SOME FEATURES OF ROCK DESTRUCTION AT THE BOTTOM OF THE WELL

Abstract

Purpose of the work was establishment of the physical nature of the phenomena occurring during the separation of a rock element from the massif under the action of external pressure and circulation of activated flushing fluids. The latter will make it possible to determine the most rational parameters of the process of destruction of rocks at the bottom of the well and the hydraulic program of circulation of the cleaning agent, and the result of this should be obtaining the maximum productivity of the drilling cycle with minimum energy consumption. Complex laboratory and analytical techniques were used to study the features of rock destruction technology, taking into account the influence of hydrostatic pressure, physicochemical parameters of the cleaning agent, features of the hydraulic program and properties of the rock mass. The main regularities of the destruction of rocks at high hydrostatic pressure are revealed directly in natural conditions. The method of physical modeling, which is the basis for the indicated studies, is characterized, first of all, by the fact that research is possible on samples that provide the maximum similarity of the destruction process, during laboratory tests, in full-scale well conditions. In the course of the experiment, boundary conditions were created that correspond to an integral rock mass, and they remain unchanged during the entire study period. To study the physical picture of the process of the influence of hydrostatic pressure on the energy intensity of rock destruction, with various parameters of the circulating medium, the well-known laws of hydrodynamics and resistance of materials, the results of experiments by other researchers, as well as data obtained in laboratory and industrial conditions were used. Designing effective modes of destruction of rocks and rational structures of technical means are possible only on the basis of knowledge of the strength characteristics of rocks that they have in natural conditions. The obtained research results are basic for the design of a rational hydraulic well cleaning program under the conditions of the action of hydrostatic pressure. The obtained experimental dependences characterizing the process of destruction of rocks at the bottom of the well with the manifestation of hydrostatic pressure can be used as the basis for the design and operation of an innovative drilling tool.