Research On Characteristics Of The Simulation BHA In Different State Of Motion

The lateral vibration of drilling pipe is destructive,which causes the eccentric wear and fatigue fracture of drilling tools as well as the downhole accident and increase of the cost of drilling.At home and abroad,there is no drilling dynamic simulation formation of the large displacement,multi-contact and open system.So study on drilling dynamic simulation formation is important to improve the service life of drilling tools,prevent the downhole accidents,and high quality,safety and fast drilling.In this paper,we use combination of experimental and theorectical analysis of the kinetics method.Firstly,through the indoor simulation experiment device of BHA motion and virbration acceleration motion simulationg in the vertical section and horizontal section,pointing out their respective motiong types and characteristics,conditions and experimental parameters influences.Secondly,according to the dynamic finite element theory,analysis model is established to simulate the BHA motion characteristic theory,and comparative of model results and experimental results.The results of the study is the simulation of drilling pipe can be divided into positive revolution or circle,arc shape swing,crescent swing,no rules of rotating,reverse vortex approximation,and backward whirl.In vertical well,rotating speed is main factor that affect the movement of the simulation BHA,and WOB,deviation angle,the distance from the downhole and size of simulation wellbore and simulation drilling pipe affect the motion of simulation BHA.In horizontal well,constraint and size of simulation wellbore and simulation drilling pipe is main factor.In simulation of BHA motion analysis model,its state of motion and vibration acceleration law is same as the results in experiment.