Research On Design And Simulation Of Crown-block Heave Compensation Test System

In the process of deep-sea oil extraction,the offshore drilling platform will be affected by waves,typhoons,currents,tides,sea breeze and other factors,is facing a vagaries of environmental conditions.With impact of the waves,floating drilling device will produce six degrees of freedom of the swing movement about ups and downs,drift,vertical drift,pitching,shaking and rolling.Among them,a periodic sinking movement happened in most situation,which make drill reciprocating motion up and down,while the bottom hole pressure changes,resulting in drill bit from the bottom and life reduced of the drill and drill pipe.And even lead to drill bit can not get into then forced shutdown,which cause huge economic losses eventually.Therefore,in order to reduce the adverse impact and reduce the drilling cost,the floating drilling device must use the sinking compensation system to compensate the drill string sinking movement.Take the design research of the crane-type drill string compensation test system,which can simulate the various working conditions under the laboratory conditions and study the compensation of the heave.In this paper,a compensatory scheme of drill string heave compensation device based on crane is proposed.The floating crane,crane pulley and load are supported by hydraulic cylinder,and the crane moves up and down along the vertical direction.First of all,based on the similarity theory,we compare with the prototype parameters of crane compensation system,then determine the compensation period of the test device,compensation stroke,crane load,drilling pressure and other parameters.According to the working principle of the test device,the hydraulic system circuit of the compensation simulation system,the load simulation system and the compensation system are designed respectively.Based on Simulink software,the force model of the crane was established.The relationship between the crane displacement and the compensating cylinder in the vertical direction was analyzed.The structure of the swinging device of the test device was designed and the position of the fixed cylinder was determined.Modeling with Simulink software,the relationship between accumulator volume and system energy consumption is analyzed and the volume of accumulator is determined.The result shows that the larger the accumulator volume and the lower energy consumption of system,the decrease of the energy consumption decreases with the increase of the volume.Under the premise of considering the space and cost,the appropriate accumulator volume can be choosen.Compensated cylinder and analog cylinder use a composite hydraulic cylinder,the load cylinder with a common piston cylinder.The cylinder diameter,wall thickness,head flange thickness,piston size and port size of the cylinder were determined by the hydraulic cylinder design method,and the strength and stability of the compensating cylinder were also checked.In addition,the wire rope,bearings,motors,hydraulic pumps and a series of components were selected and calculated.Finally,a three-dimensional model of compensation test system is obtained by using SolidWorks software.The three-dimensional software is imported into ADAMS software,and establish the mechanical model of the whole compensation test system,get the hydraulic model of the test system in AMESim software,and then the whole system is simulated and analyzed.The simulation results show that the compensation effect of the passive compensation method is obviously lower than that of the active and semi-active compensation,while the active and semi-active compensation effect is remarkable,the displacement of the parking hook is small.There have small defference between the two kinds of compensation effect.However,the energy consumption of the active compensation method is obviously higher than that of the semi-active riser compensation method.The energy consumption of the semi-active riser compensation method is 10.7kJ,which is about 5.7% of the active energy consumption and the energy saving is obvious.This provides technical support and safeguards for future testing of prototype test equipment.