U.S. patent application number 10/538330 was filed with the patent office on 2007-01-18 for cable duct device in a swelling packer.
Invention is credited to Rune Freyer.
Application Number | 20070012436 10/538330 |
Document ID | / |
Family ID | 19914267 |
Filed Date | 2007-01-18 |
United States Patent
Application |
20070012436 |
Kind Code |
A1 |
Freyer; Rune |
January 18, 2007 |
Cable duct device in a swelling packer
Abstract
A cable duct device in a swellable packer (1) of the kind in
which the packer (1) is adapted to be able of sealing an annulus
(3), and in which the swellable packer (1) is provided with at
least one opening (6) therethrough adapted to constitute a duct for
a cable (12).
Inventors: |
Freyer; Rune; (Stavanger,
NO) |
Correspondence
Address: |
ANDRUS, SCEALES, STARKE & SAWALL, LLP
100 EAST WISCONSIN AVENUE, SUITE 1100
MILWAUKEE
WI
53202
US
|
Family ID: |
19914267 |
Appl. No.: |
10/538330 |
Filed: |
December 9, 2003 |
PCT Filed: |
December 9, 2003 |
PCT NO: |
PCT/NO03/00410 |
371 Date: |
May 18, 2006 |
Current U.S.
Class: |
166/179 ;
166/65.1 |
Current CPC
Class: |
E21B 17/003 20130101;
E21B 33/12 20130101; E21B 23/06 20130101; E21B 33/127 20130101 |
Class at
Publication: |
166/179 ;
166/065.1 |
International
Class: |
E21B 33/12 20060101
E21B033/12 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 10, 2002 |
NO |
20025911 |
Claims
1. A cable duct device in a swellable packer (1) of the kind in
which the packer (1) is adapted for sealing an annulus (3),
characterized in that the swellable packer (1) is provided with at
least one through-going opening (6) adapted to constitute a duct
for a cable or pipe (12).
2. Device according to claim 1, characterized in that the
through-going opening (6) encloses the cable (12) both prior to and
after the swelling has occurred in the swellable packer (1).
3. Device according to one or more of the preceding claims,
characterized in that in its longitudinal extension the
through-going opening (6) may have any configuration.
4. Device according to one or more of the preceding claims,
characterized in that the cross section of through-going opening
(6) may have any configuration.
5. Device according to claim 1, characterized in that a cable or
pipe (12) is situated on the inside of the packer (1) within a
longitudinal recess in the outer shell of the production tubing
(2).
Description
[0001] This invention relates to a cable duct in a swelling packer.
More exactly it concerns a cable duct in a swelling packer adapted
to seal an annulus between a production tubing and a casing, for
example, or between a production tubing and the well formation in a
well.
[0002] During the completion of a well, in particular a petroleum
well, by which the well is prepared for production, a cable is
usually arranged in the well parallel to production tubing. The
cable is protectively arranged on the outside of the production
tubing.
[0003] In this context a cable is intended to be any kind of cable
or pipe, for example comprising electric lines, optical fibres,
pipe lines for pressurized fluids or injection fluids, or
combinations thereof. The cable may be adapted to conduct signals,
supply of energy and chemicals between the surface and the
well.
[0004] The term production tubing is used to illustrate the pipe
enclosed by the packer. However, the packer is suitable to seal
around any longitudinal body as well.
[0005] Due to technical conditions of the formation it may be
necessary to provide one or more packers along the production
tubing in its longitudinal extension to be able of sectioning the
annulus encircling the production tubing.
[0006] According to the prior art, inflatable or mechanical
expandable packers are used for this purpose. A mechanical
expandable packer comprises a flexible material expanding against
the casing or the walls of the formation when compressed in the
axial direction of the well.
[0007] NO 20004509 discloses a swellable packer swelling in volume
by the influence from the hydrocarbons of the well, whereby it is
sealing against the casing or the walls of the formation.
[0008] According to prior art, it has been common to provide the
packers with a cable extending through the packer and in which the
cable at its end portions on the opposite sides of the packer is
provided with connectors for the connection of the cable extending
along the production tubing. It is obvious that the connectors of
this kind may involve malfunctions, for example in the form of
leakage of the pressurized fluids, bad electric contact or
penetration of the formation fluids into the connectors. Thus, it
is desirable to arrange whole lengths of the cable along the
production tubing without having to join the cable at each
packer.
[0009] U.S. Pat. No. 6,173,788 discloses a mechanical compressible
packer provided with an outer longitudinal slot in which a cable
may be arranged. When the packer is compressed and squeezed against
the casing, the packer material is brought to squeeze sealingly
around the cable. By being situated outside of the packer the cable
is relatively poorly protected during the insertion of the
production tubing into the well. Obviously, the cable is also
subjected to relatively great loads during the mechanical
compression. The use of mechanical compressible packers has proved
to be unsuitable during the sealing against a well formation as the
relative expansion of the packers are insufficient.
