RU2642194C2 - Method to increase formation hydrocarbon yield and intensify oil-gas-condensate production by means of formation radial penetration with water jet - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method includes installing into the well a high-strength tubing, a diverter with inner channel extending therethrough, tying and possible thereof orientation in space in the interval of the lower level drilling of lateral wellbores, sealing the wellhead, installing downhole equipment comprising a water jet nozzle, control unit of the wellbore path, navigation system, working flexible tubing, a device for redistribution of flow, return valve feeding the flexible tubing, supplying liquid into the inter-string area of the tubing/flexible tubing, moving the water jet nozzle through the sealing device. Through the diverter, in contact with rock, drilling of planned length radial wellbore is conducted using the navigation system for monitoring actual position of the wellbore in the formation, and with using the control unit of the wellbore path to provide wellbore drilling along the planned path. After driving the working flexible tubing string with the nozzle through the formation, removal from the formation and well flushing is carried out up to complete discharge of slime. By actuation of the mechanical turning device, the diverter is moved to another plane. The work cycle is repeated for the next lateral wellbore. Milling of a separate port for each lateral wellbore is carried out immediately before performing the main operation for driving lateral wellbores through the diverter. When drilling the lateral wellbore, the wellbore path is determined and changed by supplying the working flexible tubing with wellbore path control unit and the navigation equipment. In order to perform drilling of radial wellbores at the following levels, the supply and working flexible tubing is extracted from the well, tubing is removed from the mechanical anchor, fitting pipe of the tubing that was preinstalled and equal to the length of the transition to the next level is removed, the tubing is seated on the mechanical anchor, and the working flexible tubing with navigation system, control unit of the wellbore path, water jet nozzle is run in into well, after that the operation for drilling of radial wellbores is repeated.

EFFECT: increased productivity of wells and hydrocarbons recovery factor, possibility to conduct address action on the formation, possibility to conduct intensification without effecting on string cement support with considerable pressure drop and chemical destruction, possibility to stimulate the formation by a significant pressure drop or chemical failure, cleaning the wellbore when drilling thereof.

3 cl, 2 dwg

Description

The invention relates to the oil and gas industry, and in particular to methods for flushing boreholes using liquids and gases, including changing the direction of the wells, and in particular to methods for increasing hydrocarbon production and stimulating production of oil and gas condensate wells by means of hydraulic radial drilling.

A number of drilling methods are known from the prior art, for example, a method carried out using a drilling device (patent RU 2118440 C1, 08.28.1998), including drilling the main wellbore and securing it with a casing string with a pipe with a guiding element, lowering the drill string with an engine, bit and oriented drilling of the first branch, while the guide element deflects the tool. If necessary, to facilitate entry into one of the curved branches into the deflecting device, a device for re-entry can be omitted, after which the second branch is drilled in the same way.

The disadvantages of the above method are the complexity of the design of the device, which leads to an increase in material costs for the construction of the well, the inability to involve the main well in operation, since the guide element is not removed from the well, a large radius of curvature of the well, which leads to the need to drill an extended interval before the branch enters productive formation, the need to casing the branch casing and cement it.

The closest analogue of the claimed invention is a method of hydraulic drilling (see US 2012/0186875, July 26, 2012), comprising a hermetic installation of a deflecting device with the inner surface of the working string at the distal end of the working string of the tubing (tubing), while the deflector is made with passing through the inner channel, and the drilling tool contains a drill tubing with an inner shaft, an approximate end and a distal end, and a through flow device having at least one channel providing the fluid communication between the annulus formed by the inner surface of the tubing string and the inner bore of the tubing, when the drilling tool is inserted into the tubing string, the method further includes connecting the drilling tool to the connecting string, the entry of the drilling tool into the tubing string, at least , parts of the drill pipe into the diverter, the flow of drilling fluid under pressure into the annulus formed between the working string of the tubing and connecting columns oh, while the drilling fluid under pressure passes through the through-flow device into the drill pipe and exits at the distal end of the drill pipe.

The disadvantages of the closest analogue is the low efficiency of the method, due to the low coverage by the radial trunks of the productive part of the formation due to the lack of navigation of the trunk and the control of their trajectory, the inability to drill long trunks due to the risk of uncontrolled escape from the reservoir and penetration into aquifers or them in the unproductive part of the well section.

The objective of the invention is to remedy these disadvantages by creating a new method of increasing hydrocarbon production and intensification of oil and gas condensate wells.

