RU2459941C1 - Development method of multi-hole branched horizontal wells - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method involves well development using tubing string and determination of inflow volumes of each branched shaft drilled from the main horizontal part of the well; at that, tubing is equipped with swab limiter, and development is performed using swabbing cycles. According to the invention, tubing string is equipped prior to lowering with hydraulic deflector with inlet holes and packer, which are located closer to the head relative to inlet channels of deflector, and swab limiter is arranged in lower part of vertical section of tubing string. Besides, development of branched shafts is performed separately for each branched shaft starting from the most distant one from the well head due to in-series introduction prior to development by means of deflector to the chosen branched shaft of tubing string and insulation of this branched shaft from the main horizontal part of the well with a packer.

EFFECT: possible individual development of each branched shaft, including strongly contaminated one, as well elimination of swab blocking, breakage of rope and occurrence of emergency situations in the well.

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Description

The invention relates to the oil industry, and in particular to the field of completion of the construction of multi-sided branched-horizontal wells (MRGS) with multidirectional horizontal trunks (branches) in relation to the main trunk and, in particular, to the development process when completing their drilling, and also applicable for development similar MRGS after carrying out work on the treatment of the bottom-hole zone (SCR).

A well-known well completion system for use in the separation of fluid flows (RF patent No. 2136856, IPC 8 E21B 43/14, E21B 7/04, E21B 7/06, published in bulletin No. 28 of 09/10/1999), produced from lateral wells, the inner ends of which are in communication with the main well, comprising a tubular casing having a plurality of drainage means spaced at an angle to one another located on its walls and designed to receive produced fluids coming from the lateral wells, characterized in that it is provided a flow divider located in a casing with The selected orientation and containing a plurality of flow passages disposed therein, spaced relative to each other, with each flow passage containing an inlet aligned with a corresponding drainage means, and these inlet openings are connected with longitudinal channels extending upward from the inlet into the flow separator holes and extending through the upper end of the flow divider.

The disadvantages of this system are:

- the system is applicable in downhole wells and cannot be used in wells with the horizontal part of the trunks pointing upward with respect to the main wellbore;

- sophisticated technology for the performance of work and the use of special equipment;

- the possibility of emergency situations when entering the trunks.

Also known is a method of developing "conventional" directional wells, incl. and “ordinary” horizontal wells with one wellbore, involves lowering the tubing with a swab limiter to the lower perforations in “ordinary” wells cased by the production string and to the shoe of the production string in “ordinary” horizontal wells with one horizontal well (RD 39- 0147585-140-96, “Technology for invoking inflow by swabbing during well development”, Bugulma, 1996, p. 29).

The disadvantage of this method is that it is applicable only for single-hole wells with the direction of the trunks from top to bottom along the section.

The closest in technical essence is the method of development of multi-hole branched-horizontal wells (RF patent No. 2299981, IPC 8 E21B 43/25 publ. In Bulletin No. 15 of 05/27/2007), which includes well development itself using tubing and determination of the inflow volumes of each wellbore, characterized in that in the horizontal part of the well with upright branches, the development of each branch is carried out without entering the trunks after replacing the drilling fluid with oil, the tubing is equipped with wound up with a swab limiter and installed at the lower points of each branch, while the development is carried out by swabbing cycles.

The disadvantages of this method are:

- firstly, the limited application of the method, since it can be used to develop multi-hole branched-horizontal wells (MRGS) with the direction of the horizontal part of the trunks (branches) upward;

- secondly, the development takes place by replacing the drilling fluid with oil, followed by the development of all the branches by swabbing cycles, while there is a gentle depression on the formation, which does not allow to effectively develop a highly contaminated productive formation (for example, acid reaction products after treatment of the bottom-hole zone), in which these branches are drilled, moreover, development is carried out from the mouth to the bottom, which can lead to contamination of already developed branch trunks;

- thirdly, the swab run down is limited by the swab limiter, which is installed on the lower points of each branch, while due to the curvature of the well during swabbing, the swab may not reach the lower point of each branch or the swab will jam in the bent section of the well and, as a result, wire breakage and an emergency in the well.

An object of the invention is to provide a method that allows for the development of multi-sided branched-horizontal wells, in which branched wells are made in different directions from the main horizontal part of the well, and mastered separately for each branched well with the possibility of efficient development of a heavily contaminated reservoir, as well as guaranteed exclusion jamming of the swab, breaking the rope and creating emergency situations in the well.

