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  • Journal article
    de Wijn AS, Riesco N, Jackson G, Trusler JPM, Vesovic Vet al., 2012,

    Viscosity of liquid mixtures: The Vesovic-Wakeham method for chain molecules

    , JOURNAL OF CHEMICAL PHYSICS, Vol: 136, ISSN: 0021-9606
  • Journal article
    Hihinashvili R, Blumenfeld R, 2012,

    Statistical-mechanical characteristics of dense planar granular systems

    , Granular Matter

    We demonstrate the use of a structural and statistical characterisation method on two types of planar disc packs. One is a very dense pack of mean coordination number 5.20 and the other of mean coordination number 4.0. Except for constraining the mean coordination number in the latter one, the different pack types were constructed by the same deposition process and had the same disc size distribution, for a fair statistical comparison. We show that the two types converge to limit statistics and that these limit statistics are different. We analyse the limit statistics and compare between both types of packs, demonstrating that the differences are directly related to the difference in the mean coordination numbers. We then find quantitatively the difference between the (inverse) compactivities of the two pack types: 1/X_{5.2}−1/X_{4}=1.5\pm 0.05 . This explicit result supports strongly the validity of Edwards approach and underpins it as a useful tool to characterise granular systems quantitatively. In particular, it also paves the way to quantify the elusive compactivity.

  • Journal article
    Jackson MD, Vinogradov J, 2012,

    Impact of wettability on laboratory measurements of streaming potential in carbonates

    , COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, Vol: 393, Pages: 86-95, ISSN: 0927-7757
  • Journal article
    Blunt M, 2012,

    Editorial for the January 2012 Issue of Transport in Porous Media

    , TRANSPORT IN POROUS MEDIA, Vol: 91, Pages: 3-3, ISSN: 0169-3913
  • Journal article
    Iglauer S, Muggeridge A, 2012,

    TIME DEPENDENCE OF FREE FALL GRAVITY DRAINAGE IN UNCONSOLIDATED SAND

    , JOURNAL OF POROUS MEDIA, Vol: 15, Pages: 721-733, ISSN: 1091-028X
  • Journal article
    Latham JP, Xiang J, Belayneh M, Nick HM, Tsang C, Blunt MJet al., 2012,

    Modelling stress-dependent permeability in fractured rock including effects of propagating and bending fractures

    , International Journal of Rock Mechanics and Mining Sciences, Vol: 57, Pages: 100-112
  • Conference paper
    Latham J, Xiang J, Latham JP, Vire A, Anastasaki E, Pain CCet al., 2012,

    COUPLED FLUIDITY/Y3D TECHNOLOGY AND SIMULATION TOOLS FOR NUMERICAL BREAKWATER MODELLING.

    , 33rd International Conference on Coastal Engineering
  • Conference paper
    Zimmerman RW, Paluszny A, 2012,

    Some New Developments in Modelling the Failure, Fracture and Fragmentation of Rocks

    , Publisher: International Society for Rock Mechanics

    ABSTRACTIn this paper, several new developments regarding the failure, fracture and fragmentation of rocks will be discussed. The first topic discussed is the development of true-triaxial failure criteria that involve all three principal stresses. The next topic is a new approach to modelling the propagation of cracks and fractures using accurate local calculations of the stress intensity factor. Lastly, a method for fracture-driven rock fragmentation with a velocity-dependent propagation law is discussed.

  • Conference paper
    Paluszny A, Tang XH, Zimmerman RW, 2012,

    A Multi-modal Approach to 3D Fracture And Fragmentation of Rock Using Impulse-Based Dynamics And the Finite Element Method

