Research And Design Based On Virtual Prototype Technology Of Drawworks Heave Compensation System

As a general rule,deepwater drilling platform is floating or semi-submersible platform.Influenced by ocean wave,platform can produce periodical heave movement which can drives hook and drill string to move together.It will result in changes of bit weight and can make unfavorable influences to drilling.So the heave compensator is necessary on the drilling platform.Drawworks heave compensation system is a new compensation technology put forward in the past few years.Compared with the traditional compensation system,Drawworks heave compensation system has the following advantages: not need to install special compensation device,taking up little platform space,compensative travel being not limited by compensation hydraulic cylinder travel,rapid response and saving drilling cost.This paper takes the drawworks heave compensation system as the studying object and puts forward a semi active heave compensation system with high compensation efficiency and low energy consumption.Automation drilling is one of key technology used in offshore drilling and has a decisive influence on drilling quality.So the study of automatic drilling based on the heave compensation system is necessary.Based on the analysis of working principle of active drawworks compensation system,this thesis put forward a semi-active compensation scheme.Hydraulic control module with energy recovery function was added.Through selecting and calculating the hydraulic system components,the hydraulic circuit was designed.At the same time,mathematical model of drawworks heave compensation system was established.Model of virtual prototype drawworks heave compensation system was established.This research used the ADAMS to set up mechanical model of drawworks heave compensation system.With the MATLAB/Simulink,this paper built the active compensation motor and hydraulic system model.This study analyzed the passive,active and semi-active drawworks heave compensation system and compared the compensation effect of three kinds of compensation.And this paper analyzed and compared the motor power and system energy consumption of active compensation and semi-active compensation under different well depth.Aimed at pressure and volume working cylinder and heave amplitude,study of simulation of semi-active drawworks heave compensation system was carried out and influence of different parameters on the compensation effect of system,motor power and energy consumption.This thesis carried out the simulation of semi-active drawworks heave compensation scheme which was based on differential planetary transmissions hardware motion-decoupling.Two new decoupling control schemes of heave compensation movement and automatic drilling motion such as double drawworks driving motion decoupling,composite control software decoupling of heave disturbance feedforward and automatic bit feed with constant drilling pressure.Through establishing model of virtual prototype of three decoupling control schemes,this paper analyzed and compared the result of simulation of three decoupling control schemes.