[0010] The object of the invention is to remedy the disadvantages
of the prior art.
[0011] According to the invention the object is obtained by means
of the features indicated in the description below and the
accompanying patent claims.
[0012] A packer enclosing a production tubing and being formed from
a swellable material is provided with a longitudinal opening
therethrough. The opening is adapted to constitute a cable duct.
Advantageously, the through-going opening is arranged relatively
close to the tubing surface outside of the production tubing. The
cross section of the through-going opening may exhibit any
geometrical form such as circular or oval. In its longitudinal
extension the opening may be straight or have another
configuration, for example S-formed or helical.
[0013] If desirable the packer may be provided with a slit
protruding from the outer circumference of the packer and into the
through-going opening to facilitate placing of the cable in the
through-going opening during the assembling work.
[0014] When the cable shall be arranged along the production
tubing, it is unnecessary to join the cable at the packers. Thus,
the cable extends protected in a manner known per se along the
production tubing and continues in a protected manner within the
through-going opening in the packer to the opposite end portion of
the packer, from where it again extends protected along the
production tubing.
[0015] After the production tubing is displaced into the well and
the swellable material has obtained contact with the
swell-activating material, the volume of the packer increases,
whereby the packer expands and sealingly encloses the cable and
seals against casing or the formation of the well.
[0016] A non-limiting example of a preferred embodiment is
described hereinafter which is illustrated in the accompanying
drawing, wherein:
[0017] FIG. 1 shows in section a packer having two cables arranged
therein during insertion into a casing;
[0018] FIG. 2 shows a packer having one cable arranged therein
after the material of the packer has swollen sufficiently so as the
packer seals around the cable and against the casing;
[0019] FIG. 3 shows a section view along I-I in FIG. 1;
[0020] FIG. 4 shows a section view along II-II in FIG. 2; and
[0021] FIG. 5 shows a section view along IIa-IIa in FIG. 2.
[0022] In the drawings the reference numeral 1 denotes a packer
manufactured from a swellable material, see below. The packer 1
encircles a production tubing 2 and is adapted to be able of
sealing an annulus 3 between the production tubing 2 and the shell
surface inside of a casing 4.
[0023] In its longitudinal extension the packer 1 is provided with
an opening therethrough which is preferentially arranged relatively
close to the shell surface outside of the production tubing 2.
[0024] Between the cylindrical surface 8 outside of the packer 1
and the through-going opening 6 there is provided a slit 10.
[0025] A cable 12 extends through the through-going opening 6.
[0026] When the cable 12 shall be arranged along the production
tubing 2, see FIG. 3, the cable 12 extends along the shell outside
of the production tubing 2, in which it is covered by a protection
(not showed) according to prior art.
[0027] At the packer 1 the cable 12 extends into the through-going
opening 6, in which the material of the packer 1 protects it. As
the through-going opening 6 is situated close to production tubing
2, the cable 12 is relatively well protected also at the inlet and
outlet of the through-going opening 6.
[0028] When the production tubing 2 along with packer 1 and cable
12 are situated in the well, the packer swells and seals the
annulus 3 by contacting a swell-activating material which may be of
water or hydrocarbons, for example, depending on the material from
which the plug is formed.
[0029] By swelling in hydrocarbons the packer 1 may be manufactured
from a rubber or rubber-like material selected from the group
comprising EPDM, styrene-butadiene rubber, natural rubber,
ethylene-propylene monomer rubber, ethylene-vinyl acetate rubber,
hydrogenated acrylonitrile-butadiene rubber,
acrylonitrile-butadiene rubber, isoprene rubber, chloroprene rubber
and polynorbornene.
[0030] When water shall be the swell-material, the packer 1 may be
formed according to U.S. Pat. No. 4,137,970 disclosing a swellable
material casting in which the material manufactured from hydrogen
dichromat being dissolved in water is mixed into a compound of
glycerol and diethylene glycol. This compound is added a portion of
polyacrylamide and then filled into a mould.
[0031] If desirable, the swellable material may be enclosed by a
web-like material.
[0032] In an alternative embodiment the slit 10 may be situated
between the through-going opening 6 and the production tubing
2.
[0033] In a further embodiment the packer 1 may be formed without
the slit 10.
[0034] The packer 1 may be constituted by two or more segments
together encircling the production tubing 2.
[0035] In FIG. 4 an embodiment is showed in which the opening 6 in
its longitudinal extension is formed with a bend 14 to provide for
a reduced longitudinal stiffness of the cable 12.
[0036] If desirable, at least one cable 12 may be arranged on the
inside of the packer (1) in a recess in the shell surface outside
of the production tubing 2.
* * * * *