Use of pro scale simulatiors to understand the effects of wettability on miscible carbon dioxide flooding and injectivity

Uzun, İlkay
This study concentrates on the modelling of three phase flow and miscible CO2 flooding in pore networks that captures the natural porous medium of a reservoir. That is to say, the network, that is a Matlab code, consists of different sided triangles which are located randomly through the grids. The throats that connect the pores are also created by the model. Hence, the lengths and the radii of the throats are varying. The network used in this research is assumed to be representative of mixed-wet carbonates in 2-D. Mixed wettability arises in real porous media when oil renders surfaces it comes into prolonged contact with oil-wet while water-filled nooks and crannies remain water-wet. The model developed is quasi-static approach to simulate two phase and three phase flows. By this, capillary pressures, relative permeabilities, saturations, flow paths are determined for primary drainage, secondary imbibition, and CO2 injection cases. To calculate the relative permeability, capillary entry pressures are first determined. Then, hydraulic conductances and flow rates of the network for each grid are obtained. Phase areas and saturations are also determined. It is accepted that the displacement mechanism in drainage and CO2 injection is piston-like whereas in imbibition it is either piston-like or snap-off. The results of the model are compared with the experimental data from the literature. Although, the pore size distribution and the contact angle of the model are inconsistent with the experimental data, the agreement of the relative permeabilities is promising. The effect of contact angle in the same network for three phase flow where immiscible CO2 is injected as a third phase at supercritical temperature (32 °C) is investigated. And it is found that, the increase in the intrinsic angles causes decrease in relative permeability values. As another scenario, two phase


Fabrication and characterization of p-Si/n-ZnO heterostructured junctions
Klason, P.; Rahman, M. M.; Hu, Q. -H.; Nur, O.; Turan, Raşit; Willander, M. (Elsevier BV, 2009-04-01)
In this paper ZnO nanorods and nanodots (with and without a SiO2 buffer layer) were grown on p-Si, forming p-n heterojunctions. The nanorod devices showed no visible electroluminescence (EL) emission but showed rectifying behavior. Covering around 60% of the length of the nanorods with PMMA produced an ideality factor of 3.91 +/- 0.11 together with a reverse saturation current of 6.53 +/- 4.2 x 10(-8) A. Up to two orders of magnitude rectification was observed for the current at bias -3 and 3 V. The nanodot...
ONDER, M; Kuzuoğlu, Mustafa (Institution of Engineering and Technology (IET), 1992-10-01)
An optimisation approach is presented for the problem of reconstructing the permittivity and conductivity profiles of a dielectric slab from the reflected and transmitted field data. The problem is treated as an optimal control problem where the norm of the difference of measured and calculated boundary data is minimised subject to the state equation governing the system. The original constrained optimisation problem is reduced to the evaluation of stationary points of an augmented functional which is obtai...
An experimental study of residual fiber strains in Ti-15-3 continuous fiber composites
Pickard, S.M.; Miracle, D.B.; Majumdar, B.S.; Kendig, K.L.; Rothenflue, L.; Çöker, Demirkan (Elsevier BV, 1995-01-01)
A simplified experimental technique to determine the axial fiber residual strain in continuously-reinforced metal matrix composites is described. The residual fiber strains in two Ti-15V-3Cr-3Al-3Sn/SiC metal matrix composites have been measured with this technique. Residual fiber strains on the order of 0.2% are measured in the as-processed condition, and the residual stresses approach zero after testing the composite in tension to failure at room temperature. A conceptual description of the effect of tens...
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Fırat, Can Ersen; Tiğrek, Şahnaz; Department of Civil Engineering (2004)
The characteristics of the subcritical, critical and supercritical flows at the rectangular free overfall were studied experimentally to obtain a relation between the brink depth and the flow rate. A series of experiments were conducted in a tilting flume with wide range of flow rate and two bed roughness in order to find the relationship between the brink depth, normal depth, channel bed slope and bed roughnesses. An equation was proposed to calculate the flow rate if only the brink depth, roughness, and c...
A Five Layer One-Dimensional PEMFC Model with Detailed Electrode Kinetics
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In this study, a non-isothermal, two-phase, one-dimensional, and steady state proton exchange membrane (PEM) fuel cell model is developed to investigate the detailed electrode kinetics in the anode and cathode catalytic regions and the effects of these reaction mechanisms on the performance of a PEM fuel cell. Langmuir-Butler-Volmer (LBV) type reaction rate expressions are suggested for both anode and cathode electrochemical reactions. A two-phase energy balance approach is used to catch the thermal transpo...
Citation Formats
İ. Uzun, “Use of pro scale simulatiors to understand the effects of wettability on miscible carbon dioxide flooding and injectivity,” M.S. - Master of Science, Middle East Technical University, 2005.