GB2499224A - Steam assisted gravity drainage hydrocarbon production - Google Patents
Steam assisted gravity drainage hydrocarbon production Download PDFInfo
- Publication number
- GB2499224A GB2499224A GB201202219A GB201202219A GB2499224A GB 2499224 A GB2499224 A GB 2499224A GB 201202219 A GB201202219 A GB 201202219A GB 201202219 A GB201202219 A GB 201202219A GB 2499224 A GB2499224 A GB 2499224A
- Authority
- GB
- United Kingdom
- Prior art keywords
- vertical portion
- wellbores
- vertical
- plane
- steam
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
- E21B43/24—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection
- E21B43/2406—Steam assisted gravity drainage [SAGD]
Abstract
A method of steam assisted gravity drainage (SAGD) hydrocarbon production is disclosed which includes drilling a formation of wellbores comprising a plurality of first wellbores 1 to 9, each having a first non-vertical portion 10, and a plurality of second wellbores 11 to 21 each having a second non-vertical portion 22. Each second non-vertical portion 22 is located at a different level below the surface to each first non-vertical portion 10. Each second non-vertical portion 22 is nonÂparallel to each first non-vertical portion 10. The method includes injecting steam into the first (upper) wellbores and producing hydrocarbon from the second (lower) wellbores.
Description
-1-
Method of Steam Assisted Gravity Drainage
The present invention relates to a method of steam assisted 5 gravity drainage (SAGD) for hydrocarbon production.
Steam assisted gravity drainage (SAGD) is an oil recovery method for producing heavy oil and bitumen from a formation in which the hydrocarbon does not freely flow and is 10 therefore difficult to retrieve to the surface.
Figure 1 shows a prior art method of producing heavy oil by SAGD. A first wellbore 100 is drilled below the surface 102 in an area having a rock formation 104 suitable for oil 15 production by SAGD. First wellbore 100 comprises a vertical portion 110 and a non-vertical portion 112 which in the example is shown as substantially horizontal. The directional drilling of wellbores using drill strings will be familiar to persons skilled in the art and will not be discussed in any 20 further detail herein. A second wellbore 200 is drilled and comprises a vertical portion 210 and a non-vertical portion 212 which is substantially horizontal in the example shown. The non-vertical portions 112 and 212 are substantially parallel and have a vertical separation of the order of 10 25 metres.
The first upper wellbore 100 is known as an injector and second lower wellbore 200 is known as a producer. High pressure steam 120 is injected into first wellbore 100. The 30 steam 120 seeps through apertures in the first wellbore 100 into the surrounding formation 104 heats and liquidises hydrocarbons 220. The liquidised hydrocarbons, such as heavy oil and bitumen then seep under gravity into second wellbore
-2-
212. The hydrocarbons 220 are then pumped out of the second wellbore 200 and retrieved at the surface 102.
This method of SAGD suffers from the drawback that when water 5 and steam break through into the second (producer) wellbore 200, hydrocarbon production effectively stops because only water is flows in second wellbore to be retrieved at the surface. This means that hydrocarbons located to the sides of the wellbores might not be retrieved.
10
A preferred embodiment of the present invention seeks to overcome the above disadvantages of the prior art.
According to an aspect of the present invention, there is 15 provided a method of steam assisted gravity drainage for hydrocarbon production, the method comprising:
drilling a plurality of first wellbores each having a first non-vertical portion; and
20
drilling a plurality of second wellbores each having a second non-vertical portion;
characterised in that each said second non-vertical portion 25 is located at a different level below the surface to each said first non-vertical portion, and wherein each said second non-vertical portion is non-parallel to each said first non-vertical portion.
30 This provides the advantage of improving steam control in a SAGD method to produce an increase in hydrocarbon production efficiency. Because the non-vertical portions of the first and second pluralities of wellbores are non-parallel to each
-3-
other, an operator is able to control the location along the length of the lower producer wellbore to which pressurised steam is applied.
5 Consequently, by first injecting steam in the upper injector wellbore located nearest the toe end of the lower producer, oil can be produced at the toe end of the lower producer. When steam breaks through at the toe of the producer, the steam injection at that location can be discontinued. Steam
10 injection can then be commenced in the upper injector wellbores located towards the heel ends of the lower producers to produce hydrocarbons from a different portion of the producer wellbores.
