ANALYSIS OF SOME PROPERTIES OF DRILLING MUD AND THEIR INFLUENCE ON WELL DRILLING PROCESS INDICATORS
Abstract
Purpose. Analytical and laboratory study of: the main challenges faced by flushing fluids. Study of the criteria of circulation processes taking place in the borehole under construction. Subsequent development of technological measures to rationalize the hydraulic washing program of the bottom hole and borehole of this specific mining operation based on the factor of reducing hydraulic losses and power for the pumps in operation.
Methods. Technological peculiarities of realization of hydraulic program of drilling wells flushing are clarified with application of modern methods of theoretical and experimental methods of studying of corresponding processes, in particular by using general principles of mathematical and physical modeling, methodical principles of processing of intermediate and final results of researches in EXCEL, MATNCAD environment, control and measuring systems and devices. Circulation borehole processes were modeled on a specially designed and appropriately equipped semi-industrial experimental stand of the educational drilling polygon of the Dnipro University of Technology with the use of appropriate equipment and devices.
Findings. It has been experimentally proved that the greatest reduction of hydraulic resistances can be obtained when using a group of pure polymeric organic compounds and with some additives; and the efficiency of hydraulic resistance reduction can reach more than 50% for these substances. It is established that introduction of active substances into the composition of flushing fluids in optimal concentrations contributes to the improvement of operational characteristics of the drilling pump. The rational concentration interval for a number of chemically active substances, which is the most effective from the point of view of providing flushing fluids with the property of complex correction of some indicators of downhole circulation processes, has been determined. The mechanism of influence of activated flushing fluids on characteristic indicators of hydraulic process of flushing fluid movement during drill string rotation in the well is analyzed.
Originality. For each chemically active substance that has a significant effect on the performance of circulation processes in a well under construction, there is a completely unambiguous interval of concentrations in the washing fluid at which its greatest effectiveness is manifested.
Practical implications. By means of detailed experimental studies it is shown that there is an effect of some chemically active substances on some components of the complex circulation well process. Rationalization of these components will allow to use reserves of available and designed drilling equipment and tools to the fullest extent. The obtained basic data are the basis for further developments to improve the quality and reliability of hydraulic programs of washing wells of various purposes and types.