    , Publisher: American Rock Mechanics Association

    ABSTRACT:A numerical method combining the finite element method (FEM) and impulse-based dynamics is proposed for the simulation of 3D fracture and fragmentation. As opposed to existing methods, fragments are not represented as a conglomeration of primitive shapes; instead, their geometry is represented using solid modeling techniques. This allows for continuum-mechanics-based fracture propagation analysis to be carried out within each fragment, with fragment interaction and movement simulated using impulse-based dynamics. This approach models multi-body interaction of non-convex 3D objects which fall, collide, and fragment using impulse-based dynamics, as opposed to a penalty-based method. Instead, object trajectories are used to estimate time-of-impact, and contact between bodies is modeled by collisions at contact locations. This approach allows material properties to be explicitly defined at the macro-scale. A 3D fracture engine models fracture propagation in the individual 3D continua based on local stress intensity factor measurements using the reduced virtual integration technique, as well as decoupled geometry and mesh representation, and on the evaluation of local failure and propagation criteria. Fractures that reach free boundaries lead to further fragmentation. The framework, presented as a multi-modal toolkit, is suitable for meso-scale simulations, and is demonstrated by a mining-specific block caving application. 1. INTRODUCTIONFragmentation simulation involves capturing two main processes: damage and cracking of single bodies, and dynamics/collision between fragments. The analysis of damage and cracking in single bodies includes challenges such as defining initial material properties and rock heterogeneities, crack nucleation, and propagation of multiple cracks. Modeling collisions between fragments includes capturing processes such as collision detection, force transfer due to impact and compression, and energy loss during collision. Challenges inclu

  • Journal article
    Cairns G, Jakubowicz H, Lonergan L, Muggeridge Aet al., 2012,

    Using time-lapse seismic monitoring to identify trapping mechanisms during CO2 sequestration

    , International Journal of Greenhouse Gas Control, Vol: 11, Pages: 316-325

    We show that it may be possible to distinguish between structurally- and capillary-trapped CO2 using time-lapse seismic monitoring of geological CO2 sequestration. Commercial reservoir simulation software was used to predict CO2 saturation in a saline aquifer over time. The output was combined with a rock physics model to calculate the elastic and seismic properties of the aquifer. As the seismic response depends on both fluid content and distribution, appropriate end-member fluid-distribution models were used to predict the possible range of seismic responses. We propose that different fluid-distribution models should be used for capillary- and structurally-trapped CO2 in a reservoir; the Hill average should be used for high, mobile CO2 saturations found during structural trapping whilst the Gassmann-Reuss average should be used for low, immobile CO2 saturations resulting from residual trapping. Far-offset seismic data was used to interpret reflections produced by the different trapping phases and cross-plotting was used to determine the trapping phase. Results indicate that structurally-trapped CO2 can be seismically imaged irrespective of fluid distribution and, importantly, a reflection may be generated off the interface between residually- and structurally-trapped CO2.

  • Journal article
    Jackson MD, Leinov E, 2012,

    On the Validity of the “Thin” and “Thick”Double-Layer Assumptions When CalculatingStreaming Currents in Porous Media

    , International Journal of Geophysics, Vol: 2012, ISSN: 1687-8868

    We find that the thin double layer assumption, in which the thickness of the electrical diffuse layer is assumed small comparedto the radius of curvature of a pore or throat, is valid in a capillary tubes model so long as the capillary radius is >200 times thedouble layer thickness, while the thick double layer assumption, in which the diffuse layer is assumed to extend across the entirepore or throat, is valid so long as the capillary radius is >6 times smaller than the double layer thickness. At low surface chargedensity (<10 mC · m−2) or high electrolyte concentration (>0.5 M) the validity criteria are less stringent. Our results suggest thatthe thin double layer assumption is valid in sandstones at low specific surface charge (<10 mC · m−2), but may not be valid insandstones of moderate- to small pore-throat size at higher surface charge if the brine concentration is low (<0.001 M). The thickdouble layer assumption is likely to be valid in mudstones at low brine concentration (<0.1 M) and surface charge (<10 mC·m−2),but at higher surface charge, it is likely to be valid only at low brine concentration (<0.003 M). Consequently, neither assumptionmay be valid in mudstones saturated with natural brines.

