U.S. patent application number 10/592344 was filed with the patent office on 2007-07-12 for system for sealing an annular space in a wellbore.
Invention is credited to Matheus Norbertus Baaijens, Martin Gerard Bosma, Erik Kerst Cornelissen.
Application Number | 20070158060 10/592344 |
Document ID | / |
Family ID | 34930231 |
Filed Date | 2007-07-12 |
United States Patent
Application |
20070158060 |
Kind Code |
A1 |
Baaijens; Matheus Norbertus ;
et al. |
July 12, 2007 |
System for sealing an annular space in a wellbore
Abstract
A system is disclosed for sealing an annular space between a
tubular element (7) extending into a wellbore (1) and a cylindrical
wall (1b) surrounding the tubular element, wherein a control line
(18) for controlling a downhole device (12, 13, 14, 15) extends in
longitudinal direction along the tubular element. The system
comprises an annular seal layer (20) extending around the tubular
element (7), the seal layer having an inner surface provided with a
recess (40) for radially receiving the control line. The seal layer
is provided with a longitudinal slit (31) defining a pair of
opposite longitudinal edges (32, 34) which are movable relative to
each other between an open position wherein the seal layer can be
radially applied to the tubular element, and a closed position
wherein the seal layer extends around the tubular element.
Inventors: |
Baaijens; Matheus Norbertus;
(Rijswijk, NL) ; Bosma; Martin Gerard; (Rijswijk,
NL) ; Cornelissen; Erik Kerst; (Rijswijk,
NL) |
Correspondence
Address: |
SHELL OIL COMPANY
P O BOX 2463
HOUSTON
TX
772522463
US
|
Family ID: |
34930231 |
Appl. No.: |
10/592344 |
Filed: |
March 9, 2005 |
PCT Filed: |
March 9, 2005 |
PCT NO: |
PCT/EP05/51039 |
371 Date: |
September 11, 2006 |
Current U.S.
Class: |
166/65.1 ;
166/179; 166/387 |
Current CPC
Class: |
E21B 33/1208 20130101;
E21B 17/1035 20130101; E21B 17/105 20130101 |
Class at
Publication: |
166/065.1 ;
166/387; 166/179 |
International
Class: |
E21B 33/12 20060101
E21B033/12 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 11, 2004 |
EP |
04251396.0 |
Claims
1. A system for sealing an annular space between a tubular element
extending into a wellbore and a cylindrical wall surrounding the
tubular element, wherein a control line for controlling a downhole
device extends in longitudinal direction along the tubular element,
the system comprising an annular seal layer extending around the
tubular element, the seal layer having an inner surface provided
with a recess for radially receiving the control line, the seal
layer being provided with a longitudinal slit defining a pair of
opposite longitudinal edges which are movable relative to each
other between an open position wherein the seal layer can be
radially applied to the tubular element, and a closed position
wherein the seal layer extends around the tubular element.
2. The system of claim 1, wherein said downhole device is an inflow
control device for controlling inflow of fluid from the earth
formation into the tubular element.
3. The system of claim 2, comprising a plurality of said seal
layers and a plurality of said inflow control devices, the seal
layers and the inflow control devices being arranged in alternating
order along the tubular element.
4. The system of claim 1, wherein the tubular element is assembled
from a plurality of tubular joints, and wherein the length of each
seal layer substantially corresponds to the length of the
respective tubular joint to which the seal layer is applied.
5. The system of claim 1, wherein the seal layer is formed of a
plurality of seal layer sections arranged adjacent each other.
6. The system of claim 1, wherein said cylindrical wall is the wall
of the wellbore.
7. The system o claim 1, wherein each seal layer comprises i a
material susceptible of swelling upon contact with a selected
fluid.
8. The system of claim 7, wherein the seal layer comprises an
elastomer material susceptible of swelling upon contact with water
from the earth formation.
9. The system of claim 8, wherein the seal layer comprises HNBR
elastomer.
10. The system of claim 7, wherein the seal layer comprises a
plurality of annular recesses formed at the outer surface of the
seal layer and regularly spaced in longitudinal direction.
11. The system of claim 1, further comprising fastening means for
fastening the seal layer in the closed position thereof to the
tubular element.
12. The system of claim 1, wherein a cover member covers the
control line and wherein the recess is adapted to radially receive
the cover member.
