Experimental studies of the borehole hydraulic extraction technology of sapropel from under peat

The article presents the results of experimental work on the borehole hydraulic production of sapropel
located under peat. The researches was carried out at Gala-Kovalevskoye and Kobylitskoye peat deposits located in Pukhovichi district of Minsk region. The work takes into account the results of theoretical calculations previously performed by the authors, which made it possible to select commercially available equipment for research conducting in field conditions. In this case, the calculations were based on real initial data that were generated at the experimental site of Gala-Kovalevskoye peat deposit.
It was established during the sapropel extraction of carbonate type with the moisture content of 76.3 %, the productivity of Denzel PX-50H high-pressure motor pump at water supply into the sapropel deposit is equal to 23 m3/h that corresponded to the productivity the suction of DDE PTR 50K motor pump. When extracting sapropel of organic type with а moisture content of 91.0 %, the capacity of Denzel PX-50H motor pump should not exceed 18–20 m3/h.
It was found that the flow rate of water in a 50 mm diameter injection hose when feeding it into a container is 3.6 m/s, and into a sapropel deposit – 3.2 m/s. The flow rate of the sapropel pulp in the transport hose is 3.1 m/s.
It is shown that the excess pressure in sapropel created by Denzel PX-50H high-pressure motor pump is 6 bar, which ensures the erosion of the sapropel deposit at a distance of 1.50 m from the well. It was determined by calculation that the critical dynamic pressure required to destroy carbonate sapropel is 0.13 MPa. Taking into account the pressure created by Denzel PX-50H motor pump, the maximum destruction distance is 1.87 m.
The presented calculations allow us to select equipment with other technical characteristics that meet the conditions of hydraulic extraction of sapropel in deposits of various types.

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