Design And Analysis Of The Pre-contoured Stator Downhole Motor

This thesis is aimed at research content of sub topic "high torque motor key technology research and prototype development" which is led and in charged by CHENGDU BEST CO for researching on pre-contoured stator down-hole motor design.Moderate multi-branched diversion sand technology is used in mining sea loose sandstone heavy oil reservoir. The well trajectory of large included angle multi-branched diversion well is complicated, conventional angle building would cause low efficiency, high frictional resistance, and limited output torque so that it can’t meet the requirements of drilling operation. The main content of the thesis is to develop a high torque, high efficiency pre-contoured stator down-hole motor and do indoor and field test in order to form engineering ability and break the multinational corporation monopoly situation of high torque motor key technology, provide drilling technology and tool for moderate multi-branched diversion sand technology in mining sea loose sandstone heavy oi01 reservoir.This paper discusses the screw motor, cycloidal type linear design process, the pre contour of screw drill design and analysis of related problems, a new algorithm is proposed for solving the linear motor and the conjugate, new algorithm to present common cycloid, epicycloid and short amplitude cycloid motor three curve; with the help of Visual Basic6.0 the development of software, complete the screw motor linear analysis system software, the design parameters optimization of short amplitude coefficient and equal amplitude coefficient, improve the working performance of the motor; pre processing contour screw motor rotor, motor stator, plastic injection process difference among both ends of rubber injection, the pre contour screw motor pre injection process; outline of the screw motor performance test in LSY-Ⅲ Motor Company Chengdu best test bench, predict profile of screw drill machine performance parameters; construction The same linear motor of phi 244 mm routine, pre outline two screw motor stator rubber 3D model into finite element analysis software, and to explore the two types of screw motor stator rubber performance differences.In view of the above problems, mainly carried out the following theoretical research:In view of the above design and research, get following conclusions:(1)、Aimed at solving pre-contoured stator down-hole motor design and analysis problems, provide new algorithm of conjugate linear, using cycloid formula to draw stator or rotator’s offset curve, realize the planetary motion of stator and rotator by using programming language cyclic algorithm, get conjugate curve; according to new algorithm of motor linear, select common internal cycloid, short width internal cycloid and short width epicycloid as motor design linear, accomplish software writing ((screw motor linear calculate analysis system V1.0》(2)、select short width internal cycloid as pre-contoured stator down-hole motor design linear, do optimization design to short width coefficients k0, offset coefficients r0,get when k0=0.8-0.9, r0=1.8-2.0, the performance of the motor show ideal conclusions, meet design requirements and further calculate gets: k0=0.86, r0=1.96.(3)、Confirm the main technic parameters of the pre-contoured stator down-hole motor, Pitch of the stator and rotator is 175mm,5 rotators, motor displacement per round 22.92(L/r), the level of motor is 3.5, design calculate flow 55L/s, theoretical speed is 143.9 R/Min, effective working differential pressure is 5.25MPa, working torque is 17701.2 N·M, corresponding effective working differential pressure, max torque is 29501.9 N·M, corresponding max effective working differential pressure.(4)、Elaborated the processing technology of (p244mm pre-contoured stator down-hole motor, select milling technology to process the spiral surface of stator. Use LXY300X NC spiral groove milling machine to process rotator of φp244mm pre-contoured motor, compare the difference between stator middle and both ends plastic injections, make sure middle plastic injection progress.(5)、By using motor performance test platform to test the working performance of pre-contoured stator down-hole motor and get the contact of "differential pressure-tator/rotator inner leakage flow" and "differential pressure-driving torque", predict the parameter performance of the motor. Single stage working differential pressure is 1.16 ～ 1.332MPa, meet the requirements. The experiment result shows, when entrance flow is 45-65L/s, working torque is 15203.0 ～17557.9Nm, working differential pressure is 5.25～6.30MPa, max torque is20718.9～24447.9N.m, meet the requirements. The rationality is verified further, the result has great meaning to field working.(6)、Thickness of the stator rubber is uniform, the deformation of the rubber is uniform under the uniform pressure and it’s less than ordinary motor rubber max deformation, about 50%. The thickness of the rubber bushing of the conventional screw motor is uneven, under the action of uniform pressure. The profile shape of the rubber sleeve cannot be deformed, thereby affecting the sealing performance of the motor. In the amount of interference in the process of selecting, uneven thickness of conventional screw rubber motor, each contact point occurred deformation range have caused some difficulties in the selection of the amount of interference, and consistent pre contour screw motor rubber thickness, the contact point method to deformation displacement are consistent, favorable in the stator and rotor assembly process over the selection of the amount of interference.The stress distribution law of the screw motor rubber bushing under uniform pressure is similar. The maximum value is located at the bottom of rubber line. Under the same load, the thickness of the pre contour liner increases, the maximum displacement increases, the maximum equivalent stress decreases, and the stress changes tend to be gentle.