RU35363U1 - Sidetracking layout - Google Patents

Description

LAYOUT BODY CUTTING LAYOUT

The utility model relates to the mining industry and is intended for sidetracking with a wedge diverter.

Known arrangement for stabilizing the direction of drilling, containing a guide rod, an elastic nadzolotny centralizer. (RF patent No. 2059785, 6 V 21 V 7/08).

However, the lack of bending moment in the layout of the support-centering element eliminates the effect of the bending moment, and the elastic supra-bay centralizer keeps the tool axis on the axis of the well.

Closest to the claimed technical essence is the layout for sidetracking, containing a riber, a weighted drill pipe (UBT), a drill pipe, a centralizer. (R.M. Gilyazov, Drilling of oil wells with sidetracks, Moscow, Nedra, 2002)

The weighted drill pipe located directly above the milling device (riber), which has sufficient rigidity, does not provide the required deflection of the layout axis, which, in turn, does not provide the necessary angle of inclination of the milling device relative to the milling casing string.

In this case, excessive wear of the surface of the wedge diverter occurs, and there are also problems with the exit of the milling device beyond the casing.

Thus, the task arose to prevent excessive wear of the wedge diverter, to orient the milling device relative to the surface of the wedge

rejecter.

20031272

MPKE21V7 / 08 I

WHICH pipe from the stresses of bending and compression at the same load on the milling device is much greater than the stresses that arise in the weighted drill pipe.

To achieve the desired shape of the axis of the flexible pipe, the outer and inner diameters of the flexible pipe and its sub-length are calculated in such a way that, at a certain load, the flexible pipe loses stability and provides a milling arrangement coaxial with the surface of the wedge, protecting the wedge and milling device from premature wear, as well as contributing to casing milling under optimal conditions.

The length of the flexible pipe coincides with the value generated by the bending of the half-wave and is determined by the formula

 10 / 0.2 / yes

(0 q

where co is the angular velocity of rotation of the tool;

I is the moment of inertia of the flexible pipe section;

q is the mass per unit length of the flexible pipe

In FIG. 1 shows the layout for sidetracking with a wedge diverter. The layout includes a milling device 1, a flexible pipe 2, a heavy drill pipe 3, a drill string 4. The wedge diverter 5 is fixed in the casing 6. The layout for cutting the side shaft works as follows. The whole arrangement is lowered into the well on drill pipes. The descent is made up to the “head of the wedge diverter 5. Turn on the mud pumps, rotate the drill string 4. Simultaneous milling of the surface of the wedge diverter 5 and the casing string 6 begins. When the rated load is reached, the flexible pipe 2 loses stability and begins to bend, while the milling device 1 begins to slide along the surface of the wedge diverter 5 and is actively introduced

1 / I

the walls of the casing 6. Milling continues until the milling device 1 completely exits the walls of the casing 6.

A flexible pipe layout has an advantage over rigid layouts. The proposed arrangement provides the necessary angle of inclination of the milling cutter to the surface of the wedge diverter, promotes intensive milling of the casing string and preserves the surface of the wedge diverter.

Claims (1)

An arrangement for cutting a casing with a wedge diverter, including a milling device, a drill pipe, a drill string, characterized in that a flexible pipe is included in the arrangement between the milling device and the drill pipe, the length of which is determined from the expression

where ω is the angular velocity of rotation of the tool; I is the moment of inertia of the flexible pipe section; q is the mass per unit length of the flexible pipe.