U.S. patent application number 10/908418 was filed with the patent office on 2005-11-17 for casing degasser tool.
This patent application is currently assigned to PRESSSOL LTD.. Invention is credited to Livingstone, James I..
Application Number | 20050252661 10/908418 |
Document ID | / |
Family ID | 35452197 |
Filed Date | 2005-11-17 |
United States Patent
Application |
20050252661 |
Kind Code |
A1 |
Livingstone, James I. |
November 17, 2005 |
CASING DEGASSER TOOL
Abstract
A casing degasser tool (CDT) is provided which is adapted to be
inserted into production piping such as casing, slotted liners, or
production tubing for use during well completion. The CDT comprises
a body having a top end, a bottom end and an outer surface, at
least one sealing element surrounding a portion of the outer
surface of the body and a connection means located at or near the
top end of the body for connecting a wire line or other pulling
device to the CDT to assist in positioning the CDT within the
production piping and for pulling the CDT through the length of the
production piping. The CDT can be used when adding joints of
production piping to prevent hydrocarbons from flowing to the
surface of the well.
Inventors: |
Livingstone, James I.;
(Calgary, CA) |
Correspondence
Address: |
BENNETT JONES
C/O MS ROSEANN CALDWELL
4500 BANKERS HALL EAST
855 - 2ND STREET, SW
CALGARY
AB
T2P 4K7
CA
|
Assignee: |
PRESSSOL LTD.
8 Lake Placid Bay SE
Calgary
CA
|
Family ID: |
35452197 |
Appl. No.: |
10/908418 |
Filed: |
May 11, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60521523 |
May 13, 2004 |
|
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|
Current U.S.
Class: |
166/369 |
Current CPC
Class: |
E21B 33/126 20130101;
E21B 41/0021 20130101; E21B 34/06 20130101 |
Class at
Publication: |
166/369 |
International
Class: |
E21B 007/12 |
Claims
What is claimed is:
1. A casing degasser tool adapted to be inserted into a joint of
production piping, the production piping having an inner wall, for
preventing the flow of hydrocarbons through the production tubing
during well completion, comprising: (a) a body having a top end, a
bottom end and an outer surface; (b) at least one sealing element
surrounding the outer surface of the body; and (c) a connection
means located at or near the top end of the body for connecting a
wire line or other pulling device to the casing degasser tool;
whereby when the casing degasser tool is inserted into the
production piping, the sealing element is in frictional engagement
with the inner wall of the production piping.
2. The casing degasser tool as claimed in claim 1 wherein the
sealing element is expandable.
3. The casing degasser tool as claimed in claim 1 wherein the
sealing element comprises an inflatable ring.
4. The casing degasser tool as claimed in claim 3 wherein the
inflatable ring expands or contracts by pumping fluids into or out
of the inflatable ring.
5. The casing degasser tool as claimed in claim 1 wherein the body
further comprises an inner cavity extending through the bottom end
of the body so that the inner cavity is in fluid communication with
the production piping.
6. The casing degasser tool as claimed in claim 5 wherein the body
further comprises a pressure relief fitting having one end in fluid
communication with the inner cavity and an opposite end adapted to
be fitted to a pipe or hose for bleeding off the hydrocarbons.
7. The casing degasser tool as claimed in claim 5 wherein the body
further comprises a pressure gauge fitting having one end in fluid
communication with the inner cavity and an opposite end adapted to
be fitted to a pressure gauge for measuring downhole pressure or a
flow prover for testing well production capability.
8. A process for running joints of production piping into a
wellbore containing flowing hydrocarbons, comprising: (a)
positioning a casing degasser tool as claimed in any of claims 1 to
7 inside a first joint of production piping, the first joint of
production piping having a top end, a bottom end and an inner wall,
such that the sealing element of the casing degasser tool is in
frictional engagement with the inner wall of the first production
piping; (b) lowering the first joint of production piping into the
wellbore bottom end first; (c) adding a second joint of production
piping, the second joint of production piping having a top end, a
bottom end and an inner wall, to the first joint of production
casing by coupling the bottom end of the second joint of production
piping to the top end of the first joint of production piping with
coupling means; (d) attaching a pulling device to the connection
means of the casing degasser tool; and (e) pulling the casing
degasser tool through the top end of the first joint of production
piping, through the bottom end of the second joint of production
tubing and into the second joint of production piping, so that the
sealing element is in frictional engagement with the inner wall of
the second joint of production piping.
9. The process as claimed in claim 8 further comprising checking
the downhole pressure by means of a pressure gauge attached to the
pressure gauge fitting of the casing degasser tool.
10. The process as claimed in claim 8 further comprising bleeding
built up pressure from the wellbore by attaching a hose or pipe to
the pressure release fitting of the casing degasser tool and
allowing the hydrocarbons to flow into a flare stack, a tank or a
pit.