15 In a preferred embodiment, each said first non-vertical portion is substantially parallel the other said first non-vertical portions and wherein each said second non-vertical portion is substantially parallel to the other said second non-vertical portions.
20
This provides the advantage of a more uniform pattern of drilled wellbores to offer increased control and more predictability to the operator when injecting steam.
25 In a preferred embodiment, each said second non-vertical portion is transverse to each said first non-vertical portion.
In a preferred embodiment, each said second non-vertical
30 portion is arranged perpendicularly to each said first non-vertical portion.
-4-
This provides the advantage of a more uniform pattern of drilled wellbores to offer increased control and more predictability to the operator when injecting steam.
5 In a preferred embodiment, each said first non-vertical portion is located in a first plane and wherein each said second non-vertical portion is located in a second plane.
This provides the advantage of a more uniform pattern of 10 drilled wellbores to offer increased control and more predictability to the operator when injecting steam.
In a preferred embodiment, said first plane is substantially parallel to said second plane.
15
This provides the advantage of a more uniform pattern of drilled wellbores to offer increased control and more predictability to the operator when injecting steam.
20 In a preferred embodiment, said first and second planes are substantially horizontal.
This provides the advantage of a more uniform pattern of drilled wellbores to offer increased control and more 25 predictability to the operator when injecting steam.
Each said second non-vertical portion may be located at a lower level below the surface to each said first non-vertical portion, the method further comprising injecting steam into 30 at least one said first wellbore.
In a preferred embodiment, the method further comprises injecting steam into a plurality of said first wellbores.
-5-
In a preferred embodiment, the method further comprises retrieving hydrocarbons produced in at least one of said second wellbores.
5
According to another aspect of the present invention, there is provided a method of steam assisted gravity drainage for hydrocarbon production in a formation comprising:
10 a plurality of first wellbores each having a first non-vertical portion; and a plurality of second wellbores each having a second non-vertical portion;
15
wherein each said second non-vertical portion is located at a lower level below the surface to each said first non-vertical portion, and wherein each said second non-vertical portion is non-parallel to each said first non-vertical portion;
20
the method comprising injecting steam into at least one said first wellbore.
This provides the advantage of improving steam control in a 25 SAGD method to produce an increase in hydrocarbon production efficiency. Because the non-vertical portions of the first and second pluralities of wellbores are non-parallel to each other, an operator is able to control the location along the length of the lower producer wellbore to which pressurised 30 steam is applied.
Consequently, by first injecting steam in the upper injector wellbore located nearest the toe end of the lower producer,
-6-
oil can be produced at the toe end of the lower producer. When steam breaks through at the toe of the producer, the steam injection at that location can be discontinued. Steam injection can then be commenced in the upper injector 5 wellbores located towards the heel ends of the lower producers to produce hydrocarbons from a different portion of the producer wellbores.
In a preferred embodiment, the method further comprises 10 injecting steam into a plurality of said first wellbores.
In a preferred embodiment, the method further comprises retrieving hydrocarbons produced in at least one of said second wellbores.
15
In a preferred embodiment, each said first non-vertical portion is substantially parallel the other said first non-vertical portions and wherein each said second non-vertical portion is substantially parallel to the other said second 20 non-vertical portions.
In a preferred embodiment, each said second non-vertical portion is transverse to each said first non-vertical portion.
25
In a preferred embodiment, each said second non-vertical portion is arranged perpendicularly to each said first non-vertical portion.
30 In a preferred embodiment, each said first non-vertical portion is located in a first plane and wherein each said second non-vertical portion is located in a second plane.
-7-
In a preferred embodiment, said first plane is substantially parallel to said second plane.
In a preferred embodiment, said first and second planes are 5 substantially horizontal.
Preferred embodiments of the present invention will now be described, by way of example only, and not in any limitative sense, with reference to the accompanying drawings, of which:
10
Figure 1 is a cross-sectional view of a formation of wellbores used in a prior art steam assisted gravity drainage method for hydrocarbon production; and
15 Figure 2 is a perspective view of a sub-surface configuration of wellbores of a method of steam assisted gravity drainage for hydrocarbon production embodying the present invention.
