The Structure Optimal Design And Finite Element Simulation Analysis To The Hydraulic Thruster

With the development of high angle well, the maturity of the horizontal well drilling technology and the increasing maturity of slim hole wells technology application, and at the same time, the increased angle, or the increase of friction of shaft wall, the poor rigidity of the drilling instrument, the traditional way of applying drilling pressure can not meet the need of construction.Hydraulic pressurizing device is commonly used in the large displacement wells, horizontal well drilling and work over job. Hydraulic thruster converts mud power into axial thrust through throttling action, it can reduce the pressure fluctuation because of the coupled vibration of drill string and the interaction between the drill bit and rock, thereby exerts a constant pressure, extends bit life, reduce drilling tool fatigue failure and improve drilling efficiency, and it is a device that can provide pressure into the high pressure mud rock fracturing pressure. Traditionally, the drilling is to rely on the lower drill collar on broken rock drilling pressure. And hydraulic pressure device is through with the drill bits and other tools to implement connection, so as to realize the flexible pressurized. Compared with traditional way of rigid drilling, the drilling efficiency of hydraulic pressurizing device is higher, and the quality is better, and the cost is lower. By using hydraulic pressurizing device can provide constant drilling pressure, and at the same time, the number of drilling string can be reduced. The problems from horizontal well and large displacement wells and can be solved.In the drilling process of directional well and horizontal well, cuttings bed, borehole trajectory which is not smooth, and poor performance of drilling fluid cause the increasing of the friction between the drill string and borehole wall, which leads to the decreasing of the hook load counter parted the friction between the drill string and borehole wall, and added on the bit. This phenomenon of backing pressure will greatly reduce the rate of penetration, which can increase the risk of drilling operation. The hydraulic thruster has been applied in our country to solve the problem of supporting pressure for decades, but that did not get very good effect, therefore, the design and research of new hydraulic thruster has a significant meaning.On the basis of current situation and existing problems of hydraulic pressure machine at home and abroad, and put forward the optimization design of hydraulic pressure machine, and put up the study. It mainly includes the following several aspects:(1) Research the paper at home and abroad as well as the development and application of hydraulic pressure machine.(2) The principle of hydraulic pressure were studied, and analyze the principle of every parts and components, and combined with the actual situation of drilling site for each parameter of the research.(3) Refer to relevant national industry standards. For hydraulic pressure device, based on the reference of previous similar device structure design, optimize the unreasonable part of or to improve. At the same time, and check all parameters for design of hydraulic pressure. And carry on the optimization design of hydraulic pressure machine:First, change the six-party drill pipe to circular cylinder, add external splines on the outer surface, And there are internal splines on the cylinder processing, The effect of torque occurs by spline fit, avoid the happening of the stuck phenomenon. Use spline connection on the main cylinder and the main piston rod, and reduce the torque when the contact pressure, and reduce the longitudinal vibration drilling string, and make sure the safety of drilling tools.Secondly, a pressure regulating system is designed. Adjust the weight on bit by changing the choke spear plug and choke ring over-current sectional area,and solve the drill down too quickly when the pressure cylinder and drill free when drill down slowly reduce drilling efficiency.At the same time, the hydraulic pressure is analyzed with mechanics and finite element simulation. And calculate the drilling pressure of hydraulic pressure machine. And for the main components of the piston rod,hydraulic pressure device and the main block is calculated and contact analysis and finite element simulation, to make sure the safety of the hydraulic pressurizing device. The subject is of certain guidance to the practical engineering problem.