WO2005042917A1 - Underbalanced well drilling and production - Google Patents

Underbalanced well drilling and production Download PDF

Info

Publication number
WO2005042917A1
WO2005042917A1 PCT/IB2004/004372 IB2004004372W WO2005042917A1 WO 2005042917 A1 WO2005042917 A1 WO 2005042917A1 IB 2004004372 W IB2004004372 W IB 2004004372W WO 2005042917 A1 WO2005042917 A1 WO 2005042917A1
Authority
WO
WIPO (PCT)
Prior art keywords
blow out
fluid
subsurface
subsea
rig
Prior art date
Application number
PCT/IB2004/004372
Other languages
French (fr)
Inventor
Gavin Humphreys
Original Assignee
Stena Drilling Ltd.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Stena Drilling Ltd. filed Critical Stena Drilling Ltd.
Priority to EP04806532A priority Critical patent/EP1700000B1/en
Priority to DK04806532T priority patent/DK1700000T3/en
Priority to BRPI0416064-9A priority patent/BRPI0416064A/en
Priority to AU2004286103A priority patent/AU2004286103B2/en
Publication of WO2005042917A1 publication Critical patent/WO2005042917A1/en
Priority to TNP2006000119A priority patent/TNSN06119A1/en
Priority to EGNA2006000408 priority patent/EG24344A/en
Priority to NO20062254A priority patent/NO338633B1/en
Priority to NO20160812A priority patent/NO339557B1/en

Links

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
    • E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
    • E21B21/08—Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure
    • E21B21/085—Underbalanced techniques, i.e. where borehole fluid pressure is below formation pressure
    • 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
    • E21B19/00—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables
    • E21B19/002—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables specially adapted for underwater drilling
    • 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
    • E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
    • E21B21/001—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor specially adapted for underwater drilling
    • 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
    • E21B33/00—Sealing or packing boreholes or wells
    • E21B33/02—Surface sealing or packing
    • E21B33/03—Well heads; Setting-up thereof
    • E21B33/035—Well heads; Setting-up thereof specially adapted for underwater installations
    • E21B33/038—Connectors used on well heads, e.g. for connecting blow-out preventer and riser
    • 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
    • E21B33/00—Sealing or packing boreholes or wells
    • E21B33/02—Surface sealing or packing
    • E21B33/08—Wipers; Oil savers
    • 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
    • E21B33/00—Sealing or packing boreholes or wells
    • E21B33/02—Surface sealing or packing
    • E21B33/08—Wipers; Oil savers
    • E21B33/085—Rotatable packing means, e.g. rotating blow-out preventers

