BOTTOM-HOLE PRESSURE PULSER Russian patent published in 1999 - IPC

FIELD: oil and gas production industry. SUBSTANCE: bush with cam-like protrusion and pin is installed in body of device for possible turning around axis and for interaction with rod. Rod is made with cam-like protrusion and with shaped slots for bush pin. Pin and cam-like protrusion of bush are located in one plane along axis. Cam-like protrusion of rod is made coaxial with one of longitudinal grooves at side of protrusion. Longitudinal movement of bush at interaction with rod is limited by protrusion of body and sleeve. When compressing load is brought to bear on packer, adapter and half-rod are moved downwards with respect to sectional body for compression of spring. Radial passages of half-rod are disconnected from radial passages in body. Other radial passages of half-rod go beyond body seal and connect with radial passage of rod located underneath of plug. Depression is created. When section rod moves upwards, cam-like protrusion of half-rod rests on cam-like protrusion of bush, thus preventing further upward movement of sectional rod. Pressure under pulser gradually levels with bed pressure, and bed pressure is restored. Creation of depressions and repressions is repeated until bush turns around its axis through 360 deg. and at upward movement of sectional rod, bed pressure is finally restored. Thus, bottom-hole zone of bed is subjected to pulsing pressure for cleaning and testing of bed before and upon treatment. Application of aforesaid embodiment of device widens its functional potentialities due to no use of repeated lowering of bed tester. EFFECT: higher efficiency. 2 cl, 6 dwg