DEVICE AND TECHNOLOGY OF CONTINUOUS WELL FLUSHING

Abstract

Link for citation: Tretyak A.Ya., Litkevich Yu.F., Kruglova T.N. Device and technology of continuous well flushing. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 5, рр.181-188. In Rus. The relevance research is due to the fact that at present a large number of accidents occur due to the stoppage of the rotation of the drill string and the cessation of flushing during the build-up of the drill string. Staying the wellbore for some time at rest, and then creating flushing fluid pressure pulses accompanying the start and stop of mud pumps, can lead to undesirable phenomena and complications in the form of sticking. Sticking can be mechanical, due to the complex geometry of the wellbore, falls into the rocks from the walls of the well, the formation of cuttings at the bottom of the well due to insufficient flushing of the well. The percentage of such accidents can reach 20. Up to 80 % of differential sticking is due to the pressure difference – hydrostatic, formed in the wellbore due to the density of the drilling fluid, and reservoir, formed in the well formation. Due to these processes, water infiltration from the drilling fluid into the formation occurs, and a thick polymer clay cake is formed on the well walls, which contributes to the formation of differential sticking, that is, the sticking of the drill string to the well walls. The purpose: to develop a device and technology for continuous flushing of wells when building a drilling tool. Objects: device and technology for continuous well flushing. Methods. A device for continuous flushing of the well, consisting of synchronously overlapping on-off valves that provide continuous flushing of the well when building up the drilling tool is proposed for manufacturing. A mobile crane switching synchronizer is described, its design and principle of operation are given. Technological methods are proposed that realize the possibility of the device operation. Results. The solution of the task set made it possible to develop the design of the device and the technology of continuous flushing of wells.