Definitions

  • This invention relates generally to drilling of wells and production from wells.
  • wells are drilled in a slightly over-balanced condition where the weight of the drilling fluid used is only slightly over the pore pressure of the rocks being drilled.
  • Drilling mud is pumped down the drill string to a drill bit and used to lubricate and cool the drill bit and remove drilled cuttings from the hole while it is being drilled.
  • the viscous drilling mud carries the drilled cuttings upwardly on the outside and around the drill string.
  • the density of the mud going downwardly to the drill bit and the mud passing upwardly from the drill bit is substantially the same. This has the benefit of reducing the likelihood of a so-called kick.
  • the downward pressure of the drilling mud column is not sufficient to balance the pore pressure in the rocks being drilled, for example of gas or other fluid, which is encountered in a formation.
  • the well may blowout (if an effective blow out preventer(BOP)is not fitted to the well) which is an extremely dangerous condition.
  • BOP blow out preventer
  • the aim is to deliberately create the situation described above. Namely, the density or equivalent circulating density of the upwardly returning mud is below the pore pressure of the rock being drilled, causing gas, oil, or water in the rock to enter the well-bore from the rock being drilled.
  • the pressure that bears down on the fonnation includes the weight of the drilling mud, whereas the pressure in the shallow formations is dictated by the weight of seawater above the formation. Because of the higher pressures involved, the drilling mud may actually be injected into the formation, fracture it and may even clog or otherwise foul the formation itself, severely impairing potential hydrocarbon production.
  • Figure 1 is a schematic depiction of one embodiment of the present invention
  • Figure 2 is an enlarged schematic depiction of the subsea shut-off assembly shown in Figure 1 in accordance with one embodiment of the present invention
  • Figure 3 is an enlarged, schematic, cross-sectional view of the spool 34 shown in Figure 2 in accordance with one embodiment of the present invention
  • Figure 4 is a schematic cross-sectional view of the rotating head shown in Figure 1 in accordance with one embodiment of the present invention.
  • both drilling and production of fluids from a formation may occur in an underbalanced condition.
  • underbalanced means that the weight of the drilling mud is less than the pore pressure of the formation.
  • dual gradient refers to the fact that the density of fluid, at some point along its course, moving away from a drill bit, is lower than the density of the fluid moving towards the drill bit. Dual gradient techniques may be used to implement underbalanced drilling. The creation of a dual-gradient or underbalanced condition may be implemented using any known techniques, including the injection of gases, seawater, and glass beads, to mention a few examples.
  • a drilling and production apparatus 11 may include a rotating head 10 which rotates a string for purposes of drilling a well in a subsea formation SF.
  • the rotating head 10 rotates the string through a surface blowout preventer (BOP) stack 12.
  • the surface blowout preventer stack 12 may include annular blowout preventers that control the flow of fluid moving upwardly from the wellhead to the overlying floating rig 14.
  • the rig 14 may be tensioned using ring tensioners 16, coupled by a pulleys 54 to hydraulic cylinders 56 to create a tensioning system 50.
  • the tensioning system 50 allows the upper portion of the apparatus 11 to move relative to the lower portion, for example in response to sea conditions.
  • the system 50 allows this relative movement and adjustment of relative positioning while maintaining tension on the casing 22, which extends from the floating rig 14 downwardly to a subsea shutoff assembly 24.
  • the surface portion of the apparatus 11 is coupled by a connector 20 to the casing 22.
  • the casing 22 is connected to the lower section of the apparatus 11 via a disconnectable latch 72 located below the sea level WL.
  • the latch 72 may be hydraulically operated from the surface to disconnect the upper portion of the apparatus 11 from the lower portion including the subsea shutoff assembly 24.
  • Also provided on the rig 14 is a source of fluid that is of a lower density than the density of mud pumped downwardly through the casing 22 from the surface in one embodiment of the present invention.
  • the lower density fluid may be provided through the tubing 60.
  • a hanger system 58 includes a tensioner 58 that rests on a support 56. The hanger system 58 tensions the tensioned tubing 26 that extends all the way down to a disconnectable subsea latch 74 above the subsea shutoff assembly 24.
  • the latch 74 may be remotely or surface operated to sever the tubing 26 from the subsea shutoff assembly 24.
  • the support 56 may include hydraulic ram devices that move like shear ram blowout preventers to grip the tubing 26.
  • the rate of lower density fluid flow through the tubing 26 from the surface may be controlled from the surface by remotely controllable valving in the subsea shutoff assembly 24, in one embodiment. It is advantageous to provide this lower density fluid from the surface as opposed to attempting to provide it from a subsea location, such as within the subsea shutoff assembly 24, because it is much easier to control and operate large pumps from the rig 14.
  • the subsea shutoff assembly 24 operates with the surface blowout preventer stack 12 to prevent blowouts. While the surface blowout preventer stack 12 controls fluid flow, the subsea shutoff assembly 24 is responsible for cutting off or severing the wellhead from the portions of the apparatus 11 thereabove, using shear rams 30a and 30b as shown in Figure 2.
  • the casing 22 may be coupled by connector 28a to the shear ram 30a.
  • the shear ram 30a The shear ram
  • the shear ram 30a is coupled by a spool 34 with flanges 32a and 32b to the shear ram 30b.
  • the shear ram 30b may be coupled through the flange 38 to a wellhead connector 28b, in turn connected to the wellhead.
  • the tubing 26 connects to a remotely controlled valve 36 that controls the rate of lower density fluid flow through the tubing 26 to the interior of the spool 34.
  • the inlet from the tubing 26 to the spool 34 is between the two shear rams 30a and 30b.
  • the injection of lower density fluid makes use of the remotely controlled valve 36 on a spool 34.
  • the spool 34 may have drilling mud, indicated as M IN , moving downwardly through the casing 22.
  • the returning mud extends upwardly in the annulus 46 surrounding the string 40 and annulus 44.
  • lower density fluid may be injected, when the valve 36 is opened, into the returning mud/hydrocarbon flow to lower its density.
  • An underbalanced situation may be created as a result of the dual densities of mud in one embodiment. Namely, mud above the valve 36 may be at a lower density than the density of the mud below the valve 36, as well as the density of the mud moving downwardly to the formation.
  • the valve 36 may include a rotating element 37 that allows the valve 36 to be opened or controlled.
  • valve 36 may be a pivoted gate valve with a hydraulic fail safe that automatically closes the valve in the event of a loss of hydraulics.
  • the valve 36 may enable the extent of underbalanced drilling to be surface or remotely controlled depending on sensed conditions, including the upward pressure supplied by the formation.
  • the valve 36 may be controlled acoustically from the surface.
  • flow control may be done most effectively at the surface, whereas shutoff control is done on the seafloor bed.
  • the pumping of the lower density fluid is also done on the surface, but its injection may be done at the subsea shutoff assembly 24, in one embodiment between the shear rams 30a and 30b.
  • the rotating head 10 is coupled to the surface blowout preventer stack 12 at a joint 70.
  • Returning fluid, indicated as M OUT. is passed through a valve 68 to an appropriate collection area.
  • the collection area may collect both mud with entrained debris, as well as production fluids such as hydrocarbons.
  • the production fluids may be separated using well known techniques.
  • the upward flow of the fluid M OUT is constrained by a packer 62.
  • the packer 62 is a rubber or resilient ring that seals the annulus around the string 40 and prevents the further upward flow of the fluids.
  • the packer 62 enables the application of a rotating force in the direction of the circular arrow from the rotating head 66 to the string 40 for purposes of drilling.
  • Seals 65 may be provided between a telescoping joint 64 and the rotating head 66 as both drilling and production may be accomplished in an underbalanced situation.
  • a subsea shutoff assembly 24 may be provided to cut off the string in the event of a failure, such as a blowout.
  • surface annular blowout preventers control fluid flow. Dual gradient drilling may be achieved through the provision of fluid from the surface through a side inlet into the region between the upper and lower ram type shear blowout preventers 30.
  • the tubing 26 for providing the density control fluid may be both tensioned and latched. As a result, dual gradient production and drilling may be achieved in some embodiments of the present invention. While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.

Abstract

Underbalanced production and drilling may be achieved by a system which uses a rotating head coupled to surface blowout preventer stack for fluid flow control. A casing connects these surface components to a subsea shutoff assembly with a pair of ram shear devices to cut off the string to the wellhead. Both the casing and an alternate line may be latched so that they may be released if necessary. The alternate line may provide fluid from the surface to the subsea shutoff assembly for purposes of varying the density of the returning mud. The rotating head may include a rubber packer to prevent upward flow of drilling fluid and production hydrocarbons and, at the same time, provide rotation to the drill string.

