PROCEDURE FOR ELIMINATION OF BEHIND- CASING FLOWS

摘要

FIELD: oil and gas industry.;SUBSTANCE: method includes expansion of a casing string in each interval of behind-the-casing flows outside limits of elastic deformation until gaps between the string and the cement as well as between the cement and the rock are eliminated. Expansion is performed by a device equipped with rollers used as working members; the device is run in at the drill string to the upper mark of the interval of required expansion above the existing or preliminary made perforation interval, thereupon by rotation of the device with simultaneous downfeed and injection of fluid, under the action of the above fluid the rollers are set to the operating position; by an impact on the inner surface of the casing string it is expanded by rolling out within the whole interval of the behind-the-casing flow or at several individual areas. At rolling-out excessive stress is generated on the walls of the casing string in order to reinforce the behind-the-casing cement by its thickening, at that the diameter of the rolling out device in the operating position is selected by 4-8.5% more than the inner diameter of the casing string before expansion.;EFFECT: speeding-up of the repair process, reducing the number of operations.;3 dwg