RU2445452C1 - Development method of high-viscosity oil deposit and bitumens, and device for heat displacement of product from horizontal wells - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: development method of high-viscosity oil deposit and bitumens involves drilling of the well with horizontal shaft, lowering to the well of casing string with perforated section in horizontal section, cementing of annular space to horizontal shaft and installation of tubing strings in casing string. Tubing string is aligned with isolation of annular space by means of packer in horizontal shaft. Heat carrier is pumped through end part of casing string. At that, horizontal shaft is drilled in the form of two parallel initial and end sections connected by means of an arc-shaped section. Before the tubing string is lowered to casing string, there lowered is production string with outlet channels arranged in end section of horizontal shaft, inlet channels arranged in initial section of horizontal shaft, and external packer. Packer is arranged between inlet and outlet channels and isolates the space between casing and production strings. Additional packer isolates the well space above horizontal shaft. After the tubing string interconnected with outlet channels and pre-equipped with partition and bypass valve, which are located closer to the working face against interconnection with outlet channel, is lowered, packer is installed between production string and tubing string and located between inlet and outlet channels of production string. At that, pumping of heat carrier is performed via tubular annulus between production string and tubing string through bypass valve, and extraction of products - via tubing string.

EFFECT: enlarging the deposit coverage area and increasing its warming-up efficiency.

2 cl, 3 dwg

Description

The invention relates to the development of oil fields using heat, mainly from reservoirs with heavy, high viscosity or bitumen oil.

The well-known "Method for the development of a heavy oil or bitumen field using double-well horizontal wells" (RF patent No. 2340768, IPC 8 Е21В 43/24, published in bulletin No. 32 dated December 10, 2008), including the injection of coolant through a double-mouth horizontal injection well, warming up the productive formation with the creation of a steam chamber and selecting products through the two-mouth horizontal production well, characterized in that the heating of the productive formation is started by injecting steam into both wells, warming the inter-well zone of the formation, reducing the viscosity of oil or bitumen is formed, and the steam chamber is created by pumping coolant with the possibility of punching the latter to the upper part of the reservoir and increasing the size of the steam chamber during the production process, in which thermograms of the steam chamber are taken, the state of its heating for uniformity of heating and the presence of temperature peaks are analyzed, and taking into account the obtained thermograms, the steam chamber is uniformly heated by changing the direction of filtration and / or the modes of pumping the coolant and selecting products, while volume pumping coolant through the mouth of the injection well and / or selection of products through the mouth of the production well at a ratio change,%: (10-90) :( 90-10).

A device for implementing this method is also known, including a double-wellhead injection and lower production wells with horizontal sections located one above the other, the injection well at the wellhead equipped with a steam generator, and the production well equipped with a submersible pump, while both wells are provided with a cable with thermal sensors.

The disadvantages of this method and the device with which this method is implemented are:

- firstly, high financial costs for the construction of a double-well well (the cost of building a double-well well is three times more expensive than a single-well well);

- secondly, high material costs associated with the fact that the temperature sensors on the cable are placed along the entire length of the shafts of the double-well wells;

- thirdly, for the effective implementation of this method, it is necessary to change the volumes of injection and selection, while the volume of injection of the coolant through the mouth of the injection well and / or the selection of products through the mouth of the producing well is changed in the ratio,%: (10-90) :( 90- 10).

The closest in technical essence is the "Method of thermal displacement of oil from a horizontal well" (patent RU No. 2067168, ЕВВ 43/24, publ. 09/27/1996), which consists in the fact that a perforated casing is installed in a drilled well, the annulus is cemented to horizontal bore, tubing is installed in the casing, they are centered in the casing using a packer, coolant is supplied through the tubing, and the product is transported through the annular annulus tvu, characterized in that the perforation of the casing is carried out along the annular generators in the end part behind the packer and at the beginning of the horizontal section directly behind the cemented annulus, the coolant is fed to the end part of the casing behind the packer, and the product is taken through the perforation of the casing at the beginning of the horizontal section .

This method is carried out by a device for the thermal displacement of horizontal well products, including lowered into a horizontal well, which is cemented to a horizontal section, tubing, a packer centering the tubular insulating annulus in a horizontal section.