Description

Underbalanced Well Drilling; And Production
Background This invention relates generally to drilling of wells and production from wells. Generally, wells are drilled in a slightly over-balanced condition where the weight of the drilling fluid used is only slightly over the pore pressure of the rocks being drilled. Drilling mud is pumped down the drill string to a drill bit and used to lubricate and cool the drill bit and remove drilled cuttings from the hole while it is being drilled. The viscous drilling mud carries the drilled cuttings upwardly on the outside and around the drill string. In a balanced situation, the density of the mud going downwardly to the drill bit and the mud passing upwardly from the drill bit is substantially the same. This has the benefit of reducing the likelihood of a so-called kick. In a kick situation, the downward pressure of the drilling mud column is not sufficient to balance the pore pressure in the rocks being drilled, for example of gas or other fluid, which is encountered in a formation. As a result, the well may blowout (if an effective blow out preventer(BOP)is not fitted to the well) which is an extremely dangerous condition. h imderbalanced drilling, the aim is to deliberately create the situation described above. Namely, the density or equivalent circulating density of the upwardly returning mud is below the pore pressure of the rock being drilled, causing gas, oil, or water in the rock to enter the well-bore from the rock being drilled. This may also result in increased drilling rates but also the well to flow if the rock permeability and porosity allowed sufficient fluids to enter the well-bore. hi this drilling environment it is general practice to provide a variety of blowout preventers to control any loss of control incidents or blowouts that may occur. A variety of techniques have been utilized for underbalanced or dual gradient drilling. Generally, they involve providing a density lowering component to the returning drilling mud. Gases, seawater, and glass beads have been injected into the returning mud flow to reduce its density. hi deep subsea applications, a number of problems may arise. Because of the pressures involved, everything becomes significantly more complicated. The pressure that bears down on the fonnation includes the weight of the drilling mud, whereas the pressure in the shallow formations is dictated by the weight of seawater above the formation. Because of the higher pressures involved, the drilling mud may actually be injected into the formation, fracture it and may even clog or otherwise foul the formation itself, severely impairing potential hydrocarbon production.
Brief Description of the DrawinRS Figure 1 is a schematic depiction of one embodiment of the present invention; Figure 2 is an enlarged schematic depiction of the subsea shut-off assembly shown in Figure 1 in accordance with one embodiment of the present invention; Figure 3 is an enlarged, schematic, cross-sectional view of the spool 34 shown in Figure 2 in accordance with one embodiment of the present invention; and Figure 4 is a schematic cross-sectional view of the rotating head shown in Figure 1 in accordance with one embodiment of the present invention.
Detailed Description In some embodiments of the present invention, both drilling and production of fluids from a formation may occur in an underbalanced condition. As used herein, "underbalanced" means that the weight of the drilling mud is less than the pore pressure of the formation. As used herein, "dual gradient" refers to the fact that the density of fluid, at some point along its course, moving away from a drill bit, is lower than the density of the fluid moving towards the drill bit. Dual gradient techniques may be used to implement underbalanced drilling. The creation of a dual-gradient or underbalanced condition may be implemented using any known techniques, including the injection of gases, seawater, and glass beads, to mention a few examples. Referring to Figure 1, a drilling and production apparatus 11 may include a rotating head 10 which rotates a string for purposes of drilling a well in a subsea formation SF. The rotating head 10 rotates the string through a surface blowout preventer (BOP) stack 12. The surface blowout preventer stack 12 may include annular blowout preventers that control the flow of fluid moving upwardly from the wellhead to the overlying floating rig 14. The rig 14 may be tensioned using ring tensioners 16, coupled by a pulleys 54 to hydraulic cylinders 56 to create a tensioning system 50. The tensioning system 50 allows the upper portion of the apparatus 11 to move relative to the lower portion, for example in response to sea conditions. The system 50 allows this relative movement and adjustment of relative positioning while maintaining tension on the casing 22, which extends from the floating rig 14 downwardly to a subsea shutoff assembly 24. The surface portion of the apparatus 11 is coupled by a connector 20 to the casing 22.
The casing 22 is connected to the lower section of the apparatus 11 via a disconnectable latch 72 located below the sea level WL. The latch 72 may be hydraulically operated from the surface to disconnect the upper portion of the apparatus 11 from the lower portion including the subsea shutoff assembly 24. Also provided on the rig 14 is a source of fluid that is of a lower density than the density of mud pumped downwardly through the casing 22 from the surface in one embodiment of the present invention. The lower density fluid may be provided through the tubing 60. A hanger system 58 includes a tensioner 58 that rests on a support 56. The hanger system 58 tensions the tensioned tubing 26 that extends all the way down to a disconnectable subsea latch 74 above the subsea shutoff assembly 24. Like the latch 72, the latch 74 may be remotely or surface operated to sever the tubing 26 from the subsea shutoff assembly 24. In one embodiment, the support 56 may include hydraulic ram devices that move like shear ram blowout preventers to grip the tubing 26. The rate of lower density fluid flow through the tubing 26 from the surface may be controlled from the surface by remotely controllable valving in the subsea shutoff assembly 24, in one embodiment. It is advantageous to provide this lower density fluid from the surface as opposed to attempting to provide it from a subsea location, such as within the subsea shutoff assembly 24, because it is much easier to control and operate large pumps from the rig 14. The subsea shutoff assembly 24 operates with the surface blowout preventer stack 12 to prevent blowouts. While the surface blowout preventer stack 12 controls fluid flow, the subsea shutoff assembly 24 is responsible for cutting off or severing the wellhead from the portions of the apparatus 11 thereabove, using shear rams 30a and 30b as shown in Figure 2.
Thus, the casing 22 may be coupled by connector 28a to the shear ram 30a. The shear ram
30a is coupled by a spool 34 with flanges 32a and 32b to the shear ram 30b. The shear ram 30b may be coupled through the flange 38 to a wellhead connector 28b, in turn connected to the wellhead. As shown in Figure 2, the tubing 26 connects to a remotely controlled valve 36 that controls the rate of lower density fluid flow through the tubing 26 to the interior of the spool 34. The inlet from the tubing 26 to the spool 34 is between the two shear rams 30a and 30b. The injection of lower density fluid, as shown in Figure 3, makes use of the remotely controlled valve 36 on a spool 34. The spool 34 may have drilling mud, indicated as MIN, moving downwardly through the casing 22. The returning mud, indicated as MOUT, extends upwardly in the annulus 46 surrounding the string 40 and annulus 44. Thus, lower density fluid may be injected, when the valve 36 is opened, into the returning mud/hydrocarbon flow to lower its density. An underbalanced situation may be created as a result of the dual densities of mud in one embodiment. Namely, mud above the valve 36 may be at a lower density than the density of the mud below the valve 36, as well as the density of the mud moving downwardly to the formation. The valve 36 may include a rotating element 37 that allows the valve 36 to be opened or controlled. As an additional example, the valve 36 may be a pivoted gate valve with a hydraulic fail safe that automatically closes the valve in the event of a loss of hydraulics. The valve 36 may enable the extent of underbalanced drilling to be surface or remotely controlled depending on sensed conditions, including the upward pressure supplied by the formation. For example, the valve 36 may be controlled acoustically from the surface. Thus, in some embodiments of the present invention, flow control may be done most effectively at the surface, whereas shutoff control is done on the seafloor bed. The pumping of the lower density fluid is also done on the surface, but its injection may be done at the subsea shutoff assembly 24, in one embodiment between the shear rams 30a and 30b. The rotating head 10, shown in more detail in Figure 4, is coupled to the surface blowout preventer stack 12 at a joint 70. Returning fluid, indicated as MOUT. is passed through a valve 68 to an appropriate collection area. The collection area may collect both mud with entrained debris, as well as production fluids such as hydrocarbons. The production fluids may be separated using well known techniques. The upward flow of the fluid MOUT is constrained by a packer 62. In one embodiment, the packer 62 is a rubber or resilient ring that seals the annulus around the string 40 and prevents the further upward flow of the fluids. At the same time, the packer 62 enables the application of a rotating force in the direction of the circular arrow from the rotating head 66 to the string 40 for purposes of drilling. Seals 65 may be provided between a telescoping joint 64 and the rotating head 66 as both drilling and production may be accomplished in an underbalanced situation. Thus, in some embodiments of the present invention, a subsea shutoff assembly 24 may be provided to cut off the string in the event of a failure, such as a blowout. At the same time, surface annular blowout preventers control fluid flow. Dual gradient drilling may be achieved through the provision of fluid from the surface through a side inlet into the region between the upper and lower ram type shear blowout preventers 30. Through the provision of the separate tubing 26 with a remotely operable latch 74, appropriate volumes of fluid can be achieved that would not be available with conventional kill and choke lines. The tubing 26 for providing the density control fluid may be both tensioned and latched. As a result, dual gradient production and drilling may be achieved in some embodiments of the present invention. While the present invention has been described with respect to a limited number of embodiments, those skilled in the art will appreciate numerous modifications and variations therefrom. It is intended that the appended claims cover all such modifications and variations as fall within the true spirit and scope of this present invention.

