Ahmad Kamal Idris

Effects of sonication radiation on oil recovery by ultrasonic waves stimulated water-flooding

Due to partial understanding of mechanisms involved in application of ultrasonic waves as enhanced oil recovery method, series of straight (normal), and ultrasonic stimulated water-flooding experiments were conducted on a long unconsolidated sand pack using ultrasonic transducers. Kerosene, vaseline, and SAE-10 (engine oil) were used as non-wet phase in the system. In addition, a series of fluid flow and temperature rise experiments were conducted using ultrasonic bath in order to enhance the understanding about contributing mechanisms. 3-16% increase in the recovery of water-flooding was observed. Emulsification, viscosity reduction, and cavitation were identified as contributing mechanisms. The findings of this study are expected to increase the insight to involving mechanisms which lead to improving the recovery of oil as a result of application of ultrasound waves.

Experimental study of the influence of silica nanoparticles on the bulk stability of SDS-foam in the presence of oil

ABSTRACT The influence of silica nanoparticles on the bulk stability of SDS-foam in the presence of oil was investigated in this study using KRÜSS dynamic foam analyzer. The bulk foam static stability was evaluated from half-decay time, liquid drainage, bubble size distribution, and change in total height and volume of the generated foams with respect to time. Results clearly showed that foam stability in the presence of oil mainly depends on the viscosity and density of the oil. Foam stability increased with the addition of silica nanoparticles due to the aggregation of the nanoparticles at the thin lamellae of the foam, which prevents spreading of the oil at the gas–liquid interface. Moreover, optimum foam stability was obtained with the modified nanosilica–SDS mixtures, while slower liquid drainage from the foam did not generally result in high foam stability. GRAPHICAL ABSTRACT

Calculation of Petrophysical Properties for Mishrif Carbonate Reservoir

The accurate calculations of petrophysical properties in carbonate reservoirs are the most challenging aspects of well log analysis. Many equations have been developed over the years based on known physical principles or on empirically derived relationships, which are used to calculate carbonate rock petrophysical properties. Carbonate reservoirs in the Middle East are very heterogeneous in terms of rock types. Therefore the reservoir should be split into layers on the basis of the dominant rock type in order to define average values and trends of petrophysical parameters in the reservoir rock. The saturation exponent (n) and cementation exponent (m) are calculated from well log data using Pickett method. The study made across the Mishrif carbonate formation, which is the shallowest formation of the hydrocarbon bearing zone in the NS oil field in the Middle East. Results show that the average formation water resistivity (Rw= 0.0243), average mud filtrate resistivity (Rmf= 0.199), Irreducible Water Saturat...

Using well logging data to predict permeability of a complex formation

One of the most challenging aspects of well log analysis is the accurate estimation of permeability in complex carbonate reservoirs. Permeability is predicted from many models by using well log data. Many correlations are developed over the years to calculate permeability based on known petrophysical properties or empirically derived relationships. The complex formation under study is Mishrif carbonate formation that is one of the shallowest hydrocarbons bearing zone in the Nasiriya oil field in the south of Iraq. The available scanned copies of well logs are digitalised by using Neurolog software. Schlumberger charts 2005 had been used for environmental corrections. These correction charts are supplied in the Interactive Petrophysics software. The Schlumberger K3 and Timur models have been used to estimate permeability of Mishrif carbonate formation. After making the environmental corrections, the porosity interpretation shows that the logging tools have a good quality of data reading. From Schlumberger and Timur models, the permeability of Mishrif formation is ranged from 6.25 to 25.21 and 5.95 to 26.81 respectively. This study was provided permeability with depth that is very important in the evaluation of the studied formation.

The use of artificial neural network to predict correlation of cementation factor to petrophysical properties in Yamamma formation

The cementation factor has specific effects on petrophysical properties in porous media. The accurate determination of this factor gives reliable saturation results and consequently hydrocarbon reserve calculations. Nasiriya oil field is the studied field, which is one of the giant oil fields in the south of Iraq. Five wells from NS-1 to NS-5 were studied wells. The study was made across Yamamma carbonate formation with depth interval from 3,156 m to 3,416 m. Environmental corrections had been made as per SLB charts 2005. Permeability, porosity, resistivity formation factor and cementation factor had been calculated using interactive petrophysical software. In this study, porosity, permeability and resistivity formation factor relationships to cementation factor were proposed using the artificial neural network model. This methodology provided very efficient performance and excellent prediction of cementation factor value with less than 10−4 mean square error (MSE). The results of this model showed that the cementation factor values ranged between 1.95 and 2.13. [Received: August 12, 2015; Accepted August 3, 2016]

Influence of Silicon Oxide and Aluminum Oxide Nanoparticles on Air and CO2 Foams Stability in Presence and Absence of Oil

One of the major issues in foam application for enhanced oil recovery (EOR) is the foam stability in presence and absence of oil. In this study, a systematic experimental study of the bulk and bubble scale stability of air and CO2 foams stabilised by sodium dodecyl sulphate (SDS) and nanoparticles were conducted. Foam-oil interactions were further study in etched glass micromodel in order to investigate and compare the foam performance at static and dynamic conditions. Influence of nanoparticles hydrophobicity and oil types on foam behaviors were assessed. Static bulk and bubble-scale experiments were conducted with KRUSS dynamic foam analyser while the flow characteristics experiments were conducted in etched glass porous medium. Results show that the foam half-life increased while the size of generated bubbles decreased with the presence of nanoparticles in the surfactant solution. Successful propagation of nanoparticles-SDS foam through capillary snap-off and lamellae division was observed in presence of oil in the porous medium. Foam stability decreases with decreasing oil viscosity and density. Except for hydrophobic aluminum oxide nanoparticles with contact angle of 118.19°, the static and dynamic stability of the air and CO2 foams increased with increasing nanoparticles hydrophobicity. The addition of nanoparticles into the surfactant solution considerably improved foam stability due to the adsorption and aggregation of the nanoparticles at the thin lamellae and plateau border. This prevents liquid drainage and film thinning by increasing film elasticity and film strength from 23.2 µm to 136µm. It can be concluded from this study, that stable air and CO2 foams can be generated with nanoparticles- surfactant mixed systems in absence and presence of oil with favourable nanoparticles hydrophobicity.

Attracting International Postgraduate Students: The Pulling Factors

A university has to carry out various marketing strategies and efforts to recruit international students as many as possible in order to fulfil one of the criteria for a world–class university status. However, to attract quality candidates with the desirable profile is becoming increasingly difficult especially when the university has to compete internationally and nationally with the existing and new emerging universities. This paper discusses the findings of a study carried out to establish the factors considered by international students before they decided to come to Universiti Teknologi Malaysia for their postgraduate studies. A total sample of 896 international students from various fields of studies for three different intakes was used in the study. The result shows that the main factors considered by them are the availability of the programme, reputation, the conduciveness of the campus environment for teaching and learning, and the location of the university. Most of them agreed that internet and education fairs or expositions are effective marketing medium for the recruitment of international students. This study provides an evidence–based framework to be considered by the University in formulating strategies and efforts to become a global player in higher education.