Flushing Fluid Dynamics in a Flowing Piston with Confusor Transition Modelling

A circulation sub is used during drilling process, as bypass circulation is necessary. The research is dedicated to the search and optimization of hydraulic parameters for planned bench testing of the piston flow assembly of the circulation sub to reduce operational costs and advance the technical level. Flowing parameters, affecting hydraulic drag, are poorly studied, that has greatly hindered the research. The importance of the study lies in researching the hydraulic impact on local resistance, which relates to the prospective method of hydraulic activation of well equipment. The research results confirm that increasing fluid rate is a more efficient option to achieve the necessary forces values and pressure differentials, compare to changing fluid density and viscosity, as it’s more effortful. The highest pressure differential does not exceed 1.6 MPa. It is recommended to adjust fluid density during device maintenance for optimal operation. Fluid viscosity changes significantly affect hydraulic drag and pressure differential, especially with higher fluid density and flow rate. An increase in viscosity by a factor of 25 leads to an increase in pressure differential of no more than 8.2 %. Thus, it is necessary to use a detachable part of the piston flow assembly in the form of a diaphragm, which allows for device adjustment, increases reliability, and repairability. Subsequently, the results of the work will be applied to the development of a test bench for similar devices, enabling the selection of optimal design and determining recommendations for its application in specific geo-tenchnical conditions.