The gas in a coal seam is clean energy source, but it also the main cause of accidents during mining mineral resources. There large pressure–relief influx upper and lower adjacent layers 1211 working face Wanfeng Coal Mine Jinhui, Shanxi Province, China. Based on evolution law overburden fractures, collaborative extraction mode “directional drilling gas-conducting fractured zone + staggered bur...

Abstract The paper deals with drilling fluid flow in a horizontal well during its drilling. As part of this work, rheological parameters water-based the addition polymers and foaming agent were used. Cuttings transport was studied at different degrees foam aeration. Besides, presents study effects flow, as rotation drill pipes on cuttings transport.

In block-matching motion estimation (BMME), the search patterns have a significant impact on the algorithm’s performance, both the search speed and the search quality. The search pattern should be designed to fit the motion vector probability (MVP) distribution characteristics of the real-world sequences. In this paper, we build a directional model of MVP distribution to describe the directiona...

The vertical or horizontal edges don’t dominate in some frames of video sequence, so the conventional discrete cosine transform (DCT) may not be the best choice for those frames. Directional DCT framework behaves better than conventional DCT in coding performance for images where directional edges dominate. In addition, the all phase biorthogonal transform (APBT), which is used in image compres...

Directional traps, both horizontal and vertical, were used to assess the behavioural impact of phenanthrene application on soil springtail communities. Avoidance was not detected. Rather, a vertical attraction of the dominant species, Folsomia manolachei, was demonstrated, as well as a decrease in horizontal movements of Lepidocyrtus lanuginosus, another important species mainly captured at the...

Shale gas comprises an increasing fraction of the US natural gas supply, but the environmental implications of shale gas extraction—a process that includes horizontal drilling and hydraulic fracturing—remain uncertain. Expanding their previous study of methane gas contamination in private drinking water wells near active drilling operations in the Marcellus shale region of northeastern Pennsylv...

The design trajectory parameters of 3D horizontal wells in X gas field are not uniform, the construction is random, and lack standardization enough to achieve rapid drilling. Based on analysis data difficulties completed well, according different types, by standardizing drilling tool assembly well design, making full use characteristics formation law, using supporting tools control sand carryin...

OBJECTIVES To investigate whether a surgeon can drill accurately a specified angle and whether surgeon experience, task repetition, drill bit size and perceived difficulty influence drilling angle accuracy. METHODS The sample population consisted of final-year students (n=25), non-specialist veterinarians (n=22) and board-certified orthopaedic surgeons (n=8). Each participant drilled a hole t...