  • Journal article
    Lawal KA, Crawshaw JP, Boek ES, Vesovic Vet al., 2012,

    Experimental Investigation of Asphaltene Deposition in Capillary Flow

    , Energy & Fuels, Vol: 26, Pages: 2145-2153
  • Journal article
    Jackson MD, Butler AP, Vinogradov J, 2012,

    Measurements of Spontaneous Potential in Chalk with Application to Aquifer Characterisation in the Southern UK

    , Quarterly Journal of Engineering Geology and Hydrogeology
  • Journal article
    Jackson MD, Gulamali MY, Leinov E, Saunders JH, Vinogradov Jet al., 2012,

    Spontaneous Potentials in Hydrocarbon Reservoirs during Waterflooding: Application to Waterfront Monitoring

    , SPE Journal
  • Journal article
    Rashid B, Bal A-L, Williams GJJ, Muggeridge Aet al., 2012,

    Using vorticity to quantify the relative importance of heterogeneity, viscosity ratio, gravity and diffusion on oil recovery

    , Computational Geosciences: modeling, simulation and data analysis, Vol: 16, Pages: 409-422
  • Journal article
    Rashid B, Muggeridge A, Bal A-L, Williams GJJet al., 2012,

    Quantifying the impact of permeability heterogeneity on secondary recovery performance

    , SPE Journal
  • Journal article
    Muggeridge A, Mahmode H, 2012,

    Hydrodynamic aquifer or reservoir compartmentalization?

    , AAPG Bulletin, Vol: 96, Pages: 315-336
  • Journal article
    Tanino Y, Blunt MJ, 2012,

    Capillary trapping in sandstones and carbonates: dependence on pore structure

    , WATER RESOURCES RESEARCH, Vol: 48
  • Journal article
    Wong HS, Zimmerman RW, Buenfeld NR, 2012,

    Estimating the permeability of cement pastes and mortars using image analysis and effective medium theory

    , Cem. Concr. Res., Vol: 42, Pages: 476-483
  • Journal article
    El-Maghraby RM, Pentland CH, Iglauer S, Blunt MJet al., 2012,

    A fast method to equilibrate carbon dioxide with brine at high pressure and elevated temperature including solubility measurements

    , Journal of Supercritical Fluids, Vol: 62, Pages: 55-59
  • Conference paper
    Latham JP, Anastasaki E, Xiang J, 2012,

    A FEMDEM NUMERICAL MODEL STUDY OF RUBBLE-MOUND STRUCTURES ARMOURED WITH CONCRETE ARMOUR UNITS

  • Journal article
    Saunders JH, Jackson MD, Pain CC, Vinogradov Jet al., 2012,

    Streaming potentials in hydrocarbon reservoir conditions

    , Geophysics, Vol: 77, Pages: E77-E90
  • Journal article
    Go J, Smalley PC, Muggeridge A, 2012,

    Using reservoir mixing to evaluate reservoir compartmentalization from appraisal data – validation using data from the Horn Mountain field, Gulf of Mexico

    , Petroleum Geoscience, Vol: 18, Pages: 305-314
  • Journal article
    Sadeghnejad S, Masihi M, Pishvaie M, Shojaei A, King PRet al., 2011,

    Utilization of percolation approach to evaluate reservoir connectivity and effective permeability: A case study on North Pars gas field

    , SCIENTIA IRANICA, Vol: 18, Pages: 1391-1396, ISSN: 1026-3098
  • Journal article
    Babaei M, King PR, 2011,

    Water flooding simulation by an adaptive upscaling - Downscaling scheme

    , 16th European Symposium on Improved Oil Recovery 2011, Pages: 16-26

    The ever-increasing level of geological details and complexity of reservoir models have created computational difficulties for reservoir simulators so that upscaling of properties such as permeability have become common in petroleum industry. In an upscaling an averaging technique is implemented to capture equivalent values for coarser scales, however in presence of heterogeneity and subgrid complex features the averaging associates with numerical dispersion errors. Alternatively researchers developed algorithms that either involves enhancing computational speed and memory capacity or tries to solve a large scale problem in decomposable parts within efficient methods known as Multiscale. As an alternative to multiscale approach, we developed modified version of an upscaling downscaling method that mimics the behaviour of a reference solution of large model by addition of a post-processing step called nested-gridding downscaling to a correctional iterative upscaling method. In doing so, we devised spatial and temporal adaptivity in both upscaling and downscaling to remedy the shortcomings of a conventional upscaling method. Although not so exact as recently developed multiscale methods in convergence to fine solution, the comparable simplicity and robustness of the algorithm makes it desirable for practical simulation of flow where the main important output is recovery curves of engaging fluids in porous media. For comparison purposes we use pressure-solver upscaling method. We examined the performance of the methods on water flooding of highly heterogeneous porous media. By increasing the accuracy of upscaling, saturation errors decrease and consequently the production curves approach to the reference fine model. The implementation of adaptivity confirms the numerical efficiency compared to fine scale simulation, however, the time saving of conventional upscaling is several order higher than the scheme of interest.

