Abstract It is found in the literature that correlations and methods used in the determination of the lifting capacity for vertical wells cannot be applied directly for calculating the lifting capacity for horizontal well section without modifications. It is therefore necessary to formulate a new experimental technique from which new lifting capacity correlation is deduced which will be applied for the determination of the lifting capacity for the horizontal well section.The phenomena of cuttings concentration accumulated in the bottom of the horizontal section which is present in horizontal wells, does not exist in the vertical sections of the well. This problem makes it necessary to conduct an experimental work in a horizontal well simulator, to exactly simulate the drilling operation in the horizontal section of the well, from which lifting capacity values are determined for different mud formulations containing different cuttings sizes, concentrations and different mud reheology circulation at different flow rates. The objective of this study is to investigate the behavior of whole cleaning in the horizontal well section and to determine the factors effecting the cleaning capacity of the mud in this section. Also to deduce correlations relating the lifting capacity of the mud in the horizontal section of the well with various drilling parameters and mud circulation conditions. This study is conducted in the laboratory using a horizontal well simulator consists of the circulating mud component similar to that present in actual drilling operations. The experimental work used consists of using four muds formulation systems mixed with different cutting sizes and concentrations. The returned cuttings are extracted from mud return line for selected given time increments and accordingly their weights and sizes are determined. It is concluded that there is an optimum cutting size for maximum lifting capacity for each cutting concentrations used. The lifting capacity observed form the experimental results is not only dependent on mud velocity, but it is also dependent on the cutting concentrations used. It was observed that when cleaning the system after each experiment, accumulation of rock cuttings were present in the bottom of the horizontal section of the model. In this study a lifting capacity correlation relating the lifting capacity with mud flow rate, cutting size, cutting concentration, mud density, and mud viscosity is generated for the horizontal section of the well. Therefore it recommended that cleaning of the horizontal section of the well should be conducted frequently (consecutively) after each drilling time increment, which means that the drilling operation is stopped and the mud circulation rate is set to maximum. A maximum mud circulation rate is needed in order to ensure that the cuttings generated by the bit are removed efficiently in the horizontal section. It is therefore recommended during drilling the horizontal section a sequential drilling and cleaning technique should be applied.
عادل محمد جالوتة (2010)

تعتبر ظاهرة تحرك الكثبان الرملية و وزحفها على الطرق الرئيسية من الظواهر الخطيرة التي تتسبب في حوادث قاتلة وعرقلة لحركة المرور، إضافة إلى الخسائر الاقتصادية الكبيرة . ومن الطرق التي تعاني مثل هذه المشاكل الطريق الرابط بين نالوت و غدامس والطريق الرابط بين الوطية و الجوش والطريق الرابط بين العزيزية و غريان وكذلك طرق الجنوب مثل طريق سبها براك وطريق سبها أوباري ... الخ ، لهذا كان من الضروري القيام بعمل دراسة ميدانية ( حقلية ) للأماكن المتضررة من الطرق وإجراء الاختبارات المعملية اللازمة واقتراح الحلول المناسبة لمعالجة هذه الظاهرة يأتي هذا البحث لدراسة ظاهرة زحف الكثبان الرملية على الطرق المتضررة من هذه الظاهرة والتي تقع في شمال وجنوب غرب ليبيا وهي طريق نالوت غدامس وطريق الجوش الوطية وطريق العزيزية غريان وطريق براك سبها ، حيث تم تحديد القطاعات المتضررة في الطرق سالفة الذكر وإجراء عملية الرفع المساحي لتلك القطاعات للتعرف على وضعية الرمال وحجمها ، حيث تم رسم قطاعات عرضية وطولية لكل القطاعات المتضررة . وكذلك إجراء اختبارات معملية للتربة المكونة لتلك الكثبان والمتمثلة في تحليل الحجم الحبيبي واختبار بركتور المعدل لمعرفة خواص التربة وتصنيفها وذلك حسب نظام تصنيف التربة