The technical result of the claimed invention is to increase the productivity of wells and the hydrocarbon recovery coefficient by additional increment of the drainage area, impact coverage, removal of the skin factor and increase of the formation matrix conductivity, providing the possibility of targeted impact on the formation due to the directed influence on the reservoir by controlled side channels, the possibility of intensification without affecting the cement support column significant pressure drop or chemical p zrusheniem; the possibility of intensification by a significant pressure drop or chemical destruction; cleaning of the wellbore during its wiring, which allows efficient use of the technology in both carbonate and terrigenous strata.

The specified objective of the invention is solved by the creation of a method of increasing hydrocarbon production and intensification of oil and gas condensate wells by means of hydro-radial radial opening of the formation, including the installation of a high-strength tubing (tubing) in the well, a diverter with an internal channel passing through it, tying it and its orientation in space in the interval the lower level of sidetracking, sealing of the wellhead, installation of downhole equipment consisting of hydra monitor nozzle, trunk trajectory control unit, navigation system, working coil, redistribution device, check valve, feeding coil, fluid supply to the tubing / coil annulus, moving the monitor nozzle through the sealing device, through the diverter into the rock contact, wiring is performed the planned length of the radial shaft using a navigation system to monitor the current position of the barrel in the reservoir, as well as using the track control unit with the thorium of the trunk to ensure that the trunk is guided along the project path, after penetrating the formation, the working coil with the nozzle is removed from the reservoir and the well is flushed until the cuttings are completely removed, by means of a mechanical rotary device, the deflector is transferred to another plane, the work cycle is repeated for the next side trunk, wherein the milling of a separate window for each sidetrack is carried out immediately before the main operation for penetrating the sidetrack through the diverter, when wiring a side trunk, the trunk path is determined and changed by supplying the working coil with a trunk path control unit and navigation equipment.

To guide radial trunks at subsequent levels, the supply and working coil is removed from the well, the tubing is torn from the mechanical armature, the tubing fitting, previously set and equal to the transition to the next level, is removed, the tubing is planted on the mechanical armature, the working coil is lowered into the well from the navigation the system, the node for controlling the paths of the trunk, the hydraulic nozzle, after which the work on posting the radial trunks is repeated.

When cutting windows in the casing for the sidetrack, an additional hydro-sandblasting device is lowered on coiled tubing, abrasive cutting of the rectangular hole with circulation is made, and then the equipment is lifted.

For one descent of the sandblasting device on coiled tubing, they cut all the necessary rectangular holes for sinking radial shafts in the casing at the same level, using a fixed rotation of the deflector due to the operation of a mechanical rotary device with a discrete angle of rotation.

The fluid is pumped through a small tubing / coil and / or small tubing / coil and the inside of the coil.

A brief explanation of the invention is presented in graphic materials.

In FIG. 1 - scheme 1 of the claimed method,

In FIG. 2 - scheme 2 of the claimed method.

In FIG. 1-2:

1 - check valve

2 - flow redistribution device,

3 - mechanical anchor,

4 - rotary device

5 - sealing device

6 - diverter

7 - navigation system,

8 - node control the path of the trunk,

9 - jet nozzle,

10 - a device for waterblast cutting,

11 - casing,

12 - high-strength tubing,

13 - supply coil

14 - working coil

15 - circumferentially milled section ("window") in the casing,

16 - a bore hole ("window"), cut in a casing by a water sandblast cutting.

The following are non-exhaustive options.

On high-strength tubing, a diverter is lowered into a well with milled “windows” in the casing in the places of sidetracking and installed with reference and, if necessary, orientation in the interval of the lower level of wiring of radial trunks. Downhole equipment on a working coil (flexible tubing) 38 mm is lowered into a well (89 mm tubing). It includes: a hydraulic monitor nozzle, a trunk path control unit, a navigation system, a working coil 32 (38) mm of the estimated length, equal to the planned length of the radial shafts (up to 500 m and more), a flow redistribution device, a check valve supplying the coil. Next, the wellhead is sealed, after which an opening fluid is supplied to the annular space of the 38 mm feed tubing / 89 mm tubing, with the admission of the feeding coil, the hydraulic nozzle with the working coil is moved through the sealing device and exits through the diverter into contact with the rock / cement. The planned length of the radial trunk is posted using the navigation system to monitor the current position of the trunk in the formation, as well as using the trunk path control unit to ensure the trunk is guided along the project path. In this case, the fluid is pumped through a small tubing / coil and / or a small tubing / coil and the inside of the coil. The pump is switched off and the diverter is turned with guaranteed accuracy using a mechanical rotary device. The sinking operation of the next trunk is repeated. After carrying out the required number of trunks at one level, they proceed to the complete raising of the coil. A fitting pipe is removed, pre-screwed in the upper part of the tubing suspension of the estimated length to go to the next level. Install the diverter on the tubing in the planned interval on the mechanical anchor. The cycle of work is repeated. After carrying out the design number of radial trunks, the coil is fully hoisted, tubing suspension 89 mm.

