Patent EA-004818-B1 (EA)
Title: Well jet device for well testing and development and operating method for said well device
IPC: F04F5/46
Filed: 2002-05-28
Abstract: 1. The well jet device for testing and developing wells; comprising, installed on the piping string down-top, an input cone with a shank, a packer with a through passage and a jet pump, in the body of which one or several active nozzles with their respective mixing chambers and passages for supplying the active medium are axially arranged, and a stepped through passage is made with a mounting seat between steps for installing a sealing assembly having an axial channel, the said device being provided with a transmitter and a receiver-transducer of physical fields, which is arranged at the jet pump side for entry of the medium pumped out of the well and installed on a cable or a wire fed through the axial passage of the sealing assembly, the output of the jet pump is connected to the piping string above the sealing assembly, the input side of the jet pump passage for supplying the pumped out medium is connected to the piping string below the sealing assembly, and the input side of the passage for supplying the working medium to the active nozzle is connected to the space surrounding the piping string, and in the body of the jet pump several passages for supplying the pumped out medium are made, the input cross-section of the input cone is located not lower than the roof of the productive stratum, the total area of the cross-sections of the passages for supplying the active medium is not less that the total area of the output cross-sections of the active nozzles, the axis of each active nozzle is parallel to the axis of the through passage in the body of the jet pump and is located from the latter at the distance L being not less than 0.55 diameter D1 of the bigger step in the through passage made in the body of the jet pump or at the distance L being not less than 0.575 diameter D2 of the lesser step in the through passage made in the body of the jet pump, the sealing assembly is movably arranged on the well-logging cable or a wire fed through the axial passage in the sealing assembly and installed with the possibility of being alternatively replaced by the functional inserts, namely, a hydrostatic testing insert, a depression insert, a blocking insert which is made with or without a bypass passage, an insert for recording curves of stratum pressure restoration in the under-packer space and an insert for hydrodynamic vibration impact on the near-well zone of the productive stratum, the diameter D3 of the axial passage in the sealing assembly is not greater than 0.6 outer diameter D4 of the sealing assembly, the axes of the sealing assembly and the functional inserts are aligned with the axis of the through passage in the jet pump; the functional inserts are made with the possibility of installing below them autonomous well instruments as well as have, in their upper part, a tool for delivery and removal of them from the body of the jet pump with the use of cable equipment, the well-logging cable or wire are made with a cap for attaching well instruments, the sealing assembly is made with the possibility of installing it on the well-logging cable or wire without disconnecting the cap from them, the transmitter and receiver-transducer of physical fields is connected to the cap of the well-logging cable with the possibility of being replaced by other well instruments, e.g., a perforator, an ultrasonic transmitter, a thermometer, a pressure gauge, a flowmeter, a sampling device, which all may be lowered, either in turns or in one assembly, along the through passage of the jet pump body on the well-logging cable or wire into the well, the outer diameter D5 of the jet pump body being at least 2 mm less than the inner diameter D6 of the casing string in the well where it is installed, the diameter D4 of the sealing assembly being at least 1 mm less than the inner diameter D7 of the piping string above the jet pump, the diameter D8 of the transmitter and receiver-transducer of physical fields being at least 1 mm less than the diameter D2 of the lower step of the through passage in the jet pump body and than the diameter D9 of the through passage in the packer, the diameter D10 of the well-logging cable or wire being at least 0.001 mm less than the diameter D3 of the axial passage in the sealing assembly, and in the lower part of the passages for supplying the pumped out medium positions for installing check valves or plugs are made. 2. The method of operation of the well jet unit in testing and developing wells, consisting in installing on the piping string, down-top, of an input cone with a shank, a packer and a jet pump in the body of which a stepped through passage with a mounting seat in made between the steps, lowering that assembly into the well, arranging the input cone not below the roof of the productive stratum, then a transmitter and receiver-transducer of physical fields is lowered into the well and arranged below the jet pump, during lowering background measurements of temperature and other physical fields from the wellhead to the well bottom are taken, and the transmitter and receiver-transducer of physical fields is removed from the well, then the packer is released, a blocking insert with a well pressure gauge is dropped into the inner cavity of the piping string, the blocking insert being seated onto the mounting seat in the through passage, the said blocking insert separates the well area into the hole clearance and the space inside the piping string, then the packer is pressure-tested by way of supplying the working agent into the hole clearance, then the blocking insert is removed with the use of cable equipment, and the transmitter and receiver-transducer of physical fields is lowered into the well together with the sealing assembly, which is movably arranged on the well-logging cable or wire above the cap on which the transmitter and receiver-transducer of physical fields is installed, the sealing assembly is installed onto the mounting seat in the through passage in the body of the jet pump while ensuring the possibility of back and forth motion of the well-logging cable or wire, then the transmitter and receiver-transducer of physical fields is arranged in the explored interval of the productive stratum, and, by supplying the working medium to the active nozzle(s) of the jet pump, several values of pressure drawdown on the stratum are successively created, and, at each value, bottom-hole pressures, the composition of the fluid coming from the stratum and the well flow rate are measured, after which the parameters of physical fields and those of bottom-hole pressure are recorded when moving the transmitter and receiver-transducer of physical fields along the well axis in the speed range from 0.1 to 100 meters per minute and at pressure drawdown values changing stepwise in the range from 0.01 to 0.99 stratum pressure or at a set value of pressure drawdown when the jet pump is either operated or shut down, then the transmitter and receiver transformer of physical fields is lifted out of the well and at the same time physical fields from the input cone to the wellhead are registered, and the functional insert for recording curves of stratum pressure restoration in the under-packer zone is lowered on the well-logging cable or wire, the said insert being provided with a pressure sensor and a sampling device, and installed in the through passage of the jet pump, a required pressure drawdown on the stratum is created with the use of the jet pump, and, after sharp stopping of supplying the liquid working medium to the jet pump, a stratum pressure restoration curve for the under-packer well zone is recorded, said recording of stratum pressure restoration curves may be done repeatedly at different initial pressure drawdown on the stratum., after that the results of exploration and testing the well are processed, and a decision is taken whether other repair works on the well are necessary in order, e.g., to raise its productivity or ensure waterproofing, such works being conducted with the use of the assembly with the jet pump, which is in the well, as well as with the alternatively changed functional inserts as well as instruments lowered into the well with the sealing assembly on the well-logging cable or wire, e.g., a perforator, an ultrasonic transmitter, a sampling device, a powder-charge pressure generator, etc., in particular with the use of an ultrasonic transmitter the stratum is impacted by acoustic waves in the pressure drawdown mode in order to de-mud the productive stratum, by using an ultrasonic generator with frequency switching and selective acting upon, first, less permeable and, then, more permeable seams of the productive stratum, and an increase in the well output is monitored, and after completion of the said works the cycle of well exploration is repeated.