Hydro-mechanical expansion device (RGМ-138/280) is required for oil well expansion up to 280 mm (diameter) at any depth of an oil well, while lowering the device.

Technical Specifications:

         External diameter of the device, mm (excluding blades)      138-0,5 
         Maximum diameter of the device (includingBlades), mm      280-0,5
         Length of the device, mm       1665 ±5
         Diameter of the central holes of nozzles,       16/13/11
         Design axial loading without rotation, max       8
         Loading at expansion (depending on diameter of a pilot trunk of an opening), hardware, max       0,2-1,0
         Consumption, litres per second (drilling mud)       8-12
         Working pressure, max, МPа        6,5 (65)
         Initial pressure of blades opening, (at diameter of a nozzle of 13 mm), МPа  
    1,5 (15)
         Frequency of rotation (depending on diameter of a pilot trunk of an opening), min      20-40
         Bottom hole temperature, °С, max       100
         Speed of descent to an opening, m/s, max       0,5
         Max. mechanical speed of drilling by boring, meters per hour, max      2
         Max. twisting moment, kN.m, max          7,6
         Connecting thread, GOST 5286-75           
          - above
          - below
         Weight, kg, max       155 ±3