Claims

What is claimed is: 1. A method comprising: producing hydrocarbons from a subsea well in an underbalanced condition using a rotating head mounted on a surface blow out preventer.
2. The method of claim 1 including using the surface blow out preventer to provide surface flow control.
3. The method of claim 2 including providing a subsurface blow out preventer in addition to said surface blow out preventer.
4. The method of claim 3 including providing subsurface shear blow out preventers.
5. The method of claim 1 including coupling said surface blow out preventers to the wellhead using casing and providing a remotely operable subsurface latch to sever the connection between said wellhead and said surface blow out preventers.
6. The method of claim 5 including tensioning said casing.
7. The method of claim 5 including providing a flow of mud through a casing to a drill bit.
8. The method of claim 7 including lowering the density of mud returning from said drill bit through said casing.
9. The method of claim 8 including providing a separate line to enable fluid to be pumped from the surface to a subsurface location to lower the density of the returning mud.
10. The method of claim 9 including providing a tensioned line to provide said fluid from said surface.
11. The method of claim 10 including providing a disconnectable latch to disconnect the line from the wellhead.
12. The method of claim 11 including providing a subsurface blow out preventer and providing said line to said subsurface blow out preventer.
13. The method of claim 12 including providing a pair of shear ram subsurface blow out preventers and pumping said fluid between said shear blow out preventers.
14. The method of claim 13 including providing a remotely operable valve to control the flow of said fluid and positioning said valve at a subsea location.
15. The method of claim 1 including providing a rotating head that transfers rotational energy to said drill string through a packer.
16. The method of claim 15 including providing said rotational energy through a resilient packer.
17. A drilling rig comprising: a rotating head; a surface blow out preventer mounted under said rotating head on said rig; and an apparatus to pump fluid to a subsea location to lower the density of drilling mud returning to said rig.
18. The rig of claim 17 including a casing coupled from said surface blow out preventer to a subsea subsurface blow out preventer.
19. The rig of claim 18 wherein said subsea blow out preventer includes a pair of shear blow out preventers.
20. The rig of claim 19 including a remotely operable latch to sever said casing from said subsea blow out preventer.
21. The rig of claim 20 wherein said casing is tensioned.
22. The rig of claim 17 including a separate line to supply lower density fluid to a subsea location to lower the density of drilling mud to be returned to said rig.
23. The rig of claim 22 wherein said line is tensioned.
24. The rig of claim 23 wherein a disconnectable latch is provided to disconnect the line at a subsea location. '
25. The rig of claim 17 including a subsurface blow out preventer and a coupling to receive said line.
26. The rig of claim 25 wherein said subsurface blow out preventer includes a pair of shear ram subsurface blow out preventers and said coupling is arranged between said pair of shear ram subsurface blow out preventers.
27. The rig of claim 26 including a valve in said line to control the flow of fluid to lower the density of said drilling mud.
28. The rig of claim 17 wherein said rotating head includes a resilient packer and a drill string and tubing, said resilient packer to seal the region between said drill string and said tubing and to transfer rotational energy from said tubing to said drill string.
29. The subsea shutoff assembly comprising: a pair of shear blow out preventers; and a device coupling said blow out preventers, said device having an inlet to receive a density lowering fluid to lower the density of drilling mud moving upwardly through said device.
30. The assembly of claim 29 including a line for supplying density lowering fluid, said line including a remotely actuatable valve.
31. The assembly of claim 30 wherein said valve automatically closes upon loss of control.
32. A method comprising: operating a subsea wellhead in an underbalanced condition; providing mud at a first density to said wellhead; and injecting, from the sea surface, a first density lowering fluid, into mud returning from said wellhead, through tensioned, latched tubing.
33. The method of claim 32 including producing hydrocarbons from a subsea well in an underbalanced condition using a rotating head mounted on a surface blow out preventer.
34. The method of claim 33 including using the surface blow out preventer to provide surface flow control.
35. The method of claim 34 including providing a subsurface blow out preventer in addition to said surface blow out preventer.
36. The method of claim 35 including providing subsurface shear blow out preventers.
37. The method of claim 32 including providing a separate line for said first density lowering fluid to be pumped from the surface to a subsurface location mud.
38. The method of claim 37 including providing a subsurface blow out preventer and providing said line to said subsurface blow out preventer.
39. The method of claim 38 including providing a pair of shear ram subsurface blow out preventers and injecting said first density lowering fluid between said shear blow out preventers.
40. The method of claim 39 including providing a remotely operable valve to control the flow of said fluid and positioning said valve at a subsea location.
41. The method of claim 33 including providing a rotating head that transfers rotational energy to said drill string through a packer.
42. The method of claim 41 including providing said rotational energy through a resilient packer.
43. A system for supplying density lowering fluid to a subsea location comprising: a surface hanger to tension and hang tubing connectable to a source of density lowering fluid; and a subsea latch to couple a first portion of said tubing to a second portion of said tubing, said latch being remotely operable to disconnect said first portion of said tubing from said second portion of said tubing.
44. The system of claim 43 including a subsea valve to control the rate of flow of fluid through said tubing.
45. The system of claim 44 wherein said valve is coupled to a connector to couple said tubing to a subsea location.
46. The system of claim 43 including a subsea shutoff assembly coupled to said tubing.
47. The system of claim 46 wherein said subsea shutoff assembly includes a pair of shear ram blow out preventers coupled to one another.
48. The system of claim 47 including a coupling to connect said shear ram blow out preventers to one another, said coupling adapted to receive said tubing, said coupling to pass drilling fluid downwardly through a central passage and upwardly through a radially displaced passage.
49. The system of claim 43 wherein said latch disconnects upon detection of a failure.
50. The system of claim 43 wherein said hanger includes a hydraulic ram to grip said tubing.
PCT/IB2004/004372 2003-10-30 2004-10-25 Underbalanced well drilling and production WO2005042917A1 (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
EP04806532A EP1700000B1 (en) 2003-10-30 2004-10-25 Underbalanced well drilling and production
DK04806532T DK1700000T3 (en) 2003-10-30 2004-10-25 Underbalanced drilling of wells and production
BRPI0416064-9A BRPI0416064A (en) 2003-10-30 2004-10-25 production and drilling of underpressure wells
AU2004286103A AU2004286103B2 (en) 2003-10-30 2004-10-25 Underbalanced well drilling and production
TNP2006000119A TNSN06119A1 (en) 2003-10-30 2006-04-24 Underbalanced well drilling and production
EGNA2006000408 EG24344A (en) 2003-10-30 2006-04-30 Underbalanced well drilling and production
NO20062254A NO338633B1 (en) 2003-10-30 2006-05-19 Method for underbalanced wellbore and system for supplying density-reducing fluid to a subsea location
NO20160812A NO339557B1 (en) 2003-10-30 2016-05-12 Drilling rig