The problem is solved by the method of developing multi-hole branched-horizontal wells, including the development of a well using a string of tubing and tubing and determining the volume of inflow of each branch hole drilled from the main horizontal part of the well, and the tubing is equipped with a swab limiter, and development carried out by swabbing cycles.

New is that the tubing string before launching is equipped with a hydraulic diverter with inlet openings and a packer located closer to the mouth relative to the diverter inlet channels, and the swab limiter is placed in the lower part of the vertical section of the tubing string, while the development of the branched trunks is carried out separately for each branched trunk starting from the furthest from the wellhead, through sequential input before development with the help of a diverter into the selected branch tubing of the tubing string and isolation this branch from the main horizontal part of the well packer.

Figure 1 and 2 shows a diagram of the implementation of the method.

Figure 3 shows a diagram of the execution of branched shafts from the main horizontal part of the well in the radial plane.

The proposed method for the development of multi-hole branched-horizontal wells is as follows.

A method for developing multi-hole branched-horizontal wells includes developing a well 1 (see Fig. 1) using a string of tubing 2 and determining the inflow volumes of each branched shaft 3 ', 3'', ..., 3 ⁿ drilled from the main horizontal part 4 of the well 1, and the tubing string 2 is equipped with a swab limiter 5, while the lower part of the tubing string 2 is equipped with a hydraulic diverter 6 with inlets 7 and a packer 8.

The packer 8 is located closer to the wellhead 1 relative to the inlet 7 of the deflector 6. The packer 8 can be of any known open-hole design, for example, an inflatable packer from Baker Oil Tools with a diameter of 114 mm, or a self-sealing cuff that does not leak from the branch trunks 3 '; 3 '' ... 3 ⁿ into the main horizontal part 4 of well 1.

The diverter 7 can be made as described in patent No. 2318111 "Hydraulic downhole deflecting node" publ. in bull. No.6 of February 27, 2008

Branched trunks 3 '; 3 '' ... 3 ^{n are} made from the main horizontal part 4 of the well 1 in different directions, and the development of branched trunks 3 '; 3 '' ... 3 ^{n is} carried out separately for each branched trunk 3 '; 3 '' ... 3 ⁿ .

ответвленного ствола 3', определяют местоположение компоновки до попадания его в ответвленный ствол 3'.To do this, lower the tubing string with the above arrangement to the bottom of the well so that the inlet openings 7 of the diverter 6 are located opposite the entrance to the branch bore 3 'adjacent to the bottom, after which alternating pressure cycles, for example 7 MPa, in the tubing string 2 and descent tubing string 2 to the bottom, by comparing the depth of the bottom, i.e. face 4 'of the main horizontal part 4 of the well 1 and bottom

branched trunk 3 ', determine the location of the layout before it hits the branched trunk 3'.

ответвленного ствола 3' составляет 500 м. Значит, производят спуск колонны НКТ 2 (см. фиг.2) до тех пор, пока отклонитель 6 входными отверстиями 7, минуя глубину 400 м, не упрется в забой 500 м, т.е. в забой

ответвленного ствола 3' скважины 1.For example, the depth of the face 4 'of the main horizontal part 4 is 400 m, and the bottom

the branched trunk 3 'is 500 m. Therefore, the tubing string 2 is lowered (see Fig. 2) until the diverter 6 by the inlet holes 7, bypassing a depth of 400 m, rests against the bottom of 500 m, i.e. into the face

branch bore 3 'of the well 1.

After that, the packer 8 is planted and the swab cycles of this branch trunk 3 'are mastered, while the swab limiter 5 in the tubing string 2 is installed in the lower part of the vertical section of the tubing string 2.

In the process of well development 1, the level is reduced to a value that creates a possible and acceptable depression for the well for the given well. The recovery of the level in well 1 is monitored to a value calculated by the geological service. Then swabbing again reduce the level and trace the restoration of the level. Swabbing cycles and control of level changes by removing the HIC with sampling is repeated until the flow of products from the reservoir is stabilized (i.e., until oil is obtained with a density characteristic of the given reservoir).

At the end of the development of the branched trunk 3 ', the packer 8 is unpacked, the layout is removed from the mastered branched trunk 3', the layout is moved from the bottom 4 'to the mouth (not shown in FIGS. 1, 2 and 3) along the main horizontal part 4 of the well 1 until it is placed opposite the entrance of the next branch shaft 3 ″, adjacent to the previously developed branch shaft 3 ′ of the well 1.

