RU2520981C1 - Well operation device - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: proposed device comprises casing, extra production string and flow string. Extra production string is used which does not extend to well head. Flow string is equipped with fixed external coupling secured above extra production string and nearby the top of extra production string. Said coupling represents that with OD larger than ID of extra operation string and not larger than OD of standard string gage for casing and with OD-to-coupling height varying from 0.70 to 0.83.

EFFECT: simplified liquidation of failures, accelerated repair.

2 dwg, 2 tbl

Description

The invention relates to the oil industry and may find application in the operation of the well.

A known method of preparing and conducting underground well repair, which describes the design of the well, including a casing string, an additional production string and tubing string (RF Patent No. 2188301, published. 08.27.2002).

Closest to the proposed invention in technical essence is a method of developing deposits of highly viscous oil and bitumen and a device for thermal displacement of products from horizontal wells (RF Patent No. 2445452, published on March 20, 2012 - a prototype). The device includes a casing string, an additional production string, tubing string, packers, valves.

A common disadvantage of the known technical solutions is the impossibility of extracting broken tubing from an additional production string.

The proposed invention solves the problem of ensuring the recovery from the well of broken tubing.

The problem is solved in that in a device for operating a well, including a casing string, an additional production string and a tubing string, according to the invention, an additional production string is used that does not reach the wellhead, the tubing string is higher than the additional production string and near from the top of the additional production casing they provide a fixed external coupling; a coupling with an outer diameter larger than the inside is used as a coupling the diameter of the additional production casing and not more than the outer diameter of the standard casing string template and with the ratio of the outer diameter to the height of the coupling ranging from 0.70 to 0.83.

SUMMARY OF THE INVENTION

At present, the well stock is aging, and the integrity (tightness) of production wells is increasingly being violated. To eliminate violations in the well, an additional production casing of small diameter is lowered, overlapping the integrity violations of the original casing. The annulus is cemented. Then perforate the interval of the reservoir and exploit the well.

However, in wells with additional columns, there is a significant drawback - in the event of a breakdown and “flight” of the tubing string to the bottom, they get jammed - an accident that entails the inability to eliminate the complication by the underground repair crews, putting the well intoactive, waiting for a major well repair. Due to the lack of specialized equipment for the elimination of these complications in additional small-diameter columns, large costs arise for the elimination of complications by the workover crews.

To avoid complications in the additional production casing associated with jamming of the broken suspension of the tubing, the following measures are proposed. The top of the additional production casing is located at a distance from the wellhead, on the tubing string above the additional production casing and close to the top of the additional production casing, the external coupling is fixed, as a coupling using a coupling with an outer diameter larger than the inner diameter of the additional production casing and not more the outer diameter of the standard casing template and with the ratio of the outer diameter to the height of the sleeve before Lah from 0.70 to 0.83.

Figure 1 and 2 presents the claimed device for the operation of the well.

The device includes a casing string 1, an additional production string 2, not reaching the wellhead 3 of the well 4, the tubing string 5 and the sleeve 6.

Figure 1 shows the device of the well when placing the string of tubing 5 above the additional production string 2. In this case, the sleeve 6 is placed below the column of tubing 5, i.e. above the additional production string 2 and at the closest distance from the top additional production casing 2. In Fig.2 shows a variant in which the string of tubing 5 is partially immersed in the additional production casing 2. In this case, the sleeve 6 is placed on the string compressor pipes 5 above the additional production casing 2 and near the top of the additional production casing 2.

The use of a coupling with an outer diameter larger than the inner diameter of the additional production string makes it impossible to pass the coupling into the additional production string 2 and, accordingly, the passage of the entire string of tubing 5. The use of the coupling 6 with an external diameter of not more than the external diameter of a standard casing string template 1 determines the passage of the sleeve 6 along the casing 1 and the simultaneous centering of the sleeve 6 and the entire string of tubing 5 in the well 4. Centering allows you to distribute the load upon impact of the coupling 6 on the additional production casing 2, to prevent bending loads, to maintain the integrity of all columns. The ratio of the outer diameter to the height of the coupling 6 in the range from 0.70 to 0.83 makes it possible to ensure the reliability of the fastening of the coupling 6 on the tubing string 5, to ensure the safety of the structure during repeated shock loads. Tests in the well showed that with the claimed range of ratios, the structure is maintained after 20 strokes of the sleeve 6 with the tubing string 5 against an additional production string 2. A decrease in the ratio below 0.70 and an excess above 0.83 causes a decrease in impact resistance.

As an example, table 1 shows the dimensions of the coupling for use in a well with different casing and additional production casing.

Table 1 No. p.p. Conventional diameter of production casing, mm Conditional diameter of the descent additional column, mm Additional Column Parameters Nominal diameters of production tubing lowered into the columns, mm Outer diameter of the used coupling (limiter), mm Height of the used coupling (limiter), mm Outer diameter mm Wall thickness mm Inner diameter mm one 168 (6 ∗), 146 (5 ∗) 114 (4 *) 114.3 7 100.3 48, 60, 73 121 150 2 146 (5 ∗) 102 (3.5 *) 101.6 6.5 88.6 48, 60 107 146 3 146 (5 ∗) 89 (3 *) 88.9 6.5 76 48 89 132

Table 2 presents the diameters of the columns in relation to the diameter of the descent templates.

table 2 No. p.p. Conventional diameter of production casing, mm The diameters of the templates run for the design of production casing (depending on the wall thickness of the columns), mm one 168 (6 *) 142-144 2 146 (5 *) 120-124.4

The application of this proposal will eliminate the jamming of the suspension in the borehole, carry out the process of liquidating the accident with a standard tool using underground well repair teams, reduce costs and reduce repair time.

Claims (1)

A device for operating a well, including a casing string, an additional production string and a tubing string, characterized in that they use an additional production string not reaching the wellhead, a tubing string above the additional production string and close to the top of the additional production string provide a fixed external clutch, as a clutch use a clutch with an outer diameter greater than the inner diameter of the additional hydrochloric production casing and the outer diameter of a standard template of the column for the casing and the outer diameter ratio to the coupling height in the range from 0.70 to 0.83.

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