U.S. patent application number 11/084863 was filed with the patent office on 2005-10-06 for method of sealing subterranean zones.
Invention is credited to Bennett, Wayne L., Herbert, Dean L..
Application Number | 20050217852 11/084863 |
Document ID | / |
Family ID | 35006111 |
Filed Date | 2005-10-06 |
United States Patent
Application |
20050217852 |
Kind Code |
A1 |
Bennett, Wayne L. ; et
al. |
October 6, 2005 |
Method of sealing subterranean zones
Abstract
A method of sealing subterranean zones is described. A first
step involves preparing a liquid slurry. A second step involves
mixing bits of rubber from recycled tires into the liquid slurry. A
third step involves pumping the liquid slurry containing the bits
of rubber down a well.
Inventors: |
Bennett, Wayne L.; (Irma,
CA) ; Herbert, Dean L.; (Edgerton, CA) |
Correspondence
Address: |
CHRISTENSEN, O'CONNOR, JOHNSON, KINDNESS, PLLC
1420 FIFTH AVENUE
SUITE 2800
SEATTLE
WA
98101-2347
US
|
Family ID: |
35006111 |
Appl. No.: |
11/084863 |
Filed: |
March 18, 2005 |
Current U.S.
Class: |
166/292 |
Current CPC
Class: |
C09K 8/508 20130101;
E21B 33/138 20130101; E21B 21/003 20130101; C09K 8/516 20130101;
C09K 8/035 20130101 |
Class at
Publication: |
166/292 |
International
Class: |
E21B 033/13 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 18, 2004 |
CA |
2,461,524 |
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A method of sealing subterranean zones, comprising the steps of:
providing bits of rubber from recycled tires; and using a liquid to
carry the bits of rubber down a well.
2. A method of sealing subterranean zones, comprising the steps of:
preparing a liquid slurry; mixing bits of rubber from recycled
tires into the liquid slurry; and pumping the liquid slurry
containing the bits of rubber down a well.
3. The method as defined in claim 2, wherein the bits of rubber are
rubber crumb bits.
4. The method as defined in claim 2, wherein the bits of rubber are
larger chopped bits of a size between 1/8 of an inch and 11/2
inches.
5. The method as defined in claim 4, wherein reinforcing fibre from
the recycled tires is mixed in with the larger chopped bits of
rubber.
6. The method as defined in claim 2, wherein the liquid slurry is a
drilling fluid.
7. The method as defined in claim 2, wherein the liquid slurry is
contains cement.
8. A method of sealing subterranean zones, comprising the steps of:
preparing a liquid slurry of drilling fluid and cement; mixing bits
of rubber from recycled tires into the liquid slurry, the bits of
rubber being a mixture of rubber crumb bits and larger chopped bits
of a size between 1/8 of an inch and 11/2 inches; and pumping the
liquid slurry containing the bits of rubber down a well under
pressure, such that the bits of rubber pack under pressure into
fractures in the subterranean zone and, when pressure is reduced,
expand.
9. The method as defined in claim 7, wherein reinforcing fibre from
the recycled tires is mixed in with the larger chopped bits of
rubber.
10. A method of sealing subterranean zones, comprising the steps
of: inserting bits of rubber from recycled tires into a well; and
pumping a liquid slurry into the well as a carrier fluid to wash
the bits of rubber down the well.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method of sealing
subterranean zones where there is loss of circulation during
drilling or a need to seal in the well during abandonment.
BACKGROUND OF THE INVENTION
[0002] U.S. Pat. No. 6,448,206 (Griffith et al 2002) relates to an
aqueous rubber latex composition and a method of using that
composition to seal subterranean zones. During drilling,
circulation of drilling fluid is sometimes interrupted when
drilling fluid is lost into fractures in subterranean zones. When
this occurs, drilling operations must be terminated until
circulation is restored. The Griffith et al patent is an example of
the sophisticated technology which has been developed to address
this problem.
SUMMARY OF THE INVENTION
[0003] The present invention relates to an alternative method of
sealing subterranean zones, which is also suitable for use in
sealing in a well which is to be abandoned.
[0004] According to the present invention there is provided a
method of sealing subterranean zones. A first step involves
providing bits of rubber from recycled tires. A second step
involves using a liquid to carry the bits of rubber down a
well.
[0005] As will hereinafter be further described, there are two ways
that this can be done. One way is to mix bits of rubber from
recycled tires into the liquid. Another way is to insert the bits
of rubber directly into the well and then use the liquid to wash
the bits of rubber down the well. Which approach is used depends
upon the requirements and limitations of the particular
application.
