Model for treatment of oil reservoirs with polymer-dispersed systems

© 2015 Springer Science+Business Media New York. We present a new mathematical model for oil displacement by water from formations using polymer-dispersed systems. It is based on the classical two-phase filtration model: the Buckley-Leverett model. The closing relations are obtained using pore and particle size distribution functions. The model takes into account such effects as narrowing and blocking of pore channels as polymer particles move through them, and also mass exchange processes

Specific features of magnetic structure formation in orbitally degenerate BiMnO3 manganite

The orbital structure and magnetic ordering of the Jahn-Teller multiferroic BiMnO3 manganite have been theoretically studied. It is shown that the orbital structure depends not only on the nearest-neighbor oxygen environment of manganese ions, but also on their next-to-nearest neighbors. The orbital structure significantly influences the magnetic order that forms as a result of competition between ferromagnetic and antiferromagnetic exchange interactions. © 2013 Pleiades Publishing, Ltd

Simulation of heat treating the oil collector using acid exposure on near-Wellbore zone

The study deals with the problem of thermal exposure on the oil reservoir using acidizing of near-wellbore zone. There is a comparison of the oil recovery factor in cases of conventional water flooding, water flooding with the injection of coolant, water flooding with acid exposure and mixed technology. The obtained results show that the joint exposure of heat and acid treatment is the most effective mode of the oil recovery

Modelling waterflooding of layered oil reservoirs at nonlinear movement law

The model of waterflooding of three-layer oil reservoir saturated with oil having non-Newtonian properties is presented. The paper deals with numerical model of oil displacement by water with the law of movement of oil from the limiting gradient shift. It is modeled a flow of non-Newtonian fluid in a porous medium in variables 'velocity - saturation'. There is a comparison with a case when a limiting gradient of oil shear is neglected. It is shown that the final oil recovery factor will be thus essentially predatory

Integral circulant graphs of prime power order with maximal energy

The energy of a graph is the sum of the moduli of the eigenvalues of its adjacency matrix. We study the energy of integral circulant graphs, also called gcd graphs, which can be characterized by their vertex count n and a set D of divisors of n in such a way that they have vertex set Zn and edge set {{a, b} : a, b in Zn; gcd(a - b, n) in D}. Using tools from convex optimization, we study the maximal energy among all integral circulant graphs of prime power order ps and varying divisor sets D. Our main result states that this maximal energy approximately lies between s(p - 1)p^(s-1) and twice this value. We construct suitable divisor sets for which the energy lies in this interval. We also characterize hyperenergetic integral circulant graphs of prime power order and exhibit an interesting topological property of their divisor sets.Comment: 25 page

Modeling thermal treatment in combination with acid treatment of a multilayer oil reservoir

© 2015 Springer Science+Business Media New York. The problem of combined thermal and acid treatment in a multilayer crude-oil reservoir is examined for two-phase flows of fluid (water and crude oil) in a porous medium. A model in the form of a "bundle" of cylindrical capillaries of different radii is used to describe changes in the porosity and permeability of the porous medium as a result of chemical reaction between the acid and rock matrix, and the coalescence rate of the channels due to dissolution of pore walls is calculated based on the Smoluchowski equation. The recovery of crude oil in conventional flooding is compared with flooding with injection of a heat-transfer agent, and flooding using acid and the combination technology. It is shown that thermal treatment combined with acid treatment of a multilayer crude-oil formation provides the most effective oil production conditions

Periodic-Orbit Theory of Anderson Localization on Graphs

We present the first quantum system where Anderson localization is completely described within periodic-orbit theory. The model is a quantum graph analogous to an a-periodic Kronig-Penney model in one dimension. The exact expression for the probability to return of an initially localized state is computed in terms of classical trajectories. It saturates to a finite value due to localization, while the diagonal approximation decays diffusively. Our theory is based on the identification of families of isometric orbits. The coherent periodic-orbit sums within these families, and the summation over all families are performed analytically using advanced combinatorial methods.Comment: 4 pages, 3 figures, RevTe

SO(10) domain-wall brane models

We construct domain-wall brane models based on the grand-unification group SO(10), generalising the SU(5) model of Davies, George and Volkas. Motivated by the Dvali-Shifman proposal for the dynamical localisation of gauge bosons, the SO(10) symmetry is spontaneously broken inside the wall. We present two scenarios: in the first, the unbroken subgroup inside the wall is SU(5) x U(1)X, and in the second it is the left-right symmetry group SU(3) x SU(2)L x SU(2)R x U(1)B-L. In both cases we demonstrate that the phenomenologically-correct fermion zero modes can be localised to the wall, and we briefly discuss how the symmetry-breaking dynamics may be extended to induce breaking to the standard model group with subsequent electroweak breaking. Dynamically localised gravity is realised through the type 2 Randall-Sundrum mechanism.Comment: 16 pages, 2 figures A new section has been added on page 12. 3 new paragraphs have been added to the end of section (IV B) 'Localising Fermions' and 1 new paragraph has been added to section (IV C)'Adding Warped Gravity'. A new reference has been added to the bibliography at position [29]. The paper has been accepted in to Phys. Rev.

h analogue of Newton's binomial formula

In this letter, the $h$--analogue of Newton's binomial formula is obtained in the $h$--deformed quantum plane which does not have any $q$--analogue. For $h=0$, this is just the usual one as it should be. Furthermore, the binomial coefficients reduce to $\frac{n!}{(n-k)!}$ for $h=1$. \\ Some properties of the $h$--binomial coefficients are also given. \\ Finally, I hope that such results will contribute to an introduction of the $h$--analogue of the well--known functions, $h$--special functions and $h$--deformed analysis.Comment: 6 pages, latex Jounal-ref: J. Phys. A: Math. Gen. 31 (1998) L75

Effective Mass Dirac-Morse Problem with any kappa-value

The Dirac-Morse problem are investigated within the framework of an approximation to the term proportional to $1/r^2$ in the view of the position-dependent mass formalism. The energy eigenvalues and corresponding wave functions are obtained by using the parametric generalization of the Nikiforov-Uvarov method for any $\kappa$-value. It is also studied the approximate energy eigenvalues, and corresponding wave functions in the case of the constant-mass for pseudospin, and spin cases, respectively.Comment: 12 page