Referring to Figure 2, a formation of wellbores is drilled 20 comprising a plurality of first wellbores 1 to 9, each having a first non-vertical portion 10 and a plurality of second wellbores 11 to 21 each having a second non-vertical portion 22. Each second non-vertical portion 22 is located at a different level below the surface to each first non-vertical 25 portion 10. Each second non-vertical portion 22 is non-parallel to each first non-vertical portion 10.
Each first non-vertical portion 10 is substantially parallel to the other first non-vertical portions 10. Each second non-30 vertical portion 22 is substantially parallel to the other second non-vertical portions 22.
-8-
In the example shown, although other configurations are possible, second non-vertical portion 22 is arranged transverse to and preferably perpendicularly to each first non-vertical portion 10.
5
As can be seen from the drawing, each first non-vertical portion 10 is located in a first plane and each second non-vertical portion 22 is located in a second plane. The first plane is substantially parallel to the second plane and the 10 first and second planes are substantially horizontal, that is parallel to the surface of the earth at the location in which the wellbores 1 to 21 are drilled.
In the example shown, each second non-vertical portion 22 is 15 located at a lower level below the surface to each first non-vertical portion 10. This means that wellbores 1 to 9 are the injector wellbores and wellbores 11 to 21 are the producer wellbores through which liquidised hydrocarbons such as heavy oil and bitumen will be produced when steam is 20 pumped into injectors 1 to 9.
Drilling such a configuration of wellbores as shown in Figure 2, and injecting steam into the producer wellbores 1 to 9 enables operation of an improved SAGD method. For example, an 25 operator first injects steam into wellbores 1, 2 and 3. Injection of steam into wellbores 1 to 3 heats the formation around the toe ends 22T of producers 11 to 21. This results in hydrocarbon production at the toe ends 22T of the producers 11 to 21 when heated liquidised hydrocarbons seep 30 into toe ends 22T. When steam and water break through at toe ends 22T from injectors 1 to 3, the steam injection into injectors 1 to 3 can be discontinued.
Steam can then be injected into injectors 4 to 6 and then 7 to 9 to produce oil towards the heel ends 22H of the producers 11 to 21. This configuration of wellbores therefore enables an operator to control the location along the non-5 vertical portion 22 of the producer wellbores 11 to 21 at which hydrocarbons such as heavy oil and bitumen are produced. This enables more oil and bitumen to be produced, using less water to be heated to steam which results in reduced operational costs.
10
It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the 15 scope of the invention as defined by the appended claims.
-10-
Claims (1)
1. A method of steam assisted gravity drainage for hydrocarbon production, the method comprising:
5
drilling a plurality of first wellbores each having a first non-vertical portion; and drilling a plurality of second wellbores each having a second 10 non-vertical portion;
characterised in that each said second non-vertical portion is located at a different level below the surface to each said first non-vertical portion, and wherein each said second 15 non-vertical portion is non-parallel to each said first non-vertical portion.
2. A method according to claim 1, wherein each said first non-vertical portion is substantially parallel the other said
20 first non-vertical portions and wherein each said second non-vertical portion is substantially parallel to the other said second non-vertical portions.
3. A method according to claim 1 or 2, wherein each said 25 second non-vertical portion is transverse to each said first non-vertical portion.
4. A method according to any one of the preceding claims, wherein each said second non-vertical portion is arranged
30 perpendicularly to each said first non-vertical portion.
5. A method according to any one of the preceding claims, wherein each said first non-vertical portion is located in a
-11-
first plane and wherein each said second non-vertical portion is located in a second plane.
6. A method according to claim 5, wherein said first plane 5 is substantially parallel to said second plane.
7. A method according to claim 5 or 6, wherein said first and second planes are substantially horizontal.
10 8. A method according to any one of the preceding claims, wherein each said second non-vertical portion is located at a lower level below the surface to each said first non-vertical portion, the method further comprising injecting steam into at least one said first wellbore.
15
9. A method according to claim 8, further comprising injecting steam into a plurality of said first wellbores.
10. A method according to claim 8 or 9, further comprising 20 retrieving hydrocarbons produced in at least one of said second wellbores.
11. A method of steam assisted gravity drainage for hydrocarbon production in a formation comprising:
25
a plurality of first wellbores each having a first non-vertical portion; and a plurality of second wellbores each having a second non-30 vertical portion;
wherein each said second non-vertical portion is located at a lower level below the surface to each said first non-vertical
-12-
portion, and wherein each said second non-vertical portion is non-parallel to each said first non-vertical portion;
the method comprising injecting steam into at least one said 5 first wellbore.
