Abstract:

We determined amplitude-phase frequency functions of the drill string for translational motion while drilling with immersed engines. It was established that amplitude-phase characteristic of the drill string changes with increasing depth of the well. When drilling in hard rocks, it is advisable to use cushion subs in order to reduce the level of reflected wave of mechanical stresses. To eliminate the impact of the reflected wave, it is necessary to apply a bit feed drive with absolutely soft mechanical characteristics. We performed analysis of dynamic modes of the process of drilling wells as a control object based on provisions of the synergetic theory of information. It is proposed to employ energoinformational approach to analyze processes in the system of control over well drilling. This is due to the fact that the drilling process evolves over time and functions under conditions of the a priori and current uncertainty in terms of parameters and structure of the object. Since such a system develops over time, it undergoes changes in the structure of design of the drill string. Therefore, in order to resolve tasks on control over the process of drilling, it is necessary to know how dynamic properties of the column change depending on depth. We identified five modes of operation in the process of drilling as a complex dynamic system: equilibrium, ordered, sorted-chaotic, randomly-ordered, and chaotic. This makes it possible to solve an important applied problem of determining amplitude-phase characteristics of the drill string depending on depth of the well, and to use them for mathematical substantiation of automated control system over drilling.  Author Biographies Vitaliai Kropyvnytska, Ivano-Frankivsk National Technical University of Oil and Gas Karpatska str., 15, Ivano-Frankivsk, Ukraine, 76019 PhD, Associate Professor Department of Computer Systems and Networks 

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