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Patent 2260191 Summary

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(12) Patent: (11) CA 2260191
(54) English Title: METHOD FOR EXPANDING A STEEL TUBING AND WELL WITH SUCH A TUBING
(54) French Title: PROCEDE POUR DILATER UNE COLONNE DE PRODUCTION EN ACIER ET PUITS AVEC LADITE COLONNE
Status: Expired
Bibliographic Data
(51) International Patent Classification (IPC):
  • E21B 43/10 (2006.01)
  • B21D 39/20 (2006.01)
  • C21D 7/12 (2006.01)
  • E21B 17/00 (2006.01)
  • E21B 23/04 (2006.01)
  • E21B 29/10 (2006.01)
(72) Inventors :
  • DONNELLY, MARTIN (Netherlands (Kingdom of the))
  • FAURE, ALBAN MICHEL (Netherlands (Kingdom of the))
  • MARKETZ, FRANZ (Netherlands (Kingdom of the))
  • STEWART, ROBERT BRUCE (Netherlands (Kingdom of the))
  • LOHBECK, WILHELMUS CHRISTIANUS MARIA (Netherlands (Kingdom of the))
(73) Owners :
  • SHELL CANADA LIMITED (Canada)
(71) Applicants :
  • SHELL CANADA LIMITED (Canada)
(74) Agent: SMART & BIGGAR
(74) Associate agent:
(45) Issued: 2007-11-27
(86) PCT Filing Date: 1997-06-30
(87) Open to Public Inspection: 1998-01-08
Examination requested: 2002-04-09
Availability of licence: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): Yes
(86) PCT Filing Number: PCT/EP1997/003489
(87) International Publication Number: WO1998/000626
(85) National Entry: 1998-12-29

(30) Application Priority Data:
Application No. Country/Territory Date
96201809.9 European Patent Office (EPO) 1996-07-01

Abstracts

English Abstract




A tubing (4) made of a formable steel grade which is subject to strain
hardening without incurring any necking or ductile fracturing as a result of
the
expansion process is expanded by moving an expansion mandrel (5) having a
non-metallic tapering outer surface through the tubing, thereby increasing the

strength of the tubing while expansion forces remains low.


French Abstract

L'invention concerne une colonne de production (4) constituée d'une qualité d'acier ductile, qui est soumise à un écrouissage sans que le processus de dilatation n'entraîne de rétrécissement ou de rupture ductile. On dilate la colonne de production en déplaçant à l'intérieur un mandrin de dilatation (5) ayant une surface externe conique non métallique, ce qui augmente la résistance de ladite colonne sans augmenter les forces de dilatation.

Claims

Note: Claims are shown in the official language in which they were submitted.




-12-


CLAIMS:


1. A method of expanding an at least partly solid
steel tubing which is made of a formable steel grade subject
to strain hardening, the method comprising the step of
moving an expansion mandrel having a tapering expansion
section which has a tapering ceramic outer surface, through
the tubing thereby plastically expanding the tubing.

2. The method of claim 1, wherein the tubing is made
of a formable steel grade having a yield strength-tensile
strength ratio which is lower than 0.8 and a yield strength
of at least 275 MPa.

3. The method of claim 1 or 2, wherein the tubing is
made of a steel having a yield strength-tensile strength
ratio which is between 0.6 and 0.7.

4. The method of claim 1, 2 or 3, wherein the tubing
is made of a dual phase (DP) high-strength low alloy (HSLA)
steel.

5. The method of claim 4, wherein the tubing is made
of Sollac grade DP55.TM. or DP60.TM. having a tensile strength of
at least 550 MPa or Nippon grade SAFH 540 D.TM. or SAFH 590 D.TM..
6. The method of claim 1, 2 or 3, wherein the tubing
is made of a formable high-strength steel grade which is
selected from the following group of steel grades:

- an ASTM A106 high-strength low alloy (HSLA)
seamless pipe;

- an ASTM A312 austenitic stainless steel pipe,
grade TP 304 L;

- an ASTM A312 austenitic stainless steel pipe,
grade TP 316 L; and



-13-



- a high-retained austenite high-strength hot
rolled steel which is known as TRIP.TM. steel.

7. The method of any one of claims 1 to 6, wherein
the tubing is expanded such that the external diameter of
the expanded tubing is at least 20% larger than the external
diameter of the unexpanded tubing and wherein the strain
hardening exponent n of the formable steel of the tubing is
at least 0.16.