Further, depending on the angle of change (see FIG. 3), the directions of this branch 3 ’relative to the originally developed branch 3’ of the well 1 create several pressure cycles in the tubing string 2, depending on the angle of rotation for each pressure generation cycle. For example, (see figure 2), the deviation angle between the branched trunks 3 'and 3' 'made of the main horizontal barrel 4 of the well 1 is 150 ° (clockwise), and the deflector changes its angle of inclination with each cycle of pressure increase up to 7 MPa in the tubing string 2 by 30 ° (clockwise).

Thus, 5 cycles of pressure increase in the tubing string 2 are performed, while the deflection angle of the inlet openings 7 (see FIGS. 2 and 3) of the deflector 6 will correspond to the deflection angle of the branched shaft 3 ″ from the main horizontal part 4 of the well 1.

, при этом проводят сравнение глубины забоев, т.е. забоя 4' основной горизонтальной части 4 скважины 1 и забоя

ответвленного ствола 3'' и определяют местоположение положения компоновки до попадания его в ответвленный ствол 3''.Then carry out the descent of the tubing string 2 to the bottom of this branch trunk

, while comparing the depth of the faces, i.e. face 4 'of the main horizontal part 4 of the well 1 and bottom

branch 3 "and determine the location of the position of the layout before it hits the branch 3".

ответвленного ствола 3'' составляет 350 метров. Значит, производят спуск колонны НКТ 2 до тех пор, пока отклонитель 6 входными отверстиями 7 не упрется в забой 350 м, т.е. в забой

ответвленного ствола 3'' скважины 1.For example, the depth of the bottom 4 'of the main horizontal trunk 4, as described above, is 400 meters, and the bottom

The 3 '' branched trunk is 350 meters. This means that the tubing string 2 is run down until the diverter 6 by the inlet 7 rests against the bottom 350 m, i.e. into the face

3 '' branched borehole 1.

After that, the packer 8 is planted and the swab cycles of this branch 3 '' well 1 are mastered, while the swab limiter 5 in the tubing string 2 continues to be at the level of the roof of the producing formation 9 and does not change its position.

At the end of the development of the branched trunk 3 ’, the packer 8 is unpacked, the layout is removed from the mastered branched trunk 3 ″, the layout is moved from the bottom 4 ′ to the mouth (not shown in FIGS. 1, 2 and 3) along the main horizontal part 4 of well 1 to its location opposite the entrance of the next branched shaft 3 ⁿ , adjacent to the previously mastered branched trunk 3 ″ well 1.

Further, the above operations for the development of the branched trunk 3 ″ are repeated with the remaining branched trunks 3 ⁿ . Thus, the diverter allows you to get into the branches of the trunks 3 ⁿ depending on the direction (angle of inclination) of each branched trunk 3 ⁿ relative to the axis of the main horizontal part 4 of the well 1. The packer 8 hermetically cuts off the mastered branch trunk, for example, 3 'from other branch trunks 3 '' ... 3 ⁿ and the horizontal part 4 of well 1 during development.

The proposed method allows for the development of multi-sided branched-horizontal wells in which the branched shafts are made in different directions from the main horizontal part of the well and are mastered separately for each branched shaft due to the hermetic fit of the packer at the inlet of the branched shaft. In addition, the presence of a packer makes it possible to efficiently master a highly contaminated productive formation due to a sharper depression, and the placement of a swab limiter in the tubing string at the level of the top of the productive layer is guaranteed to prevent jamming, wire breakage and emergency situations in the well.

Claims (1)

A method for developing multi-hole branched-horizontal wells, including developing a well using a tubing string — tubing and determining the inflow volumes of each branch hole drilled from the main horizontal part of the well, the tubing being equipped with a swab limiter, and the development is carried out by swab cycles, characterized in that the tubing string before launching is equipped with a hydraulic diverter with inlets and a packer located closer to the mouth relative to the inlet channels of the deviation Itel, and the swab limiter is placed in the lower part of the vertical section of the tubing string, while the development of the branched trunks is carried out separately for each branched trunk, starting from the farthest from the wellhead, by sequential input before the development using the diverter into the selected branched trunk of the tubing string and isolation of this branch from the main horizontal part of the well with a packer.

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