U.S. patent application number 09/771005 was filed with the patent office on 2001-06-07 for method of creating a wellbore in an underground formation.
Invention is credited to Coon, Robert Joe, Frank, Timothy John, Martin, David.
Application Number | 20010002626 09/771005 |
Document ID | / |
Family ID | 23113535 |
Filed Date | 2001-06-07 |
United States Patent
Application |
20010002626 |
Kind Code |
A1 |
Frank, Timothy John ; et
al. |
June 7, 2001 |
Method of creating a wellbore in an underground formation
Abstract
A method of creating a wellbore in an underground formation
comprising drilling a borehole in the underground formation using a
drilling tubular, capable of being expanded, to which a downhole
motor driving a drill bit has been connected, and, after drilling
to the desired casing setting depth, expanding the drilling tubular
into place to line the borehole by applying a radial load to the
drilling tubular and removing said load from the drilling
tubular.
Inventors: |
Frank, Timothy John;
(Houston, TX) ; Coon, Robert Joe; (Houston,
TX) ; Martin, David; (AB Rijswijk, NL) |
Correspondence
Address: |
Beverlee G. Steinberg
Shell Oil Company
Intellectual Property
P.O. Box 2463
Houston
TX
77252-2463
US
|
Family ID: |
23113535 |
Appl. No.: |
09/771005 |
Filed: |
January 26, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09771005 |
Jan 26, 2001 |
|
|
|
09289882 |
Apr 9, 1999 |
|
|
|
Current U.S.
Class: |
175/57 ; 166/207;
175/171; 175/320 |
Current CPC
Class: |
E21B 17/20 20130101;
E21B 33/14 20130101; E21B 29/10 20130101; E21B 7/20 20130101; E21B
43/103 20130101 |
Class at
Publication: |
175/57 ; 175/171;
175/320; 166/207 |
International
Class: |
E21B 007/00 |
Claims
I claim:
1. A method of creating a wellbore in an underground formation
comprising drilling a borehole in the underground formation using a
drilling tubular, capable of being expanded, to which a downhole
motor driving a drill bit has been connected, and, after drilling
to a desired casing setting depth, expanding the drilling tubular
into place to line the borehole by applying a radial load to the
drilling tubular and removing said load from the drilling
tubular.
2. The method of claim 1, wherein the drilling tubular is stored on
a reel before the drilling and unreeled from the reel during the
drilling.
3. The method of claim 1, wherein the material of the drilling
tubular is capable of sustaining a plastic deformation of at least
10% uniaxial strain.
4. The method of claim 1, wherein an expandable mandrel or swage
section, being an integral part of the drilling bit, is latched
with the drilling tubular and is pulled back through the drilling
tubular after drilling to the desired casing setting depth,
expanding the drilling tubular on the way out the wellbore.
5. The method of claim 1, wherein an expandable mandrel or swage
section is built on the top of the bit, latched on to the bit with
the drilling tubular and pulled back through the drilling tubular
after drilling to the desired casing setting depth, expanding the
drilling tubular on the way out the wellbore.
6. The method of claim 1, wherein after drilling to the desired
casing setting depth the drilling tubular is expanded by moving an
expansion unit through the drilling tubular from the top until the
unit reaches the bottom of the tubular, whereafter the unit latches
onto the drilling bit or device and the drilling is continued.
7. The method of claim 1, wherein a sealing material in a fluidic
state is pumped between the drilling tubular and the wellbore wall
prior to applying said radial load to the drilling tubular which
sealing material sets after the radial expansion.
8. The method of claim 7, wherein the sealing material sets by the
mechanical energy exerted to the sealing material by the radial
expansion of the drilling tubular.
9. The method of claim 7, wherein the sealing material sets by
circulating the sealing material between the drilling tubular and
the wellbore wall and putting a hardener into the sealing
material.
10. The method of claim 1, wherein a drill fluid is utilized that
can be turned into an external sealing material after the radial
expansion.
11. The method of claim 1, wherein formation flow is sealed off by
radially expanding the drilling tubular.
12. The method of claim 7, wherein the expansion mandrel is
utilized as a wiper plug for removing sealing fluid from the inside
of the drilling tubular after the expansion.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation of patent
application Ser. No. 09/289,882 filed Apr. 9, 1999.
FIELD OF THE INVENTION
[0002] The invention relates to a method of creating a wellbore in
an underground formation comprising drilling a borehole in the
underground formation using a drilling tubular, capable of being
expanded, to which a downhole motor driving a drill bit has been
connected, and, after drilling to the desired casing setting depth,
expanding the drilling tubular into place to line the borehole by
applying a radial load to the drilling tubular and removing said
load from the tubular after the expansion.