8. The method of any one of claims 1 to 7, wherein
the expansion mandrel comprises a tapering expansion section
which has a smooth ceramic outer surface which is oriented
at an acute angle A which is between 5° and 45° with respect
to a longitudinal axis of the mandrel and which induces the
tubing to expand such that the average roughness of the
inner surface of the tubing decreases as a result of the
expansion process.

9. The method of claim 8, wherein the ceramic outer
surface of the tapering expansion section is made of
zirconium oxide and is oriented at an acute angle A which is
between 15° and 30° with respect to a longitudinal axis of
the mandrel.

10. The method of any one of claims 1 to 9, wherein
the tubing is expanded by pumping the expansion mandrel
through the tubing.

11. The method of claim 7, wherein the tubing is
expanded by pumping the expansion mandrel through the tubing
and wherein the expansion mandrel comprises a sealing
section which is located at such a distance from the
expansion section that when the expansion mandrel is pumped
through the tubing the sealing section engages a plastically
expanded part of the tubing.



-14-


12. The method of claim 10 or 11, wherein the tubing
is expanded inside an underground borehole and the expansion
mandrel contains a vent line for venting any fluids that are
present in the tubing ahead of the expansion mandrel to the
surface.

13. The method of claim 10 or 11, wherein the tubing
is expanded inside an underground borehole such that the
outer diameter of the expanded tubing is slightly smaller
than the internal diameter of the borehole or of any casing
that is present in the borehole and any fluids that are
present in the borehole and tubing ahead of the expansion
mandrel are vented to surface via the annular space that
remains open around the tubing after the expansion process.
14. The method of any one of claims 1 to 13, wherein
the tubing is lowered into an underground borehole after
reeling the tubing from a reeling drum.

15. A well provided with a tubing which is expanded
using the method of any one of claims 1 to 14, wherein the
tubing serves as a production tubing through which
hydrocarbon fluid is transported to the surface and a
reelable service or kill line passes through at least a
substantial part of the length of the interior of the
tubing, through which line fluid can be pumped towards the
bottom of the borehole while hydrocarbon fluid is produced
via the surrounding production tubing.

16. A well provided with a tubing which is expanded
using the method according to any one of claims 1 to 12,
wherein the tubing is expanded against the inner surface of
a casing which is present in the borehole.

Description

Note: Descriptions are shown in the official language in which they were submitted.



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METHOD FOR EXPANDING A STEEL TUBING AND WELL WITH SUCH A
TUBING
The invention relates to expansion of tubings. More
particularly the invention relates to a method of
expanding a steel tubing by moving an expansion mandrel
through the tubing.
Numerous methods and devices are known for expansion
of tubings.
European patent specification 643794 discloses a
method of expanding a casing against the wall of an
underground borehole wherein the casing is made of a
malleable material which preferably is capable of plastic
deformation of at least 25% uniaxial strain and the
casing may be expanded by an expansion mandrel which is
pumped, pulled or pushed through the casing.
Other expansion methods and devices are disclosed in
German patent specification No. 1583992 and in US patent
specification Nos. 3,203,483; 3,162,245; 3,167,122;
3,326,293; 3,785,193; 3,489,220; 5,014,779; 5,031,699;
5,083,608 and 5,366,012.
Many of the known expansion methods employ an
initially corrugated tube and the latter prior art
reference employs a slotted tube which is expanded
downhole by an expansion mandrel.
The use of corrugated or slotted pipes in the known
methods serves to reduce the expansion forces that need
to be exerted to the tube to create the desired
expansion.
A method is known from US patent specification No. 5,366,012. In
this known method a slotted tube is expanded by an
expansion mandrel having a tapering expansion section.


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- 2 -

It is an object of the present invention to
provide a method for expanding an at least partly solid,
i.e. unslotted, tubing which requires exertion of a low
force to expand the tubing and which provides a tubing

having a larger diameter and higher strength than the
unexpanded tubing and which can be carried out with a tubing
which already may have a tubular shape before expansion.

The method according to the invention thereto
comprises the step of moving an expansion mandrel of which
the tapering expansion section has a tapering ceramic outer

surface through an at least partly solid tubing which is
made of a formable steel grade which is subject to strain
hardening without incurring any necking and ductile
fracturing as a result of the expansion process.

A broad aspect of the invention provides a method
of expanding an at least partly solid steel tubing which is
made of a formable steel grade subject to strain hardening,
the method comprising the step of moving an expansion

mandrel having a tapering expansion section which has a

tapering ceramic outer surface, through the tubing thereby
plastically expanding the tubing.