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US10/697,204 US7032691B2 (en) 2003-10-30 2003-10-30 Underbalanced well drilling and production
US10/697,204 2003-10-30

Publications (1)

Publication Number Publication Date
WO2005042917A1 true WO2005042917A1 (en) 2005-05-12

Family

ID=34550303

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2004/004372 WO2005042917A1 (en) 2003-10-30 2004-10-25 Underbalanced well drilling and production

Country Status (10)

Country Link
US (3) US7032691B2 (en)
EP (3) EP1808569B1 (en)
AU (1) AU2004286103B2 (en)
BR (1) BRPI0416064A (en)
DK (3) DK2161404T3 (en)
EG (1) EG24344A (en)
ES (3) ES2393434T3 (en)
NO (2) NO338633B1 (en)
TN (1) TNSN06119A1 (en)
WO (1) WO2005042917A1 (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8033335B2 (en) 2006-11-07 2011-10-11 Halliburton Energy Services, Inc. Offshore universal riser system
GB2482181A (en) * 2010-07-23 2012-01-25 Peter Robert Goodall Preventing and ameliorating leakage from a subsea well in the event of failure
US8201628B2 (en) 2010-04-27 2012-06-19 Halliburton Energy Services, Inc. Wellbore pressure control with segregated fluid columns
US8281875B2 (en) 2008-12-19 2012-10-09 Halliburton Energy Services, Inc. Pressure and flow control in drilling operations
WO2013050826A1 (en) * 2011-10-05 2013-04-11 Redden David B Backup wellhead blowout prevention system and method
US8820405B2 (en) 2010-04-27 2014-09-02 Halliburton Energy Services, Inc. Segregating flowable materials in a well
US8833488B2 (en) 2011-04-08 2014-09-16 Halliburton Energy Services, Inc. Automatic standpipe pressure control in drilling
US9080407B2 (en) 2011-05-09 2015-07-14 Halliburton Energy Services, Inc. Pressure and flow control in drilling operations
US9249638B2 (en) 2011-04-08 2016-02-02 Halliburton Energy Services, Inc. Wellbore pressure control with optimized pressure drilling
US9605507B2 (en) 2011-09-08 2017-03-28 Halliburton Energy Services, Inc. High temperature drilling with lower temperature rated tools