الموحد ، وتحديد أقصى كثافة جافة ونسبة المياه المناظرة لها ، ونسبة الرطوبة ، كما تم دراسة تضاريس كل منطقة يقع فيها القطاع المتضرر والتعرف على مصادر المياه بها ،والظروف المناخية مثل اتجاهات الرياح السائدة وسرعتها وباستخدام النتائج المتحصل عليها والدراسات السابقة التي قامت بها العديد من الدول التي تتأثر بهذه الظاهرة والتي استعرضنا منها في هذا البحث دراسة كل من الولايات المتحدة الأمريكية والكويت والجزائر ومصر ، تم اقتراح ثلاثة حلول لعلاج هذه الظاهرة وهي مقطع الديناميكا الهوائية والذي تم تجربته في دولة الكويت ، والحل الاستثماري وهو اقتراح قام به الباحث بالرجوع إلى حجم المرور اليومي على القطاعات المتضررة ، و الاقتراح الثالث يتمثل في التثبيت البيولوجي مع مصدات الرياح لتثبيت التربة . وقد تم تحديد أفضل الحلول العلاجية لكل قطاع . Abstract The main aim of this study is to analyze and evaluate the movement and creeping of the sand dune on the main roads considered as dangerous phenomena which caused accidents and resulted in hindering traffic movement. It also caused great economical losses. The roads which suffer from this problem are Nalut - Gadams road, Al Gush – Al Wtyah road and Azizia - Garyian road. Similarly in the south of the Libya there are many roads which suffer from the movement and creeping of the sand dunes, such as Sebha - Brak road, Sebha - Obary road ....ECT. To study this problem it is very important to do a field study about roads that suffer from this problem and need laboratory tests in order to suggest suitable solutions for the treatment of this phenomenon.This study, as indicated above, analyzed and evaluated the movement and creeping of the sand dunes phenomenon in the damged roads located in North and South West of the country. These roads include Nalut-Gadams road, Al Gush-Al watyah road, Sebha-Brak road and Azizia-Gryan road.After identifying the critical section in the above mentioned roads, the researcher carried out a surveying work for sections to identify the sand passivism in relation to the damaged sections and its volume. In this regard, cross sections and longitudinal sections were drawn. Also laboratory sand tests were conducted .These tests include: Sieve Analysis Test. Modified Proctor Test.for identifying sand classifications and characteristics according to its unified system, identifying water dry density and percentage of the parallel water, percentage the humidity. In addition, a study was carried out on the topographic relief of each critical sections to identify the water sources and climatic conditions such as the speed and directions of the dominated winds.The application of the main findings of this study, and other previous studies done by some other countries influenced by this phenomenon, such as United States of America, Kuwait, Algeria and Egypt conclude to three solutions for treating this phenomenon. These solution include: 1- Aerodynamic Profile section which tested in Kuwait. 2- Investment solution which depend on the daily traffic size on the hurt sections. 3- Biological fixing with wind obstructs for fixing the sand. Finally, the best solution for each section was determined.
أبوبكر موسى محمد (2009)

In this paper, an orthopedic robot-assisted drilling system is presented. The system consists of a six degree of freedom robot manipulator equipped with a multi axis force/torque sensor and an electrical drilling tool attached to the robot end-effector. The purpose of the system is to enable the orthopedic surgeons to drill the patient bone using the robot manipulator and automatically detect the bone breakthrough during bone fixation process. The breakthrough is detected by measuring the forces acting on the drilling tool tip. This will reduce/eliminate the need for X-rays imaging used in traditional bone fixation. The system has been tested on sheep bone. The result has shown that, the bone drilling operation can be handled by a robot manipulator to improve the quality of the drilling operation. With this system, the bone breakthrough can be easily detected and further damage of the healthy patient tissue would be avoided. This will lead to fast patient recovery and short hospital stay.
Azeddien Kinsheel, Zahari Taha, J. Lee(1-2008)