As a result of strain hardening the tubing becomes
stronger during the expansion process since for any further
increment of expansion always a higher stress is required

than for the preceding expansion.

It has been found that the use of a formable steel
grade for the tubing in combination with a ceramic tapering
outer surface of the expansion mandrel has a synergetic
effect since the resulting expanded tubing will have an
adequately increased strength while the expansion forces
remain low. The low yield strength and high ductility of
the tubing before expansion enables, if the tubing is to be


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- 2a -

used in an underground borehole, the use of a tubing which
is reeled from a reeling drum into the borehole.

It is observed that in the art of metallurgy the
terms strain-hardening and work-hardening are synonyms and
are both used to denote an increase of strength caused by
plastic deformation.

The term formable steel grade as used in this
specification means that the tubing is able to maintain


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WO 98/00626 PCT/EP97/03489
- 3 -
its structural integrity while being plastically deformed
into various shapes.
Ways of determining forming characteristics of a
steel are set out in the Metals Handbook, 9th edition,
volume 14, Forming and Forging, issued by ASM
Internationa.L, Metals Park, Ohio (USA).
The term necking refers to a geometrical effect
leading to non-uniform plastic deformations at some
location by occurrence of a local constriction. From the
point of nec:{ing on, the continual work hardening in the
necked region no longer compensates for the continual
reduction of the smallest cross-section in the neck, and
therefore, the load carrying capacity of the steel
decreases. W:Lth continuing loading, practically all
further plasi--ic deformation is restricted to the region
of the neck, so that a highly non-uniform deformation
occurs to develop in the necked region until fracture
occurs.
The term ductile fracturing means that a failure
occurs if pliistic deformation of a component that
exhibits duc,--ile behaviour is carried to the extreme so
that the component separates locally into two pieces.
Nucleation, growth and coalescence of internal voids
propagate to failure, leaving a dull fibrous rupture
surface. A detailed description of the terms necking and
ductile frac-:uring is given in the handbook "Failure of
Materials in Mechanical Design" by J.A. Collins second
edition, issl.ied by John Wiley and Sons, New York (USA) in
1993.
Preferably the tubing is made of a high-strength
steel grade with formability and having a yield strength-
tensile strength ratio which is lower than 0.8 and a
yield strength of at least 275 MPa. When used in this


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specification, the term high-strength steel denotes a
steel with a yield strength of at least 275 MPa.
It is also preferred that the tubing is made of a
formable steel grade having a yield stress/tensile stress
ratio which is between 0.6 and 0.7.
Dual phase (DP) high-strength, low-alloy (HSLA)
steels lack a definite yield point which eliminates
Luders band formation during the tubular expansion
process which ensures good surface finish of the expanded
tubular.
Suitable HSLA dual phase (DP) steels for use in the
method according to the invention are grades DP55'"' and
DP60TM developed by Sollac having a tensile strength of at
least 550 MPa and grades SAFH 540 DTM and SAFH 590 DT'
developed by Nippon Steel Corporation having a tensile
strength of at least 540 MPa.
It is observed that US patent specification
No. 4,938,266 discloses a method for producing dual phase
steels.
Other suitable steels are the following formable
high-strength steel grades
- an ASTM A106 high-strength low alloy (HSLA) seamless
pipe;
- an ASTM A312 austenitic stainless steel pipe, grade
TP 304 L;
- an ASTM A312 austenitic stainless steel pipe, grade
TP 316 L; and
- a high-retained austenite high-strength hot-rolled
steel (low-alloy TRIP steel) such as grades
SAFH 590 ETM, SAFH 690 E'"" and SAFH 780 ETM developed by
Nippon Steel Corporation.
The above-mentioned DP and other suitable steels each
have a strain hardening exponent n of at least 0.16 which
allows an expansion of the tubing such that the external