12. A method according to claim 11, further comprising injecting steam into a plurality of said first wellbores.
10 13. A method according to claim 11 or 12, further comprising retrieving hydrocarbons produced in at least one of said second wellbores.
14. A method according to any one of claims 11 to 13, 15 wherein each said first non-vertical portion is substantially parallel the other said first non-vertical portions and wherein each said second non-vertical portion is substantially parallel to the other said second non-vertical portions.
20
15. A method according to claim 11 to 14, wherein each said second non-vertical portion is transverse to each said first non-vertical portion.
25 16. A method according to any one of claims 11 to 15, wherein each said second non-vertical portion is arranged perpendicularly to each said first non-vertical portion.
17. A method according to any one of claims 11 to 16, 30 wherein each said first non-vertical portion is located in a first plane and wherein each said second non-vertical portion is located in a second plane.
-13-
18. A method according to claim 17, wherein said first plane is substantially parallel to said second plane.
19. A method according to claim 17 or 18, wherein said 5 first and second planes are substantially horizontal.
20. A method substantially as hereinbefore described with reference to the accompanying drawings.
•.'????.• INTELLECTUAL
*.*. .V PROPERTY OFFICE
14
Application No: GB 1202219.0 Examiner: Mr David Hotchkiss
Claims searched: 1-20 Date of search: 12 April 2012
Patents Act 1977: Search Report under Section 17
Documents considered to be relevant:
Category
Relevant to claims
Identity of document and passage or figure of particular relevance
X
1-9
W02010/084369 A1
(TOTAL) See figure 5
A
_
CA2647088 A1
(CHEN) See figures 1 & 2
A
_
W02008/011704 A1
(UTI) See figures 4b - d
Categories:
X
Document indicating lack of novelty or inventive
A
Document indicating technological background and/or state
step
of the art.
Y
Document indicating lack of inventive step if
P
Document published on or after the declared priority date but
combined with one or more other documents of
before the filing date of this invention.
same category.
&
Member of the same patent family
E
Patent document published on or after, but with priority date
earlier than, the filing date of this application.
Field of Search:
Search of GB, EP, WO & US patent documents classified in the following areas of the UKC :
International Classification:
Subclass
Subgroup
Valid From
E21B
0043/24
01/01/2006
Intellectual Property Office is an operating name of the Patent Office www.ipo.gov.uk
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB201202219A GB2499224A (en) | 2012-02-09 | 2012-02-09 | Steam assisted gravity drainage hydrocarbon production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB201202219A GB2499224A (en) | 2012-02-09 | 2012-02-09 | Steam assisted gravity drainage hydrocarbon production |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201202219D0 GB201202219D0 (en) | 2012-03-28 |
| GB2499224A true GB2499224A (en) | 2013-08-14 |
Family
ID=45929849
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB201202219A Withdrawn GB2499224A (en) | 2012-02-09 | 2012-02-09 | Steam assisted gravity drainage hydrocarbon production |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2499224A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008011704A1 (en) * | 2006-07-24 | 2008-01-31 | Uti Limited Partnership | In situ heavy oil and bitumen recovery process |
| CA2647088A1 (en) * | 2008-12-18 | 2010-06-18 | Zhong Chen | Horizontal to horizontal thermal exploitation design |
| WO2010084369A1 (en) * | 2009-01-20 | 2010-07-29 | Total S.A. | Method for extracting viscous petroleum crude from a reservoir |
-
2012
- 2012-02-09 GB GB201202219A patent/GB2499224A/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008011704A1 (en) * | 2006-07-24 | 2008-01-31 | Uti Limited Partnership | In situ heavy oil and bitumen recovery process |
| CA2647088A1 (en) * | 2008-12-18 | 2010-06-18 | Zhong Chen | Horizontal to horizontal thermal exploitation design |
| WO2010084369A1 (en) * | 2009-01-20 | 2010-07-29 | Total S.A. | Method for extracting viscous petroleum crude from a reservoir |
Also Published As
| Publication number | Publication date |
|---|---|
| GB201202219D0 (en) | 2012-03-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |