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Patent 2457307 Summary

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(12) Patent: (11) CA 2457307
(54) English Title: HYBRID COILED TUBING/FLUID PUMPING UNIT
(54) French Title: SERPENTIN/POMPE A FLUIDE HYBRIDE
Status: Expired and beyond the Period of Reversal
Bibliographic Data
(51) International Patent Classification (IPC):
  • E21B 19/22 (2006.01)
  • E21B 15/00 (2006.01)
  • E21B 21/00 (2006.01)
  • E21B 21/16 (2006.01)
  • E21B 43/16 (2006.01)
(72) Inventors :
  • COSTALL, DOUGLAS (Canada)
  • FOSTER, ROBERT JOSEPH (Canada)
(73) Owners :
  • LEADER ENERGY SERVICES LTD.
(71) Applicants :
  • LEADER ENERGY SERVICES LTD. (Canada)
(74) Agent: MOFFAT & CO.
(74) Associate agent:
(45) Issued: 2008-02-12
(22) Filed Date: 2004-03-08
(41) Open to Public Inspection: 2004-05-15
Examination requested: 2004-03-08
Availability of licence: N/A
Dedicated to the Public: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): No

(30) Application Priority Data:
Application No. Country/Territory Date
2,421,376 (Canada) 2003-03-07

Abstracts

English Abstract

Method and apparatus for servicing of a bore hole in the earth, comprising a first sub-assembly adapted for the insertion and removal of a continuous length of coiled tubing into and from the bore hole, a second sub-assembly adapted for the vaporization of liquified gas and the pumping of the resulting gas through the coiled tubing into the bore hole and a platform to support both the first and second sub-assemblies thereon.


French Abstract

La présente concerne une méthode et un appareil pour l'entretien d'un trou de forage dans le sol, comprenant un premier sous-ensemble adapté pour l'insertion et le retrait d'une longueur continue de tube spiralé dans le trou de forage, un deuxième sous-ensemble adapté pour la vaporisation de gaz liquéfié et le pompage du gaz résultant à travers le tube spiralé dans le trou de forage et une plate-forme pour soutenir à la fois les premier et second sous-ensembles.

Claims

Note: Claims are shown in the official language in which they were submitted.


THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Apparatus for the servicing of a bore hole in the earth, comprising:
a first sub-assembly adapted for the insertion and removal of a continuous
length of coiled tubing into and from said bore hole; and
a second sub-assembly adapted for the vaporization of liquified gas and the
pumping of the resulting gas through said coiled tubing into said bore hole,
said
second sub-assembly including first heat exchanger means for vaporization of
said
liquified gas, said heat exchanger means allowing heat transfer between a heat
transferring fluid and said liquified gas, and means for loading an internal
combustion
engine to produce heat within said means for loading, wherein at least a
portion of
said heat transferring fluid is circulated through said means for loading for
the transfer
of said heat to said fluid, said means for loading having a first inlet for
said heat
transferring fluid and an outlet for the discharge thereof, said means for
loading
comprising a water brake drivingly connected to said internal combustion
engine; and
platform means adapted to support said first and second sub-assemblies
thereon.
2. The apparatus of claim 1 wherein said heat transferring fluid is heated in
part
by waste heat from an internal combustion engine.
3. The apparatus of claims 1 or 2 additionally comprising a first reservoir
having
an inlet for receiving said heat transferring fluid from said outlet of said
water brake
and an outlet for the discharge of said heat transferring fluid to said first
heat
exchanger.
4. The apparatus of claim 3 including a first pump for circulating said heat
exchanging fluid through said water brake and said first heat exchanger.
5. The apparatus of claim 4 wherein said first pump has an intake in fluid
communication with said outlet of said first reservoir and a discharge in
fluid
-11-

