RU2471969C1 - Strengthening method of uncased part of well by means of range pipe expansion - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: strengthening method of uncased part of the well by means of range pipe expansion method involves straightening of shaped pipes with hydraulic pressure in the well and gauging of inner diameter by means of a flaring device with flaring elements to the diameter exceeding the initial one. Gauging including expansion of inner diameter of shaped pipes and their cylindrical sections is performed per one or several passes with flaring device with the chosen flaring force and variable projection of flaring elements, which allows tightly pressing the external surface of shaped pipes and their cylindrical sections to well walls and obtaining the inner diameter of expanded pipes, which exceeds outer diameter of further lowered layout by the value of required gap.

EFFECT: method is easy to apply, allows improving insulation quality of complicated zones by installation of expanded pipes due to tight and sealed pressure of expanded pipes to well walls with simultaneous increase in service life of flaring device.

2 dwg

Description

The invention relates to the oil industry, in particular to drilling and workover of wells and is intended to isolate the zones of complications by installing expandable pipes in the well.

The well-known "Method of isolating the zones of complications in the well with a profile blocker" (patent RU No. 2355617, ЕВВ 29/10, publ. 10.10.2008, bull. No. 28), equipped with end packer elements, including its descent into the well, installation against the zone complications, pressure adjustment and calibration of the inner surface with a flare prior to pressing against the walls of the well, and during calibration, choose a longitudinal flare feed so that small recesses form in the form of single and whether a multi-helix along the entire length of the profile overlap.

Closest to the invention in technical essence is the "Method of isolating the zones of complications in the well with profile shutoffs" (AS No. 1679030, ЕВВ 33/13, published on September 23, 1991, Bull. No. 35), including straightening it in the well internal pressure and calibration of the inner diameter with a flare, while on the section of the profile overlap, installed against the absorption zone, a disconnecting packing element is placed above and below the latter, and the calibration of the inner diameter of this section is carried out to a diameter 3-5% higher than odny.

The disadvantages of these methods are:

- high energy costs when calibrating the shutoff, since the calibration is carried out by a flare tool that is not adjustable for the outreach of the rollers in the working position, which leads to accelerated wear of the flare tool, landings and tool jamming when the shutter is installed in narrowed sections of the wellbore;

- poor-quality isolation of the zones of absorption, gas or water manifestations in the wellbores of a slightly larger diameter than the nominal one, since when calibrated by a flare mill that is not adjustable for the reach of the rollers and in the working position, tight expansion of the expanded pipes to the walls of the well is not ensured.

The technical task of the method is to improve the quality of isolation of the zones of complications by installing expandable pipes due to the tight and tight pressing of the expandable pipes to the walls of the well with a simultaneous increase in the flare resource.

The technical problem is solved by the method of fastening the uncased part of the well by the method of range expansion of pipes, including the alignment of the profile pipes by hydraulic pressure in the well and calibration of the inner diameter by a flare mill with rolling elements with a diameter exceeding the original one.

What is new is that the flare housing is supplied inside with a tapered shaft spring-loaded upward, made to move downward by the action of the injected fluid and interacting with the expanding tapered surfaces of the rollers, and calibration, including the expansion of the internal diameter of the profile pipes and their cylindrical sections, is carried out in one or more passages with a flare tool with a selected flaring force and a variable overhang of the rolling elements, which allows the outer th surface profile pipes and cylindrical portions of the walls of the well and to receive the inner diameter of the extended pipes, exceeding the outer diameter of the subsequent layout of flushing the amount necessary clearance.

Figure 1 shows the installation diagram of the profile overlapper during flaring; figure 2 - the descent of the bit through a flared profile overlap.

The method is carried out in the following sequence.

According to the results of geophysical studies, the profile blocker 1 (Fig. 1) is lowered into the uncased part of the well 2, for example, to block the complication zone 3. The profile blocker 1 is straightened by creating hydraulic pressure in it, after which a calibration is carried out, including the expansion of the inner diameter of the profile pipes 4 and their cylindrical sections 5 flare 6. Flare 6 works as follows. When flarer reaches 6 expandable pipes, the pipe string begins to rotate while simultaneously creating axial load and flushing the pipe cavity and the device with fluid injection. In this case, under the influence of the pressure differential on the nozzle 7, the conical shaft 8, acting on the lower thrust sleeve 9 and compressing the spring 10, moves down to the stop, interacting with the conical surface 11 from the inside with the expanding surface 12 of the rollers 13, and displays the rollers 13 in working position. The rollers 13 interact with an expandable pipe, which is calibrated along the entire length with a calibrating surface 14. The pressure drop is selected so that when the narrowed sections of the well are reached, with an increase in the expansion force of the pipe, the rollers 13 extrude the conical shaft 8 upward. In this case, the diameter of the flaring is slightly reduced. After passing through the narrowed section, the flaring force decreases, while the conical shaft 8 moves downward, pushing the rollers 13 to a larger size. The fastening of the wells in the described manner allows tightly and tightly pressing the profile pipes 4 (Fig. 1) and their cylindrical sections 5 to the walls of the well 2. In this case, the minimum diameter of the flare is chosen so that it is larger than the outer diameter of the subsequent run-down assembly, for example, bit 15, by the amount of clearance required _Δ d.

The proposed method is simple to use, it allows to improve the quality of isolation of the zones of complications by installing expandable pipes due to the tight and tight pressing of the expandable pipes to the walls of the well with a simultaneous increase in the flare resource.

Claims (1)

The method of fastening the uncased part of the well by the method of range expansion of pipes, including straightening the profile pipes with hydraulic pressure in the well and calibrating the inner diameter with a flare mill with rolling elements with a diameter exceeding the original one, characterized in that the flare casing is provided with a taper shaft spring-loaded upward, made to move down under the action of the injected fluid and interacting with the expanding surfaces of the rollers, and calibration, including irradiation of the inner diameter of the profile pipes and their cylindrical sections is carried out in one or more passes by a flare tool with a selected flaring force and a variable overhang of the rolling elements, which allows tightly and hermetically pressing the outer surface of the profile pipes and their cylindrical sections to the borehole walls and obtain the inner diameter of the expanded pipes, superior outer diameter of the subsequent descent assembly by the amount of clearance required.

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