RU2269632C1 - Multilateral well building method - Google Patents

Abstract

FIELD: well building, particularly to erect well clusters.

SUBSTANCE: method involves lowering pipe string provided with diverter at pipe string end in casing pipe; cutting casing pipe within predetermined interval; lowering flexible pipe with nozzle until flexible pipe enters into opened casing pipe zone under the action of the diverter in alternation with supplying pressurized liquid via flexible pipe provided with nozzle; performing translational flexible pipe movement to create additional well bores having necessary lengths along with removing the flexible pipe to create predetermined number of additional bores; finally removing the flexible pipe from the casing pipe. The diverter has several guiding channels, spring-loaded centralizer and beveled lower end surface. Before casing pipe lowering in the well the casing pipe is provided with rigidly secured hollow insert comprising technological body with through orifices and bush with movable stop. The bush has beveled upper end surface. Inner surface of technological body comprises technological groove. The bush is inserted in the technological body in air-tight manner so that the bush closes through orifices and movable stop is arranged in the technological groove. During casing pipe lowering operation through orifices are located in predetermined opening interval along with following casing pipe securing, diverter displaces bush with movable stop downwards up to reaching technological groove end, beveled upper and lower end surfaces of the bush and the diverter cooperate with each other to register outlet orifices of guiding channels with the through orifices. After each additional well bore forming flexible string with nozzle is removed only from diverter to create predetermined number of additional bores.

EFFECT: reduced number of trips and prevention of pipe string rotation during well building.

2 dwg

Description

The invention relates to the oil and gas industry, namely the construction of bushes of oil and gas wells.

The well-known "Method of construction of a multilateral well" (AS No. 1798466, MKI E 21 B 7/06, publ. BI No. 8, 02.28.93), including drilling a vertical main shaft, installation and fastening in the main barrel of the drum with guiding columns located in its plane and a deflecting unit in the lower part, alternately drilling, drilling and securing additional trunks, while drilling the lower section of the main trunk, increase its diameter, the drum is installed directly above the lower section of the main shaft, and The well bore holes are carried out through the wall of the latter.

The disadvantages of this method are:

firstly, the need to drill the main trunk of a large diameter, which requires a lot of time, especially during the construction of deep wells, and, as a result, large material costs;

secondly, the presence of guide columns also leads to an increase in the cost of building a multilateral well;

thirdly, such a layout of the well is complicated both during construction and during operation.

The closest in technical essence and the achieved result is the "Method and device for horizontal drilling of wells" (US patent No. 5413184, IPC E 21 B 7/08, published 09/05/1995), which includes the descent into the casing to a predetermined depth of the string pipes, at the end of which the diverter is located, descent into the string of pipes of the flexible shaft with the cutter at the end before interacting with the diverter, rotation with the translational movement of the flexible shaft with the cutter, which, as a result of interaction with the diverter, opens the casing and enters the formation at the specified расстояние distance with obtaining a technological channel, removing a flexible shaft with a milling cutter from the well, lowering a flexible pipe with a nozzle into the pipe string before entering the casing opening under the action of a deflector, supplying liquid under pressure through a flexible pipe with a nozzle with simultaneous translational movement to increase the technological channel to the required length.

The disadvantages of this method are: the need for the construction of a multilateral well to perform sequential operations — turning the pipe string to the required angle, lowering the flexible shaft with the cutter, cutting the channel, deepening the channel with the help of flexible pipes with a nozzle under the influence of the fluid pressure, and so for each horizontal additional well , which leads to large losses of time and, as a result, to significant material and financial costs (see the instruction Rad-Tech International Inc. no construction of wells (US No. 5413184), including multilateral).

The technical task of the invention is to reduce material and financial costs due to: reducing the number of hoisting equipment and eliminating the rotation of the pipe string during the construction of a multilateral well using flexible pipes with a nozzle under the influence of fluid pressure, opening the casing in the radial direction, depending on the required amount additional trunks without violating its integrity.

