knowledge of the orientation of horizontal in situ stresses is important to some areas of oil and gas field development plans. borehole breakouts observed in image logs and drilling-induced fractures are the main parameters for the determination of the stresses’ directions in situ. in this work, the orientations of borehole breakouts were investigated as a function of depth in oil wells a and b...

There are images in which some directional edges other than the vertical or horizontal ones dominate. So the conventional discrete cosine transform (DCT) may not be the best choice for them. Directional DCT framework is able to provide a better coding performance for image blocks that contain directional edges. In addition, the all phase biorthogonal transform (APBT) algorithm can improve the p...

Simple and computationally efficient drill string models running real-time describing motion in all axes directional wells are important for the implementation of closed-loop control assisted monitoring during drilling operations. This paper proposes a new simplified three-dimensional model based on parametric curve lumped-parameter modeling, where Kane’s method is used to establish equations m...

The deformation patterns and failure mechanisms of pressurised cavities at shallow depth are relevant to many geotechnical applications, including tunnelling horizontal directional drilling. In this paper, an experimental study a reduced-scale cavity under geostatic stress is presented, in order measure the effect length, vertical soil density on failure. X-ray computed tomography used acquire ...

Knowledge of the orientation of horizontal in situ stresses is important to some areas of oil and gas field development plans. Borehole breakouts observed in image logs and drilling-induced fractures are the main parameters for the determination of the stresses’ directions in situ. In this work, the orientations of borehole breakouts were investigated as a function of depth in oil wells A and ...

This study is to examine UX design patterns depending on touch gestures on smart-phones for mobile web service. As for user experiences regarding touch gestures on a smart-phone, directional motions such as horizontal or vertical movements were more frequent than zoon-in/out and rotation, and such motions were often combined for navigation and invitation functions. Dragging was directional both...

Directional drilling systems generate complex curved boreholes in the earth’s crust for the exploration and harvesting of oil, gas and geothermal energy. In practice, boreholes drilled with such systems often show instability-induced borehole spiraling, which negatively affects the borehole quality and increases drag losses while drilling. This paper presents a dynamic state-feedback controller...

this paper examines differences in performances of a range of torsionally stiff and flexible single story buildings designed with the provisions of iranian standard 2800. seismic nonlinear dynamic time history behavior of eight building models subjected to seven horizontal bi-directional design spectra compatible ground motions are investigated. these models cover a wide range of very torsional...