[0006] The method, as described above, concurrently addresses two
problems. The first problem is the sealing of subterranean zones.
The second problem is that of finding a useful end purpose for used
vehicle tires. There are mountains of used vehicle tires, which
have been collected and are awaiting recycling. The used vehicle
tires are either ground to form rubber crumb bits or chopped into
somewhat larger bits. Although one can use either the rubber crumb
bits or the larger chopped bits, a mixture of the two sizes is
preferred. The rubber crumb bits can fit into smaller spaces. The
larger chopped bits can fill larger spaces. When the bits of rubber
are placed under pressure, they compress and are forced into
fractures in the subterranean zone. When pressure is reduced, the
bits of rubber expand to fill voids and more securely engage the
fractures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] These and other features of the invention will become more
apparent from the following description in which reference is made
to the appended drawings, the drawings are for the purpose of
illustration only and are not intended to in any way limit the
scope of the invention to the particular embodiment or embodiments
shown, wherein:
[0008] FIG. 1 is a side elevation, in section, depicting the
sealing of fractures in a subterranean zone of well in accordance
with the teachings of the present method.
[0009] FIG. 2 is a side elevation, in section, depicting the
sealing in of well which is to be abandoned in accordance with the
teachings of the present method.
[0010] FIG. 3 is a side elevation, in section, depicting the
sealing in of an open hole well which is to be abandoned in
accordance with the teachings of the present method.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] The preferred method of sealing subterranean zones will now
be described with reference to FIGS. 1 through 3.
[0012] Referring to FIG. 1, a first step involves preparing a
liquid slurry 12. It is preferred that the slurry be a mixture of
drilling fluid and cement. It will be appreciated that drilling
fluid alone could be used or a liquid cement could be used alone.
In the illustrated embodiment, the mixing is taking place in the
mud tanks 14 of the drilling rig. A second step involves mixing
bits of rubber 16 from recycled tires into liquid slurry 12. It is
preferred that the bits of rubber be a mixture of rubber crumb bits
and larger chopped bits of a size between 1/8 of an inch and 11/2
inches. It will be appreciated that rubber crumb bits alone could
be used or larger chopped bits alone could be used. The rubber
crumb bits are capable of fitting into smaller spaces. The larger
chopped bits are capable of filling larger spaces. In the
illustrated embodiment, bits of rubber 16 are supplied out of a
hopper 18. A third step involves pumping liquid slurry 12
containing bits of rubber 16 down a well 20 under pressure. In the
illustrated embodiment, this is done with a high pressure pump 22.
Every drilling rig is equipped with such a high pressure pump 22.
When pumped down well 20, bits of rubber pack 16 under pressure
into fractures 24 in subterranean zone 26. When pressure is
reduced, the bits of rubber 16 expand and more effectively fill
fractures 24. It is desirable to include reinforcing fibre 28 from
the recycled tires with the larger chopped bits of rubber. The
reinforcing fibre 28 helps to bind the bits of rubber in
position.
[0013] Referring to FIG. 2, there is illustrated another
application for the method. In this application, well 20 is to be
abandoned. In such an application, liquid cement is used in liquid
slurry 12 and all of well 20 is filled. As with the first
application, bits of rubber 16 are compressed when under pressure
and expand when pressure is reduced.
[0014] Referring to FIG. 3, with open holes there is sufficient
room to modify the method somewhat. With an open hole, bits of
rubber 16 can be inserted directly into well 20. It need not be
mixed into liquid slurry 12. Liquid cement is used in liquid slurry
12 and used to push bits of rubber 16 down well 20. The process of
doing so mixes liquid slurry 12 containing cement with bits of
rubber 16. Although the end result is essentially the same,
dropping bits of rubber 16 into well 20 first is believed to result
in a greater density in the bits of rubber 16 down well 20. The
reason for this is that there are limits as to the proportion of
bits of rubber 16, which can be passed through pump 22 without
clogging pump 22.
[0015] In this patent document, the word "comprising" is used in
its non-limiting sense to mean that items following the word are
included, but items not specifically mentioned are not excluded. A
reference to an element by the indefinite article "a" does not
exclude the possibility that more than one of the element is
present, unless the context clearly requires that there be one and
only one of the elements.
[0016] It will be apparent to one skilled in the art that
modifications may be made to the illustrated embodiment without
departing from the spirit and scope of the invention as hereinafter
defined in the Claims.
* * * * *