Results 111 to 120 of about 248,377 (289)

Study on Drill String Fatigue Life in Deepwater Drilling

open access: yesShiyou jixie, 2016
Dynamic response of the deepwater drilling platform increases alternating loads of the drilling string.As a consequence,the calculation of drill string fatigue life becomes more complicated.By using the numerical simulation method,a method for studying ...
Wang Jiajia, Chen Jianmin
doaj  

Analysis on the dynamics of flexible drillstring under different drilling parameters

open access: yesFrontiers in Earth Science
During the operation of the drill string, it displays a degree of flexibility. Simultaneously, its dynamic properties, influenced by complex stress conditions, manifest nonlinearity and uncertainty.
Jifei Cao   +8 more
doaj   +1 more source

Qualification of a computer program for drill string dynamics

open access: yes, 1985
A four point plan for the qualification of the GEODYN drill string dynamics computer program is described. The qualification plan investigates both modal response and transient response of a short drill string subjected to simulated cutting loads applied
Carne, T. G.   +2 more
core  

Discovery of edodine, a natural compound from Lentinula edodes with antibacterial activity for the biological control of fire blight pathogen Erwinia amylovora

open access: yesPest Management Science, EarlyView.
Novel edodine was identified from Lentinula edodes HK761, exhibiting biocontrol potential against fire blight by affecting motility, intracellular ATP level, and cell division of Erwinia amylovora. Abstract BACKGROUND In the search for biological resources with antibacterial activity against Erwinia amylovora, the culture filtrate of Lentinula edodes ...
Yeong Seok Kim   +7 more
wiley   +1 more source

Reaming While Drilling Drillstring Structure Optimization and Application Performance Evaluation

open access: yesShiyou jixie, 2016
The reaming tool BHA is the most important controllable factor during reaming while drilling operations,whereas the irrational drill string structure could lead to intensified drill string vibration.In view of this,the drill string-formation finite ...
Zhang Qiang, Fu Jianhong, Li Haoran
doaj  

The Myth of Decarbonized Oil: Technological Fixes, Climate Delay, and the Politics of Low‐Carbon Fossil Fuels

open access: yesSustainable Development, EarlyView.
ABSTRACT The idea of “decarbonized oil” has become increasingly visible in climate, energy, and corporate transition debates as oil and gas actors seek to reconcile continued fossil fuel production with net‐zero commitments. This article offers a critical narrative review of the concept, asking what political work the idea of decarbonized oil performs ...
Jacob Kwakye
wiley   +1 more source

EXPERIMENTAL AND NUMERICAL STUDIES OF DRILL-STRING DYNAMICS [PDF]

open access: yes, 2011
A drill string is the transmission component of rotary drill-rig system used for mining petroleum and natural gas resources. The drill-string system is essentially a long slender structure whose length can be in kilometers. Additionally, the drill-string
Liao, Chien-Min
core   +1 more source

Influence of Physical Parameters on Acoustic Transmission Characteristics of Drill String Channel

open access: yesShiyou jixie, 2019
The in-depth study of the transmission characteristics of sound waves in the drill string is of great significance for the development of sound transmission systems. The drill string is considered as pipeline composed of different uniform circular tubes.
Huang Mingquan, Zhao Guoshan, Tan Zhe
doaj  

Innovative 3D‐bioprinted microfibers in calcium phosphate cement platform with Nell‐1 to activate nerve‐bone axis for synergistic bone, vasculature, and nanofibrous nerve regeneration

open access: yesSmart Molecules, EarlyView.
A 3D‐bioprinted platform with stem cells activates “nerve‐bone” signaling by enabling the spatiotemporal delivery of Nell‐1. This activation enhances neurovascular and bone regeneration through the CYFIP1 cascade. In rat calvarial defects, the platform doubled bone regeneration and nerve repair and tripled vascular density, resulting in superior ...
Minjia Zhu   +11 more
wiley   +1 more source

Early Inspection of Drill String Fatigue Damage Based on Metal Magnetic Memory Method

open access: yesShiyou jixie, 2017
Drill string fracture frequently occurred during drilling operation seriously affected the exploration and development of oil and gas resources.To address the issue,the metal magnetic memory (MMM) detection technique was applied to the drill string ...
Hu Zhibin   +6 more
doaj  

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