Below is another possible example with a variation according to scheme 2 of the method (see example and Fig. 2 below) of the invention, in no way limiting all possible options for its implementation. For convenience, an example is given with links to graphic materials.

[1] An assembly consisting of a deflector (6) having a through channel with a lateral outlet, a sealing device (5), and a rotary device (4) is lowered into a well plugged and prepared for radial drilling (RWP) of a well on high-strength tubing (12) mechanical anchor (3).

The layout may also include additional elements that are not limited to this list: line voltage compensator, disconnector, check valves and more.

Using the geophysical method, the diverter is attached by the side channel to the interval of the casing milled around the circumference (15). The tubing assembly is planted on a mechanical anchor (3) taking into account the binding so that the diverter exit (6) coincides with the open (circumferentially milled) part of the casing string (15).

[2] There is another way (see Fig. 2) to ensure that the lateral exit of the deflector (6) is communicated with the formation by using a sandblasted “window” of rectangular cross-section (16) in the casing (11). To accomplish this task, the above-described layout descends into the unmilled casing, it is landed on a mechanical anchor (3) with geophysical attachment.

[3] Next, in the tubing (12) on the coil (13), a device for hydro sandblasting (10) is lowered, which enters the joint with the diverter and the end with the nozzle is sent to the casing wall (11). By pumping fluid into the coil (13), fluid circulation is created with exit from the well along the annulus between the casing (11) and tubing (12). Abrasive material (quartz sand, proppant, etc.) is added to the fluid flow on the surface, which, passing through the nozzle of the device (10), destroys the wall of the casing with the creation of a through hole (16). The creation of a rectangular section of the through hole (16) is provided by moving down the nozzle of the device for sandblasting (10). After cutting a hole in the casing and lifting sandblasting equipment from the well, they begin the operation of radial channeling.

In the particular case, for one descent of the sandblasting device on coiled tubing, they cut all the necessary rectangular holes for sinking radial trunks at the same level, using a fixed rotation of the deflector due to the operation of a mechanical rotary device with a discrete rotation angle.

[4] In the well (Fig. 1) tubing (12) on the feed coil (13) with a flow redistribution device (2), a check valve (1) is lowered for the RWP assembly, consisting of a hydraulic nozzle (9), a trunk path control unit (8), navigation system (7), working coil (14). Additional components, not limited to this list of downhole equipment, may also be included in the layout for the RWP.

[5] When lowering the coil (14) and (13) into the tubing (12), flushing fluid is supplied to the annular space of the coil (13) / tubing (12) to equalize the pressure in the well. When the installation depth of the mechanical anchor (3) is reached, the flow rate of the flushing fluid is increased to the design mode, complete circulation is achieved with the solution going through the tubing annulus (12) / casing (11). The planned length of the radial shaft is posted using the navigation system (7) to monitor the current position of the barrel in the formation, as well as using the trunk path control unit (8) to ensure the trunk is guided along the projected path. The flushing fluid exiting the well is directed through the cleaning system back to the well.

[6] By lowering the coil (13), the coil (14) is moved down, the nozzle (9) exits the diverter (6) and the casing (11), and then the radial shaft is hydromonitor drilled through the productive layer of the projected length.

[7] The geographic coordinates of the bottom face of the radial shaft in the formation and their attachment to the lithological section are determined using the navigation system (7), which transmits information to the surface via a cable communication channel. In order to guide the radial shaft along the projected trajectory, change its trajectory when approaching the boundary of the selected interval of the formation, a node for controlling the trajectory of the trunk (8) is used, which is controlled from the surface via a hydraulic or cable communication channel.

[8] After reaching the design end point (bottom) of the radial shaft, the hydro-monitor nozzle (9) on the coil (14) is removed from the formation with its placement below the sealing device (5). Through flushing, complete tubing clearance (12) / casing (11) is removed from the sludge.

[9] After the circulation is stopped by the hoisting operation of the coil (14) with passage through the rotary device (4), the required number of times (each passage of the coil through the rotary device provides the deflector for a certain discrete angle), the deflector is rotated for the angle projected for the next trunk.

