Simulation And Laboratory Simulation Of Heave Compensation System Load In Deep Sea Floating Drilling Platform

In order to ensure the safety and efficiency of ultra-deep floating drilling operation,the heave compensation system must be used to maintain the stability of the bottom hole pressure of the drill string when the floating platform is used for ultra-deep drilling operation.Because the drill string in ultra-deep drilling is very long,it is difficult to directly use the drill pressure at the bottom of the drill string as the feedback signal of the heave compensation system;the control of the drill pressure is usually realized by the heave compensation system to compensate the displacement of the hook at the top of the drill string.The relationship between the variation range of bit pressure and the variation range of hook displacement depends on the load of heave compensation system,i.e.the stiffness of drill string.This paper mainly studies the influence of stiffness and stiffness of drill string on the compensation performance of drill string heave compensation system.The combination of simulation and experimental research is the best way to verify the solution.In order to explore the relationship between the stiffness of drill pipe and the accuracy of heave compensation system,the following work has been done:1.After understanding the workflow of deep-sea drill string,the axial force analysis of the load of the drill string heave compensation system is completed.The stiffness of drill string is solved by simulation software and theoretical calculation,and the axial stiffness and the axial deformation of drill string are obtained.2.The relationship between the laboratory model and the actual model is deduced by dimensional analysis method,and the selection of spring stiffness and mass block for laboratory simulated load is completed.3.The simulation model of winch heave compensation model system based on open variable pump and proportional valve is established by using AMESim software.The speed characteristics of winch controlled by servo motor and proportional valve are simulated and analyzed respectively.The control system of winch heave compensation model system is designed by using Simulink and AMESim simulation.The relationship between the compensation range of the drill string heave system and the stiffness of the drill string.4.According to the control principle of the winch heave compensation system test-bed,a winch heave compensation model system based on open variable pump and proportional valve is built.The relationship between the compensation range of the drill string heave compensation system and the stiffness of the drill string is verified by experiments.