Simulation And Safety Evaluation Of Slotted Screen In Heavy Oil Thermal Horizontal Well

As one of the important ways of thermal recovery of heavy oil,horizontal wells are widely used in major heavy oil reservoirs at home and abroad.Thermal mining often brings sand production damage to the formation.As a traditional sand control tool,slotted screen pipe has superior flow performance and high formation adaptability,and has high matching degree with sand control completion process requirements of heavy oil horizontal wells.However,the complex wellbore structure of horizontal wells and the special technology of thermal recovery lead to the complex working conditions of screen pipe in the process of entry and service,which have a great impact on its structure and safety performance.The simulation and safety performance evaluation of the working conditions of slotted screen pipe in the process of entry and service are the key steps to optimize and improve the applicability and integrity of sand control and completion design.In this paper,based on theoretical analysis,combined with the method of simulation and laboratory experiments,the working conditions of the slotted screen are classified.Through the analysis of the force under friction,buckling,bending and other working conditions in the process of loading,the passage and safety of the bending section are studied.The stress and fatigue behavior of the sieve tube under thermal stress were studied by combining theory with simulation.The indoor experimental simulation of corrosion erosion and other conditions was carried out,the corresponding prediction model was established,and the safety performance evaluation method under various conditions was given.The results show that the complex force of the sieve tube in the process of entering is mainly concentrated in the curved section of the wellbore,and the buckling,bending and other behaviors generated when passing through this section are the key factors restricting its passing.The length,thickness and diameter of the sieve tube are important factors affecting the safety performance of the sieve tube in the process of entering.The increase of temperature in the process of thermal recovery has obvious influence on the strength of the screen pipe.The high temperature will significantly reduce the structural strength of the screen pipe,and the periodic heat injection at the bottom of the well will lead to thermal stress fatigue of the screen pipe.Corrosion reduces the thinning strength of the pipe wall,and the safety performance of the sieve tube will not meet the production requirements when the corrosion depth of the sieve tube reaches the critical value.Liquid production,sand production and other parameters are important factors affecting the safety performance of screen pipe erosion,and the rationality of production system must be considered when selecting screen pipe.