Abstract Natural gas has become an important source of energy in the world. Throughout the 19th century, natural gas was used almost exclusively as a source of light and its use remained localized because of lack of transport structures, making it difficult to transport large quantities of natural gas long distances. There was an important change in 1890 with the invention of leak-proof pipeline couplings, but transportation of natural gas to long distance customers did not become practical until the 1920s as a result of technological advances in pipelines. Moreover, it was only after World War II that the use of natural gas grew rapidly because of the development of pipeline networks and storage systems. Gas pipe lines are operated under steady state conditions. However, when transporting high temperature wet gas the gas getting cooled and heavy components condensate, Hence, pigs is usually are wanted to clean the pipe line to reduce pressure drop along the pipe In this study an existing pipeline was studied under steady and unsteady state. HYSYS and ProFES programs were utilized. Result show that gas temperature changes with time and distance. Results show that temperature and gas approach the ambient temperature at about 20 Km of pipe line length consequently, liquid phase volume fraction increase in first 20 Km of the pipe.
عدلي عمر احمد (2011)

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)

استخدام المواد المركبة في التطبيقات الصناعية نمى بشكل سريع وذلك لمميزاته المناسبة التي تشمل ارتفاع نسب المقاومة والمتانة بالنسبة للوزن , وقد أصبحت المواد المركبة بديل المواد المعدنية في العديد من التطبيقات. المواد الثيرموبلاستيكية المركبة تم دراستها في هذه الرسالة حيث استعمل البولي اثيلين كقالب ودعم بإضافة ألياف الزجاج بنسب مختلفة ( 10% , 20% , 30% ) , وتم دراسة تأثير إضافة ألياف الزجاج على الخواص الميكانيكية للعينات. تم الحصول على العينات المركبة باستخدام جهاز البثق وإجراء التجارب لتقيم جريان المنصهر عند درجات الحرارة العالية حيث لاحظنا زيادة الجريان بزيادة الضغط . كما تم تطوير علاقات رياضية لتمثيل علاقات الإجهاد – الانفعال للعينات المركبة المتحصل عليها ,تم الحصول على ثوابت هذه العلاقات الرياضية. كما تم دراسة علاقات زمن الانهيارات للعينات المركبة , وتم تحسين طاقة الكسر للمواد المركبة التي تؤخر من ظاهرة الانهيار. إضافة ألياف الزجاج أدى إلى زيادة زمن الانهيار وتقليل طاقة الكسر. Abstract The use of composite materials in industry applications has grown rapidly, owing to their favorable characteristics, including high strength and stiffness to weight ratios, composite materials have been considered replacement of metals in numerous structural applications.Thermoplastic composite was studied in this thesis where high density polyethylene is used as a matrix and reinforced with different percentages of fiber glass ranging from (10%, 20%, 30%). The influence of addition of fibreglass on mechanical and thermal properties was studied. A pilot plant extruder is used to prepare the needed samples, where experimental investigation is carried out to evaluate the melt flow and the impact behaviour of the melt mixture at high temperature in the extruder. The flow rate increased by increased pressure. A mathematical correlation was developed to represent the stress – strain correlations of the composites used in this work. The combined model would be able to predict the creep, relaxation and recovery of composite materials, the constants of the model was obtained in area where the retardation effect is dominating. Time to failure correlation with stress was studied for the prepared composite material and mathematical correlation is established. The energy absorbed at fracture is improved for the composite material leading to a considerable delay in failure phenomenon. When added fibreglass led to increase time to failure and decrease energy of fracture.
ابتسام خليفة ابولجام (2008)