Abstract This study is to develop the specifications of the present cement products so as to comply with the quality and quantities requirements of the local market. The subject of this thesis is to present the results of a series of laboratory trials on a number of raw material mixtures prepared to produce moderate and high sulfate resistance cement at EL- Mergheb cement factory which currently produces ordinary Portland cement. At first, six different raw material sample mixtures were prepared from marlstone,marl and iron ore. The clinker (cement ) produced from these samples was within the moderate sulfate resistance cement ( MSRC ) specifications which mainly requires the tri calcium aluminate (C3A) to be less than 8 % by weight. The trial runs on other three raw material samples made that from mixing marlstone , clay , and iron ore produced clinker specifications that were out of those for MSRC namely, C3A is greater than 8 % . This means that the addition of clay to the raw mix prevents the production of cement with MSRC specifications. This was due to the high percentage of Al2O3 in the clay . The specifications of the clinker products based on these results , MSRC was successfully produced at the factory from raw material mixtures ( marlstone, marl and iron ore ) without any clay addition . Finally three raw mix samples were prepared from marlstone, marl, iron ore, and sand and tested in the laboratory to explore the possibility of producing high sulfate resistance cement ( HSRC) which requires C3A to be less than 5 % . The results of these laboratory trials showed that when the sand in the raw mix is kept under 1.80 % , the produced clinker specifications are within those of HSRC. The permission to carry out these trials in the factory is underway. The expected economic benefits from producing both MSRC and HSRC is highly feasible. Both types will be sold in local market without any additional operating or capital costs .
صالح محمد صالح (2013)

Abstract Matrix acidizing is a stimulation method commonly used to remove near wellbore damage and restore original formation permeability. It involves the injection of acid into formations at pressures below the fracture pressure. Acid flows down the well into the reservoir, and then reacts with the rock such that any near wellbore permeability damage created by meling or completion fluids can be removed and apparent permeability increased. A matrix acidizing treatment can be' applied to either a sandstone or a carbonate reservoir. Different acids are used because different minerals are involved in these treatments. Hydrochloric acid (HCI) is usually used in carbonate reservoirs to react with carbonates. Hydrofluoric acid (HF) or mixture of Hydrofluoric acid (HF) with Hydrochloric acid (HCI) is commonly used in sandstone porous media to react with silicates and feldspars in the rock. Since the mechanisms of acid reactions with these two types of rock are different, results of the treatments are different as well. In sandstone matrix acidizing, permeability increase behind the acid front is relatively homogeneous. The flow and reaction of acid in carbonate porous media results in the formation of highly conductive flow channels, commonly referred to as wormholes. In the present work we have studies the first study to test the optimal acid flux theory presented by Wang (1) with several independent sets of experimental data. The model was comparing with field data. The second study we use model presented by McCune and Fogler.(2) This previous studies on mathematical modeling of the chemical reactions between sandstone and mud acid. This model is lumped-parameter model. The lumped-parameter model simplifies the chemistry of the dissolution of sandstone minerals with mud acid. The models are compared with the experimental data at different flow rates.
عبد ربه ادريس بوسدرة (2010)

Abstract Deposition of undesirable materials on water wall side of boiler tube that are operated under forced circulation boiling conditions can cause serious trouble in steam boilers. The present study is concerned with the scaling characteristics of water in the boilers. The effects of heat flux and water velocity were evaluated for water having a total hardness and calcium hardness in the range (TH= 380 to 390 ppm asCaCO3 ) and(CaH= 250 to 298 ppm asCaCO3) respectively. The heat flux ranged from (1.05 x 105) to and water velocity in a vertical annular test section range from 0.51 to 0.75 m/sec (1.67 to 2.5 ft/sec) . The test section consisted of an annular duct 0.050 m (2.0-in) O.D. and 0.033 m (1.33-in ) I.D. A 0.30 m (12-in) section of the concentric core of the annulus was electrically heated. Hot water at 97.0 (370.1) was circulated through the annulus where boiling occurred on the heated section. The temperature range at the Surface of heated section in the annulus was from (105 - 118 ). The results of five tests are reported in this study. The fouling resistance vr. time curves reached an asymptotic value and the average of fouling resistance for Runs (1-5) had been plotted. Chemical analysis of scale deposits indcated that Calcium carbonate and Silica were the man Constituents. At constant surface temperature an increase in velocity from 0.51 to 0.75 m/sec (1.67 -2.5 ft/sec), caused about a 20 percent reduction in the asymptotic fouling resistance.
عادل محمد شنقير (2008)