The technical problem is solved by the method of constructing a multilateral well, including the descent into the casing of the pipe string, at the end of which there is a diverter, the opening of the casing in the required interval, the alternation of the descent into the pipe string of the flexible pipe with the nozzle before the entrance, under the action of the diverter, into the opening zone of the casing , the flow of fluid under pressure through a flexible pipe with a nozzle with its simultaneous translational movement to form additional shafts of the required length with the removal of the flexible pipe to obtain the required number of additional shafts, after which the flexible pipe with the nozzle is finally removed from the casing.

What is new is that the casing string is additionally equipped with a rigidly fixed hollow insert containing a through hole and a sleeve with a movable stop, while the sleeve has a beveled end surface on top and a technological groove is made on the inner surface of the technological case, the sleeve being inserted into the technological case hermetically, blocking the through holes, and its movable stop is located in the technological groove, while during the descent, the through holes set in the required opening interval, followed by mounting the casing, and the diverter is equipped with several guide channels, a spring centralizer and a beveled end surface from the bottom, and during the descent, the diverter shifts the sleeve with a movable stop until the end of the technological groove, while the upper and lower beveled end surfaces , respectively, the sleeve and the diverter, interacting with each other, set the output holes of the guide channels opposite the through holes, and ibkuyu nozzle column after forming each additional trunk is removed only from the whipstock to obtain the necessary number of additional trunks.

Figure 1 shows a diagram of the layout of the casing before the formation of the additional barrel.

Figure 2 shows a diagram of the formation of an additional barrel.

An example of a specific implementation.

The method of constructing a multilateral well is as follows.

The casing 1 (see Fig. 1) is equipped with a rigidly fixed hollow insert 2 before being lowered into the well, containing a technological housing 3 with through holes 4 and a sleeve 5. At the top, the sleeve 5 has a beveled end surface 6. The sleeve 5 is hermetically inserted into the technological case 3 and connected to it by means of shear elements 7. The sleeve 5 overlaps the through holes 4 of the hollow insert 2, which, during the descent of the casing 1, are installed in the required opening interval opposite the reservoir 8. On the inner surface, Technological technologically housing slot 3 is executed 9, wherein the movable pawl 10 is in turn rigidly coupled to the sleeve 5. Process groove 9 by the movable stopper 10 restricts the axial movement of the sleeve 5 downwards.

Next, casing string 1 is cemented using any of the existing technologies (not shown in FIG.). After waiting for the cement to solidify into the casing 1, the pipe string 11 with the deflector 12 is lowered. The deflector 12 inside is equipped with several guide channels 13 (see Fig. 1), and on the side a spring centralizer 14 in contact with the inner surface of the casing 1 during the descent. From below, the deflector 12 is provided with a beveled end surface 15. The deflector 12 is rotatable relative to the pipe string 11.

As an example, consider a deflector 12 having two guide channels 13 ′ and 13 ″.

The diverter 12 is lowered into the well and at some point with its lower beveled end surface 15 comes into contact with the upper beveled end surface 6 of the sleeve 5. As a result, the diverter 12 is rotated relative to the pipe string 11 by a certain angle and sits on the upper beveled end surface 6 of the sleeve 5, which is fixed by the appearance of the weight of the pipe string 11 on the weight indicator located at the wellhead (not shown in Fig.).

Next, unload the pipe string 11 with the diverter 12 to the sleeve 5 (Figure 2), while with the estimated load, the shear element 7 is destroyed. The sleeve 5 with a movable stop 10 located in the technological groove 9 is lowered down until the movable stop 10 abuts against the lower end of the technological groove 9. Next, the pipe string 11 with the deflector 12 is allowed down until it sits again on the upper beveled end surface 6 of the sleeve 5. Since the movable stop 10 of the sleeve 5 is located in the technological groove 9, when they are axially moved downward, the sleeve 5 is not rotated relative to the technological housing 3, therefore, the outlet openings of the guide channels 13 of the deflector 12 are installed pouring opposite through holes 4 of the body 3 technological hollow insert 2.

