A well jet device operating method comprises running a jet pump into a well, releasing a packer above a productive formation, pumping hydraulic fracturing fluid though a blocking insert in the pump channel, extracting the blocking insert, running flexible pipe into the well through a sealing unit and arranging the lower end thereof at lower formation perforation interval level. The formation is drained, fluid for washing a bottomhole is supplied by the flexible pipe, maintaining the ratio between pipe pressure value and a casing annulus working medium pressure within a range greater than or equal to 0.98. When at least two volumes of hydraulic fracturing fluid is extracted, the pipe fluid supply is stopped. At least 5 minutes after, off the working medium supply to the pump nozzle is shut off, in examining the formation for evaluating the productivity thereof and in bringing the well into operation.