Assessment of the types of public building maintenance contracts in Saudi Arabia

The study revealed that Fixed Price, Cost Plus and Purchased Labour contracts are the top three maintenance contracts adopted whilst Unit Price, Cost Plus A Percentage Fee contracts are alternatives used in the Kingdom. Some other types of maintenance contract were thought to be inappropriate by ministry departments.     

Attitudes towards mobile banking: are there any differences between users and non-users?

Extant research has focused on monitoring the behaviour of people who use mobile banking (MB) but it has paid little attention to understanding the impact of information technology usage behaviour due to cultural differences. Humans are the weakest link in information technology adoption; past research has shown that not all users are predisposed to change their behaviour radically and adopt new channels of banking. This paper examines the demographic patterns of users and non-users of MB. The paper also investigates the attitudinal influences of users and non-users of MB based on innovation attributes. Using empirical research, the study identifies constructs of innovation attributes that were perceived to be significantly different among the users and non-users of MB. The study provides valuable insights into MB in Saudi Arabia that have not been previously investigated. From a practical point, findings of this study will be particularly useful to banks, financial institutions and telecommunication service providers.     

Preliminary investigation for the production of wet-process phosphoric acid from Saudi phosphate ores

This paper represents the first published report of a preliminary investigation of the possibility of using Saudi phosphate ores for the production of wet-process phosphoric acid.     

Thermodynamics of ionic-association in aqueous solutions of Ca and Mg organic salts using ion-selective electrode technique—II. benzoate, o-toloate, o-chlorobenzoate and salycylate

The stoichiometric association constants, K, the thermodynamic association constant, K_A, and the other thermodynamic parameters such as ΔS°, ΔH° and ΔG° for the association between each of the Ca and Mg ions with benzoate, o-toloate, o-chlorobenzoate and salycylate have been determined at 25°C, 35°C and 45°C in aqueous media. Ion-selective electrode technique has been used in the measurements of Ca and Mg ion activitiesThe trend of association behavior of both Ca and Mg aromatic salts could not be explained on the basis of pK_a of the mother organic acids but could be explained based on the trend of Hammet function σ of these salts themselves relative to the corresponding benzoate salt.     

Subtractive Clustering-Based K-means Technique for Determining Optimum Time-of-Day Breakpoints

In many countries, the most widely used method for timing plan selection and implementation is the time-of-day (TOD) method. In TOD mode, a few traffic patterns that exist in the historical volume data are recognized and used to find the signal timing plans needed to achieve optimum performance of the intersections during the day. Traffic engineers usually determine TOD breakpoints by analyzing 1 or 2?days worth of traffic data and relying on their engineering judgment. The current statistical methods, such as hierarchical and K-means clustering methods, determine TOD breakpoints but introduce a large number of transitions. This paper proposes adopting the Z-score of the traffic flow and time variable in the K-means clustering to reduce the number of transitions. The numbers of optimum breakpoints are chosen based on a microscopic simulation model considering a set of performance measures. By using simulation and the K-means algorithm, it was found that five clusters are the optimum for a major arterial in Al-Khobar, Saudi Arabia. As an alternative to the simulation-based approach, a subtractive algorithm-based K-means technique is introduced to determine the optimum number of TODs. Through simulation, it was found that both approaches results in almost the same values of measure of effectiveness (MOE). The proposed two approaches seem promising for similar studies in other regions, and both of them can be extended for different types of roads. The paper also suggests a procedure for considering the cyclic nature of the daily traffic in the clustering effort.     

DEPOSITIONAL AND DIAGENETIC BARRIERS,BAFFLES AND CONDUITS: PERMIAN – CARBONIFEROUS UNAYZAH RESERVOIR,NUAYYIM FIELD,CENTRAL SAUDI ARABIA

The Unayzah Formation is one of the most important Palaeozoic reservoir systems in Saudi Arabia. In the Nuayyim field, Central Saudi Arabia, it produces light, sweet crude oil and consists of three main reservoir units, in descending stratigraphic order: Unayzah A, B and C. These reservoir units include a wide range of depositional facies deposited under a variety of climatic conditions, from high‐latitude glacio‐fluvial to more temperate playa/lacustrine, floodplain and braided‐fluvial to hot‐arid aeolian environments. Together with the diagenetic changes superimposed on the various depositional facies, this has produced complex reservoir heterogeneity. The effects of this diagenetic and sedimentologic complexity on reservoir quality and compartmentalization are the subject of this paper. Approximately 816 ft of core and 611 core plug samples were examined from three wells which penetrate, completely or in part, the Unayzah reservoir. We combine petrographic and scanning electron microscope analysis with porosity and permeability data and calculated pore throat dimensions to identify fluid conduits, barriers and baffles to fluid flow. A rock classification scheme is proposed which takes into account whether the pore‐level control on fluid flow is due to depositional or diagenetic processes and the composition of depositional or diagenetic phases within the pores. Distinguishing depositional versus diagenetic controls on fluid flow is important for predicting the three‐dimensional geometry of conduits, barriers and baffles, and a priori knowledge of potential reactions between injected fluids and reservoir rocks is important for designing enhanced oil recovery fluids. In the three wells studied, it appears that the Unayzah reservoir is compartmentalized vertically due to the occurrence of diagenetic and depositional barriers and baffles. There is insufficient data to assess the lateral or areal extent of the barriers, baffles and fluid conduits, but the understanding of pore‐level controls on reservoir quality and the rock classification schemes introduced here will provide a starting point for future studies. These studies should combine well logs, seismic and engineering data with data presented here to assist mapping conduits, barriers and baffles across the field. The proposed classification schemes may also prove to be useful for assessing reservoirs in other fields both within Saudi Arabia and elsewhere.     

MINERALOGICAL, PORE AND PETROPHYSICAL CHARACTERISTICS OF THE DEVONIAN JAUF SANDSTONE RESERVOIR, HAWIYAH FIELD, EASTERN SAUDI ARABIA

Throughout the subsurface of the Arabian Peninsula, the approximately 460ft thick, Devonian Jauf Formation generally consists of well-compacted, low-porosity sandstones and shales, but it also includes friable and highly porous sandstones which form significant gas and condensate reservoir intervals. The mineralogy and pore properties of these reservoir intervals at the Hawiyah field (part of the giant Ghawar structure) were studied by integrating petrographic data with petrophysical measurements of reservoir sandstone samples.
The reservoir sandstones are mainly composed of quartz arenites containing small amounts of altered potassium feldspar grains, authigenic illite and chlorite. Based on the pore types, which reflect the habits of the intergranular clays, three reservoir sandstone types have been defined: Type A, characterized by macroporosity; Type B, with microporosity; and Type C, with combined laminations of Types A and B. The dominance of pore-lining clay (as in Type A) or pore-filling clay (as in Type B) is the principal factor controlling the petrophysical properties of the samples. Types A and C sandstones contain macro pores, but irreducible water saturation is high (25 to 45%) compared to clean samples elsewhere, because of the presence of micropores associated with clay. In Type B sandstones the irreducible water saturation is commonly greater than 40% because all the pores spaces are in the microporosity range. The irreducible water saturation in Type B sandstones increases rapidly as porosity decreases. When porosity is less than 10%, the corresponding permeability is 0.2 mD, but no economic production can be expected because water saturation is as high as 100%. In the producing intervals, authigenic clays result in low electrical resistivity due to high water saturation; however, water-free gas is produced.     

