Effect of Pulsed Jet on Pore Pressure of Deep Formation Rock

Wang, Yong; Ni, Hongjian; Wang, Ruihe; Lei, Peng; Huang, Bin; Liu, Shubin; Li, Ning

doi:10.1155/2021/2217787

Cited by 51 publications

(1 citation statement)

References 18 publications

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“…According to references [20][21][22][23][24], the frequency of the fluctuation of cutting force depends on the following:…”

Section: Improvement Of Pdc Bit-rock Contact Force Modelmentioning

confidence: 99%

An Improved Model to Characterize Drill-String Vibrations in Rotary Drilling Applications

Wang¹,

Ni²,

Wang³

et al. 2022

Fluid Dynamics &Amp; Materials Processing

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A specific model is elaborated for stick-slip and bit-bounce vibrations, which are dangerous dynamic phenomena typically encountered in the context of rotary drilling applications. Such a model takes into account two coupled degrees of freedom of drill-string vibrations. Moreover, it assumes a state-dependent time delay and a viscous damping for both the axial and torsional vibrations and relies on a sawtooth function to account for the cutting force fluctuation. In the frame of this theoretical approach, the influence of rock brittleness on the stability of the drill string is calculated via direct integration of the model equations. The results show that the rock brittleness has a great influence on the rotational speed and bit depth.

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“…According to references [20][21][22][23][24], the frequency of the fluctuation of cutting force depends on the following:…”

Section: Improvement Of Pdc Bit-rock Contact Force Modelmentioning

confidence: 99%

An Improved Model to Characterize Drill-String Vibrations in Rotary Drilling Applications

Wang¹,

Ni²,

Wang³

et al. 2022

Fluid Dynamics &Amp; Materials Processing

Self Cite

View full text Add to dashboard Cite

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Seismic performance loss evaluation of reinforced concrete frame structure based on updatable damage model

Li,

Lu,

Teng

2024

Earthquake Engineering and Resilience

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As structural seismic damage develops, the internal force transfer and damage weight relationship of component are constantly changing, and the fixed weighted coefficient is adopted by the traditional weighted method, which cannot reflect the changes in the structural damage state. The structure is a network formed by connecting a large number of components, and the network state undergoes complex changes with the development of component damage. In this paper, a novel method for component damage transfer to structural seismic performance loss is proposed using network shortest paths. First, a directed weighted complex network based on force transfer direction and component stiffness is constructed for reinforced concrete (RC) frame structures. Then, the component damage is calculated by the degradation of its stiffness and is used to update the weight distribution of the damage network. Finally, the structural performance loss is evaluated by the degradation of damage network efficiency. Results show that the proposed method with an updated component weight relationship is able to reflect the true loss of structural performance according to the finite element dynamic elastic‐plastic analysis of RC frame structures. For the structural performance loss degree (none, slight, moderate, severe, complete), the proposed method and the weighted method both exhibit high accuracy (number correctly classified/total number of samples) when structural performance loss is none, severe, or complete loss. The accuracy of the proposed method is significantly higher than that of the weighted method when structural performance loss is slight and moderate loss, with 58.1% and 84.2% improvement, respectively. For structural typical damage modes (global, local, and weak layer damage mode), the proposed method and the weighted method both exhibit high accuracy when structures exhibit global damage mode. The accuracy of the proposed method is significantly higher than that of the weighted method when structures exhibit local and weak layer damage mode. The accuracy of the proposed method is stable at 95.2%, while the accuracy of the weighted method is 76.2% and 70.2%, respectively. Overall, the weighted method exhibits high accuracy when structural performance loss is less than slight loss or greater than moderate loss, while the proposed method exhibits high accuracy throughout the entire process of structural performance loss, especially in moderate loss.

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Efficacious constrained layer damping of carbon black‐reinforced nitrile butadiene rubber‐polyvinyl chloride blend vulcanizates: A comprehensive study

Sharma,

Kumaraswamy,

et al. 2024

Polymer Engineering & Sci

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We report efficacious vibration damping of carbon black reinforced nitrile butadiene rubber‐polyvinyl chloride blend (NVC) vulcanizates in a constrained layer damping (CLD) configuration. The objective is to compare numerical simulations using finite element method (FEM) and the widely used Ross‐Kerwin‐Ungar (RKU) model with the experimental results. NVC blend (50:50 by weight), was compounded with carbon black as reinforcing filler and vulcanized using a sulfur‐based curative system. Significant reinforcement and toughening were observed for the carbon black reinforced vulcanizates compared to the pristine blend. The viscoelastic properties of the vulcanizates were assessed using dynamic mechanical analysis (DMA), exploring their behavior concerning temperature variations and different frequencies to generate the Prony series coefficients for input in FEM analysis. Vibration damping experiments were conducted using the Oberst beam method in a single cantilever mode, with steel as the vibrating substrate, aluminum as the constraining layer, and the NVC vulcanizates as viscoelastic materials (VEM). Numerical simulations were performed using FEM to analyze mode shapes and frequency response function (FRF), and the RKU model was employed to quantify CLD system loss factors (SLF). The salient finding of this study was the observed SLF values in the range of 0.08–0.20 in the frequency regime of 200–2000 Hz. These values qualify the studied material as effective VEMs for CLD treatment of structural vibrations. This study supports design optimization efforts in a wide range of engineering applications where effective vibration damping is critical.Highlights Enhancement of NVC blend properties through carbon black reinforcement. Detailed analysis of viscoelastic behavior using DMA. Validation of findings through experimental modal analysis. Promising results in terms of system loss factors for CLD applications.

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Effect of Pulsed Jet on Pore Pressure of Deep Formation Rock

Cited by 51 publications

References 18 publications

An Improved Model to Characterize Drill-String Vibrations in Rotary Drilling Applications

An Improved Model to Characterize Drill-String Vibrations in Rotary Drilling Applications

Seismic performance loss evaluation of reinforced concrete frame structure based on updatable damage model

Efficacious constrained layer damping of carbon black‐reinforced nitrile butadiene rubber‐polyvinyl chloride blend vulcanizates: A comprehensive study

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