RU95100927A - Method of isolation of formations in well by shaped shutoff device - Google Patents

Abstract

FIELD: oil and gas producing industry, particular, isolation of zones of complication in well drilling. SUBSTANCE: casing pipes 2 are shaped by the known method to form cylindrical ends 4 and two longitudinal corrugations (folds) 6. Simultaneously, shaped part is calibrated and cylindrical ends 4 are upset up to diameter of circumscribed circle round shaped part after its calibration. Then, sections 9 of shaped pipes 2 adjacent to cylindrical ends 4 and intended for installation on the ends of shutoff device 1 are additionally upset to diameter of circumscribed circle round sections 9 which is smaller by 2-3% as compared with diameter of circle circumscribed round their middle part after its calibration. Made over perimeter of sections 9 with interval of 200-300 mm are closed seams (hoops) 11 whose height is taken such that diameter of circle circumscribed round them is approximately equal to the diameter of circle circumscribed round middle shaped part of pipes 2 after their calibration. Prepared pipes 2 are joined to one another so that pipes with hoops 11 on the ends of shutoff device and in folds 8 of these end pipes 2 on their sections 9 sealing compound is placed. Then, shutoff device 1 is lowered on the drill string to the required interval of well and is installed there by the known method by hydraulic expansion of its wall to press against well wall with subsequent expansion. As a result of embedding of hoops 11 into well wall, annular hollows 15 are formed between them in which sealing compound fills over the entire perimeter that ensures reliable and tight isolation of formations in the well. EFFECT: higher reliability and tightness of formation isolation.

Claims (1)

The invention relates to the oil and gas industry, in particular to the isolation of zones of complications of well drilling. The goal is to increase the reliability and tightness of reservoir separation. Casing pipes 2 are profiled in a known manner with the formation of cylindrical ends 4 and two longitudinal corrugations (folds) 6. At the same time, the profile part is calibrated and the cylindrical ends 4 are upset to the diameter of the circumscribed circle around the profile part after calibration. Then, sections 9 of profile tubes 2 adjacent to the cylindrical ends 4, which are intended to be installed at the ends of the overlap 1, are additionally deposited to the diameter of the circle described around the sections 9, which is 2 to 3% smaller compared to the diameter of the circle described around their middle part after calibration , and along the perimeter of sections 9 with an interval of 200 - 300 mm, closed scars (rims) 11 are made, the height of which is taken to be such that the diameter of the circle described around them is approximately equal to the diameter of the circle described g of the middle profile of the pipe 2 after calibration. Finished pipes 2 are screwed together, placing pipes with rims 11 at the ends of the overlap, and sealant is laid in the folds 8 of these end pipes 2 at their sections 9. Then, the shutter 1 on the drill pipe string is lowered to the required interval of the well and installed there in a known manner by hydraulic expansion of its wall until it is pressed against the wall of the well, followed by flaring. In this case, as a result of the insertion of the rims 11 into the borehole wall, annular cavities 15 are formed between them, into which the sealant flows around the entire perimeter, which ensures reliable and tight separation of the layers in the borehole.