Families Citing this family (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7487837B2 (en) * 2004-11-23 2009-02-10 Weatherford/Lamb, Inc. Riser rotating control device
US7836946B2 (en) 2002-10-31 2010-11-23 Weatherford/Lamb, Inc. Rotating control head radial seal protection and leak detection systems
US7237623B2 (en) * 2003-09-19 2007-07-03 Weatherford/Lamb, Inc. Method for pressurized mud cap and reverse circulation drilling from a floating drilling rig using a sealed marine riser
US7032691B2 (en) * 2003-10-30 2006-04-25 Stena Drilling Ltd. Underbalanced well drilling and production
WO2005100737A1 (en) * 2004-04-16 2005-10-27 Vetco Aibel As System and method for rigging up well workover equipment
US8826988B2 (en) 2004-11-23 2014-09-09 Weatherford/Lamb, Inc. Latch position indicator system and method
US7926593B2 (en) 2004-11-23 2011-04-19 Weatherford/Lamb, Inc. Rotating control device docking station
BR122017010168B1 (en) * 2005-10-20 2018-06-26 Transocean Sedco Forex Ventures Ltd. METHOD TO CONTROL PRESSURE AND / OR DENSITY OF A DRILLING FLUID
US8459361B2 (en) * 2007-04-11 2013-06-11 Halliburton Energy Services, Inc. Multipart sliding joint for floating rig
US7997345B2 (en) 2007-10-19 2011-08-16 Weatherford/Lamb, Inc. Universal marine diverter converter
US8844652B2 (en) 2007-10-23 2014-09-30 Weatherford/Lamb, Inc. Interlocking low profile rotating control device
US8286734B2 (en) 2007-10-23 2012-10-16 Weatherford/Lamb, Inc. Low profile rotating control device
US8322432B2 (en) 2009-01-15 2012-12-04 Weatherford/Lamb, Inc. Subsea internal riser rotating control device system and method
US9359853B2 (en) 2009-01-15 2016-06-07 Weatherford Technology Holdings, Llc Acoustically controlled subsea latching and sealing system and method for an oilfield device
US9567843B2 (en) * 2009-07-30 2017-02-14 Halliburton Energy Services, Inc. Well drilling methods with event detection
US8347983B2 (en) 2009-07-31 2013-01-08 Weatherford/Lamb, Inc. Drilling with a high pressure rotating control device
US8471560B2 (en) * 2009-09-18 2013-06-25 Schlumberger Technology Corporation Measurements in non-invaded formations
WO2011067353A2 (en) * 2009-12-02 2011-06-09 Stena Drilling Limited Assembly and method for subsea well drilling and intervention
US8347982B2 (en) 2010-04-16 2013-01-08 Weatherford/Lamb, Inc. System and method for managing heave pressure from a floating rig
US8403059B2 (en) * 2010-05-12 2013-03-26 Sunstone Technologies, Llc External jet pump for dual gradient drilling
AU2011258027A1 (en) 2010-05-28 2012-12-20 David Randolph Smith Method and apparatus to control fluid flow subsea wells
US9175542B2 (en) 2010-06-28 2015-11-03 Weatherford/Lamb, Inc. Lubricating seal for use with a tubular
US20120006559A1 (en) * 2010-07-09 2012-01-12 Brite Alan D Submergible oil well sealing device with valves and method for installing a submergible oil well sealing device and resuming oil production
US20120045285A1 (en) * 2010-08-23 2012-02-23 Oil Well Closure And Protection As Offshore structure
US8783359B2 (en) 2010-10-05 2014-07-22 Chevron U.S.A. Inc. Apparatus and system for processing solids in subsea drilling or excavation
US8746345B2 (en) * 2010-12-09 2014-06-10 Cameron International Corporation BOP stack with a universal intervention interface
US8820412B2 (en) * 2011-09-16 2014-09-02 Chevron U.S.A. Inc. Methods, systems and apparatus for circulating fluid within the annulus of a flexible pipe riser
US9033049B2 (en) * 2011-11-10 2015-05-19 Johnnie E. Kotrla Blowout preventer shut-in assembly of last resort
US9328575B2 (en) * 2012-01-31 2016-05-03 Weatherford Technology Holdings, Llc Dual gradient managed pressure drilling
AU2013221574B2 (en) 2012-02-14 2017-08-24 Chevron U.S.A. Inc. Systems and methods for managing pressure in a wellbore
GB2520182B (en) * 2012-04-27 2017-01-11 Schlumberger Holdings Wellbore annular pressure control system and method using gas lift in drilling fluid return line
US10113377B2 (en) * 2012-06-21 2018-10-30 Superior Energy Services—North America Services, Inc. Drive systems for use with long lateral completion systems and methods
WO2014062664A2 (en) * 2012-10-15 2014-04-24 National Oilwell Varco, L.P. Dual gradient drilling system
US10294746B2 (en) * 2013-03-15 2019-05-21 Cameron International Corporation Riser gas handling system
CA2925472C (en) 2013-11-27 2018-03-27 Landmark Graphics Corporation Method and apparatus for optimized underbalanced drilling
GB201501477D0 (en) * 2015-01-29 2015-03-18 Norwegian Univ Sci & Tech Ntnu Drill apparatus for a floating drill rig
CA3169134C (en) * 2015-02-13 2023-03-28 Conocophillips Company Method and apparatus for filling an annulus between casing and rock in an oil or gas well
WO2017010985A1 (en) * 2015-07-13 2017-01-19 Landmark Graphics Corporation Underbalanced drilling through formations with varying lithologies
US11208862B2 (en) * 2017-05-30 2021-12-28 Trendsetter Vulcan Offshore, Inc. Method of drilling and completing a well
CN108180012A (en) * 2017-12-21 2018-06-19 黄明道 Deepwater drilling platform IBOP valves and preventer joint pressure test tool and pressure-measuring method
CA3123190C (en) * 2019-01-18 2023-08-01 Halliburton Energy Services, Inc. Pressure switch

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5848656A (en) * 1995-04-27 1998-12-15 Moeksvold; Harald Device for controlling underwater pressure
WO2003023181A1 (en) * 2001-09-10 2003-03-20 Ocean Riser Systems As Arrangement and method for regulating bottom hole pressures when drilling deepwater offshore wells
US20030070840A1 (en) * 2001-02-15 2003-04-17 Boer Luc De Method and apparatus for varying the density of drilling fluids in deep water oil drilling applications

