Study On Penetration Resistance Of Conductor Casing

During the installation of oil and gas drilling structures in soil there are possibilities of washout,hydraulic fracture or other drilling problem endangering the soil foundation.Soil is characterized by strain rate dependency and when soils are sheared and remoulded it exhibits a soften behaviour.There has been convectional design method established on the principle of rate-independent perfectly plastic soil.On the other hand conductor casing is a structural foundation designed to provide protection to drilling and production equipment,and provides a stable support for the wellhead and Christmas tree.There have been many works on structures driven into the soil using a range of piling technique,but less study on the conductor casing soil interaction behaviour.In this thesis a vertically loaded conductor casing penetrating soft and stiff clay soil has been studied using finite element numerical methods.This project has reviewed fundamentals and existing theories for piles,pile-soil interaction,test and analytical methods whose theories is analogous to conductor casing.Johnson-Cook constitutive model was applied in this numerical analysis to take into account Stain rate.The Johnson-Cook(JC)constitutive model and Arbitrary Lagrangian-Eulerian method(ALE),using ABAQUS/Standard and Explicit were employed for the analysis to simulate deformations during the conductor casing penetration process.This study has considered only the right half of a simplified geometry of the conductor casing,modelled as a cylindrical pipe of 60 m length with outer diameter of 0.76 m and a thickness of 0.025 m.This analysis will show stresses effect on the conductor behavior in the soil and allow for the estimation of the effects of conductor casing penetration process.