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)

نظرا للنقص الكبير في كمية المياه الجوفية نتيجة لنقص كمية مياه الأمطار و المياه الصالحة للشرب عامة وعدم وفرة المياه في المناطق النائية وشبه القاحلة حيث تتوفر الطاقة الشمسية وتشح المياه مما يجعل للطاقة الشمسية أهمية كبيرة في تحليه المياه و التقليل من استعمال الطاقة التقليدية التي تصاحبها انبعاثات المسببة للمشاكل البيئية مثل الانحباس الحراري.الهدف من هدا البحث هو تصميم و دراسة تجريبية لأداء المحليات الشمسية نوعية الحوض(basin type solar still ) والمقطر الشمسي نوعية الفتيلة المبللة (tilted –wick solar still ) و المربوطة بالمجمعات الشمسية لغرض تسخين المياه قبل دخولها للمقطر. وقد تم استعارة نموذج رياضي مناسب لمحاكاة أداء المحليات الشمسية التي يتم دراستها ومقارنة الجانب العملي مع الجانب النظري و الذي يستفاد منه في معالجة المشاكل المتوقعة في تصميم المقطر . وقد تم مقارنة معدل إنتاجية المياه في وجود مجمع شمسي وفى عدم وجوده. حيث وجدنا أن معدل إنتاجية نوع (tilted wick) فى وجود مجمع شمسي كان 5.307lm2day عند معدل إشعاع شمسي 676.537wm2 ,وإنتاجية نوع ((basin في وجود مجمع شمسي day 3.333lm2 عند إشعاع شمسي 696.19wm2 , وإنتاجية نوع (basin) في عدم وجود مجمع شمسي day 3.025lm2 عند معدل إشعاع شمسي 721.49wm2 وقد وجدنا أن تركيز الأملاح الصلبة الدائبة كانت 3080mg/l ونقصت بعد عملية التحلية إلى 36.8mg/l و تركيز أيون الكلور كان 475mg/l و نقص إلى 2.2mg/l . حيث تعتبر الطاقة الشمسية هي من أكثر أنواع الطاقة ملائمة للاستعمال في الوقت الحالي لولا انخفاض معدل الاستفادة منها حاليا على نطاق تجارى واسع وتجرى الآن أبحاث كثيرة لتطوير وإيجاد وسائل مناسبة للحصول على الطاقة الكافية. Abstract The problem of drinking water shortage is a worldwide issue that made millions of people suffers this shortage. Different classical energy processes were used to partly solve the problem, but they were suitable only for large population areas due to their high capital, operation and maintenance cost. For these reasons, alternative methods must be sought for rural arid areas. This method uses solar energy to drive basin-type and tilted-wick-type solar stills to produce distilled water. The performance of the stills was also studied when they were connected to external solar collector to preheat the feed water to the stills. The present work deals with studying and modeling of solar stills. The basic idea of the work is to check the production of basin still and tilted wick still using solar energy for solar desalination, using brackish water with total dissolved solids (T.D.S) equal to 3080mg/l and ion chloride concentration of 475mg/l)(35) and solar energy. The still is basically a rectangular basin lined with black or blackened porous material that acts as the solar energy collector. The still was constructed from galvanized iron steel with dimensions 52×75×6 cm. the base area of 52×75 cm. The still inclined at 13o. Distilled water volume collected was recorded continuously for each hour. The productivity of tilted type still with preheated water was 5.307 L/m2 day at an average solar radiation of 676.537 w/m2. The productivity of basin type solar still with preheated water was 3.333L/m2day at an average solar radiation 696.19 w/m2. The productivity of basin type solar still without preheated water was 3.025 L/m2day at an average solar radiation 721.49w/m2. The T.D.S is 36.8mg/l, and ion chloride concentration is 2.2mg/l(35). The developed mathematical model from energy and mass balance on the system was used to predict the performance of the still. It was found that the model predicted inlet temperature and glass temperature well with that one’s measured experimentally. The productivity predicted from the model was far from that measured experimentally. This was due to the many assumption made in the development of the model.
زينب أحمد دالي (2011)