Next, flexible pipes 16 with a nozzle 17 (see FIG. 2) are lowered into the pipe string 11 until they enter through the guide channel 13 'of the deflector 12 into the opening interval of the casing 1 opposite the reservoir 8, which is fixed on the mouth by the weight indicator and right there a mark is applied at the wellhead (not shown in FIG.) on the flexible pipe 16 — the beginning of the formation of the additional barrel 18. Next, liquid is supplied under pressure through the flexible pipe 16 with the nozzle 17 with simultaneous translational movement, as a result of which an additional barrel is formed in the reservoir 8 18, which increases to the required length. Then the flexible pipe 16 with the nozzle 17 is removed from the additional barrel 18 of the casing string 1 and the diverter 12 of the pipe string 11 to the above mark plus the length of the guide channel 13 '. Then the flexible pipe 16 with the nozzle 17 is led into the second guide channel 13 ″ of the deflector 12 - this is determined by the reduction in the weight of the flexible pipe 16 (according to the weight indicator) when it is lowered to the mark on the mouth. Then form a new additional barrel 18 '. To this end, under the action of the pressure of the fluid supplied through the flexible pipes 16 with the nozzle 17, a second additional barrel 18 'of the required length L is formed in a predetermined interval.

In cases where at the mouth the mark of the flexible pipe 16 drops significantly lower without changing the weight, the flexible pipe 16 is removed to the mark plus the length of the guide channel 13 ', after which the flexible pipe 16 is rotated by a small angle so that its natural residual curvature changes its orientation, and again try again until the flexible pipe 16 stops at the mark, which is fixed by the weight indicator. In practice, getting into the next guide channel 13 ″ by a flexible pipe is ensured in 1-3 attempts in the presence of four guide channels 13 in the deflector 12.

At the end of the construction of the required number of additional shafts 18, the flexible pipe 16 with the nozzle 17 is removed from the casing 1, and the pipe string 11 with the diverter 12 is completely unloaded on the sleeve 5, as a result, the movable stop 10 located in the technological groove 9 is destroyed, and the sleeve 5 falls on the bottom of the well. If necessary, the sleeve 5 can be drilled, as it is made of cast iron.

In the above example, we considered the option of constructing a cluster well with two additional shafts 18, similarly, work is carried out for the required number of additional shafts 18, but for this it is necessary to use a diverter 12 with the number of guide channels 13 and, accordingly, the through holes 4 of the technological building 3, equal to the number of additional trunks 18.

Using the proposed method due to opening the casing in the radial direction, depending on the required number of additional shafts, does not violate its integrity and reduces the number of hoisting equipment, and the possibility of a deflector with several guide channels freely rotate relative to the pipe string to the required angle eliminates the operation of turning the string pipes, which together allows to reduce material and financial costs for the construction of a cluster well Saws with the use for driving a flexible pipe with a nozzle under the influence of fluid pressure.

Claims (1)

A method of constructing a multilateral well, including the descent into the casing string of the pipe string, at the end of which the diverter is located, opening the casing string in the required interval, the alternation of the descent into the pipe string of the flexible pipe with the nozzle before entering, under the action of the diverter, into the opening area of the casing string, fluid supply under pressure through a flexible pipe with a nozzle with its simultaneous translational movement to form additional trunks of the required length with the extraction of the flexible pipe to obtain the required number of additional shaft, after which the flexible pipe with the nozzle is finally removed from the casing, characterized in that the casing is additionally equipped with a rigidly fixed hollow insert containing a through hole and a sleeve with a movable stop, before the runoff, and the sleeve has a beveled end surface on top and a technological groove is made on the inner surface of the technological case, and the sleeve is sealed into the technological case, blocking the through holes, and the movable stop is located in the technological groove, while during the descent, the through holes are installed in the required opening interval with the subsequent casing fastening, the diverter being equipped with several guide channels, a spring centralizer and an oblique end surface from the bottom, and during the descent, the diverter shifts the sleeve with the movable focusing until the end of the technological groove, while the upper and lower beveled end surfaces of the sleeve and diverter, respectively, interacting with each other , establish the outlet openings of the guide channels opposite the through holes, and the flexible column with the nozzle after the formation of each additional barrel is removed only from the deflector to obtain the required number of additional shafts.

Images