Results 11 to 20 of about 197,455 (212)
Propagation characteristics and control technology of blasting vibration in neighborhood tunnel
Frontiers in Earth Science, 2023 During the tunnel construction process using the drilling and blasting method, the induced blasting vibration always poses a great threat to the stability and safety of the adjacent tunnel supporting structure.
Zixiu Qin +6 more
doaj +1 more source
Oil & Gas Science and Technology, 2021 The single-cone bit has become the first choice for slim hole sidetracking and deep well drilling with its unique rock breaking method and high ROP (Rate Of Penetration), with its main failure mode being of early excessive wear of the cutting teeth.
Kong Chunyan +3 more
doaj +1 more source
Impact of drill core contamination on compound-specific carbon and hydrogen isotopic signatures
Organic Geochemistry, 2019 Abstract Compound-specific carbon and hydrogen isotope ratios are routinely measured on extractable organic matter to decipher biogeochemical processes and events in Earth history. To deliver accurate interpretations, it is paramount that isotopic values are derived from indigenous compounds and are not the result of contamination.
Schinteie, Richard +6 more
openaire +2 more sources
Research on drag reduction technology for long boreholes drilling in coal mine
Gong-kuang zidonghua, 2020 In view of problem in long boreholes drilling in coal mine that frictional resistance between the drill string and the borehole wall seriously affects the transmission of weight-on-bit and hinders the further increase of the borehole depth, drag ...
WANG Siyi, ZHAO Jiangpeng, YANG Dongdong
doaj +1 more source
Minimizing Drill-String-Induced Wellbore Instability
Day 1 Sun, February 19, 2023, 2023 Every year the petroleum industry spends more than an estimated $6 billion in mitigating wellbore instabilities that account for nearly half of the drilling-related NPT (non-productive time).
Soukat Kumar Das +3 more
semanticscholar +1 more source
Application of Composite Deflecting Model in Horizontal Well Drilling
Mathematical Problems in Engineering, 2020 Based on current issues of difficulties in controlling horizontal well trajectory and high cost in drilling deflecting, a compound deflecting BHA (bottom hole assembly) with diameter-adjustable stabilizer (DAS) and bending-adjustable housing (BAH) is ...
Shaohu Liu, Zhichao Zhu
semanticscholar +1 more source
Development and Field Test of the Same-Frequency Different-Phase Compound Impact Tool
Shiyou jixie, 2023 A same-frequency different-phase compound impact tool was developed to improve the rock-breaking efficiency of PDC bits in hard formations, increase the penetration depth of cutters, and eliminate the “stick-slip” phenomenon of the downhole bit.The ...
Ye Daohui +5 more
doaj
Shiyou jixie, 2023 The development and application of the torsional impact drilling model improve the efficiency of breaking rocks along the wellbore circumference.To enhance the rock-breaking efficiency of the compound impact drilling and the optimal torsional-axial ...
Qi Yue +5 more
doaj
Shiyou jixie, 2023 Previous researches on rock-breaking efficiency under compound impact neglect the effects of the phase difference between axial and torsional impact loads.Therefor,such effects were discussed.The single-cutter rock-breaking numerical model of PDC bit ...
Xi Yan +5 more
doaj
Annals of Clinical and Translational Neurology, EarlyView.ABSTRACT Background Cognitive impairment is a common non‐motor symptom in Multiple Sclerosis (MS), negatively affecting autonomy and Quality of Life (QoL). Innovative rehabilitation strategies, such as semi‐immersive virtual reality (VR) and computerized cognitive training (CCT), may offer advantages over traditional cognitive rehabilitation (TCR ...
Maria Grazia Maggio +8 more
wiley +1 more source