CA 02260191 1998-12-29
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diameter of the expanded tubing is at least 20% larger
than the external diameter of the unexpanded tubing.
Detailed explanations of the terms strain hardening,
work hardening and the strain hardening exponent n are
given in chapters 3 and 17 of the handbook "Metal
Forming-Mechanics and Metallurgy", 2nd edition, issued by
Prentice Hall, New Jersey (USA), 1993.
Suitably, the expansion mandrel contains an expansion
section that has a conical ceramic outer surface. It is
observed that US patent specification No. 3,901,063
discloses a plug having a conical ceramic outer surface
for use in tube-drawing operations. If the expansion
mandrel is pumped through the tubing then the mandrel
preferably comprises a sealing section which is located
at such a distance from the tapering expansion section
that when the expansion mandrel is moved through the
tubing by means of exerting a hydraulic pressure behind
the mandrel tr.e sealing section engages a plastically
expanded part of the tubing. This will generally be
achieved if said distance is at least three times the
wall thickness of the expanded tubing.
The use of' a ceramic conical surface reduces friction
forces during the expansion process and by having a
sealing section which engages the expanded tube it is
avoided that hydraulic forces would result in an
excessive expansion of the tubing.
In such caLse it is preferred that the expansion
mandrel contains a vent line for venting to the surface
any fluids that are present in the borehole and tubing
ahead of the expansion mandrel.
Alternatively the tubing is expanded such that the
outer diameter of the expanded tubing is slightly smaller
than the internal diameter of the borehole or of any
casing that is present in the borehole and any fluids
that are present in the borehole and tubing ahead of the
;aN1ENDED SHEEi'


CA 02260191 1998-12-29
- Sa -

expansion mandrel are vented to surface via the annular
space that remains open around the tubing after the
expansion process.

MD03/TS6025PC7.'

AMENDED SHEET


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The invention also relates to a well provided with a
tubing which is expanded using the method according to
the inventior-. In such case the tubing may serve as
production tubing through which hydrocarbon fluid is
transported to the surface and a reelable service and/or
kill line passes through at least a substantial part of
the length of: the tubing, through which line fluid can be
pumped towarcis the bottom of the borehole while
hydrocarbon fluid is produced via the surrounding
production tubing. The use of such an expanded production
tubing allows the use of almost the full wellbore for the
transport of hydrocarbon fluids so that a relatively slim
borehole may be utilized to attain the desired production
rate.
Alternatively the tubing may be expanded against the
inner surface of a casing which is present in the bore-
hole. In such case the tubing may either be used as a
production ttibing and/or as a protective cladding for
protecting the well casing against corrosive well fluids
and damage from tools that may be lowered into the well
during maintenance and workover operations.
These anci other objects, features and advantages of
the method and well system according to the present
invention will be apparent from the accompanying claims,
abstract and the following detailed description with
reference to the accompanying drawing, in which
Fig. 1 is schematic longitudinal sectional view of an
underground borehole in which a tubing is expanded in
accordance w:-th the method according to the invention.
Now referring to Fig. 1, there is shown a borehole
traversing arl underground formation 1 and a casing 2 that
is fixed within the borehole by means of an annular body
of cement 3.


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A production tubing 4 which is made of a dual phase,
high-strength low-alloy (HSLA) steel or other formable
high-strength steel is suspended within the casing 2.
An expansion mandrel 5 is moved in longitudinal
direction through the tubing 4 thereby expanding the
tubing 4 such that the outer diameter of the expanded
tubing is slightly smaller than or is about equal to the
internal diarreter of the casing 2.
The expansion mandrel 5 is equipped with a series of
ceramic surfaces 6 which restrict frictional forces
between the pig and tubing 4 during the expansion
process. In the example shown the semi top angle A of the
conical cerair.ic surface that actually expands the tubing
is about 25 . It has been found that zirconium oxide is a
suitable ceramic material which can be formed as a smooth
conical ring. Experiments and simulations have shown that
if the semi cone top angle A is between 20 and 30 the
pipe deforms such that it obtains an S-shape and touches
the tapering part of the ceramic surface 6 essentially at
the outer tip or rim of said conical part and optionally
also about halfway the conical part.
The experiments also showed that it is beneficial
that the expanding tubing 4 obtains an S-shape since this
reduces the length of the contact surface between the
tapering part of the ceramic surface 6 and the tubing 4
and thereby also reduces the amount of friction between
the expansior.~. mandrel 5 and the tubing 4.
Experiments have also shown that if said semi top
angle A is smaller than 15 this results in relatively
high frictior.al forces between the tube and pig, whereas
is said top angle is larger than 30 this will involve
redundant plastic work due to plastic bending of the
tubing 4 which also leads to higher heat dissipation and