BACKGROUND OF THE INVENTION
[0003] Expansion methods and devices are disclosed in German patent
specification No. 1583992 and in U.S. Pat. Nos. 3,162,245 to Howard
et al; 3,167,122 to Lang; 3,203,483 to Vincent; 3,326,293 to
Skipper; 3,489,220 to Kinley; 3,785,193 to Kinley et al; 5,014,779
Meling et al; 5,031,699 to Artynov et al; 5,083,608 to Abdrakhmanov
et al; and 5,366,012 to Lohbeck.
[0004] 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.
[0005] 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.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a method
for expanding a solid, i.e. unslotted, tubing which requires
exertion of a 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.
[0007] There is provided a method of creating a wellbore in an
underground formation comprising drilling a borehole in the
underground formation using a drilling tubular, capable of being
expanded, to which a downhole motor driving a drill bit has been
connected, and, after drilling to the desired casing setting depth,
expanding the drilling tubular into place to line the borehole by
applying a radial load to the drilling tubular and removing the
load from the drilling tubular.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present invention will now be described, by way of
example, with reference to the accompanying drawings, in which:
[0009] FIG. 1 is a diagrammatic representation of a first
embodiment of the subject invention prior to expanding the
liner;
[0010] FIG. 2 is a diagrammatic representation of the present
invention, similar to FIG. 1, showing the expansion of the
liner;
[0011] FIG. 3 is a diagrammatic representation of a second
embodiment of the subject invention prior to expanding the liner;
and
[0012] FIG. 4 is a diagrammatic representation of the present
invention, similar to FIG. 3, showing the expansion of the
liner.
DETAILED DESCRIPTION
[0013] The method according to the invention thereto comprises the
step of moving an expansion mandrel through solid drilling tubing
thereby at least partially plastically expanding the tubing against
the borehole wall. The solid tubing, which is expanded, 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. The expansion mandrel used has a non-metallic
tapering surface along at least part of its length.
[0014] As a result of strain hardening, the tubing becomes stronger
during the expansion process. Any further increment of expansion
always requires a higher stress than for the preceding
expansion.
[0015] It has been found that the use of a formable steel grade for
the tubing, in combination with a non-metallic tapering 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.
[0016] 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.
[0017] The term formable steel grade as used in this specification
means that the tubing is able to maintain its structural integrity
while being plastically deformed into various shapes.
[0018] 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 International, Metals Park, Ohio (USA).
[0019] 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 necking 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. With
continuing loading, practically all further plastic 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.
[0020] The term ductile fracturing means that a failure occurs if
plastic deformation of a component that exhibits ductile behavior
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 fracturing
is given in the handbook Failure of Materials in Mechanical Design
by J. A. Collins, second edition, issued by John Wiley and Sons,
New York (USA) in 1993.
[0021] 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 specification, the term high-strength steel
denotes a steel with a yield strength of at least 275 MPa.
[0022] 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.
[0023] 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.
[0024] Suitable HSLA dual phase (DP) steels for use in the method
according to the invention are grades DP55 and DP60 developed by
Sollac having a tensile strength of at least 550 MPa and grades
SAFH 540 D and SAFH 590 D developed by Nippon Steel Corporation
having a tensile strength of at least 540 MPa.
[0025] Other suitable steels are the following formable
high-strength steel grades
[0026] an ASTM A106 high-strength low alloy (HSLA) seamless
pipe;
[0027] an ASTM A312 austenitic stainless steel pipe, grade TP 304
L;
[0028] an ASTM A312 austenitic stainless steel pipe, grade TP 316
L; and
[0029] a high-retained austenite high-strength hot-rolled steel
(low-alloy TRIP steel) such as grades SAFH 590 E, SAFH 690 E and
SAFH 780 E developed by Nippon Steel Corporation.
[0030] 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 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.
[0031] After the radial expansion of the drilling tubular, the
tubular serves as a liner for the borehole.
[0032] The principle behind the present invention is that by using
a one trip drilling and expandable lining system a well 10 can be
drilled and lined all in one step by radially expanding the
drilling tubular 12 after the drilling.
[0033] The system utilizes tubulars 12 that are capable of being
radially expanded, i.e. made of a formable steel grade. Therefore,
the material of the drilling tubular is advantageously capable of
sustaining a plastic deformation of at least 10% uniaxial
strain.
[0034] The low yield strength and the high ductility of the tubing
before expansion enables the use of a tubing which is reeled on a
reeling drum. Therefore the drilling tubular, is preferably stored
on a reel before the drilling and unreeled from the reel into the
borehole during the drilling.
[0035] Preferably, an expandable mandrel or swage section 14 (see
FIGS. 1 and 2) forms an integral part of downhole motor 18 and the
drilling bit 16 and is latched with the drilling tubular and is
pulled back through the latching tubular 20 after drilling to the
desired casing setting depth. The mandrel expands the drilling
tubular on its way out of the wellbore.
