SUCKER-ROD PUMPING UNIT FOR OPERATION OF MARGINAL WELLS Russian patent published in 1997 - IPC

FIELD: oil-and-gas producing industry. SUBSTANCE: tubing string is separated by two pumping devices into two stages of lifting. It is separated at the preset depth by separating pumping-over device. It is installed at the preset height from lower pumping device. This height is determined by the value of accumulating chamber and depth of lowering of downhole pumping unit. It consists of two concentric strings: hollow sucker rods and tubings. Tubings above separating pumping-over device form two channels. Tubings form channel for lifting well production through annular space. Hollow rods form channel for supply of chemical reagents. Below the separating pumping-over device, the intertubing annular space is communicated from upper side with wellbore annular space, and from the other side, through guide and intake chambers is communicated with pump and lower part of hollow rod to tubing string. Separating pumping-over device consists of body with radial channels, sleeve and separating piston. The latter is fitted on hollow rod. Rod is rigidly connected with hollow rods. Located on rod are check, intake and pressure valves. Lower and upper partitions on rod form, correspondingly, upper and lower chambers. Lower chamber communicated through intake gas valve is communicated with hollow of lower part of hollow rods and, through pressure valve, with hollow rod. Upper chamber, through intake gas valve is communicated with wellbore annular space. Installed on upper partition is pressure valve for gas. Device for supply of chemical reagents includes vessel for chemical reagents. The vessel is connected, from one side, with gas pipeline, and from the other side, with pipeline. The latter is communicated with additional sleeve and upper part of string of hollow rods. They pass above separating pumping-over device through sleeve and further on, through radial annular channels are connected with accumulation chamber. EFFECT: higher efficiency. 1 dwg