CA 02260191 2004-11-08
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- 8 -
to disruptions of the forward movement of the pig 5
through the tubing 4. Hence said semi top angle A is
preferably selected between 15 and 30 and should always
be between 5 and 45 .
ExperimentS have also shown that the tapering part of
the expansion mandrel 5 should have a non-metallic outer
surface to avoid galling of the tubing during the
expansion process. The use of a ceramic surface for the
tapering part of the expansion mandrel furthermore caused
the average roughness of the inner surface of the
tubing 4 to decrease as a result of the expansion
process. The experiments have also shown that the
expansion mandrel 5 provided with a ceramic tapering
surface 6 could expand a tubing 5 made of a forinable
steel such that the outer tubing diameter D2 after
expansion was at least 20% larger than the outer diameter
Dl of the unexpended tubing and that suitable formable
steels are dual phase (DP) high-strength low.alloy (HSLA)
steels known as DP55TM and DP60TM; ASTM A106 HSLA seamless
pipe, ASTM A312 austenitic stainless steel pipes, grades
TP 304 L and TP 316 L and a high-retained austenite high-
strength hot rolled steel, known as TRIPTM steel manu-
factured by the Nippon Steel Corporation.
The mandrel 5 is provided with a pair of sealing
rings 7 which are located at such a distance from the
conical ceramic surface 6 that the rings 7 face the
plastically expanded section of the tubing 4. The sealing
rings serve to avoid that fluid at high hydraulic
pressure would be present between the conical ceramic
surface 6 of the mandrel 5 and the expanding tubing 4
which might lead to an irregularly large expansion of the
tubing 4.


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- 9 -
The expansion mandrel 5 is provided with a central
vent passage 7 which is in communication with a coiled
vent line 8 through which fluid may be vented to the
surface. After completion of the expansion process the
pig 5 may be pulled up to surface by the vent line and a
coiled kill and/or service line (not shown) may be
lowered into the expanded tubing 4 to facilitate
injection of kill and/or treatment fluids towards the
hydrocarbon f'luid inflow zone which is normally be done
via the annulus between the production tubing and the
well casing. However, if the tubing 4 is expanded to a
smaller diameter then the residual annular space between
the casing 2 and expanded tubing 4 can be used for
venting of fluids during the expansion process and for
injection of fluids during the production process, in
which case there is no need for using a vent line 8 and
kill and/or s.ervice lines.
In conventional wells it is often necessary to use a
production tubing having an outer diameter which is less
than 50% of the inner diameter of the well casing to
enable a smooth insertion of the tubing even if the well
is deviated and the casing has an irregular inner
surface. Therefore it is apparent that the in-situ tubing
expansion method according to the present invention
enhances an efficient use of the wellbore.
It will be understood that instead of moving the
expansion mar.Ldrel through the tubing by means of
hydraulic pressure, the mandrel can also be pulled
through the tubing by means of a cable or pushed through
the tubing by means of pipe string or rod.
The method according to the invention can also be
used to expand tubings that are used outside a wellbore,
for example to expand oilfield tubulars at surface


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WO 98/00626 PCT/EP97/03489
- 10 -
facilities or to expand a tubing inside an existing
tubing which has been damaged or corroded.
The invention will now be further described on the
basis of the following comparative experiments.
Experiment 1
An expansion mandrel having a conical ceramic surface
(semi top angle A of cone = 20 ) was moved through a
conventional oil field tubular, known as casing grade L80
13% Cr, which is a widely used casing type, having an
initial outer diameter of 101.6 mm (4"), an initial wall
thickness of 5.75 mm, a burst pressure of 850 bar and a
strain hardening exponent n = 0.075. The expansion
mandrel was designed such that the outer diameter of the
expanded tubular would be 127 mm, so that the increase in
diameter would be 20%. The tubular burst during the
expansion process. Analysis showed that the ductility
limit of the material had been exceeded so that ductile
fracturing occurred.
Experiment 2
An experiment was carried out with a coiled tubing of
the type QT-800 which is increasingly used as a pro-
duction tubing in oil or gas wells. The tubing had an
initial outer diameter of 60.3 mm, a wall thickness of
5.15 mm, a burst pressure of 800 bar and a strain
hardening exponent n= 0.14. An expansion mandrel was
moved through the tubing which mandrel comprised a
conical ceramic surface such that the semi top angle A of
a cone enveloping the conical surface was 5 and which
was designed such that the outer diameter of the expanded
tubing would be 73 mm (increase of about 210). This
tubing burst during the expansion process. Analysis
revealed that due to high friction forces the expansion