13. (canceled)
Description
[0001] The present invention relates to a system for sealing an
annular space between a tubular element extending into a wellbore
and a cylindrical wall surrounding the tubular element, wherein a
control line for controlling a downhole device extends in
longitudinal direction along the tubular element. In the field of
hydrocarbon fluid production from a wellbore it is generally
required to seal the annular space formed between a production
conduit extending into the wellbore and a surrounding casing or
liner, or between the casing or liner and the wellbore wall. In
such applications many times one or more control lines for power
transmission or signal transmission extend through the annular
space. Various packers have been applied to provide such sealing
functionality. Some of these have terminal connections at either
end for connecting the control lines to the packers. Although such
packers may provide adequate sealing capability, it has been
experienced that assembly of the packers and control lines to the
tubular element at a well site can be difficult.
[0002] U.S. Pat. No. 6,173,788 discloses a packer for sealing an
annular space between a tubular element extending into a wellbore
and a wellbore casing, wherein a control line for controlling a
downhole device extends in longitudinal direction through a recess
formed in the outer surface of the packer. It is a drawback of the
known system that the control line needs to involve bends at both
ends of the packer since the recess is radially displaced from the
outer surface of the tubular element. Another drawback of the known
system occurs if the tubular element is provided with a plurality
of the known packers mutually spaced along the tubular element.
Generally such packers are pre-assembled to respective portions of
the tubular element, termed "subs", which are to be connected to
adjacent portions of the tubular element by threaded connections.
As a result, upon assembly of the tubular element, it may occur
that the recesses of the respective packers become non-aligned.
[0003] It is an object of the invention to provide an improved
system for sealing an annular space between a tubular element
extending into a wellbore and a cylindrical wall surrounding the
tubular element, which system overcomes the drawbacks of the prior
art.
[0004] In accordance with the invention there is provided a system
for sealing an annular space between a tubular element extending
into a wellbore and a cylindrical wall surrounding the tubular
element, wherein a control line for controlling a downhole device
extends in longitudinal direction along the tubular element, the
system comprising an annular seal layer extending around the
tubular element, the seal layer having an inner surface provided
with a recess for radially receiving the control line, the seal
layer being provided with a longitudinal slit defining a pair of
opposite longitudinal edges which are movable relative to each
other between an open position wherein the seal layer can be
radially applied to the tubular element, and a closed position
wherein the seal layer extends around the tubular element.
[0005] It is thereby achieved that the control line can be extended
along the tubular element before the seal layer is radially applied
to the tubular element thereby obviating the need to include bends
in the control line. In case the tubular element is provided with a
plurality of seal layers, it is furthermore achieved that the seal
layers can be assembled to the tubular element such that the
recesses of the respective seal layers are suitably aligned with
the control line.
[0006] It is to be understood that the control line can function to
transmit signals to or from the downhole device, for example to
actively control the downhole device or to transmit measured
signals, or to transmit power to or from the downhole device.
[0007] Preferably the system further comprises fastening means for
fastening the seal layer in the closed position thereof to the
tubular element.
[0008] The system of the invention can suitably be applied in
combination with an inflow control device for controlling inflow of
fluid from the earth formation into the tubular element, wherein
the control line is arranged to control the inflow control
device.
[0009] Suitably each seal layer includes a material susceptible of
swelling upon contact with a selected fluid. Thus the seal layer is
activated by contact with the selected fluid (for example water or
hydrocarbon fluid), which implies that it is no longer required to
activate the seal layer by mechanical or hydraulic means. This is
an important advantage since such swelling seal layers can be made
significantly longer than conventional packers.
[0010] In a preferred embodiment the system of the invention
includes a plurality of said seal layers and a plurality of said
inflow control devices, the seal layers and the inflow control
devices being arranged in alternating order along the tubular
element. The annular space is thereby divided into a number of
compartments whereby cross-flow of fluid between different
compartments is substantially prevented, and inflow of formation
fluid from each compartment into the tubular element is controlled
by the respective inflow control device in communication with the
compartment.
[0011] In order to prevent or reduce formation water bypassing each
seal layer through the rock formation opposite the seal layer, it
is preferred that the seal layer is significantly longer than a
conventional packer. For example, in a preferred embodiment the
length of the seal layer substantially corresponds to the length of
the respective tubular joint to which the seal layer is applied. In
this respect it is to be understood that the seal layer suitably is
assembled from a plurality of short seal layer sections positioned
adjacent each other along the tubular joint. Seal layer sections
having a length of between 0.5-2.0 meter, for example about 1
meter, allow convenient handling on the drilling rig floor.
