DEVELOPMENT OF AN EXPERIMENTAL SETUP FOR INVESTIGATING THE PROCESS OF CREATING PROTECTIVE MECHANICAL COLMATATION OF FRESH WATER FORMATIONS

Abstract

Abstract. When drilling oil and gas wells we often encounter  fresh water formations occurring at relatively shallow depths and their penetration is accompanied by toxic drilling mud filtrate invasion from an open wellbore. The protection of fresh water formations against contamination is possible by creating protective mechanical colmatation in the process of drilling in with the use of environmentally-friendly components based on substances of organic origin in drilling mud formulations. Underground fresh water is found practicaly on the whole territory of Ukraine. Investigated was the impact of dynamic processes during drilling in formations on the strength and blocking ability of the protective zone against drilling mud toxic filtrate invasion in the process of continuing drilling for intermediate casing string after uncovering fresh water formations. The experimental setup for research of the processes of protective mechanical colmatation of fresh water formations was designed and made.  Researches on filtration resistance change of the created zones of protective colmatation under the conditions of hydropulse load action on the bottomhole zone of the formation in the course of drilling were carried out. The formulation of envionmentally-friendly drilling mud is offered.