Results 11 to 20 of about 16,082 (297)

Study on the Structure and Tribological Behavior of Zn - Ni Coating by Pack - Cementation [PDF]

open access: yesCailiao Baohu, 2021
In order to improve the friction and wear properties of 45 steel’s surface surface, a Zn - Ni coating was prepared on 45 steel’s surface by pack - cementation method.
ZHANG Jin, LIN Yuan - hua, GUO Meng - xin, XIANG - Huan, RAN Xue - lin, HUANG Min
doaj   +1 more source

Experimental and Numerical Study on Air Flow Behavior for a Novel Retractable Reverse Circulation Drill Bit of Casing-while-Drilling (CwD)

open access: yesGeofluids, 2021
A reverse circulation Down-The-Hole (DTH) hammer drill bit in Casing-while-Drilling (CwD) processes is designed and applied to drilling under complicated formation.
Bo Qi   +7 more
doaj   +1 more source

Analysis of Materials and Modern Technologies for PDC Drill Bit Manufacturing

open access: yesУспехи физики металлов, 2020
The article presents a review of polycrystalline diamond composite (PDC) drill bit manufacturing technologies and used metals in order to provide surface quality and accuracy as well as to attract a wider range of scientists to find new technologies and ...
L. Ya. Ropyak, T. O. Pryhorovska, K. H. Levchuk
doaj   +1 more source

Orthogonal experimental research on the structural parameters of a novel drill bit used for ice core drilling with air reverse circulation

open access: yesJournal of Glaciology, 2019
A new type of ice core drill bit, designed with a vane swirler, was developed for ice core drilling with air reverse circulation. An orthogonal experimental design method was employed to investigate the effects of the swirler structure parameters on the ...
Pinlu Cao   +4 more
doaj   +1 more source

Stick-slip vibration behaviors of BHA and its control method in highly-deviated wells

open access: yesAlexandria Engineering Journal, 2022
Stick-slip vibration is a common phenomenon met in oil gas drilling, especially in the complex trajectory wells such as highly-deviated wells, it will cause the earlier failure of BHA (bottom hole assembly) and lower drilling efficiency.
Weiji Liu   +3 more
doaj   +1 more source

Experiment on the influence of downhole drill string absorption & hydraulic supercharging device on bottom hole WOB fluctuation

open access: yesEnergy Reports, 2023
Large amplitude and high frequency WOB (weight on bit) fluctuation will lead to problems such as low rock breaking efficiency, short service life and slow drilling speed. This problem is particularly prominent in hard and difficult to drill formation and
Liu Yongwang   +5 more
doaj   +1 more source

Dynamic Characteristics of Downhole Bit Load and Analysis of Conversion Efficiency of Drill String Vibration Energy

open access: yesEnergies, 2021
The longitudinal vibration of the drill pipe contains considerable energy which can be used to improve the rock-breaking efficiency during drilling. It is very important to the development of drilling speed-up tools to have a comprehensive understanding ...
Yuqiang Xu   +2 more
doaj   +1 more source

An impedance approach to reduce the contact-instability whilst drilling with active heave compensation [PDF]

open access: yes, 2012
The bit-bounce, or contact-instability, phenomenon which occurs in the drill string suspended from a floating vessel with an active drill string compensator to maintain a steady weight on the drill bit is investigated.
Hatleskog, Jan, Dunnigan, Mathew Walter
core   +1 more source

Analytical and experimental study of a reverse circulation drill bit with an annular slit

open access: yesAdvances in Mechanical Engineering, 2016
A new type of drill bit designed with an annular slit was developed to enhance the reverse circulation effect of the down-the-hole hammer drilling technology. A computational fluid dynamics code, Fluent, was used to simulate the flow phenomena inside the
Pinlu Cao   +4 more
doaj   +1 more source

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