[0012] The invention will be described in more detail hereinafter
by way of example, with reference to the accompanying drawings in
which:
[0013] FIG. 1 schematically shows a wellbore in which an embodiment
of a conduit and seal layer used in the method of the invention is
applied;
[0014] FIG. 2A schematically shows a cross-sectional view of the
conduit of FIG. 1;
[0015] FIG. 2B schematically shows the seal layer before
application to the conduit;
[0016] FIG. 3 schematically shows a longitudinal section of the
seal layer when applied to the conduit;
[0017] FIG. 4 schematically shows a longitudinal section of seal
layer when applied to the conduit; and
[0018] FIG. 5 schematically shows detail A of FIG. 4.
[0019] In the drawings like reference numerals relate to like
components.
[0020] Referring to FIG. 1 there is shown a wellbore 1 formed in an
earth formation 2 for the production of hydrocarbon fluid, the
wellbore 1 having a substantially vertical upper section 1a and a
substantially horizontal lower section 1b extending into a zone 3
of the earth formation from which hydrocarbon fluid is to be
produced. The earth formation zone 3 is fractured whereby there is
a risk that water from other formation zones (not shown) enters the
lower wellbore section 1b via fractures in formation zone 3. The
upper wellbore section 1a is provided with a casing 4 cemented in
the wellbore by a layer of cement 5, and a wellhead 6 is arranged
on top of the wellbore 1 at surface 7. A production liner 7 extends
from the lower end part of the casing 4 into the substantially
horizontal wellbore section 1b. A production tubing 9 provides
fluid communication between the wellhead 6 and the production liner
7, the production tubing 9 being suitably sealed to the production
liner 7 by packer 10.
[0021] The production liner 7 is provided with a plurality of
inflow control devices in the form of inflow control valves 12, 13,
14, 15 spaced along the length of the liner 7. Each inflow control
valve 12, 13, 14, 15 is electrically connected to a control center
16 at surface via a set of control lines 18 extending along the
outer surface of the production liner 7 and the inner surface of
the casing 4, so as to allow each inflow control valve 12, 13, 14,
15 to be opened or closed from the control center 16.
[0022] A plurality of seal layers 20, 22, 24, 26 is arranged in the
annular space 28 between the production liner 7 and the wall of
wellbore section 1b, wherein the seal layers 20, 22, 24, 26 and the
inflow control valves 12, 13, 14, 15 are arranged in alternating
order along the production liner 7. Each seal layer 20, 22, 24, 26
includes a material susceptible of swelling upon contact with water
from a water-bearing layer of the earth formation 2, such material
preferably being HNBR elastomer.
[0023] Referring to FIGS. 2A and 2B there is shown a cross-section
of the production liner 7 and the seal layer 20 before application
of the seal layer to the production liner 7. The set of control
lines 18 is enclosed by a cover member 30 which is fastened to the
outer surface of the production liner 7 by suitable fastening means
(not shown). The seal layer 20 has a longitudinal slit 31 defining
a pair of opposite longitudinal edges 32, 34 allowing the seal
layer 20 to be movable between an open position (as shown in FIG.
2) in which said edges 32, 34 are displaced from each other so as
to allow the seal layer 20 to be radially applied in the direction
of arrow 35 to the production liner 7, and a closed position (as
shown in FIG. 3) in which said edges 32, 34 are located adjacent
each other so as to allow the seal layer 20 to substantially
enclose the production liner 7. Furthermore, the seal layer 20 is
provided with pairs of bores 36, 38 spaced at regular longitudinal
distances along the seal layer 20. The bores 36, 38 of each pair
are formed at the respective longitudinal edges 32, 34, and are
formed so as to allow a bolt (referred to hereinafter) to be
extended through the aligned bores 36, 38 in order to fasten the
seal layer 20 to the production liner 7. The seal layer 20 is
provided with a longitudinal recess 40 formed at the inner surface
thereof for accommodating the set of control lines 18 and the cover
member 30.
[0024] In FIG. 3 are shown the production liner 7 and the seal
layer 20 after the seal layer 20 has been radially applied to the
production liner 7 so as to enclose the production liner 7. The
seal layer 20 is clamped to the conduit by a plurality of bolt/nut
assemblies 42, each bolt/nut assembly 42 extending through a
corresponding pair of the bores 36, 38.
