Analysis of models of oil-by-water displacement through the microstructure

Two major arrangements describing the oil-by-water displacement process, i.e., Muskat’s model without taking into account the surface tension on the free boundary and the Buckley-Leverett model based on the surface tension, are considered. These arrangements were subject to theoretical and numerical study, which made it possible to uncover their self-contradictorines

Mesoscopic dynamics of solid-liquid interfaces. A general mathematical model

A number of chemical and physical processes occur at interfaces where solids meet liquids. Among them is heap and in-situ leaching, an important technological process to extract uranium, precious metals, nickel, copper and other compound. To understand the main peculiarities of these processes a general mathematical approach is developed and applie

Simulation of geological faults with discrete element method

We present an algorithm for simulation of the Earth’s crust tectonic movements and formation of the geological faults and near-fault damage zones. The algorithms are based on the Discrete Elements Method, and it is implemented using CUDA technology. We used to simulate faults formation due to different scenarios of tectonic movements. We considered the displacements with dipping angles varied from 30 to 90 degrees; i.e., up to vertical throw. For each scenario, we performed simulations for some statistical realizations. To characterize the simulated faults and damage zones, we consider the strains distribution and apply data clustering and Karhunen-Loeve analysis to distinguish between different forms of the fault zones. In particular, clustering analysis shows that displacements with high and low dip angles form completely different geological structures. Nearly vertical displacements, high dip angles, form wide V-shaped deformation zones, whereas the at displacements cause narrow fault-cores with rapidly decreasing strains apart from the fault core. Results of the presented simulations can be used to estimate mechanical and seismic properties of rocks in the vicinity of the faults and applied further to construct models for seismic modeling and interpretation, hydrodynamical simulations, history of matching simulation, etc

Feasibility of time-lapse seismic methodology for monitoring the injection of small quantities of CO2 into a saline formation, CO2CRC Otway Project

A key objective of Stage 2 of the CO2CRC Otway Project is to explore the ability of geophysical methods to detect and monitor injection of greenhouse gas into a saline formation. For this purpose, injection of some 10,000 30,000 tonnes of CO2-rich mixture into the Paaratte formation, a saline aquifer located at a depth of about 1,400 m, is planned. Before such an injection experiment is undertaken, we assess the feasibility of geophysical monitoring using computer modelling. To examine the detectability of the plume we need to estimate the time-lapse signal and time- lapse noise. The time lapse signal is modelled using flow simulations, fluid substitution and seismic forward modelling. In order to assess the applicability of time-lapse seismic to monitor the injection, the predicted signal is compared to the time-lapse noise level from the recent 4D seismic survey acquired at the Otway site in 2009-2010. The methodology is applied to two alternative reservoir intervals located at a depth of 1392-1399 m and 1445-1465 m below the sea level, respectively. These intervals are considered to be the two possible options for the injection. The results show that injection into the lower interval will produce a plume of a larger thickness and smaller lateral extent, and a seismic response that is more likely to be detectable. The developed feasibility assessment workflow, and the results of its application to the Otway site, can be used to assess the ability of seismic methods to detect and monitor greenhouse gas leakage in other CCS projects

Inversion method for initial tsunami waveform reconstruction

This paper deals with the application of the <i>r</i>-solution method to recover the initial tsunami waveform in a tsunami source area by remote water-level measurements. Wave propagation is considered within the scope of a linear shallow-water theory. An ill-posed inverse problem is regularized by means of least square inversion using a truncated SVD (singular value decomposition) approach. The method presented allows one to control instability of the numerical solution and to obtain an acceptable result in spite of ill-posedness of the problem. It is shown that the accuracy of tsunami source reconstruction strongly depends on the signal-to-noise ratio, the azimuthal coverage of recording stations with respect to the source area and bathymetric features along the wave path. The numerical experiments were carried out with synthetic data and various computational domains including a real bathymetry

Analysis of models of oil-by-water displacement through the microstructure

Two major arrangements describing the oil-by-water displacement process, i.e., Muskat’s model without taking into account the surface tension on the free boundary and the Buckley-Leverett model based on the surface tension, are considered. These arrangements were subject to theoretical and numerical study, which made it possible to uncover their self-contradictorines

Mesoscopic dynamics of solid-liquid interfaces. A general mathematical model

A number of chemical and physical processes occur at interfaces where solids meet liquids. Among them is heap and in-situ leaching, an important technological process to extract uranium, precious metals, nickel, copper and other compound. To understand the main peculiarities of these processes a general mathematical approach is developed and applie

Parallel numerical simulation of wave propagation in 3D elastic medium with application of the Laguerre transform

Abstract. In this paper, we apply an approach for numerical simulation of elastic waves in heterogeneous mediu

Recovery of transport and geometrical properties of rock by statistical analysis of microtomographic images

We present numerical analysis of four microCT images of a Bentheimer outcrop sandstone sample acquired with different resolution. On the base of statistical analysis we show that the porosity and poretoskeleton distribution can be reliably obtained on samples of about 150 voxels with resolution coarser than 3 micrometers. In contrast, the statistically representative volume to determine complex properties such as permeability, tortuosity, or geometrical properties of the pore space may exceed 500 voxels and cannot be estimated reliably from conventional CT-scans. To overcome this difficulty we apply truncated Gaussian field technique for statistical simulation of images. We show that this technique allows to reproduce images with given porosity, pore-to-skeleton distribution, and permeability. However, geometrical properties of the simulated images do not match those of original CT-scans, and require higher-order statistics