Family Cites Families (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3324017A (en) * 1958-06-12 1967-06-06 Sinclair Research Inc Method for copolymerizing an alkylidene bisacrylamide and an ethylenic monomer employing radiation
US4091881A (en) * 1977-04-11 1978-05-30 Exxon Production Research Company Artificial lift system for marine drilling riser
WO1988000277A1 (en) * 1986-07-07 1988-01-14 B.W.N. Vortoil Pty. Ltd. Method for startup of production in an oil well
US5662181A (en) * 1992-09-30 1997-09-02 Williams; John R. Rotating blowout preventer
NO305138B1 (en) * 1994-10-31 1999-04-06 Mercur Slimhole Drilling And I Device for use in drilling oil / gas wells
US6065550A (en) * 1996-02-01 2000-05-23 Gardes; Robert Method and system for drilling and completing underbalanced multilateral wells utilizing a dual string technique in a live well
US5873420A (en) * 1997-05-27 1999-02-23 Gearhart; Marvin Air and mud control system for underbalanced drilling
US6216799B1 (en) 1997-09-25 2001-04-17 Shell Offshore Inc. Subsea pumping system and method for deepwater drilling
US6273193B1 (en) * 1997-12-16 2001-08-14 Transocean Sedco Forex, Inc. Dynamically positioned, concentric riser, drilling method and apparatus
US6263982B1 (en) * 1998-03-02 2001-07-24 Weatherford Holding U.S., Inc. Method and system for return of drilling fluid from a sealed marine riser to a floating drilling rig while drilling
US6913092B2 (en) * 1998-03-02 2005-07-05 Weatherford/Lamb, Inc. Method and system for return of drilling fluid from a sealed marine riser to a floating drilling rig while drilling
US6325159B1 (en) * 1998-03-27 2001-12-04 Hydril Company Offshore drilling system
AU764993B2 (en) * 1999-03-02 2003-09-04 Weatherford Technology Holdings, Llc Internal riser rotating control head
EG22117A (en) * 1999-06-03 2002-08-30 Exxonmobil Upstream Res Co Method and apparatus for controlling pressure and detecting well control problems during drilling of an offshore well using a gas-lifted riser
US6450262B1 (en) 1999-12-09 2002-09-17 Stewart & Stevenson Services, Inc. Riser isolation tool
US6484816B1 (en) * 2001-01-26 2002-11-26 Martin-Decker Totco, Inc. Method and system for controlling well bore pressure
US6966392B2 (en) * 2001-02-15 2005-11-22 Deboer Luc Method for varying the density of drilling fluids in deep water oil and gas drilling applications
US6536540B2 (en) * 2001-02-15 2003-03-25 De Boer Luc Method and apparatus for varying the density of drilling fluids in deep water oil drilling applications
US7090036B2 (en) * 2001-02-15 2006-08-15 Deboer Luc System for drilling oil and gas wells by varying the density of drilling fluids to achieve near-balanced, underbalanced, or overbalanced drilling conditions
US6802379B2 (en) * 2001-02-23 2004-10-12 Exxonmobil Upstream Research Company Liquid lift method for drilling risers
WO2002068787A2 (en) 2001-02-23 2002-09-06 Exxonmobil Upstream Research Company Method and apparatus for controlling bottom-hole pressure during dual-gradient drilling
CA2344627C (en) * 2001-04-18 2007-08-07 Northland Energy Corporation Method of dynamically controlling bottom hole circulating pressure in a wellbore
US6672390B2 (en) * 2001-06-15 2004-01-06 Shell Oil Company Systems and methods for constructing subsea production wells
AU2002320329A1 (en) 2001-07-09 2003-01-29 Baker Hughes Incorporated Drilling system and method for controlling equivalent circulating density during drilling of wellbores
US6745857B2 (en) * 2001-09-21 2004-06-08 National Oilwell Norway As Method of drilling sub-sea oil and gas production wells
GB2400871B (en) * 2001-12-03 2005-09-14 Shell Int Research Method for formation pressure control while drilling
US6904981B2 (en) * 2002-02-20 2005-06-14 Shell Oil Company Dynamic annular pressure control apparatus and method
NO318220B1 (en) * 2003-03-13 2005-02-21 Ocean Riser Systems As Method and apparatus for performing drilling operations
US7237623B2 (en) * 2003-09-19 2007-07-03 Weatherford/Lamb, Inc. Method for pressurized mud cap and reverse circulation drilling from a floating drilling rig using a sealed marine riser
US7032691B2 (en) * 2003-10-30 2006-04-25 Stena Drilling Ltd. Underbalanced well drilling and production
US7021402B2 (en) * 2003-12-15 2006-04-04 Itrec B.V. Method for using a multipurpose unit with multipurpose tower and a surface blow out preventer
US7237613B2 (en) * 2004-07-28 2007-07-03 Vetco Gray Inc. Underbalanced marine drilling riser
US7658228B2 (en) * 2005-03-15 2010-02-09 Ocean Riser System High pressure system
US7836973B2 (en) * 2005-10-20 2010-11-23 Weatherford/Lamb, Inc. Annulus pressure control drilling systems and methods
CA2867382C (en) * 2006-11-07 2015-12-29 Halliburton Energy Services, Inc. Method of drilling by installing an annular seal in a riser string and a seal on a tubular string

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5848656A (en) * 1995-04-27 1998-12-15 Moeksvold; Harald Device for controlling underwater pressure
US20030070840A1 (en) * 2001-02-15 2003-04-17 Boer Luc De Method and apparatus for varying the density of drilling fluids in deep water oil drilling applications
WO2003023181A1 (en) * 2001-09-10 2003-03-20 Ocean Riser Systems As Arrangement and method for regulating bottom hole pressures when drilling deepwater offshore wells