Wind energy resource assessment for five locations in Saudi Arabia

The analysis of recently collected wind data at five sites in Saudi Arabia namely, Dhulum, Arar, Yanbu, Gassim and Dhahran is presented. The five sites represent different geographically and climatologically conditions. The data collected over a period spanned between 1995 and 2002 with different collection periods for each site. Daily, monthly and frequency profiles of the wind speed at the sites showed that Dhulum and Arar sites have higher wind energy potential with annual wind speed average of 5.7 and 5.4 m/s and speeds higher than 5 m/s for 60 and 47% of the time, respectively. The two sites are candidates for remote area wind energy applications. The costal site's, i.e. Yanbu and Dhahran wind speed data indicated that the two sites have lower annual wind speed averages and wind blows at speed higher than 5 m/s during afternoon hours. That makes the two sites candidates for grid connected wind systems for electrical load peak shaving. The data of Gassim site showed that the site has the lowest wind energy potential compared to the others. The annual energy produced by a Nordex N43 wind machine is estimated to be 1080, 990, 730, 454 and 833 MWh for Dhulum, Arar, Yanbu, Gassim and Dhahran, respectively. The analysis showed that the estimated annual energy produced by the machine based on 10 min averaged data is 2.5% higher than the estimated energy based on 30 min averaged data.     

EFFECT OF MICRITE CONTENT ON CALCITE CEMENTATION IN AN UPPER JURASSIC CARBONATE RESERVOIR,EASTERN SAUDI ARABIA

Cementation is a primary factor reducing the porosity of carbonate rocks. It is a challenge to accurately model cementation for reservoir quality prediction because cementation is often a syndepositional process. In addition, cementation requires fluid flow to transport chemical species for precipitation within the pore spaces in a sediment. The development of fully‐coupled depositional‐hydrogeochemical models for cementation prediction is desirable, but the parameters which control the extent of cementation need to be identified and evaluated. This study uses petrographic data from 583 carbonate samples from 15 wells in an Upper Jurassic (Kimmeridgian) reservoir at a giant oilfield in eastern Saudi Arabia to investigate the controlling effects of micrite content on cementation in carbonate rocks. The results indicate that the amount of cement decreases with increasing micrite content in the carbonate rocks analysed. In addition, a modified Houseknecht method has been developed to assess the relative fractions of porosity reduction in carbonate sediments due to compaction and cementation. The method highlights variations in depositional porosity for different rock textures and distinguishes microporosity from interparticle porosity. In the studied samples, the total porosity loss due to compaction and cementation is generally less than 45%, and samples lose more porosity due to compaction than cementation. The relative importance of compaction and cementation in reducing porosity is different for different rock textures: wackestones and mudstones lose porosity mostly as a result of compaction, while grainstones, mud‐lean packstones and packstones lose porosity due to both compaction and cementation.     

An exploratory study for investigating the critical success factors for cloud migration in the Saudi Arabian higher education context

Saudi universities have at their disposal a huge number of low cost IT resources to aid in teaching, research and learning. By migrating to cloud services, Saudi universities will be moving data and programs from local servers to the internet, thereby providing users with the ability to access and share information at any time from multiple devices. The migration to cloud-based IT resources is not yet widespread in Saudi universities due to several challenges including security, legal policies and implementation. At present, there is lack of research and guidance for Saudi universities on how to overcome these challenges and how contextual factors can influence the successful migration to the educational clouds.This research presents a framework for the successful migration to cloud technology in the Saudi Arabian universities. In this research, a set of key critical success factors (CSFs) were identified by synthesizing components from studies concerned with the migration of cloud for higher education and factors identified from the successful implementation of WBL (Web Based Learning) and ERP (Enterprise Resource Planning) on higher education in Saudi Arabia. Based on this knowledge, the proposed framework was evaluated via expert review and a survey by IT specialists from the Saudi universities. The initial CSFs were updated based on the expert reviews and the results were analysed. Based on the findings at this stage, additional CSFs were added to the framework as suggested by the experts. Subsequently, in order to confirm the reviewed CSFs, additional investigation via a structured online questionnaire was conducted and the outcome was analysed via one-sample t-test with the data integrity analysed via Cronbach’s alpha. The outcome indicated the majority of CSFs to be statistically significant except the Physical Location CSF. Potential future study and contributions are discussed.