[10] In those cases when the casing was annually milled during the preparation of the well for radial drilling of the casing or all the necessary rectangular holes for drilling radial trunks at the same level were cut in one coiled tubing, they proceed to the operation [6], then sequentially performing operations [7], [8], [9].

[11] In those cases when annular milling of the casing string was not performed during the preparation of the well for radial drilling, after lifting the assembly on the coil (14) from the well, they proceed to operation [3], then sequentially perform operations [4], [5 ], [6], [7], [8], [9].

[12] In order to switch to the subsequent level of penetration of radial trunks after completing the penetration of all planned radial trunks at the same level, they lift from the layout well on a coil (13), (14). The tubing is torn off (12) from the mechanical armature (3) and the tubing fitting pipe of the calculated length (set in advance) is removed from the well and the deflector is raised to the next upper level.

[13] The tubing assembly is planted on a mechanical anchor (3) so that the outlet of the diverter (6) coincides with the open (milled) part of the casing (15).

[14] In those cases when annular milling of the casing was not performed during the preparation of the well for radial drilling of the formation, the output of the deflector (6) should coincide with the design interval for hydro-sandblasting in the casing (16). To cut this hole, work is underway [3].

[15] To conduct radial shafts at each level of the well section, the following works are performed [4], [5], [6], [7], [8], [9].

[16] To move to each subsequent level for the purpose of posting the next design radial shafts, work is performed [12], [13], [14].

[17] Work on radial wellbore wiring at each level of a well section is sequentially repeated [4], [5], [6], [7], [8], [9].

[18] After posting the planned number of radial shafts at all levels of the well cut and flushing the well from the sludge, the tubing is torn off (12) from the mechanical armature (3) and the tubing is completely lifted (12).

[19] Next, according to an individual work plan, they begin to develop the well.

Thus, the application of the claimed method provides:

- increase in well productivity and hydrocarbon recovery coefficient due to additional increment of drainage area, impact coverage, removal of skin factor and increase in matrix conductivity;

- the possibility of targeted impact on the reservoir due to the directional wiring of controlled lateral shafts of great length;

- the possibility of intensification without affecting the cement support of the column significant pressure drop and chemical destruction;

- the possibility of intensification with the impact on the formation of a significant pressure drop or chemical destruction;

- cleaning the wellbore during its wiring, which allows the efficient use of technology in both carbonate and terrigenous strata.

Claims (3)

1. A method of increasing hydrocarbon recovery of reservoirs and intensifying production of oil and gas condensate wells by means of hydro-radial radial drilling of a formation, including installing high-strength tubing (tubing) into the well, a diverter with an internal channel passing through it, tying it and its possible orientation in space in the interval of the lower wiring level sidetracks, sealing the wellhead, installing downhole equipment, consisting of a hydraulic nozzle, a path control unit trunk, navigation system, working flexible tubing, flow redistribution device, non-return valve, feeding flexible tubing, fluid supply into the annular space of the tubing / flexible tubing, moving the nozzle through the sealing device, through the diverter into contact with the rock, the planned length of the radial the trunk using the navigation system to monitor the current position of the trunk in the reservoir, as well as using the node to control the path of the trunk to ensure wiring the wellbore along the projected path, after the working flexible tubing with the nozzle is taken out of the reservoir, the nozzle is removed from the reservoir and the well is flushed until the cuttings are completely removed, the deflector is moved to another plane by means of a mechanical rotary device, the cycle of work is repeated for the next side trunk, characterized in that milling a separate window for each sidetrack is carried out immediately before the main operation for penetrating the sidetracks through the diverter, when posting the sidetrack about divide and change the trajectory of the trunk by supplying the working flexible tubing with a node for controlling the trajectory of the trunk and navigation equipment, while for supplying radial trunks at subsequent levels, the feeding and working flexible tubing is removed from the well, the tubing is torn from the mechanical armature, the tubing fitting, previously installed and removed, is removed and equal to the length of the transition to the next level, make tubing landing on a mechanical anchor, working flexible tubing with a navigation system, a path control unit are lowered into the well the barrel with a hydraulic nozzle, after which the work on wiring the radial trunks is repeated. 2. The method according to p. 1, characterized in that when cutting the windows in the casing for the sidetrack, an additional hydro-sandblasting device is lowered on coiled tubing, abrasive cutting of the rectangular hole with circulation is made and then the equipment is lifted. 3. The method according to p. 1, characterized in that the fluid is pumped through a small tubing annulus / flexible tubing and / or a small tubing annulus / flexible tubing and the inside of the flexible tubing.

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