METHOD FOR REMOVING SAND-CLAY PLUG IN WELL AND ITS DEVELOPMENT UNDER CONDITIONS OF ABNORMALLY LOW FORMATION PRESSURES Russian patent published in 2015 - IPC E21B37/00 

FIELD: oil and gas industry.

SUBSTANCE: hydraulic hammer is installed on the lower end of a flexible pipe and lowered to a well to a location place of a sand-clay plug. A coiled tubing unit is located on the well head. A bench of foam-forming liquid (FFL) of design length is formed in an axial duct of the flexible pipe. Mechanical action on the sand plug surface is performed by the hydraulic hammer at its movement and pumping through it of FFL benches with further generation of foam in inter-pipe space in each bench by bubbling through it of a bench of gas supplied from the axial duct of the flexible pipe through the hammer. After the plug is removed, development of the well is performed by continuous supply of gas to the axial duct of a flexible string of pipes and by invoking an influx at reduction of pressure below the formation one.

EFFECT: improving efficiency of removal of a sand-clay plug and development of a well.

1 dwg