11. The process as claimed in claim 8 further comprising testing
well production capability by means of a flow prover attached to
the pressure gauge fitting of the casing degasser tool.
12. A process for running joints of production piping into a
wellbore containing flowing hydrocarbons, comprising: (a)
positioning a casing degasser tool as claimed in any of claims 1 to
7 inside a first joint of production piping to be lowered into the
well bore, the first joint of production piping having an inner
wall, such that the sealing element of the casing degasser tool is
in frictional engagement with the inner wall of the first
production piping; (b) lowering the first joint of production
casing into the wellbore; (c) adding additional joints of
production piping to the first joint of production piping until all
the joints of production piping have been added; (d) attaching a
pulling device to the connection means of the casing degasser tool;
and (e) pulling the casing degasser tool through the joints of
production piping to the surface of the well.
13. The process as claimed in claim 12 further comprising checking
the downhole pressure by means of a pressure gauge attached to the
pressure gauge fitting of the casing degasser tool.
14. The process as claimed in claim 12 further comprising bleeding
built up pressure from the wellbore by attaching a hose or pipe to
the pressure release fitting of the casing degasser tool and
allowing the hydrocarbons to flow into a flare stack, a tank or a
pit.
15. The process as claimed in claim 12 further comprising testing
well production capability by means of a flow prover attached to
the pressure gauge fitting of the casing degasser tool.
Description
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/521,523, filed May 13, 2004.
FIELD OF THE INVENTION
[0002] The present invention relates to an apparatus and method
useful for well completion of a wellbore containing hydrocarbons.
In particular, the present invention relates to an apparatus
adapted to be inserted into production piping, such as casing,
slotted liners, or tubing, to control the flow of fluids from the
reservoir through the production piping during well completion
operations and further relates to a process using said apparatus
for running joints of production piping into a wellbore to form a
completed well.
BACKGROUND OF INVENTION
[0003] Current technology uses kill fluids to stop the flow of
reservoir fluids (e.g. hydrocarbons) so that well completion
operations such as running production piping in the wellbore or
installing a wellhead assembly at surface can be accomplished
without the presence of hydrocarbons. Conventional kill fluids
known in the art are typically aqueous liquids such as water or
weighted fluids such as drilling mud. The kill fluid applies a
hydrostatic pressure against the reservoir fluid, which typically
is greater than the pressure exerted by the reservoir fluid
attempting to intrude into the wellbore.
[0004] This overbalanced hydrostatic pressure, however, can cause
damage to reservoirs, in particular, to reservoirs containing
swelling clays or reservoirs having a pressure well below the
hydrostatic pressure of the kill fluid being used. Hydrocarbon
reservoirs with high permeability and porosity can also be damaged
with the use of kill fluids.
[0005] The present invention provides an apparatus and method for
carrying out completion activities without the need to kill the
flow of hydrocarbons by means of kill fluids.
SUMMARY OF THE INVENTION
[0006] A casing degasser tool (CDT) is provided which is adapted to
be inserted into production piping such as casing, slotted liners,
or production tubing. One CDT embodiment comprises a body having a
top end, a bottom end and an outer surface, and at least one
expandable sealing element surrounding a portion of the outer
surface of said body. The expandable sealing element can be formed
from a material such as expandable rubber, rubber and steel,
fiberglass or other composite material, and can be expanded such
that it provides a fluid tight seal with the inside wall of the
production piping. For example, the sealing element can be an
inflatable ring wherein the inflatable ring expands or contracts by
pumping fluids into or out of the inflatable ring.
[0007] In another embodiment, the CDT comprises at least one
sealing element surrounding a portion of the outer surface of said
body, wherein each sealing element has a fixed dimension, which
dimension depends upon the inner diameter of the completion piping
for which it is designed. Thus, in this embodiment, the sealing
element dimension can vary for each type of production tubing but
will still provide a fluid tight seal when the CDT is inserted
therein. Hence, it is understood that the sealing element of the
CDT can come in different sizes to ensure that the CDT always fits
snuggly inside the production piping having a range of different
inside diameters.
[0008] The body further comprises a connection means located at or
near the top end of the body for connecting a wire line or other
pulling device to the CDT to assist in positioning the CDT within
the production piping and for pulling the CDT through the length of
the production piping.
[0009] In one embodiment, the body further comprises an inner
cavity extending through the bottom end of the body so that the
bottom end of the body is in fluid communication with the inside of
the production piping when the CDT is inserted therein. In this
embodiment, the body may further comprise a pressure relief fitting
and/or a pressure gauge fitting.
