METHOD AND DEVICE FOR SECONDARY PENETRATION OF PRODUCTIVE BEDS IN OIL WELLS Russian patent published in 2006 - IPC E21B43/112 

FIELD: oil production, particularly methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells.

SUBSTANCE: method involves lowering device connected to pipe string to perforation interval; increasing pressure in pipes and perforating casing pipe wall by extension crush roll; performing water-jet cement stone and rock cutting. To perform perforation operation device with crush roll is used. The crush roll is provided with rim having high-strength teeth with heights at least 2 mm grater than wall thickness of casing pipe to be perforated, with lip angles of not more than 60° and with contact surface blunting of not more than 1 mm. Casing pipe is perforated by device reciprocation to provide roll movement and to press roll teeth in casing pipe. Device creates 20-50 slots per 1 running meter of casing pipe within the limits of one perforation row so that bridges are created between the slots. Device comprises body, hydraulic cylinder, hollow rod-like piston, wedge, which controls crush roller axis. The roller has rim with high-strength teeth, which provide roll movement during device reciprocation to create 20-50 slots per 1 running meter within the limits of one perforation row as productive bed is fully opened. Teeth heights are at least 2 mm grater than wall thickness of casing pipe to be perforated. Teeth lip angle is not more than 60°. Contact surface blunting is not more than 1 mm. Water-jet nozzle is mounted to direct jet into slots and so that jet bypasses bridges during tool stopping.

EFFECT: provision of full productive bed penetration along with retaining casing pipe ability to withstand side rock pressure.

2 cl, 2 dwg