The Experts below are selected from a list of 1140 Experts worldwide ranked by ideXlab platform

Su Kanhua - One of the best experts on this subject based on the ideXlab platform.

  • Review of Coupled Analysis between the Casing String and the Seabed Soil for Deepwater Drilling
    Journal of Chongqing University of Science and Technology, 2012
    Co-Authors: Su Kanhua
    Abstract:

    The drilling platform,riser,BOP stacks and the underwater Casing String are connected as a unit when deepwater drilling operating.The load of the marine environment acting on the drilling causes the dynamic interaction between the Casing String and the seabed soft soil.Then the seabed soil plays a supportive role to the Casing Strings,and the stability of subsea wellhead or Casing String becomes increasingly concerned.It will result in a lot of loss sometimes,therefore,the research on the wellhead mechanical stability for deepwater drilling and the interactions between the Casing String and seabed soft soil are reviewed.

Han Zhi-yong - One of the best experts on this subject based on the ideXlab platform.

  • Discussing on formula of tri-axial tension strength of Casing String
    Journal of China University of Petroleum, 2011
    Co-Authors: Han Zhi-yong
    Abstract:

    The formula of calculation tri-axial tension strength of Casing String given by SY/T5322-2000 design method of Casing String strength and SY/T 5724-2008 structure and strength design of Casing String is incorrect,which has a plus sign "+" instead of minus sign "-" in the radical of it.This conclusion can be obtained by theoretical derivation and comparing with the theory of two-axial stress ellipse.Another mistake is that the method of calculating axial force is incorrect.It is very important that two kinds of axial forces of actual axial force and effective axial force must be correctly distinguished and used in the combinational strength design of Casing String.The actual axial force calculated by pressure-area method must be used when tri-axial stress strength theory is used to the combinational strength design of Casing String,but the effective axial force is calculated by buoyancy-factor method in the two standards,so that the confusion and mistake are made.

  • Discussion on the new design standard for tri-axial stress anti-collapse strength of Casing String
    Journal of the University of Petroleum China, 2004
    Co-Authors: Han Zhi-yong
    Abstract:

    A main problem about calculation of axial stress in the Casing anti-collapse design using tri-axial stress strength theory in the new standard of design method for Casing String strength was discussed. It is pointed that the actual axial stress should be calculated using the pressure-area method. The very important formula for describing the relationship among actual axial stress, effective axial stress and fiction stress was given. Finally the correct formulas for Casing anti-collapse design using tri-axial stress strength theory were also given. Some new suggestions to improve the Casing strength design were presented.

Zhichuan Guan - One of the best experts on this subject based on the ideXlab platform.

  • A Theoretical Model of Residual Magnetic Field around a Pre-Magnetized Casing String
    Energies, 2020
    Co-Authors: Yucai Shi, Zhichuan Guan, Dongyue Jia, Xu Yuqiang, Yang Weixing, Duanrui Zhang
    Abstract:

    In the field of petroleum drilling engineering, passive magnetic ranging technology is generally used for specialized drilling operations such as connecting relief wells, preventing wellbore collisions, guiding parallel horizontal wells, etc. Although pre-magnetized Casing Strings have been used to improve the detection distance and accuracy, the theoretical mechanism is not well understood. Based on the equivalent current model of a permanent magnet, a theoretical magnetic field model around the pre-magnetized Casing String was established by using the vector potential method and vector superposition principle and validated by the COMSOL Multiphysics software. Our results show that connecting pre-magnetized individual Casings with homogeneous magnetic poles can enlarge the magnetic induction intensity around the total Casing String. Furthermore, the magnitude close to the Casing coupling is significantly larger than that close to the middle of the individual Casing. Connecting pre-magnetized individual Casings with heterogeneous magnetic poles results in a low magnetic induction intensity around the total Casing String. In order to improve the detection distance and accuracy of the magnetic ranging, the pre-magnetized individual Casings should be connected with homogeneous magnetic poles. The results of this study can provide guidelines for the development of passive magnetic ranging technology.

  • Dynamic Response of the Casing String in Seabed Soil for Deepwater Drilling
    Applied Mechanics and Materials, 2012
    Co-Authors: Kan Hua Su, Zhichuan Guan
    Abstract:

    The marine riser has transfer dynamic cyclic load to the top of Casing String when deepwater drilling operating. Considering with the nonlinear characteristics of seabed soil, the variable String cross section, and the axial load on the top of String, a dynamic differential equation of Casing String below mud line and its numerical solution were established. Results illustrate that, the lateral displacement, the bending moment, and the shear of the Casing String are not equal when lateral dynamic cyclic loading achieves amplitude due to the soil hysteresis effect. The diameter and wall thickness of conductor have less affect to String vibration frequency, cannot adjust the String natural frequency by adjusting these parameters. The natural frequency of Casing String in sand is bigger than it in clay. The undrained shear strength of soil has great effect on the natural frequency of Casing String in clay. The lateral displacement amplitude is highest when the vibration frequency of Casing String at its natural frequency.

Moe Key - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Two-Dimensional Corrosion Cavity on Casing Strength
    Petroleum Drilling Techniques, 2008
    Co-Authors: Moe Key
    Abstract:

    Casing String placed in the environment filled with fluid for a long time is prone to be corroded.Such cavities have various types including shallow-circular cavity,half-circular cavity and deep-circular cavity.Stress distributions and stress concentration factor(SCF) around those cavities are discussed.The effects of SCF on Casing burst strength and Casing collapse strength are analyzed and modified formulae are presented accordingly.The conclusion is that,with a constant open diameter,with the increase of cavity depth,the SCF increases and the Casing strength decreases.

  • Evaluation of Casing String Fatigue Strength under Alternating Stress Amplitude in Casing Drilling
    Petroleum Drilling Techniques, 2007
    Co-Authors: Moe Key
    Abstract:

    Casing Strings stand various alternating stress during Casing drilling.Formulas to calculate Casing String fatigue strength were developed under different drilling parameters for symmetrical circle and asymmetrical circle alternating stress.Effects of alternating stress amplitude on Casing fatigue strength are illustrated.A case analysis was provided with actual conditions in Casing drilling.The calculation results indicate that fatigue strength value calculated using asymmetrical circle model was larger than that of using symmetrical model,which indicates that the calculation result using symmetrical model is more conservative and therefore has higher safety coefficient.

Xiaoyu Huang - One of the best experts on this subject based on the ideXlab platform.

  • Multivariate Global Sensitivity Analysis for Casing String Using Neural Network
    International Journal of Computational Methods, 2020
    Co-Authors: Pan Wang, Shiwang Tan, Xiaoyu Huang
    Abstract:

    To evaluate the safety of Casing String is an important task in the oil exploitation. In this paper, the Casing String with complex environment is investigated and the global sensitivity analysis (...

  • Multivariate Global Sensitivity Analysis for Casing String Using Neural Network
    International Journal of Computational Methods, 2019
    Co-Authors: Pan Wang, Shiwang Tan, Xiaoyu Huang
    Abstract:

    To evaluate the safety of Casing String is an important task in the oil exploitation. In this paper, the Casing String with complex environment is investigated and the global sensitivity analysis (SA) technique is employed to identify the influential factors on the safety. Since the damage of Casing String is of different kinds, three failure modes are mainly considered in the analysis. Then, the multivariate global SA technique is employed to identify the influential factors for the three failure modes simultaneously. Due to the full-size FE analysis of Casing String which involves contact analysis of tread, being computationally expensive, a simplified model with full constraints are constructed. Then, to compute the multivariate global sensitivity efficiently, the neural network which is used to surrogate the FE model is employed to perform SA.