  • Journal article
    Iglauer S, Wuelling W, Pentland CH, Al-Monsoori SK, Blunt MJet al., 2011,

    Capillary-Trapping Capacity of Sandstones and Sandpacks

    , SPE JOURNAL, Vol: 16, Pages: 778-783, ISSN: 1086-055X
  • Journal article
    Lawal KA, Vesovic V, Boek ES, 2011,

    Modeling Permeability Impairment in Porous Media due to Asphaltene Deposition under Dynamic Conditions

    , ENERGY & FUELS, Vol: 25, Pages: 5647-5659, ISSN: 0887-0624
  • Journal article
    Alajmi H, King PR, 2011,

    Numerical assessment of cold and hot-water floods for a heavy-oil sandstone reservoir in middle east

    , 16th European Symposium on Improved Oil Recovery 2011, Pages: 961-975

    A combination of growing energy demand and oil price has been stimulating interests in heavy oil (HO) resources and the methods of exploiting them. Hence, the primary objective of this study is to establish feasible development concepts, among proven technologies, for a heavy oil reservoir in the Middle East. Other objectives include understanding the physics of "selected" EOR methods, and developing a robust screening tool for sandstone HO resources. To accelerate decision-making, a relatively simple screening procedure has been developed and implemented. With this tool, less favourable options have been eliminated, keeping only the 'best' options for further evaluation. For preliminary numerical simulations, a homogenous, three-phase and multi-component numerical model was constructed using known (average) geological, petrophysical and fluid properties of the targeted sector of Reservoir 'X'. Several simulation runs were conducted, investigating the effects of petrophysical properties and operating variables on performances of cold and hot-water flood processes. Simulation results show that the positive impacts of thermal injection on oil production are not instantaneous - they only become noticeable after appreciable number of pore volumes injected. In addition to yielding higher ultimate recovery, the preliminary results also indicate that high-temperature operation accelerates performance.

  • Journal article
    Markicevic B, Bijeljic B, Navaz HK, 2011,

    Dynamics and stability of two-potential flows in the porous media

    , PHYSICAL REVIEW E, Vol: 84, ISSN: 1539-3755
  • Journal article
    Alkhatib AM, King PR, 2011,

    Applying real options theory in determining optimal policies for a surfactant flood

    , Society of Petroleum Engineers - SPE Enhanced Oil Recovery Conference 2011, EORC 2011, Vol: 2, Pages: 1139-1150

    Wide scale implementation of surfactant EOR faces many challenges mainly due to the uncertainty in field application. It is important to have the ability to manage this uncertainty to produce optimal implementation policies. This paper suggests the use of Real Options theory as a possible decision making and evaluation method in surfactant flooding. Real Option theory is based on the concepts of the options traded in stock markets applied to real projects. Real Options theory provides a dynamic framework to manage uncertainty and it also provides evaluation methods to produce quantifiable outputs. The Least Squares Monte Carlo (LSM) algorithm is the evaluation method used in this paper. The algorithm was applied using an example case based on a synthetic reservoir model. The option evaluated was that of finding the optimal time for starting the surfactant flood. It was assumed that the life of the reservoir was 10 years. The option decision nodes were chosen to be at the start of years 4, 5, 6 and 7. The analysis was performed using Schlumberger's ECLIPSE as the numerical simulator for the surfactant flood and a code was written in MATLAB to run the different simulations and the LSM algorithm. The LSM algorithm demonstrated that, at this basic level, it can produce an optimal policy for a specific option. It was found that most of the optimal surfactant flood starting-times were at year 6. This was mostly due to its proximity to the breakthrough time of the model which was during year 5. The optimal injection policies recommended achieved, on average, an increase in recovery efficiencies of 0.123, 0.147 and 0.141 for Cases 1, 2 and 3 respectively in contrast to the no-option scenario of initiating the surfactant flood at the start of the reservoir life (year 0). These values represent the value of the flexibility in initiating surfactant flooding. This method is being considered for more complex and realistic situations. Copyright 2011, Society of Petroleum Engineer

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