methodology of the paper can be used for analysis and diagnosis problems with formation hydraulic fracturing. The efficiency of the calculations allows using the presented methodology to solve inverse problems of determining the efficiency of the hydraulic fracturing operation.

Heat and mass transfer in a metal hydride reactor: combining experiments and mathematical modelling

Heat transfer in porous metal hydride (MH) beds determines efficiency of MH devices. We present a COMSOL Multiphysics numerical model and experimental investigation of heat and mass transfer in a MH reactor filled with 4.69 kg of AB5 type alloy (Mm0.8La0.2Ni4.1Fe0.8Al0.1). To achieve an agreement between the model and experiments it is necessary to include a flow control device (inlet valve or flow regulator) into the model. We propose a simplified and easy-to-calculate boundary condition based on a porous domain with variable permeability at reactor inlet. The permeability of the domain is connected with hydrogen mass flow by a PID controller. Thus, boundary conditions for the inlet pressure and mass flow are coupled and heat transfer inside the reactor could be calculated without additional assumptions applied to heat and mass transfer in the MH bed.

Fluid Mechanics at the Interface between a Variable Viscosity Fluid Layer and a Variable Permeability Porous Medium

Coupled parallel flow of fluid with pressure-dependent viscosity through an inclined channel underlain by a porous layer of variable permeability and variable thickness is initiated in this work. Conditions at the interface between the channel and the porous layer reflect continuity assumptions of velocity, shear stress, pressure and viscosity. Viscosity is assumed to vary in terms of a continuous pressure function that is valid throughout the channel and the porous layer. Model equations are cast in a form where the pressure as an independent variable and solutions are obtained to illustrate the effects of flow and media parameters on the dynamics behaviour of pressure-dependent viscosity fluid. A permeability and a viscosity adjustable control parameters are introduced to avoid unrealistic values of permeability and viscosity. This work could serve as a model for flow over a mushy zone.

An approach for modelling spatial variability in permeability of cement-admixed soil

This paper presents a framework for modelling the random variation in permeability in cement-admixed soil based on the binder content variation and thereby relating the coefficient of permeability to the unconfined compressive strength of a cement-admixed clay. The strength–permeability relationship was subsequently implemented in random finite element method (RFEM). The effects of spatial variation in both strength and permeability of cement-admixed clays in RFEM is illustrated using two examples concerning one-dimensional consolidation. Parametric studies considering different coefficient of variation and scale of fluctuation configurations were performed. Results show that spatial variability of the cement-admixed clay considering variable permeability can significantly influence the overall consolidation rate, especially when the soil strength variability is high. However, the overall consolidation rates also depend largely on the prescribed scales of fluctuation; in cases where the variation is horizontally layered, stagnation in pore pressure dissipation may occur due to soft parts yielding.

Fluid Mapping-While-Drilling De-Risks Reservoir and Fluid Data Acquisition Workflow in a Brown Field

Located offshore Malaysia, Field A is a highly complex elongated anticlinal structure with hundreds of faults. It includes over 70 hydrocarbon bearing sands deposited in a lower coastal plain environment. Producing since the late 1970s, Field A has gone through several asset rejuvenation plans. The latest one aimed at appraising and draining several untapped fault blocks. Although no major surprises were expected in terms of lithologies, uncertainties remained on fluids’ nature in multiple sands and on the possible isolation of the fault blocks. This paper illustrates how an operating company introduced a new while-drilling downhole formation fluid data acquisition workflow to successfully de-risk and address these challenges. Conventional formation evaluation is challenging in these fluvial environments, as it includes laminated reservoir, variable permeability, and presence of light, potentially saturated, hydrocarbons. Lessons learned from the previous rejuvenation campaign highlighted the importance of formation testing and downhole fluid analysis (DFA). The planned campaign required drilling two complex 3D profile wells (80-degree tangent followed by 35-degree drop through the targets). Pre-drill discussion raised various concerns: potential well control issues due to pumping light hydrocarbons in the borehole; sticking risk due to complex well trajectory and potential depletion; in-situ evaluation of CO2 for well deliverability analysis; and the number of logging runs, wiper, and post-drilling cleaning trips. In addition, the financial constraints on infill development called for the need of early, real-time enabled decisions for perforation and completion optimization. The selected drilling bottomhole assembly consisted of an integrated multi-physics logging-while-drilling toolstring including fluid mapping-while-drilling (FMWD) technology to de-risk the fluid acquisition program. The integration of pressures and DFA measurements with petrophysical data helped to identify and understand the distribution of fluids and fault blocks connectivity. The campaign proved to be very successful. All sand horizons were pressure tested, providing a fluid pressure profile description yielding gradients where applicable, differential pressure estimation, and connectivity information. The uncertainty associated with petrophysical fluid identification was addressed, and the use of FMWD showed no free gas in the tested zones. Fault block isolation was proven. Reservoir fluid and mobility profiling helped to optimize the well perforation and completion strategy and assess the producibility of the wells. The acquisition sequence was safely performed in one trip from bottom to top with no overpull observed. No wiper or post-drilling cleaning trips were required due to continuous mud circulation during data acquisition. This paper describes how this operating company successfully introduced a new while-drilling downhole formation fluid data acquisition workflow in a brown field. The workflow positively impacted the field development decisions. The FMWD de-risked data gathering operation under tight economical constraints and addressed formation evaluation and drilling and completion challenges during the evaluation of untapped blocks in Field A.