The disadvantages of this method and device for its implementation are:

- firstly, a small heating area of the reservoir, associated with the design of a horizontal well, and low heating efficiency, due to the fact that only the near-barrel part of the horizontal section is heated to a greater extent;

- secondly, according to the design of the device, heated, highly viscous oil or bitumen rises along the annulus, from where the pumping of oil is technologically difficult, in addition, the rate of rise of the heated oil through the annulus is much lower than the inside of the tubing string, and this is especially important because during the rise, the heating of highly viscous oil and bitumen cools.

The objective of the invention is to provide a method for developing a deposit of highly viscous oil or bitumen, which allows to increase the coverage area by heating the deposit and the efficiency of its heating, as well as to create a device that allows, at the same time as the coolant is injected, to select heated high viscosity oil or bitumen along the inner space of the tubing string using a pump.

The problem is solved by the method of developing deposits of highly viscous oil and bitumen, including drilling a well with a horizontal wellbore, lowering a casing with a perforated section in a horizontal wellbore, cementing the annulus to a horizontal well, installing tubing in the casing, centering them with isolation of the annulus by a packer in a horizontal wellbore, coolant injection through the end part of the casing, and selection through the perforation of the casing us at the beginning of the horizontal section.

What is new is that the horizontal trunk is drilled in the form of two parallel initial and final sections connected by an arcuate section, before the tubing is lowered into the casing, the production string is lowered with output channels located in the final section of the horizontal shaft, input channels placed in the initial section of the horizontal shaft , an external packer located between the input and output channels isolating the space between the casing and production casing, and an additional packer, isolator the well is located above the horizontal wellbore, and after lowering the tubing connected to the output channels and pre-equipped with a baffle and a bypass valve located closer to the bottom of the communication with the output channels, the packer is installed between the production string and tubing and placed between the input and output channels of the production string, moreover, the coolant is pumped through the annulus between the production string and the tubing through the bypass valve, and the selection of products through the tubing.

A new device is also a device for thermal displacement of products from horizontal wells, including pipes that have been lowered into a horizontal wellbore that is cemented to a horizontal wellbore, tubing, a packer that centers and insulates the annular space of the tubing in a horizontal wellbore.

New is that the well, made in the form of two parallel initial and final sections connected by an arcuate section, is additionally equipped with a production string located outside the tubing, with output channels on the final section of the horizontal well and input channels on the initial section of the horizontal well, and the packer is installed between the production string and tubing on the arcuate section of the horizontal trunk, and the production string from the outside between the input and output channels is equipped with an external pa An infer made by inflatable and connected with the inner space of the production string from the mouth of the packer and an additional packer isolating the borehole above the horizontal wellbore, the input channels of the production string bypass channels communicating with the tubing, and the output channels with annular space through the bypass valve located closer to the bottom relative to the bypass channels and consisting of a housing with an internal hollow pipe, in which radial channels are made, separated by a partition and, moreover, the radial channels located from the septum on the side of the output channels of the production string are closed by a spring piston spring-loaded towards the mouth with an annular piston that is capable of longitudinal limited movement in the housing with compression of the spring and the opening of these radial channels.

In figures 1 and 2 schematically shows a method of developing deposits of highly viscous oil and bitumen and a device for thermal displacement of products from horizontal wells.

The figure 3 in longitudinal section shows the proposed bypass valve.

The proposed method is as follows.

A method for developing a highly viscous oil and bitumen deposit involves drilling a well 1 (see FIG. 1) with a horizontal wellbore 2 in the form of two parallel initial 3 and final 4 sections connected by an arcuate section 5.

Casing 6 is lowered into the well 1 with perforated sections 7 and 7 'in the horizontal wellbore 2, the annulus 8 is cemented to the horizontal wellbore 2.

Production casing 9 is lowered into the casing 5 of the well 1 with output channels 10 located in the final section 4 of the horizontal shaft 2 and input channels 11 located in the initial section 3 of the horizontal shaft 2.

Between the input 10 and output 11 channels, the production casing 9 is equipped with an external packer 12, isolating the space between the casing 6 and production 9 columns, as well as an additional packer 13, isolating the borehole 14 above the horizontal barrel 1.

