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

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 229
Author(s):  
Yuqiang Xu ◽  
Hongning Zhang ◽  
Zhichuan Guan
Keyword(s):  
Energy Conversion ◽  
Conversion Efficiency ◽  
Rotation Rate ◽  
Longitudinal Vibration ◽  
Drill Pipe ◽  
Energy Conversion Efficiency ◽  
Elastic Stiffness ◽  
Positive Influence ◽  
Drill String ◽  
String Vibration

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 of the energy conversion efficiency of downhole drill string vibration. In this paper, the characteristics of downhole bit load and longitudinal vibration of drill string under different conditions were studied in the experiment, and the analysis method of energy conversion efficiency from drill string vibration to spring potential energy was proposed. The experimental analysis showed that the fluctuation of the downhole bit load was reduced by 10%–90% after the spring was installed in the bottom hole assembly. The rotation rate and the spring elastic stiffness had a significant and positive influence on the fluctuation amplitude of the downhole bit load. Meanwhile, the longitudinal vibration amplitude and acceleration of the drill string peaked at the elastic stiffness of 1 kN/mm. The closer the spring position to the drill bit was, the more severe the longitudinal vibration of the drill string above the spring component was. The bit load and the rotation rate had a positive influence on the severity of longitudinal vibration. The analysis of energy conversion efficiency showed that the available mechanical energy range of the longitudinal vibration of the drill pipe was about 200–420 kW. The work power of the drill string vibration to the spring component increased sharply and then decreased with the increasing of elastic stiffness. The energy conversion efficiency came to the optimal value when the elastic stiffness was between 1 kN/mm and 2 kN/mm. Increasing the rotation rate, keeping the bit load below 134.5 kN and installing the spring component near the drill bit are beneficial for improving the energy conversion efficiency of drill string vibration. This paper reveals the main factors affecting the energy conversion efficiency of drill string vibration and their influencing laws, and determines the range of WOB, rotation speed, spring position and stiffness to obtain the best energy conversion efficiency.

First-principles study on the electronic and optical properties of the orthorhombic CsPbBr3 and CsPbI3 with Cmcm space group

2021 ◽  
Author(s):  
Xianhao Zhao ◽  
Tianyu Tang ◽  
Quan Xie ◽  
like gao ◽  
Limin Lu ◽  
...  
Keyword(s):  
Optical Properties ◽  
Solar Cells ◽  
Energy Conversion ◽  
Conversion Efficiency ◽  
First Principles ◽  
Energy Conversion Efficiency ◽  
Space Group ◽  
Absorbing Materials ◽  
Halide Perovskites ◽  
Lead Halide

The cesium lead halide perovskites are regarded as effective candidates for light-absorbing materials in solar cells, which have shown excellent performances in experiments such as promising energy conversion efficiency. In...

Metal-like electrical conductivity in LaxSr2−xTiMoO6 oxides for high temperature thermoelectric power generation

2017 ◽  
Vol 46 (18) ◽  
pp. 5872-5879 ◽  
Author(s):  
Mandvi Saxena ◽  
Tanmoy Maiti
Keyword(s):  
Power Generation ◽  
Electrical Conductivity ◽  
High Temperature ◽  
Energy Conversion ◽  
Thermoelectric Power ◽  
Conversion Efficiency ◽  
Energy Conversion Efficiency ◽  
Power Generators ◽  
Thermoelectric Power Generation

Increasing electrical conductivity in oxides, which are inherently insulators, can be a potential route in developing oxide-based thermoelectric power generators with higher energy conversion efficiency.

Performance Improvements in Cooker-Top Gas Burners for Small Aspect Ratio Changes

2017 ◽  
Vol 9 (4) ◽  
Author(s):  
Robson L. Silva ◽  
Bruno V. Sant′Ana ◽  
José R. Patelli ◽  
Marcelo M. Vieira
Keyword(s):  
Energy Conversion ◽  
Fuel Consumption ◽  
Conversion Efficiency ◽  
Minimum Energy ◽  
Energy Conversion Efficiency ◽  
Energy Performance ◽  
Operating Conditions ◽  
Lower Fuel Consumption ◽  
Performance Improvements ◽  
Aspect Ratios

This paper aims to identify performance improvements in cooker-top gas burners for changes in its original geometry, with aspect ratios (ARs) ranging from 0.25 to 0.56 and from 0.28 to 0.64. It operates on liquefied petroleum gas (LPG) and five thermal power (TP) levels. Considering the large number of cooker-top burners currently being used, even slight improvements in thermal performance resulting from a better design and recommended operating condition will lead to a significant reduction of energy consumption and costs. Appropriate instrumentation was used to carry out the measurements and methodology applied was based on regulations from INMETRO (CONPET program for energy conversion efficiency in cook top and kilns), ABNT (Brazilian Technical Standards Normative) and ANP—National Agency of Petroleum, Natural Gas (NG) and Biofuels. The results allow subsidizing recommendations to minimum energy performance standards (MEPS) for residential use, providing also higher energy conversion efficiency and/or lower fuel consumption. Main conclusions are: (i) Smaller aspect ratios result in the same heating capacity and higher efficiency; (ii) higher aspect ratios (original burners) are fuel consuming and inefficient; (iii) operating conditions set on intermediate are lower fuel consumption without significant differences in temperature increases; (iv) Reynolds number lower than 500 provides higher efficiencies.

Improvement of energy-conversion efficiency from laser to proton beam in a laser-foil interaction

2008 ◽  
Vol 78 (4) ◽  
Author(s):  
Y. Nodera ◽  
S. Kawata ◽  
N. Onuma ◽  
J. Limpouch ◽  
O. Klimo ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Proton Beam ◽  
Conversion Efficiency ◽  
Energy Conversion Efficiency

TiO2 cement for high-performance dye-sensitized solar cells

RSC Advances ◽  
2016 ◽  
Vol 6 (87) ◽  
pp. 83802-83807 ◽  
Author(s):  
Yu Hou ◽  
Shuang Yang ◽  
Chunzhong Li ◽  
Huijun Zhao ◽  
Hua Gui Yang
Keyword(s):  
Solar Cells ◽  
Energy Conversion ◽  
Conversion Efficiency ◽  
High Performance ◽  
Dye Sensitized Solar Cells ◽  
Energy Conversion Efficiency ◽  
Dye Sensitized ◽  
Degussa P25 ◽  
Sensitized Solar Cells

An energy conversion efficiency of 8.31% is reached by using a cemented photoanode for dye-sensitized solar cells, attaining a 31.1% improvement over the standard Degussa P25 sample.

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