The Mechanical Research And Software Realization Of Workover Tubing String Under Several Typical Working Conditions

Due to oil and gas resources are increasingly exhausted in the world,the permeability of oil and gas wells is extremely low,so the growth of oil and gas production is more and more dependent on large displacement wells and horizontal wells.The large displacement wells have the characteristics of long horizontal section,high slope and long open hole.In the operation process,the working environment of workover tubing is very complex,and complex deformation,which may lead to the failure of workover tube,leading to operation accidents,and mission can not be done.In order to solve such problems,the following work was done 。In the background of the workover tubing string mechanics,the important research results of the domestic and foreign scholars in the string mechanics are investigated.Using the principle of cubic spline interpolation fitting curve,fitting the well trajectory curve of the extended reach well,and the fitting method is programmed.By assuming the working condition of the large displacement well,the kinematics equation and constitutive equation of the workover rig are established,the mechanical characteristics of workover tubing string is analyzed,and the mechanical model of the workover pipe string is deduced.Using the finite difference method,the numerical analysis of the model,is programmed.The data of three typical conditions of the decentralized column,hoisting string and drilling operation prove the feasibility of the model prediction analysis.The Software Realization of the workover rig pipe mechanics model is done,through the database technology,the workover rig,database and hole trajectory database are established,the wellbore trajectory curve and workover pipe are analyzed visually.