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It is the purpose of this research to provide a brief background to the South African Petroleum Industry and to focus in particular to Petronet with regards to finding an amicable solution to dispose the excess intermixture created, as a result of the Oil Industry reviewing the current blend rate at which intermixtures can be blended into pure products. The pipelines operated by Petronet are mainly multi-product pipelines i.e. many different refined petroleum products use the same pipeline at the same time and there is a level of co-mixing between each product which is termed intermixture. The primary method that Petronet disposes intermixture is on continuous process into pipeline deliveries to clients (commonly known as blending). This means that while a delivery to a client is being made, careful analysis and calculation are done to blend some intermixture into this delivery, making absolute certain that the end product to the client remain within the predetermined specification. Originally, Petronet was allowed to blend 0,5% diesel into petrol and 0,25% petrol into diesel, provided that in the case of petrol the FBP of 215°C was not exceeded and that the residue content did not exceed 2%. With Motorcar manufacturers now producing hi-tech cars that require high quality fuel to be compatible with the extended service intervals, Industry have revised the original blending rates of diesel into petrol from 0,5% to 0, 25%. This means that Petronet cannot blend more intermixture as it did in the past, as a result there will be an accumulation of excess intermixture. The impact of this revision has and is adversely affecting the nature in which Petronet operates. This research seeks to explore alternative methods in which Petronet can use to address the excess intermixture problems. Three solutions are identified namely: short, medium and long term solution. The short being the sale of excess intermixture, the medium being the re-processing of excess intermixture by refineries and the long term sustainable solution is for Petronet to invest in its own Refractionator unit. This unit would be the ultimate and the best solution as it allows Petronet to re-process the intermixture back to its base and this product can then be blended back at a much higher rate. / Thesis (MBA)-University of Natal, 2003.

This dissertation analyses the history of the politics of pollution and petroleum refining in South Africa during the first decade of Apartheid, focusing on the country's first two oil refineries, both of which were built by multinational oil companies in Durban in the 1950s and 60s. It traces the origins of the development of environmental regulation in relation to oil refinery pollution. The dissertation outlines the development of a sense of disillusionment caused by the persistence of pollution problems associated with petroleum refining in the face of failed attempts at technological and expert interventions. The study identifies the existence of a civic culture amongst Bluff residents founded on ratepayer and landowner identities, through which they were able to exercise considerable purchase on the local State. Ultimately, the story of how two petroleum refineries ended up in the midst of residential communities in south Durban's represents a reiteration of the importance of race to the development of local urban landscapes during Apartheid. / Thesis (M.A.)-University of KwaZulu-Natal, Durban, 2004

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Congressional reform is the focus of my study. Congress (but primarily the House of Representatives) attempted to reform its workings from 1968 through 1975, so it might be more effective in developing comprehensive policies on national issues, and more independent of the executive branch. Reform raised expectations that the legislature would reassert its policy-making role, which had diminished during the preceding thirty years. My study examines the influence of these changes on the congressional decision-making process, including their impact on the important role played by external actors, interest groups and especially the President, who reacted to these changes. The study examines the process through an analysis of the development and passage of the most controversial provision, dealing with oil-price controls (Title IV), of Congress' major energy bill of 1975, the Energy Policy and Conservation Act (H.R. 7014). On 15 December 1975, Congress passed the Energy Policy and Conservation Act (EPCA) which President Gerald R. Ford signed into law on 22 December. The EPCA (Public Law 94-163) extended oil-price controls until 1979. The oilpricing provision had significant national and international economic and political implications. Merely to trace the tortuous chronicle of oil-pricing policy would be informative. But this study will go further by using this account to analyze congressional decision-making in the period immediately following Congress' attempts at reform. My study shows that although reforms eroded old norms and power centres, significantly altering some aspects of congressional decision-making (again primarily in the House), they did not create institutional mechanisms or distribute internal powers in such a way that Congress could independently initiate and develop comprehensive national policies. Congress remained more dependent on the President than many of its members understood. The final substance of the oil-pricing policy reflected the characteristic congressional decision-making process, which had become even more dispersed as it was democratized by reform. The committee system, without a strong executive or party control, divides issues in a way that limits decision-makers' options.

