Inversion of reservoir fluid mobility from the frequency-dependent seismic data-a case study of gas-bearing reservoirs

The reservoir fluid mobility is by definition the ratio of rock permeability to fluid viscosity. This attribute can be applied to reservoir physical property and permeability evaluation. So far, the only means of obtaining the reservoir fluid mobility over a large range of exploration areas is based on the extraction method. However, the location of high fluid mobility obtained by the extraction method is close to the reservoir interface. To obtain the fluid mobility in the middle of the reservoir, an approximate inversion method of reservoir fluid mobility from frequency-dependent seismic data is proposed. Firstly, we calculate the reservoir fluid mobility coefficient using well data according to the relationship of fluid parameters. Then, we establish an inversion equation based on the low-frequency reflection coefficient and the reservoir fluid mobility. Taking the reservoir fluid mobility coefficient calculated from well data as a priori constraint, the low-frequency model is subsequently constructed and applied with the inversion equation to obtain an inversion objective function. Next, the inversion equation is solved by the basis pursuit algorithm. Finally, the proposed reservoir fluid mobility inversion method is applied to synthetic and real data of gas-bearing reservoirs. The real data processing results show that the proposed reservoir fluid mobility inversion method can estimate the fluid mobility in the actual position of the reservoir more effectively.

Chemical elements migration in water-travertin system (Tomsk region, Russia)

To assess the mobility of chemical elements in carbonate, formation processes have calculated the water migration coefficient -Kx and the geochemical mobility coefficient -Kn. The series of geochemical mobility were constructed. The elements that can be deposited and that can be accumulated in water have been distinguished. It is shown that anionic elements - Cl, S, Br, I, U, As, as well as elements such as Na, Mg, Mo, Zr well pass into solution from rocks and remain in the water. Elements such as Ca, Fe, Al, Mn, Si, Ba, Zn, Pb, Co, Hg, Ti, La, Ag, Sn, Cr are most fully deposited in travertines.

The Study of the Mobility Coefficient for Chain Aggregates in Quasi-Two-Dimensional Samples of Magnetic Fluids

The paper deals with the study of the mobility coefficients for the chain aggregates of different structures in quasi-two-dimensional magnetic fluids. Note that the quasi-two-dimensional samples contain rings also, not only chains, but this work is devoted to the investigation of the chain mobility only. We have used the Density Functional Theory to obtain the equilibrium concentrations for chain aggregates of different structures. When we know the concentrations we can obtain the mobility coefficients of chains.

Multiple finger propagation modes in Hele-Shaw channels of variable depth

We consider the propagation of an air finger into a wide fluid-filled channel with a spatially varying depth profile. Our aim is to understand the origin of the multiple coexisting families of both steady and oscillatory propagating fingers previously observed in experiments in axially uniform channels each containing a centred step-like occlusion. We find that a depth-averaged model can reproduce all the finger propagation modes observed experimentally. In addition, the model reveals new modes for symmetric finger propagation. The inclusion of a spatially variable channel depth in the depth-averaged equations leads to: (i) a variable mobility coefficient within the fluid domain due to variations in viscous resistance of the channel; and (ii) a variable transverse curvature term in the dynamic boundary condition that modifies the pressure jump over the air–liquid interface. We use our model to examine the roles of these two distinct effects and find that both contribute to the steady bifurcation structure, while the transverse curvature term is responsible for the distinctive oscillatory propagation modes.

Simulations of Anisotropic Grain Growth Subject to Thermal Gradients Using Q-State Monte Carlo

The Q-state Monte Carlo, Potts model is used to investigate 2D, anisotropic, grain growth of single-phase materials subject to temperature gradients. Anisotropy is simulated via the use of nonuniform grain boundary surface energies, and thermal gradients are simulated through the use of variable grain boundary mobilities. Hexagonal grain elements are employed, and elliptical Wulff plots are used to assign surface energies to grain lattices. The mobility is set to vary in accordance with solutions to a generalized heat equation and is solved for two separate values of the mobility coefficient. Among other findings, the results reveal that like isotropic grain growth, under the influence of a thermal gradient, anisotropic grain growth also demonstrates locally normal growth kinetics.

Application of Effective Potential Approach to Ion Dynamics Investigation in Field Asymmetric Ion Mobility Spectrometry Conditions

The theory of ion motion in field asymmetric ion mobility spectrometry (FAIMS) conditions has been developed on the bases of an effective field approach and applied to cylindrical and spherical geometries of FAIMS analyzers. The resulting analytical formulae relate compensation voltage to ion characteristics such as non-linear ion mobility coefficient, ion mobility and ion mass and charge. They permit taking into account ion inertia at small pressure of a buffer gas and at high ion mass.