[0025] Referring to FIGS. 4 and 5 there is shown the seal layer 20
and the production liner 7 in longitudinal section. The production
liner 7 is assembled from a number of tubular joints 44 having a
standard length of about 10 m (30 ft), whereby each seal layer 20,
22, 24, 26 extends substantially the full length of the respective
tubular joint 44 to which the seal layer 20 is applied. Each such
joint 44 is provided with respective connector portions 48 at
opposite ends thereof for interconnecting the various joints 44.
The outer surface of the annular seal layer 20 is provided with a
plurality of annular recesses 46 regularly spaced along the length
of the seal layer 20.
[0026] During normal operation, the production liner 7 is assembled
from the respective tubular joints 44 and from respective short
sections of tubular element (termed "subs"; not shown) which
include the respective control valves 12, 13, 14, 15. Assembly
occurs at the well site in progression with lowering of the
production liner 7 into the wellbore 1. The set of control lines 18
together with the cover member 30 is fed to the production liner 7,
and fixedly connected thereto, simultaneously with lowering of the
production liner 7 into the wellbore 1. Each seal layer 20, 22, 24,
26 is then radially applied to the production liner 7 at the
desired location thereof in a manner that the recess 40 encloses
the cover member 30 (and hence the control lines 18). The seal
layer 20 is then moved to its closed position so as to enclose the
tubular joint 44, and fixed to the tubular joint 20 by fastening
the bolt/nut assemblies 42 extending through the respective pairs
of bores 36, 38. The other seal layers 22, 24, 26 are assembled to
the respective tubular joints 44 in a similar manner. The
production liner 7 is installed in the wellbore 1 such that the
seal layers 20, 22; 24, 26 and the inflow control valves 12, 13,
14, 15 are located in the earth formation zone 3 containing
hydrocarbon fluid.
[0027] After the wellbore 1 has been suitably completed,
hydrocarbon fluid is allowed to flow from earth formation zone 3
into the wellbore section 1a and from there via the inflow control
valves 12, 13, 14, 15 into the production liner 7 and the
production tubing 9. In the event that formation water enters the
annular space between the production liner 7 and the wellbore wall,
one or more of the seal layers 20, 22, 24, 26 which become into
contact with the formation water will swell until further swelling
is prevented by the wellbore wall. The annular recesses 46 enlarge
the contact area of the seal layers with formation water, thereby
promoting swelling of the seal layers. Once the swollen seal layers
20, 22, 24, 26 become compressed between the production liner 7 and
the wellbore wall, further migration of the formation water through
the annular space is prevented. In order to determine the location
of water inflow, a test is carried by successively opening and/or
closing the inflow control valves 12, 13, 14, 15 and simultaneously
measuring the inflow of formation water. The location of inflow is
determined from an observed reduced (or eliminated) inflow of
formation water as a result of closing of one or more specific
inflow control valves 12, 13, 14, 15. Once the location of water
inflow has been determined, one or more of the inflow control
valve(s) 12, 13, 14, 15 at the location of inflow are closed so
that inflow of formation water into the production liner 7 is
thereby eliminated.
[0028] Swelling of each seal layer 20, 22, 24, 26 also results in
adequate sealing of the seal layer against the production liner 7
and the cover member 30 so as to prevent fluid migration between
the seal layer and the production liner or the cover member 30.
[0029] Instead of allowing the seal layer to swell by virtue of
contact with water from the earth formation, such swelling can be
triggered by bringing the seal layer into contact with water-base
wellbore fluid pumped into the wellbore.
[0030] Furthermore, the seal layer can be made of a material
susceptible of swelling upon contact with hydrocarbon fluid, such
as crude oil or diesel. In such application the seal layer can be
induced to swell upon contact with hydrocarbon fluid produced from
the wellbore. Alternatively the seal layer can be induced to swell
by pumping hydrocarbon fluid, such as diesel or crude oil, into the
wellbore. The latter procedure has the advantage that premature
swelling of the seal layer during lowering of the tubular element
into the wellbore, is prevented.
[0031] Also, a hybrid system can be applied including seal layer
sections susceptible of swelling upon contact with hydrocarbon
fluid, and seal layer sections susceptible of swelling upon contact
with water from the earth formation.
* * * * *