Aidarkhan Kaltayev

Numerical Modeling of the Effects of Disproportionate Permeability Reduction Water-Shutoff Treatments on Water Coning

In the present paper, we analyze numerically the disproportionate permeability reduction (DPR) water-shutoff (WSO) treatments in oil production well, i.e., the ability to reduce relative permeability (RP) to water more than to oil. The technique consists of bullhead injection of polymer solutions (gelant) into the near-wellbore formation without zone isolation. By assuming the low dissolution of polymer in oil and the low mobility of the gel in porous medium, we reduced the compositional model of the process to a simple twophase model, with RP and capillary pressure (PC) dependent on the water and gel saturation. We proposed the extension of the LET correlations used to calculate RP and PC for the case of three phases (oil–water–gel). The problem is divided into two stages: the polymer injection and the post-treatment production. Both of these processes are described by the same formal mathematical model, which results from incompressible two-phase flow equations formulated in terms of normalized saturation and global pressure. The thermal effects caused by the injection of a relatively cold aqueous solution are taken into account. The numerical solution shows favorable results for the DPR WSO treatments. Other techniques, such as the creation of impermeable barrier and downhole water sink (DWS) technology, are also tested in order to check the validity of the developed numerical model with experimental data. [DOI: 10.1115/1.4007913]

Theoretical and Numerical Prediction of the Permeability of Fibrous Porous Media

In this paper, the permeability of ordered fibrous porous media for normal flows is predicted theoretically and numerically. Moreover, microscopic velocity profiles in the “unit cell” are investigated in detail for normal flows. Porous material is represented by a “unit cell” which is assumed to be repeated throughout the media and 1D fibers are modeled. Fibers are presented as cylinders with the same radii. Planar flow that perpendicular to the axes of cylinders is considered in this paper. All numerical calculations are performed using Gerris program [6]. The quantitative comparison of numerical and theoretical results of computation of the permeability of ordered fibrous media is reasonably good and is about 10–15%.

Notice of Retraction Supersonic Flow with Perpendicular Injection of a Hydrogen

A computational fluid dynamics code for multispecies, Favre-Averaged Naveir-Stokes equations is developed to simulate the turbulent supersonic two-dimensional reacting flow. The explicit ENO scheme (third order of accuracy) has been used to solve the system of equations, and algebraic Baldwin-Lomaxs turbulence model to calculate the eddy viscosity coefficient. For the description of processes of reaction of hydrogen the seven chemical reactions Spurks mechanism is adopted. Computer code was validated by the solution of the two-dimensional chemically reacting supersonic hydrogen-air flow, where the main air flow was entering in the planar channel and hydrogen is injected perpendicularly from the slots of the walls. Influence of boundary conditions for the temperature on the walls on turbulent mixture is investigated.

Self-Organization Phenomena in Underground Hydrogen Storages

The problem of underground hydrogen gas mixture storage is that unlike natural gas, hydrogen gas mixture undergoes chemical changes in underground storage and thus the concentration of hydrogen and carbon dioxide is reduced, and the concentration of methane increases. It has been found that these changes occur because of the activity of methanogenic bacteria populations inhabiting in a reservoir. This chemical activity, which caused by the bacterial activity, as well as gas and water flow in the reservoir causes the phenomenon of self-organization such as the occurrence of autowave spatial structures, the dynamics of which is characterized by a multiplicity of different scenarios, including the occurrence of chaos and the jump from one scenario to another. In this paper we developed a qualitative theory of self-organization scenarios in the underground hydrogen storage depending on the external and internal parameters. Development of the theory and computer models of transport in underground hydrogen storage will be based on the relating of models of multiphase composite flows in porous media with model of dynamics of bacterial populations which will be based on mechanism of chemotaxis (internal chemical mechanism by which bacteria are able to detect the presence of nutrients in the distance and move in that direction).

Enhancement of the In-Situ Leach Mineral Mining Process by the Hydrodynamic Method

In this paper, a hydrodynamic method of enhancement of mineral extraction is numerically studied. Results of the preliminary performed computing and experimental data show that during the mineral extraction process a stagnation zone is formed in layer. Formation of the stagnation zone is caused by the absence of reagent flow in it. Such zones result in reduction of the degree of the deposit development. In this connection, there is a need to conduct research on improving the mineral extraction degree by controlling a seepage in a layer. Therefore, the hydrodynamic method is used to engage stagnation zones into the leaching process. The hydrodynamic method of enhancement based on changing reagent flow direction during the in-situ leach process by reversing the wells.