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9127511B2 (en) 2006-11-07 2015-09-08 Halliburton Energy Services, Inc. Offshore universal riser system
US8033335B2 (en) 2006-11-07 2011-10-11 Halliburton Energy Services, Inc. Offshore universal riser system
US8887814B2 (en) 2006-11-07 2014-11-18 Halliburton Energy Services, Inc. Offshore universal riser system
US9051790B2 (en) 2006-11-07 2015-06-09 Halliburton Energy Services, Inc. Offshore drilling method
US9127512B2 (en) 2006-11-07 2015-09-08 Halliburton Energy Services, Inc. Offshore drilling method
US9376870B2 (en) 2006-11-07 2016-06-28 Halliburton Energy Services, Inc. Offshore universal riser system
US8881831B2 (en) 2006-11-07 2014-11-11 Halliburton Energy Services, Inc. Offshore universal riser system
US8776894B2 (en) 2006-11-07 2014-07-15 Halliburton Energy Services, Inc. Offshore universal riser system
US9085940B2 (en) 2006-11-07 2015-07-21 Halliburton Energy Services, Inc. Offshore universal riser system
US9157285B2 (en) 2006-11-07 2015-10-13 Halliburton Energy Services, Inc. Offshore drilling method
US8281875B2 (en) 2008-12-19 2012-10-09 Halliburton Energy Services, Inc. Pressure and flow control in drilling operations
US8286730B2 (en) 2009-12-15 2012-10-16 Halliburton Energy Services, Inc. Pressure and flow control in drilling operations
US8820405B2 (en) 2010-04-27 2014-09-02 Halliburton Energy Services, Inc. Segregating flowable materials in a well
US8261826B2 (en) 2010-04-27 2012-09-11 Halliburton Energy Services, Inc. Wellbore pressure control with segregated fluid columns
US8201628B2 (en) 2010-04-27 2012-06-19 Halliburton Energy Services, Inc. Wellbore pressure control with segregated fluid columns
GB2482181B (en) * 2010-07-23 2015-07-29 Peter Robert Goodall Preventing and ameliorating leakage from a subsea well in the event of failure
GB2482181A (en) * 2010-07-23 2012-01-25 Peter Robert Goodall Preventing and ameliorating leakage from a subsea well in the event of failure
US8881829B2 (en) 2010-10-07 2014-11-11 David B. Redden Backup wellhead blowout prevention system and method
US8833488B2 (en) 2011-04-08 2014-09-16 Halliburton Energy Services, Inc. Automatic standpipe pressure control in drilling
US9249638B2 (en) 2011-04-08 2016-02-02 Halliburton Energy Services, Inc. Wellbore pressure control with optimized pressure drilling
US9080407B2 (en) 2011-05-09 2015-07-14 Halliburton Energy Services, Inc. Pressure and flow control in drilling operations
US9605507B2 (en) 2011-09-08 2017-03-28 Halliburton Energy Services, Inc. High temperature drilling with lower temperature rated tools
WO2013050826A1 (en) * 2011-10-05 2013-04-11 Redden David B Backup wellhead blowout prevention system and method
US10233708B2 (en) 2012-04-10 2019-03-19 Halliburton Energy Services, Inc. Pressure and flow control in drilling operations

Also Published As

Publication number Publication date
EP1808569B1 (en) 2010-07-28
DK2161404T3 (en) 2012-12-17
EP2161404B1 (en) 2012-08-29
US20090314544A1 (en) 2009-12-24
NO20062254L (en) 2006-07-28
ES2393434T3 (en) 2012-12-21
AU2004286103A1 (en) 2005-05-12
NO339557B1 (en) 2017-01-02
DK1808569T3 (en) 2010-11-08
ES2305892T3 (en) 2008-11-01
EP1808569A3 (en) 2009-06-17
AU2004286103B2 (en) 2008-02-14
EP1808569A2 (en) 2007-07-18
NO20160812L (en) 2006-07-28
EP1700000A1 (en) 2006-09-13
EP2161404A2 (en) 2010-03-10
US20060191716A1 (en) 2006-08-31
EG24344A (en) 2009-02-11
EP2161404A3 (en) 2010-04-14
EP1700000B1 (en) 2008-04-23
US7032691B2 (en) 2006-04-25
US20050092522A1 (en) 2005-05-05
ES2349789T3 (en) 2011-01-11
US8176985B2 (en) 2012-05-15
DK1700000T3 (en) 2008-07-28
TNSN06119A1 (en) 2007-11-15
BRPI0416064A (en) 2007-01-02
NO338633B1 (en) 2016-09-19

Similar Documents

Publication Publication Date Title
US7032691B2 (en) Underbalanced well drilling and production
US6142236A (en) Method for drilling and completing a subsea well using small diameter riser
AU764993B2 (en) Internal riser rotating control head
US7134498B2 (en) Well drilling and completions system
US8978774B2 (en) System and method for drilling a subsea well
EP2281103B1 (en) Systems and methods for subsea drilling
US7497266B2 (en) Arrangement and method for controlling and regulating bottom hole pressure when drilling deepwater offshore wells
NO338632B1 (en) Apparatus and method for controlling formation fluid flow into a borehole production tube
WO2004044366A2 (en) Method and apparatus for varying the density of drilling fluids in deep water oil drilling applications
US20060180312A1 (en) Displacement annular swivel
WO2019022601A1 (en) System and method for casing drilling with a subsea casing drive
AU2008201481B2 (en) Underbalanced well drilling and production
US11873626B2 (en) Large diameter water well control
US11585171B2 (en) Managed pressure drilling systems and methods

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2004286103

Country of ref document: AU

WWE Wipo information: entry into national phase

Ref document number: PA/a/2006/004879

Country of ref document: MX

ENP Entry into the national phase

Ref document number: 2004286103

Country of ref document: AU

Date of ref document: 20041025

Kind code of ref document: A

WWP Wipo information: published in national office

Ref document number: 2004286103

Country of ref document: AU

WWE Wipo information: entry into national phase

Ref document number: 2004806532

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 2004806532

Country of ref document: EP

ENP Entry into the national phase

Ref document number: PI0416064

Country of ref document: BR

WWG Wipo information: grant in national office

Ref document number: 2004806532

Country of ref document: EP