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In the conventional direction-parallel and contour-parallel tool path strategies for the pocket machining, the cutting force and vibration are aggravated at inflection points and the sharp corners due to the drawbacks of these tool path strategies. In order to address the issues, a cycloid and spiral integrated tool path generation method for pocket machining of aircraft structural parts is proposed. Firstly, the cycloid tool path is used to slot the pocket where the cutting force can be reduced. Secondly, the spiral tool path is utilized for the machining of pocket bottom where the machining chatter can be avoided and the stability of the tool path can be guaranteed. Thirdly, the corner-looping based tool path is embedded for the improvement of machining condition in corners. Meanwhile, the clothoid curve segment is adopted so as to smooth the transition of tool paths by taking the advantage of its continuous curvature change. Experimental results show that, by using the proposed method, cutting force condition can be improved and the vibration during machining can be reduced, while the surface machining quality is also satisfied. [ABSTRACT FROM AUTHOR]

ADMa-1H Well is the first extended-reach horizontal well in AHDEB Oilfield of Iraq. Till now, its horizontal section length is the longest, and its vertical depth also is the greatest in all completed horizontal wells. It makes a new record in which a set of normal MWD tools and screwdrill were used to drill a horizontal section of Ø152.4 mm with a length of 1500 m. In view of some difficulties in extended-reach horizontal wells, such as well trajectory control, high drag and torque in horizontal section, easy fluid loss and stuck pipe, etc., through wellbore configuration design optimization, BHA and drilling parameter selection and research in well trajectory control technology, we finally realized high quality in the whole wellbore of ADMa-1H well with no occurrence of downhole troubles. The success of this well provides precious experience for drilling of extended-reach horizontal wells in AHDEB Oilfield. [ABSTRACT FROM AUTHOR]