SU1184919A1 - Device for centering casings in borehole - Google Patents

Abstract

A CENTER FOR CENTERING CLEANING COLUMNS IN A WELL, containing centering spring strips connected at the upper and lower ends by couplings, mounted inside the centering spring strips, a deflection deflector, made in the form of spring strips, which is designed in such a way that it is necessary to set the center height of the deflection, which is designed in such a way that it is necessary to get to the center. wells, the upper and lower ends of the spring plates of the deflection limiter are fitted with couplings, with the upper and lower sleeves of the deflection limiter being connected respectively to the bottom and top In this case, the couplings of the centering spring strips are adjustable, and the diameters of the centering axes of the tapping strips and the limiter of the deflection are chosen from the ratio do-dB "2B", where the maximal outer diameter formed by the centering spring strips, mm; de is the maximal outer diameter obsided by spring strips og (deflection wedge, mm; (L t is the permissible eccentricity between the axes of the borehole and the casing, mm cx 4; about

Description

The invention relates to a drilling technique, in particular to devices for centering casing strings in a well.

The purpose of the invention is to improve the reliability of casing centering in inclined wells.

FIG. 1 shows a casing centering device, a general view; in fig. 2 shows section A-A in FIG. one; in fig. 3 shows a device for centering casing strings in operating condition on an inclined section of the wellbore; in fig. 4 shows section A-A in FIG. 3

The device for centering the casing in the well consists of centering spring bars 1, which are connected at the upper and lower ends by sleeves 2. Inside the centering spring bars 1, there is a deflection stop, made in the form of spring bars 3, the upper and lower ends of which are connected by sleeves 4 The upper and lower couplings 4 are connected respectively with the lower and upper couplings 2 by adjustable rods 5. Adjustable pulls 5 are passed through the hinged joints of the coupling segments and are equipped with position locks 6, e.g. kami, and adjusting nuts 7. The diameters of the spring bars 1 and 3 are chosen from the ratio

do - dB42B,

where do is the maximum outer diameter formed by the centering spring bars 1, mm; db is the maximum outer diameter formed by spring bars 3 deflection limit, mm;

- permissible eccentricity between the axes of the borehole and the casing, mm.

The device works as follows.

Directly on the borehole, based on the value of the allowable eccentricity for the entire wellbore or certain parts of it in the device, adjust the diameter difference using the adjusting nuts 7 so that the ratio

do - de 42L

The device prepared in this way is installed in the usual way at the calculated location on the casing string and lowered into the well. In places of curvature and inclined sections of the wellbore, the centering spring bars 1 rest against the borehole walls and under the influence of forces from the side of the casing string are compressed,

 decreasing in diameter and increasing in length. At the same time, under the influence of adjustable t g 5, the spring plates 3 of the deflection limiter increase in diameter until the spring

strips 1 and 3 do not form one common circle, i.e. until all or part of the spring bars rest against the wall of the well. At the same time, the device will become rigid with respect to reducing the gap h and increasing the eccentricity e. When the forces acting on the spring plates decrease, the gap between the casing and the borehole wall b will increase and the eccentricity e will decrease.

Claims (1)

DEVICE FOR CENTER CENTER CENTERING IN A WELL, containing centering spring bars, connected at the upper and lower ends by couplings, deflection deflector installed inside center spring bars, made in the form of spring bars, characterized in that, in order to increase the reliability of centering the casing in inclined wells the upper and lower ends of the spring bars of the deflection limiter are provided with couplings, the upper and lower couplings of the deflection limiter are connected respectively to the lower and upper couplings s centerand ruyuschih adjustable rods of the springs and the diameters of the centering spring strips and deflection limiter are selected from the relation do- dg 4 2B where ^ o-maximum outer diameter formed by the centering spring slats, mm; de —maximum outer diameter formed by the spring bars of the deflection limiter, mm; permissible eccentricity between the axis of the wellbore and casing, mm (/) FIG. Ϊ