Next, the tubing string 15 is lowered into the production string 9 so that after lowering the lower end 16 of the tubing string 15 is communicated at the bottom 17 of the well 1 with output channels 10 of the production string 9, which in turn communicate with the perforated section 7 '. Also at the face 17, the tubing string 5 is pre-equipped with an overflow valve 18 and a baffle 19.

The packer 20 is installed closer to the bottom 17 with the valve 18 between the production string 9 and tubing 15 and is located between the input 11 and output channels 10 of the production string 9.

The tubing string is equipped with a pump 21 of any known design, for example a screw.

The coolant is injected (see Fig. 1), for example, steam, at a temperature of 220 ° C along the annular space 22 between the production string 9 and tubing 15 through the bypass valve 18, which opens at hydraulic pressure on it, for example, when the pressure of the injected coolant P = 3 MPa. Then, through the opened bypass valve 18, the coolant enters the inner space 23 of the tubing string 5 behind the bypass valve 18, through which it reaches the lower end 16 of the tubing string 15, where it communicates with the output channels 10 of the production string 9, which in turn communicate with the perforated section 7 ' casing string 6. Next, the coolant passes through the perforated section 7 'of the casing string 6 into the reservoir, where it forms a vapor chamber (not shown in FIG.).

During the coolant injection, the calculated temperature regime of the coolant injection (for example, 220 ° C and the pressure of the injected coolant P = 5 MPa) is maintained in such a way that the steam forming the vapor chamber effectively heats the reservoir and does not condense into water.

As the coolant is injected, high-viscosity oil and bitumen are heated, which are liquefied, that is, the viscosity decreases, and when heated, the high-viscosity oil and bitumen enter through the perforated section 7 of the casing 6 into the borehole 14 between the casing 6 and production 9 columns.

From the borehole space 24, the highly viscous oil and bitumen in a heated state through the bypass channels 24 enter the tubing string 15, from where they enter the pump 21, which selects the heated, highly viscous oil and bitumen to the surface.

A device for thermal displacement of products from horizontal wells, for example, horizontal well 1 (see Fig. 1) with horizontal wellbore 2, is made in the form of two parallel initial 3 and final 4 sections connected by an arcuate section 5 made, for example, with a radius R = 50-60 m.

A casing 6 with a perforated section 7 is lowered into the well 1, which is cemented in the annulus 8 to the horizontal bore 2.

Well 1 is additionally equipped with production casing 9 with output channels 10 in the final section 4 of the horizontal shaft 2 and input 11 in the initial section 3 of the horizontal shaft 2

Outside the production casing 9 between its input 11 and output 10 channels is equipped with an external packer 12, made inflatable and connected with the internal space of the production casing 9 from the mouth side, as well as an additional packer 13, isolating the borehole 14 above the horizontal shaft 2.

The output channels 10 of the production casing 9 are in communication with the annular space 22 through the bypass valve 18.

The bypass valve 18 (see figure 3) consists of a housing 26 with an internal hollow pipe 27, in which there are made radial channels 28 connected to the tubing 15 and separated by a partition 19, and the radial channels 28 are located from the partition 19 from the side of the output channels 10 operational the columns 9 and are closed by a preloaded spring 29 towards the mouth with an annular piston 30 configured for longitudinal limited movement in the housing 26 with compression of the spring 29 and the opening of these radial channels 28.

Between the production string 9 and tubing 15 (see Fig. 1), a packer 20 is installed on the arcuate section 5 of the horizontal barrel 2, centering and isolating the annular space of the tubing 15 in the horizontal barrel 2, the input channels 11 of the production string 9 bypass channels 24 in communication with the internal tubing string space 15.

The bypass valve 18 is located closer to the bottom 17 relative to the bypass channels 25. The tubing string 15 is equipped with a pump 21 of any known design, for example a screw.

The device operates as follows.

The coolant is injected (see Fig. 1), for example, steam, at a temperature of 220 ° C, is carried out using a steam generator (not shown in Figs. 1 and 2) installed at the wellhead 1 through the annulus 22 between the production string 9 and tubing 15 .

