METHOD FOR WELL CLEANING FROM PROPPANT PLUG Russian patent published in 2009 - IPC E21B37/00 E21B21/00 

FIELD: oil and gas production.

SUBSTANCE: invention is related to oil and gas production industry and is intended for treatment of wells in case there is a tight sand and clay plug. Device comprises vessel connected to lift column via adapter by means of hydraulic cylinder to a connection nozzle with ring piston pulled through axial channel of adapter, spring-loaded circular piston with a hollow stem, which is installed inside hydraulic cylinder and is connected to a body of breaking mechanism, in axial channel of which the following components are serially installed - throttle orifice with throttling axial channel, seat with longitudinal slots on external surface and pusher that is pressed by spring to end of throttle orifice, end valve that covers lower end of pusher and rests on seat, being connected to tube, which in its turn is connected to internal crown and adjustment nut with calibrated holes. Hollow stem and body are arranged accordingly with a circular bore on external and internal sides, in which split spring ring is installed. In axial channel of lift pipe string there is a control mechanism in the form of partition with throttle and axial channels, equipped with a check valve in the form of seat, ball and cage. Pusher of breaking mechanism is arranged as hollow and is equipped with a check valve in the form of seat, ball and cage installed with clearance in axial channel of throttle orifice. Area of cross section of throttle channel of partition exceeds area of cross section of throttle channel of orifice. Total area of calibrated holes of adjustment nut and axial opening of internal crown exceeds total area of partition throttling channel and throttling channel of throttle orifice.

EFFECT: improved efficiency of breaking and plug removal.

2 cl, 6 dwg