Patent EA-004817-B1 (EA)
Title: Method of operation of a well jet device in well testing and development and the well jet device for carrying out said method
IPC: F04F5/44
Filed: 2002-04-24
Abstract: 1. The method of operation of the well jet unit in testing and developing wells, which includes installation of a jet pump with a through passage and a packer onto the piping string, lowering of that assembly into the well, release of the packer and creation of a required pressure drawdown in the area below the packer by pumping the process fluid out of the area below the packer with the jet pump, characterized in that the piping string is additionally provided with: an assembly for disconnecting and connecting the piping string, a valve assembly with a mounting seat for installation of a check valve, a shank with an input cup, and a recirculation valve installed in the wall of the piping string above the said jet pump; first the piping string is assembled by successively installing, top-down on the piping string, a jet pump, an assembly for disconnecting and connecting of the piping string, a valve assembly with the mounting seat for installing a check valve, a packer and a shank with an input cup; when lowering the assembly the packer is installed at least 50 meters above the roof of the productive stratum and the input cup is installed no more than 2 meters above the roof of that stratum, after releasing the packer a perforator on a well-logging cable is lowered into the well together with a sealing assembly installed thereon which is seated onto the mounting seat in the through passage of the jet pump, the said perforator being arranged against the productive stratum, further a required pressure drawdown onto the stratum is created with the use of the jet pump, the perforator is blasted, and the stratum is drained until the process fluid under the packer is completely replaced by the stratum fluid; then the perforator together with the sealing assembly are lifted to the surface, a transmitter and receiver-transducer of physical fields with the sealing assembly are lowered into the well on the well-logging cable, a valve insert with a check valve, which is seated onto the mounting seat in the through passage in the valve assembly, as well as a blocking insert with the bypass passage, which is seated onto the mounting seat in the valve assembly and separates the inner cavity of the piping string and the area around the piping string, are dropped into the well; thereafter a lightweight fluid or an inert gas is supplied to the area around the piping string through the recirculation valve, peening it into the inner cavity of the piping string, thus lowering the hydrostatic pressure in the well bottom zone; and the well is put into flowing operation, and after the well output is reduced due to the depletion of the stratum energy the well is deadened through the recirculation valve with a higher density fluid thus closing the check valve preventing the higher density fluid from entering into the area under the packer, the blocking insert is removed, a depression insert with an autonomous pressure gauge and a flowmeter is dropped into the piping string, and the stratum fluid is pumped out of the well at different pressure drawdown by supplying the liquid working medium to the active nozzle of the jet pump, simultaneously measuring the well output at the surface and under the jet pump, then the depression insert with the autonomous pressure gauge and the flowmeter is removed out of the well, their readings of the bottom-hole pressures and flow rates are obtained, a flow rate vs. bottom-hole pressure data is plotted and by interpreting the plot the size of the pump required for forced oil production is determined; then, with the use of the assembly for disconnecting and connecting of the piping string, the jet pump with the above-arranged piping string is disconnected, lifted to the surface, an oil production pump of required capacity is lowered on the piping string and connected to the piping string part remaining in the well by using the assembly for disconnecting and connecting of the piping string, and the well is put into forced operation. 2. The well jet unit, which comprises, being installed on the piping string, a packer and a jet pump with the active nozzle, the mixing chamber and the through passage with the mounting seat for installation of the sealing assembly with the axial passage, the said jet unit further comprises a transmitter and receiver-transducer of physical fields, which is arranged in the area below the packer on the side of entry of the pumped-out medium into the jet pump and installed on the well-logging cable fed through the axial passage of the sealing assembly, the output of the jet pump is connected to the area around the piping string, the input of the passage in the jet pump for supplying the pumped out medium is connected to the inner cavity of the piping string below the sealing assembly, and the input of the passage for supplying the working medium to the active nozzle is connected to the inner cavity of the piping string above the sealing assembly, characterized in that the piping string is provided with a shank with the input cup, the valve assembly with the mounting seat for installing the valve insert with the check valve, the assembly for disconnecting and connecting the piping string, and the recirculation valve installed in the wall of the piping string above the jet pump; the packer is made with the central passage; the sealing assembly is installed with the possibility of being replaced by other functional inserts: a blocking insert, a pressurizing insert, a depression insert and an insert for recording stratum pressure restoration curves with the use of autonomous well gauges; the receiver-transducer of physical fields is made with the possibility of being replaced by a perforator or an instrument for acoustic impact on a stratum or strata; the above being taken into account, the diameter D14 of the passage for supplying the working medium is not less than the inner diameter D13 of the mixing chamber, the diameter D6 of the through passage below the mounting seat is at least 0.7 mm less than its diameter D3 above the mounting seat, the diameter D4 of the sealing assembly is at least 1.4 mm less than the diameter D1 of the inner cavity of the piping string, the diameter D5 of the axial passage in the sealing assembly is at least 0.008 mm greater than the diameter D2 of the well-logging cable, the diameter D10 of the transmitter and receiver-transducer of physical fields is at least 1.4 mm less than the diameter D6 of the through passage below the mounting seat, the diameter D9 of the central passage in the packer is at least 1.4 mm greater than the diameter of the transmitter and transducer of physical fields, the diameter D8 of the through passage in the valve assembly below the mounting seat for the valve insert is at least 0.7 mm less than its diameter D7 above the mounting seat, the diameter D16 of the valve insert with the check valve is at least 1 mm less than the diameter D6 of the through passage in the jet pump under the mounting seat, the outer diameter D15 of the jet pump is at least 2 mm less than the inner diameter D11 of the casing string, the inner diameter D13 of the mixing chamber is within 1.2 to 1.4 inner diameters D12 of the nozzle, the distance L1 between cross-sections of the nozzle and the mixing chamber is within 0.4 to 1.4 inner diameters D12 of the nozzle, and the length L2 of the sealing assembly is not less than its outer diameter D4; the blocking insert has a bypass passage with the diameter D17 being at least 20 mm and is provided with the head for the purpose of being removed out of the well, and the transmitter and receiver-transducer of physical fields are made with the possibility of being operated in the area under the packer both when the jet pump is operated and when it is shut down.