Stress Analysis And Stress Distribution Numerical Simulation Of Shale Horizontal Wells

The exploitation of shale oil and gas requires large-scale fracturing.Such high-strength construction will cause different degrees of damage to the casing.Therefore,it is important to analyze the casing stress and stress distribution in the horizontal section of shale horizontal wells,which is of great engineering significance for preventing casing damage.This paper investigates a large number of relevant literatures at home and abroad,and conducts research on the following contents:(1)This paper calculates the frictional force and axial force of the vertical section and the horizontal section casing during the running process,and calculates the frictional force and axial force of the curved section casing during the running process based on the soft rod model and the rigid rod model.The results show that the axial load of the casing decreases with the increase of the well depth.As the depth of the well increases,the frictional resistance can be small before the slanting section,and the it gradually increased after the slanting section.(2)In this paper,ABAQUS finite element simulation software is used to simulate the distribution of casing stress in the process of fracturing with some factors.The results show that for every 1 ~oC increased in the formation temperature,the stress acting on the casing increased by 2Mpa.Under uneven load,the maximum equivalent stress of the casing is obviously increased,and the radial stress distribution of the casing is uneven.(3)The ABAQUS software was used to simulate the influence of temperature and uneven load coupling factors on the stress distribution of the casing.The research shows that the casing has characteristics of small force at the two cross-section ends and large force in the middle section,and the radial section of the middle section casing is unevenly stressed.Because of the uneven distribution of stress,the casing is deformed elliptical.(4)The stress distribution law of the casing is analyzed under the consideration of the actual casing internal pressure,temperature and uneven load.The research shows that the overall stress of the whole casing is large,and the stress values of the two axial planes with the phase angle difference of 90 degrees are very different,which causes the casing to undergo elliptical deformation.