The article deals with the results of research on the use of thermomechanical methods of soil development during drilling for diagnosing the technical condition and repair of pipelines in various climatic condition. The design and technical characteristics of a drilling rig with the use of a gas turbine unit as a source of heat and electric energy are given. The description of the mathematical model of the thermomechanical effect of heat flow on the soil is given. The model is based on classical laws and equations of continuum mechanics. The method of determining the effective stresses in the soil depending on pressure surges and flow surges is given. The analysis of influence of density of a heat flux at heat exchange and mass transfer, on thermodynamic and gasdynamic characteristics of process of influence of a heat flux on a ground is carried out. The results of the studies showed a significant difference between the calculated values of tensile stresses in the soil when the soil is heated from 10 to 200 °C from the values of stresses determined by mathematical models that do not take into account heat transfer and mass transfer. Thus, at phase transitions and mass transfer of moisture (with a change in moisture content from 40 to 10%), the calculated deformation (shrinkage) of the soil from the horizontal surface was 25 %. At the same time, shear stresses increased from 0.3 to 1.5 MPa, which, in the presence of a difference in the moisture content and temperature fields, is comparable to stresses. Experimental – industrial designs and scientific bases for creation of new generation of the thermomechanical drilling tool for well diagnostics and repair of pipelines with application of mobile gas-turbine engine as sources of thermal and electric energy are developed.
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