[0036] Alternatively, an expandable mandrel or swage section is
advantageously built on the top of the drilling bit, latched on to
it with the drilling tubular and pulled back through the drilling
tubular after drilling to the desired casing setting depth. This
movement of the mandrel expands the drilling tubular as the former
is on its way out the wellbore.
[0037] According to yet another preferred embodiment of the present
invention (see FIGS. 3 and 4) the drilling tubular 12 is expanded
after drilling to the desired casing setting depth by moving an
expansion unit 22 through it on a vent line 24 from the top until
the expansion unit reaches the bottom of the tubular. The expansion
unit can then latch onto the drilling bit 16 or device and the
drilling continued.
[0038] The expansion mandrel is suitably equipped with a series of
ceramic surfaces (not shown) which restrict frictional forces
between the mandrel and tubing during the expansion process. The
semi top angle A of the conical ceramic surface that actually
expands the tubing is advantageously about 25.degree.. 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.degree.
and 30.degree. the pipe deforms such that it obtains an S shape and
touches the tapering part of the ceramic surface essentially at the
outer tip or rim of said conical part and optionally also about
halfway the conical part.
[0039] Experiments also showed that it is beneficial that the
expanding tubing obtains an S-shape since this reduces the length
of the contact surface between the tapering part of the ceramic
surface and the tubing and thereby also reduces the amount of
friction between the expansion mandrel and the tubing.
[0040] Experiments have also shown that if said semi top angle A is
smaller than 15.degree. this results in relatively high frictional
forces between the tube and mandrel, whereas if said top angle is
larger than 30.degree. this will involve redundant plastic work due
to plastic bending of the tubing which also leads to higher heat
dissipation and to disruptions of the forward movement of the
mandrel through the tubing. Hence said semi top angle A is
preferably selected between 15.degree. and 30.degree. and should
always be between 5.degree. and 45.degree..
[0041] Experiments have also shown that the tapering part of the
expansion mandrel 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 to decrease as a result of the expansion process. The
experiments have also shown that the expansion mandrel provided
with a ceramic tapering surface could expand a tubing made of a
formable steel such that the outer tubing diameter D2 after
expansion was at least 20% larger than the outer diameter D1 of the
unexpanded tubing and that suitable formable steels are dual phase
(DP) high-strength low alloy (HSLA) steels known as DP55 and DP60;
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 TRIP steel manufactured by
the Nippon Steel Corporation.
[0042] The mandrel is suitably provided with a pair of sealing
rings (not shown) which are located at such a distance from the
conical ceramic surface that the rings face the plastically
expanded section of the tubing. The sealing rings serve to avoid
fluid, at high hydraulic pressure, being present between the
conical ceramic surface of the mandrel and the expanding tubing as
this might lead to an irregularly large expansion of the
tubing.
[0043] The expansion mandrel is suitably provided with a central
vent passage (also not shown) which is in communication with a
coiled vent line (not shown) through which fluid, displaced from
the annulus, may be vented to the surface.
[0044] Alternatively, this fluid can be forced into the formation
behind or below the expanded drilling tubular which serves now as a
liner. Depending on the situation the expansion mandrel and/or bit
can be left at the bottom of the hole, or through the use of a
retrieving head and detachable mounting the mandrel and the bit can
be retrieved and pulled back to the surface inside the newly
expanded tubular. This may be done by the vent line
[0045] A coiled kill and/or service line may be lowered into the
expanded tubing to facilitate injection of kill and/or treatment
fluids towards the hydrocarbon fluid inflow zone. This is normally
done via the annulus between the production tubing and the well
casing.
[0046] Advantageously a sealing material in a fluidic state is
pumped between the drilling tubular and the wellbore wall prior to
applying said radial load to the drilling tubular. This sealing
material sets after the radial expansion thus sealing any remaining
annular area. Preferably this sealing material sets by the
mechanical energy exerted to it by the radial expansion of the
drilling tubular.
[0047] Alternatively, the sealing material may set by circulating
it between the drilling tubular and the wellbore wall while putting
a hardener into it.
[0048] Sealing fluids and the corresponding hardeners are well
known to the person skilled in the art.
[0049] Another very much preferred possibility is the utilization
of a drilling fluid that can be turned into an external sealing
material after the radial expansion.
[0050] By radially expanding the drilling tubular the formation
flow is suitably sealed off, if necessary with the aid of a sealing
means, as mentioned hereinbefore.
[0051] After the borehole has been completed by the radial
expansion of the drilling tubular the expansion mandrel is
advantageously utilized as a wiper plug for removing any remaining
sealing fluid from the inside of the drilling tubular after the
expansion. The invention also relates to a wellbore in an
underground formation which has been created by the present
method.
[0052] The advantage of the present method is that it saves time
and allows for multiple contingency liners while minimizing loss of
hole diameter compared to conventional well construction
methods.
* * * * *