[0010] The pressure relief fitting has one end in fluid
communication with said inner cavity and an opposite end for
connecting a pipe or hose thereto to bleed off hydrocarbons to the
surface when necessary during a well completion operation. A flow
prover can also be connected to the pressure relief fitting instead
of a pipe or hose to test for well production capability at the
completion of running the production piping. The pressure relief
fitting further comprises a sealing means for keeping the pressure
relief fitting sealed until the pipe, hose or flow prover is
connected thereto.
[0011] Similarly, the pressure gauge fitting has one end in fluid
communication with said inner cavity and an opposite end for
connecting a pressure gauge or other instrumentation package
thereto for measuring downhole pressure. The pressure gauge fitting
further comprises a sealing means for keeping the pressure gauge
fitting sealed until the pressure gauge or other instrumentation
package is connected thereto.
[0012] A process of running joints of production piping into a
wellbore that contains flowing hydrocarbons, which uses the CDT of
the present invention, is also provided. The process comprises
placing the CDT inside a first joint of production piping, said
production piping having a top end and a bottom end, and lowing the
production piping into the wellbore bottom end first. The CDT is
preferably positioned near the top end of the first joint of
production piping and at least one sealing element is in frictional
engagement with the inside wall surface of the production piping to
provide a fluid tight seal.
[0013] The process further comprises adding a second joint of
production piping, said second joint of production piping also
having a top end and a bottom end, to the first joint of production
piping by coupling the bottom end of said second production piping
to the top end of the first production piping with coupling means
known in the art. A wire line or other pulling device is then
attached to the CDT by first passing it through the second joint of
production piping and then attaching it to the connection means
located at or near the top of the body of the CDT.
[0014] Finally, the CDT is pulled through the top end of the first
joint of production piping, through the bottom end of said second
joint of production piping and into the second joint of production
piping. The wire line or other pulling device that is connected to
the top end of the body of the CDT is then removed and the process
is repeated until all joints of production piping have been coupled
together.
[0015] To aid in the pulling of the CDT through the production
piping, a lubricant such as pipe thread dope may be added to the
inside surface of the production piping.
[0016] In another embodiment of the process, the CDT can simply
remain positioned in the first joint of production piping at all
times during the addition of each new joint of production piping
and the CDT pulled through all production piping at once when the
well is completed.
[0017] In one embodiment, when the running of the production piping
is complete (i.e., all of the joints of production piping have been
connected together), well production capability can be tested by
connecting a flow prover to the pressure relief fitting of the CDT.
The CDT can then be removed by means of the wire line or other
pulling device that is connected to the CDT.
[0018] In another embodiment, the process of running production
casing into wellbore further comprises periodically checking the
downhole pressure by means of a pressure gauge attached to the
pressure gauge fitting of the CDT. In another embodiment, the
process further comprises bleeding built up pressure from the
wellbore, should the downhole well pressure starts to become a
concern, by attaching a hose or pipe to the pressure release
fitting of the CDT. The pressure then can be bled down by attaching
the opposite end of the hose or pipe to a blewie line and allowing
the built up hydrocarbons in the well to flow into a flare stack, a
tank or a pit.
[0019] This invention may have one or more of the following
advantages over the use of kill fluids to stop the flow of
hydrocarbons during completion operations:
[0020] (1) time and money can be saved because there is no need to
use kill fluids;
[0021] (2) in low and under pressure reservoirs there is less
formation damage as compared to the damage caused as a result of
the hydrostatic weight of the kill fluid;
[0022] (3) in dehydrated and clay swelling reservoirs there are no
fluids to cause damage;
[0023] (4) it provides an alternative method to using a snubbing
unit;
[0024] (5) it allows reverse circulated center discharge drilled
wells to be completed without having to kill the well;
[0025] (6) wellbores can be safely bled down prior to the
installation of the wellhead without using kill fluids;
[0026] (7) well production capability can be tested by connecting a
flow prover to the pressure relief fitting at the completion of
running the production piping; and
[0027] (8) slotted casing and liners can be run into the wellbore
without the need to kill the well.
BRIEF DESCRIPTION OF DRAWINGS
[0028] FIG. 1 is a schematic of the casing degasser tool of the
present invention.
[0029] FIG. 2 is a schematic of the casing degasser tool inside a
joint of production piping.
DETAILED DESCRIPTION
[0030] FIG. 1 schematically illustrates an embodiment of the
present invention. Casing degasser tool 15 comprises a body 7
having a closed top end 2, an open bottom end 4 and an inner cavity
8. Disposed around the outside surface 13 of body 7, at or near
bottom end 4, are a plurality of sealing elements 11, formed from a
material such as rubber or the like. When casing degasser tool 15
is placed inside a joint of production piping, sealing elements 111
provide a fluid tight seal with the inside wall of the production
piping.
