Optimization On Magnetic Torque Drive Of Hydraulic-Magnetic Hole Cleaning Tool

In the process of drilling,it is difficult to carry cuttings in horizontal well section and it is easy to form cuttings bed.Therefore,a new type of hydraulic magnetic drive cuttings remover has been developed,but the influence mechanism of its magnetic torque drive,the best magnetic circuit structure and magnet configuration are not clear.Therefore,the finite element numerical simulation method and the magnetic Coulomb numerical calculation method are used to analyze the factors that affect the magnetic torque transmission.At the same time,according to the Halbach magnet array structure,the magnetic circuit parameters of the magnetic transmission mechanism are further optimized to obtain the optimal magnet configuration.The results show that:(1)The transfer efficiency of magnetic torque can be improved by increasing the flux density of air gap,reducing the magnetic resistance of magnetic circuit and increasing the storage of static magnetic energy;(2)The magnetic torque increases first and then decreases with the increase of the couple pairs,and the magnetic torque of 12 pairs of couples reaches the maximum;(3)Under the condition of large thickness and high coverage area of permanent magnet,the negative positive array model is generated The magnetic torque is far better than that produced by the radial array model under the same configuration;(4)The hydraulic magnetic drive cuttings remover is used together with the conventional 5-inch drill pipe to meet the structural support requirements,the shell thickness is 9-10 mm,and the permanent magnet layout is negative positive array model.There are 12 pairs of pairs of pairs of pairs of pairs of magnetic couple,9.5-10.5mm for the thickness of permanent magnet,and 100% full coverage for the coverage area;(5)The absolute error between the indoor experimental results and the results of various calculation methods is less than 17%,which can meet the accuracy requirements of Engineering calculation.The results show that the models are reasonable,and Halbach array structure can better excite magnet efficiency,which can be used as a technical means of structural optimization design of the tool.