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pressure had exceeded the burst pressure of the pipe
during the expansion process.
Experiment 3
An experiment was carried out with a seemless pipe
made of a formable steel grade known as ASTM
A 106 Grade B. The pipe had an initial outer diameter of
101.6 mm (4"), an initial wall thickness of 5.75 mm and a
strain hardening exponent n = 0.175.
An expansion mandrel was pumped through the pipe,
which mandrel comprised a ceramic conical surface such
that the semi top angle A of a cone enveloping the
conical surface was 20 and such that the outer diameter
of the expanded pipe was 127 mm (5") and the outer
diameter incileased by 21%.
The pipe was expanded successfully and the hydraulic
pressure exerted to the mandrel to move the mandrel
through the pipe was between 275 and 300 bar. The burst
pressure of the expanded pipe was between 520 and
530 bar.

Representative Drawing
A single figure which represents the drawing illustrating the invention.
Administrative Status

For a clearer understanding of the status of the application/patent presented on this page, the site Disclaimer , as well as the definitions for Patent , Administrative Status , Maintenance Fee  and Payment History  should be consulted.

Administrative Status

Title Date
Forecasted Issue Date 2007-11-27
(86) PCT Filing Date 1997-06-30
(87) PCT Publication Date 1998-01-08
(85) National Entry 1998-12-29
Examination Requested 2002-04-09
(45) Issued 2007-11-27
Expired 2017-06-30

Abandonment History

There is no abandonment history.

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Registration of a document - section 124 $100.00 1998-12-29
Application Fee $300.00 1998-12-29
Maintenance Fee - Application - New Act 2 1999-06-30 $100.00 1999-05-03
Maintenance Fee - Application - New Act 3 2000-06-30 $100.00 2000-05-04
Maintenance Fee - Application - New Act 4 2001-07-02 $100.00 2001-04-27
Request for Examination $400.00 2002-04-09
Maintenance Fee - Application - New Act 5 2002-07-01 $150.00 2002-04-30
Maintenance Fee - Application - New Act 6 2003-06-30 $150.00 2003-04-23
Maintenance Fee - Application - New Act 7 2004-06-30 $200.00 2004-03-30
Maintenance Fee - Application - New Act 8 2005-06-30 $200.00 2005-04-03
Maintenance Fee - Application - New Act 9 2006-06-30 $200.00 2006-05-09
Maintenance Fee - Application - New Act 10 2007-07-02 $250.00 2007-04-20
Final Fee $300.00 2007-09-12
Maintenance Fee - Patent - New Act 11 2008-06-30 $250.00 2008-05-13
Maintenance Fee - Patent - New Act 12 2009-06-30 $250.00 2009-05-12
Maintenance Fee - Patent - New Act 13 2010-06-30 $250.00 2010-05-13
Maintenance Fee - Patent - New Act 14 2011-06-30 $250.00 2011-05-19
Maintenance Fee - Patent - New Act 15 2012-07-02 $450.00 2012-05-22
Maintenance Fee - Patent - New Act 16 2013-07-02 $450.00 2013-05-08
Maintenance Fee - Patent - New Act 17 2014-06-30 $450.00 2014-05-15
Maintenance Fee - Patent - New Act 18 2015-06-30 $450.00 2015-06-10
Maintenance Fee - Patent - New Act 19 2016-06-30 $450.00 2016-06-08
Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
SHELL CANADA LIMITED
Past Owners on Record
DONNELLY, MARTIN
FAURE, ALBAN MICHEL
LOHBECK, WILHELMUS CHRISTIANUS MARIA
MARKETZ, FRANZ
STEWART, ROBERT BRUCE
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Abstract 1998-12-29 1 64
Representative Drawing 1999-04-06 1 13
Description 1998-12-29 12 458
Claims 1998-12-29 3 121
Drawings 1998-12-29 1 33
Cover Page 1999-04-06 1 46
Description 2004-11-08 13 471
Claims 2004-11-08 3 113
Representative Drawing 2007-10-26 1 15
Cover Page 2007-10-26 1 47
Correspondence 1998-12-29 4 219
Correspondence 1999-03-16 1 53
PCT 1998-12-29 20 738
Assignment 1998-12-29 3 166
Prosecution-Amendment 2002-04-09 1 53
Prosecution-Amendment 2004-05-07 3 115
Prosecution-Amendment 2004-11-08 11 427
Prosecution-Amendment 2005-11-02 2 106
Prosecution-Amendment 2006-05-02 3 105
Correspondence 2007-09-12 1 37