[0031] Sealing elements 11 may also be made of expandable rubber
and the like so that sealing element 11 can be expanded by means of
pumping fluid or air therein or by means of an electric current.
This assists in the frictional engagement of the sealing element
with the inside wall of the production piping to ensure a fluid
tight seal. Further, the sealing element can then be contracted
slightly to facilitate the pulling of the casing degasser tool 15
through the production piping.
[0032] At or near top end 2 is connection means 1 to which a wire
line or other pulling devices known in the art can be attached for
positioning the casing degasser tool 15 within the joint of
production piping and for pulling the casing degasser tool 15
through the joint of production piping.
[0033] The top end 2 of body 7 further comprises pressure relief
fitting 5 having threaded end 9, which is in fluid communication
with the inner cavity 8. Pressure relief fitting 5 comprises a
sealing means (not shown), which seals the pressure relief fitting
5 until a pipe, or hose (shown as pipe 19 in FIG. 2) is connected
to pressure relief fitting 5 by thread means. The pressure relief
fitting 5 and pipe or hose connected thereto are used to bleed off
hydrocarbons from the wellbore to the surface of the well, when
necessary during a well completion operation. It is understood that
a flow prover (not shown) or other instrumentation can also be
connected to the pressure relief fitting 5 by thread means for
testing well production capability after well completion.
[0034] Casing degasser tool 15 further comprises pressure gauge
fitting 3 having threaded end 10, which is in fluid communication
with the inner cavity 8. Pressure gauge fitting 3 comprises a
sealing means (not shown), which seals the pressure gauge fitting 3
until a pressure gauge or other instrumentation package is attached
thereto by thread means for measuring downhole pressure.
[0035] FIG. 2 schematically illustrates casing degasser tool 15
when it is situated inside production piping 21 and said production
piping 21 is situated within a wellbore. Sealing elements 111 of
casing degasser tool 15 are shown in frictional engagement with the
inside wall 23 of production piping 21 to create a tight fluid
seal. Reservoir hydrocarbons 13 are thus prevented from flowing out
of production casing 21 by sealing element 11. Further, top end 2
of casing degasser tool 15 is closed so as to prevent the flow of
hydrocarbons through the inner cavity 8 of casing degasser tool 15.
Finally, pressure gauge fitting 3 and pressure relief fitting 5 are
also in the sealed position, unless pipe, tubing, pressure gauges
and other instrumentation are connected thereto, and thus
hydrocarbons cannot escape therethrough.
[0036] A surface control system comprising a surface blowout
preventor (not shown) can also be used in combination with the
present invention. A surface blow out preventor will prevent the
flow of any hydrocarbons that may escape on the outside of the
production piping through the annulus formed between the outer wall
of the production piping and the wellbore wall during well
completion.
[0037] Once a new joint of production piping is added to existing
production piping 21, wire line 6 is fed through the new joint of
production piping and through production piping 21 and attached to
connection means 1. Casing degasser tool 15 is then pulled first
through the top of production piping 21 and then through the bottom
of the newjoint of production casing so as to position casing
degasser tool 15 preferably in the upper portion of the new piece
of production casing. It is understood that during the addition of
each joint of production casing, wire line 6 is first removed and
then reattached to pull the casing degasser tool 15 into the newly
added joint of production piping.
[0038] In the alternative, casing degasser tool 15 can remain
situated in the first joint of production piping until all
subsequent joints of production piping have been added. Wire line 6
is then threaded through all interconnected joints of production
piping and attached to connection means 1. Casing degasser tool 15
is then pulled through all joints of production piping upon well
completion.
[0039] To facilitate the movement of the casing degasser tool 15
through production piping, sealing element 11, if expandable, may
be slightly contracted to allow casing degassing tool 15 to move
more freely through the production piping. In the alternative, if
sealing element 11 is not expandable, a lubricant such as pipe
thread dope may be added to the inside surface of each joint of
production piping to facilitate the movement of the degasser tool
15 through the production piping.
[0040] Pressure of formation 27 is monitored by connecting a proper
pressure gauge (not shown) to pressure gauge fitting 3. When
necessary to bleed off pressure from formation 27, hose or pipe 19
is connected to pressure relief fitting 5 and hydrocarbons 13 are
flared through a blewie line (not shown) attached to the opposite
end of pipe 19 or put into tank or pit (not shown). In the
alternative, a flow prover (not shown) can be connected to pressure
relief fitting 5 at the completion of running the production piping
to test for well production capability.
[0041] While the foregoing is directed to one embodiment of the
present invention, other and further embodiments of the invention
may be devised without departing from the basic scope thereof. It
is intended that the appended claims cover all such modifications
and variations as fall within the true spirit and scope of the
invention.
* * * * *