When the coolant reaches the bypass valve 18 under the influence of hydraulic pressure, it acts on the annular piston 30, which is spring-loaded by the spring 28 towards the mouth and moves under the action of the hydraulic fluid’s hydraulic pressure, compresses the spring 29, radial channels 28 open and the coolant enters the interior 23 tubing string 15 behind the bypass valve 18, through which reaches the lower end 16 of the tubing string 15, which communicates with the output channels 10 of the operational number the sheaths 9, which in turn communicate with the perforated section 7 'of the casing 6. Next, the coolant passes through the perforated section 7' of the casing 6 into the reservoir where it forms a vapor chamber (not shown in Fig.).

During the coolant injection, the calculated temperature regime of the coolant injection (for example, 220 ° C and the pressure of the injected coolant P = 5 MPa) is maintained in such a way that the steam forming the vapor chamber effectively heats the reservoir and does not condense into water.

As the coolant is injected, high-viscosity oil and bitumen are heated, which are liquefied, that is, the viscosity decreases and, when warmed up, the high-viscosity oil or bitumen enters through the perforated section 7 of the casing 6 into the borehole 14 between the casing 6 and production 9 columns.

From the borehole space 14, the highly viscous oil and bitumen in a heated state through the bypass channels 24 enter the tubing string 15, from where they are received at the pump 21, which selects the heated viscous oil and bitumen to the surface.

The proposed method allows to reduce the time for heating a deposit of highly viscous oil or bitumen, as well as to increase the coverage area by heating and the efficiency of heating the reservoir due to the fact that the horizontal wellbore is made in the form of two parallel initial and final sections connected by an arcuate section, and the presence of a process valve included in the device, allows you to select the heated high-viscosity oil and bitumen with a pump through the tubing string.

Claims (2)

1. A method of developing a reservoir of highly viscous oil and bitumen, including drilling a well with a horizontal wellbore, lowering a casing string with a perforated section in a horizontal wellbore, cementing the annulus to a horizontal wellbore, installing tubing in the casing, centering them with isolation of the annulus by a packer in a horizontal wellbore, coolant injection through the end part of the casing string, and selection through the perforation of the casing string at the beginning of the horizontal section production line, characterized in that the horizontal trunk is drilled in the form of two parallel initial and final sections connected by an arcuate section, before the tubing is lowered into the casing, the production string is lowered with output channels located in the final section of the horizontal trunk, input channels located in the initial section of the horizontal the trunk, an external packer located between the inlet and outlet channels isolating the space between the casing and production string, and an additional packer, gilding the borehole space above the horizontal wellbore, and after lowering the tubing connected to the output channels and pre-equipped with a baffle and a bypass valve located closer to the bottom of the communication with the output channels, the packer is installed between the production string and tubing and placed between the input and output channels of the production string, moreover, the coolant is pumped through the annulus between the production string and tubing through the bypass valve, and the selection of products - p about tubing. 2. A device for thermal displacement of horizontal well products, including tubular pipes lowered into a horizontal well that is cemented to a horizontal well, tubing, a packer that centers and isolates the annular space of an ICT in a horizontal well, characterized in that the well made in the form of two parallel starting and ending sections connected by an arcuate section, additionally equipped with a production casing located outside the tubing with output channels n and in the final section of the horizontal wellbore and inlet - in the initial section of the horizontal wellbore, and the packer is installed between the production casing and tubing in an arcuate section of the horizontal wellbore, and the production casing is external between the inlet and outlet channels equipped with an external packer made inflatable and in communication with the interior of the production casing from the mouth of the packer, and an additional packer isolating the borehole above the horizontal wellbore, and the input channels the operating casing bypass channels are connected with the tubing, and the weekend with the annular space through the bypass valve located closer to the bottom relative to the bypass channels and consisting of a housing with an internal hollow pipe, in which there are radial channels separated by a partition, and the radial channels located from the partition from the side of the output channels of the production casing, they are blocked by an annular piston spring-loaded towards the mouth, made with the possibility of a longitudinal limited movement niya in the housing with compression of the spring and the opening of these radial channels.

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