نتایج جستجو برای: drilling tendency

تعداد نتایج: 62380  

Rotational drilling was a revolution in drilling technology. It made the drilling process more efficient and faster and more depth of well could be achieved through rotation method. Besides all of its advantages, the rotation approach induced some problems like pipe sticking and downhole cleaning to the drilling procedure. Hole cleaning and reduction of torque and drag seems to be vital in incl...

Journal: :نشریه دانشکده فنی 0
وحید عزیزی حسین معماریان آرش خسروی

numerous parameters influence bit selection process, which considering all them is not normally feasible. existing methods use limited number of these parameters to choose a suitable bit for a specific drilling condition. one of the widely used methods is cost per foot. specific energy and drilling strength are another methods currently used for bit selection. different methods of bit selection...

Journal: :Journal of dental education 2008
Ioannis Marras Nikolaos Nikolaidis Georgios Mikrogeorgis Kleoniki Lyroudia Ioannis Pitas

This article presents a novel virtual teeth drilling system designed to aid dentists, dental students, and researchers in getting acquainted with teeth anatomy, the handling of drilling instruments, and the challenges associated with drilling procedures during endodontic therapy. The system is designed to be used for educational and research purposes in dental schools. The application features ...

2014
José Díaz-Álvarez Alvaro Olmedo Carlos Santiuste María Henar Miguélez

Carbon Fiber Reinforced Polymer (CFRPs) composites are extensively used in structural applications due to their attractive properties. Although the components are usually made near net shape, machining processes are needed to achieve dimensional tolerance and assembly requirements. Drilling is a common operation required for further mechanical joining of the components. CFRPs are vulnerable to ...

2016
Yali Hou Changhe Li Hongliang Ma Yanbin Zhang Min Yang Xiaowei Zhang

To overcome strong drilling force and over high temperature during orthopedic surgery, the four medical drills with different geometrical shapes by using superhard materials were designed. The bone drilling temperature field of superhard drill was theoretical analyzed. Results showed that brazed step drill has the most ideal drilling temperature. It controls the maximum bone temperature below 4...

Journal: :Endocrinology 2014
Christopher D Kassotis Donald E Tillitt J Wade Davis Annette M Hormann Susan C Nagel

The rapid rise in natural gas extraction using hydraulic fracturing increases the potential for contamination of surface and ground water from chemicals used throughout the process. Hundreds of products containing more than 750 chemicals and components are potentially used throughout the extraction process, including more than 100 known or suspected endocrine-disrupting chemicals. We hypothesiz...

2013
Chuanliang Yan Jingen Deng Baohua Yu

Wellbore instability in oil and gas drilling is resulted from both mechanical and chemical factors. Hydration is produced in shale formation owing to the influence of the chemical property of drilling fluid. A new experimental method to measure diffusion coefficient of shale hydration is given, and the calculation method of experimental results is introduced. The diffusion coefficient of shale ...

2012
Yusuke Kasahara Hiromasa Kawana Shin Usuda Kouhei Ohnishi

BACKGROUND Drilling is used in the medical field, especially in oral surgery and orthopaedics. In recent years, oral surgery involving dental implants has become more common. However, the risky drilling process causes serious accidents. To prevent these accidents, supporting systems such as robotic drilling systems are required. METHODS A telerobotic-assisted drilling system is proposed. An a...

1999

This paper presents main results of a shale stability study, related to the understanding of shale/ fluid interaction mechanisms, and discusses shale strength correlation. The major shale/ fluid interaction mechanisms: Capillary, osmosis, hydraulic, swelling and pressure diffusion, and recent experimental results are discussed. Factors affecting the shale strength are discussed, and a sonic com...

2007
M. Schneider

Laser drilling is a well-established process in aerospace industry. However quality and geometry of holes do not get under control in an absolute way. Moreover, drilling understanding is complicated due to the number of parameters and physical phenomena. Laser and matter have some own parameters which are not constant with temperature, and so could not be fitted. In this paper, we describe the ...

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