Vasylyshyn V. Improving efficiency of threaded connections oil pipe.

Thesis is devoted to theoretical and experimental investigation of important scientific and technical problems increase efficiency of threaded joints of casing and tubing. Reliability analysis mounting and operation of gas wells showed that disability casing and tubing mainly related to structural and technological deviations of threaded connections. In this regard, the necessity of developing threaded joints in enhancing their integrity, improved methods of calculating the parameters of efficiency. Improved method for determining the axisymmetric stress-strain state of thick-walled cylindrical shell- tube using three-dimensional equations of elasticity. A complete system of equations to determine the stress and strain in the casing and tubing, which is under complex loading. A method for assessing the compatibility of the tubing down hole environment , especially in the extraction of shale gas, and the four approaches to assessing the residual life of tubing . Retrieved refined patterns influence of design and operating factors on the performance of threaded pipe connections that are most responsible element columns. A graph-analytic study of geometrical parameters of threaded connections, including threaded discharging grooves, thereby creating a multi-dimensional vibrational graph-analytic model for the optimization of geometrical parameters. Developed and proposed a device for sealing joints coupling casing. The device is patented in Ukraine for utility model and was pilot tested for tightness. The results of laboratory tests tubing fatigue curve obtained parameters and the method of predicting the residual life of its essential value of probability not destruction.