High molecular weight (HMW) hydrocarbons (defined herein as C35+ compounds) are difficult to characterise by conventional analytical methods. Very few studies have reported precise and reproducible quantification of such compounds in fossil fuels. Nonetheless, such components have important effects on the physical and biological fate of fossil fuels in the geosphere. For example, the phase behaviour of waxy gas condensates is significantly affected by the varying proportions of HMW compounds. Similarly HMW compounds are amongst the most resistant petroleum components to biodegradation. The current study reports the development of reproducible quantitative high temperature capillary gas chromatography (HTCGC) methods for studying both these aspects of the chemistry of HMW hydrocarbons. In addition those hydrocarbons which remain unresolved when analysed by gas chromatography (so called unresolved complex mixtures UCMs) are also studied. UCMs may account for a large portion of the hydrocarbons in many fossil fuels yet very little is known about their composition. Knowledge of these compounds may be important in enhancing the prediction of phase behaviour. Oxidative degradation and GC-MS is used to elucidate the types of structures present within the UCM. The concentrations of C3S4h. ydrocarbons in two unusually waxy gas condensates from high temperature wells in the North Sea were determined by HTCGC. The whole C, 5+ fraction comprised about 20% of the total hydrocarbons and consisted of compounds with carbon numbers extending up to and beyond Coo. By paying particular attention to sample dissolution and injection, good reproducibility and precision were obtained. For example, for authentic n-C, to n-C60 alkanes a relative standard deviation of under 5% for manual injection, linear response factors (1.01 Cm to 0.99 C6), and a linear calibration for 5 ng to 25 ng on-column were found. Limits of detection are reported for the first time for HMW n-alkanes. The limits were found to be as low as 0.8 ng for Cto to 1.87 ng for C60. Tristearin is proposed as a suitable HTCGC internal standard for quantification since the FID response factor (1.1) was close to that of the HMW n-alkanes and response was linear. Importantly, when co-injected with the two waxy North Sea condensates, tristearin was adequately separated from the closest eluting alkanes, n-C59 and n-C60 under normal operating conditions. Qualitative characterisation of the HMW compounds in the waxy gas condensates and in synthetic wax blends (polywax 1000) using HTCGC-EI MS and HTCGC-CI MS produced molecular ions or pseudo molecular ions for n-alkanes up to n- C6o. The spectra of some HMW compounds contained fragment ions characteristic of branched compounds but detailed characterisation was very limited. This study has also shown, for the first time, the significance of the unresolved complex mixture in gas condensatesU. CM hydrocarbonsa ccountedf or over 20% of the total hydrocarbons in a waxy North sea condensateT. he condensatew as first distilled and the distillate UCMs isolated. Thesew ere found to be between 64 to 97 % unresolved after molecular sieving (5A) and urea adduction. The UCMs were oxidised using CrO3/AcOHw hich produced5 -12% C02, and 55-83% dichloromethane-solublep roducts. Thus 65-94% of the original UCMs were accounted for as oxidation products. The remainder were thought to be water soluble acids which could not be determined in the presence of the AcOH reagent. Of the recovered oxidised products, 27- 81 % were resolved and these comprised mainly n-monocarboxylic acids (19-48 %). The average chain length was found to be C12 indicating the average length of alkyl groups. Branched acids, ketones, ketoacids, ndicarboxylic acids, branched dicarboxylic acids, lactones, isoprenoid acids, alkylcyclohexane carboxylic acids and toluic acids accounted for the majority of the remaining resolved products. The distillate UCMs all showed variations in amountso f productsb ut not in composition. Retro-structurala nalysis suggestedth at the UCM in the gasc ondensatew as mainly aliphatic and branched.T he numbero f isomerso f simple brancheda lkaneso ver the UCM molecular weight range (determined by cryoscopy) was calculated to be over 15000. Overall, oxidation provided structural information for about half of the UCM. HTCGC was also used to measure the biodegradability of HMW alkanes in a waxy Indonesian oil. Traditional alkane isolation techniques (TLC and CC) discriminated against HMW compounds above C40 whereas adsorption onto alumina in a warm cyclohexane slurry provided an aliphatic fraction still rich in HMW compounds and suitable as a biodegradation substrate. A waxy Indonesian oil was subjected to 136 day biodegradation by Pseudomonas fluorescens. Extraction efficiencies of over 90 % (RSD <5 %) were obtained for n-alkanes up to C6o using continuous liquid-liquid extraction. Over 80 % of the oil aliphatic fraction was degraded within 14 days. After 136 days only 14% of the original aliphatic fraction remained, yet surprisingly no decreases in the concentrations of compounds above C45 were observed. However, the use of a rapid screening biodegradation method proved conclusively that Pseudomonasfluorescens was capable of utilising n-alkanes up to C60 once the bacteria had acclimated to the HMW alkanes. This is the first report of bacterial utilisation of an n-alkane as large as C.

This thesis presents the results of the investigations in two areas, i.e. non-Newtonian annular flow and cuttings transport in drilling annuli at various angles. In the first part of the thesis, a review of the fundamentals and the previous studies on laminar concentric annular flow of non-Newtonian fluids is given at first. Then two parallel theoretical studies are performed, respectively, on: a. Laminar eccentric annular flow of power-law and Bingham plastic fluids. In this analysis, a new method is used which treats an eccentric annulus as infinite number of concentric annuli with variable outer radius. The analytical solutions of the shear stress, shear rate, velocity and the volumetric flowrate/pressure gradient are obtained over the entire eccentric annulus. This analysis is useful in design of any engineering operations related to eccentric annular flow such as oil drilling operations. b. Laminar helical flow of power-law fluids through concentric annuli. A group of dimensionless equations are derived in this analysis for the profiles of the apparent viscosity, angular and .axial velocities, and for the volumetric flowrate. These equations are essential when one needs to simulate the helical flow conditions in various engineering operations. In addition, another group of dimensionless equations are also derived for pressure gradient calculations which can be used directly by drilling engineers to predict the reduction of the annular friction pressure drop caused by drillpipe rotation during drilling operations. The second part of the thesis is dedicated to the investigations into the problems directly related to cuttings transport through drilling annuli at various angles. First, both theoretical and experimental studies on settling velocities of drilled cuttings in drilling fluids are conducted using new approaches to account for the non-Newtonian nature of drilling fluids and for the shape irregularity of drilled cuttings. Based on experimental results, a generalised model is developed for calculating settling velocities of variously shaped particles in power-law fluids. Then, the effects of various parameters on cuttings transport during drilling operations are analysed based on the previous and the present studies. After that, an extensive theoretical analysis for the previous studies on the minimum transport velocity (MTV) in solid-liquid mixture flow through pipelines, on initiation of sediment transport in open channels and on MTV for cuttings transport in deviated wells is presented. At last, theoretical studies on the minimum transport velocity for cuttings transport in drilling annuli at various angles are conducted and two parallel general correlations are developed. When these correlations are experimentally verified and numerically established in the future, they can be served as general criteria for evaluating and correlating the effects of various parameters on cuttings transport, and as a guideline for cuttings transport programme design during directional drilling.

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