CALCULATION OF RATIONAL BENDING MOMENTS OF LOCKING THREADED CONNECTIONS BT AND WDP FOR DRILLING DEEP WELLS

Abstract

The paper considers one of the problems of safe construction of deep wells, which is related to the reliability of threaded connections of drill string elements. The reliability of locking threaded connections, for the most part, depends on the value of the screwing torque, which must be optimal. The optimal screwing torque was studied on full-scale samples of threaded connections, which were subjected to cyclic loads on special laboratory equipment.

During the research, strain gauges were used that recorded the load values not only on the threaded connection itself, but also on the nearest parts of the pipe body. Thus, the static strength characteristics of the pipe body, which have mostly always been neglected by scientists, were taken into account.

Based on laboratory studies that require industrial confirmation, the limits of the maximum permissible values of the screwing torque for different sizes of lock threaded connections have been established in order to increase their durability in the conditions of operation of deep wells. In addition to the calculation ratios that make it possible to calculate the stress value in the most dangerous cross-section of the structure, the results of the studies specified in the corresponding tables 1 and 2 are also given for pipes of different strength types under conditions of different values of the Poisson's ratio. All information, in particular, the value of the screwing torque in the tables is given in values corresponding to SI.