communication with said inlet to said first heat exchanger and said first
inlet to said
water brake.
6. The apparatus of claim 5 additionally comprising a second heat exchanger
having first and second inlets and first and second outlets, said first inlet
being in fluid
communication with said internal combustion engine to receive heated coolant
therefrom, said first outlet being in fluid communication with said internal
combustion
engine for the return of said coolant thereto, said second outlet being in
fluid
communication with said inlet to said first pump and said second inlet being
in fluid
communication with an outlet of said first heat exchanger for receiving said
heat
transferring fluid therefrom.
7. The apparatus of claims 5 or 6 wherein said water brake includes one or
more
secondary inlets in fluid communication with said discharge of said first
pump, and
sized for the delivery of a reduced amount of heat transferring fluid into
said water
brake.
8. The apparatus of claim 6 including valve means disposed between said first
pump and said first inlet of said water brake, said valve being operable to
control the
flow of said heat transferring fluid through said first inlet of said water
brake.
9. The apparatus of claim 8 wherein, when said valve means are closed, heat
transferring fluid continues to be discharged in a reduced amount into said
water
brake through said secondary inlets for cooling and lubrication.
10. The apparatus of claim 8 wherein said heat transferring fluid flowing
through
said secondary inlets is directed at seals and/or bearings in said water
brake.
11. The apparatus of claim 9 including an air line for delivering pressurized
air into
said first inlet of said water brake when said valve means are closed, wherein
said
pressurized air forces said heat transferring fluid from said water brake to
substantially empty the same.
-12-

12. The apparatus of claim 11 wherein said substantially empty water brake
imposes reduced or no loading on said internal combustion engine without being
drivingly disconnected therefrom.
13. The apparatus of claims 8 or 12 including a vessel for pressurized air,
said
vessel being located above said first reservoir and having an inlet in fluid
communication therewith and an outlet for delivery of said pressurized air
through
said air line to said water brake.
14. The apparatus of claim 13 wherein said air line includes a one-way check
valve therein permitting the flow of pressurized air into said water brake but
preventing the flow of heat transferring fluid into said vessel.
15. The apparatus of any one of claims 1 to 14 including a second pump for
pumping said liquified gas through said first heat exchanger and into said
bore hole.
16. The apparatus of claim 15 including a tank for said liquified gas.
17. The apparatus of claim 16 including a third pump disposed in fluid
communication between said tank and said second pump for boosting the pressure
of said liquified gas into said second pump.
18. The apparatus of claim 17 wherein said first, second and third pumps are
hydraulically actuated.
19. The apparatus of claim 18 including a hydraulic pump for actuation of said
first,
second and third pumps.
20. The apparatus of claim 19 wherein said hydraulic pump is drivingly
connected
to said internal combustion engine.
-13-

21. The apparatus of claim 20 including a gearbox drivingly connected to said
internal combustion engine, said gearbox having two outlets, said water brake
being
drivingly connected to one of said outlets and said hydraulic motor being
drivingly
connected to the other of said outlets.
22. The apparatus of claim 21 including a third heat exchanger for
transferring
heat from hydraulic fluid circulating through said first, second and third
pumps to said
heat transferring fluid.
23. The apparatus of any one of claims 1 to 22 wherein said liquified gas is
liquified nitrogen.
24. A hybrid coiled tubing and pumping rig for servicing a well comprising:
a coiled tubing spool;
coiled tubing wound about said spool;
a coiled tubing injector for injecting said coiled tubing into said well;
a guide arch for guiding said coiled tubing into said injector;
a flameless heating unit for heating a liquified gas to produce gas, said
flameless heating unit including:
a heat exchanger for vaporizing said liquified gas by heat transfer between a
heat exchanging fluid and said liquified gas;
a source of heat for said heat exchanging fluid including a water brake
drivingly connected to a prime mover;
a first pump for pumping said heat exchanging fluid through said heat
exchanger and said water brake; and
a reservoir for said heat exchanging fluid wherein said heat exchanging fluid
is circulated from said reservoir, through said second pump, said heat
exchanger,
said water brake and back to said reservoir; and
a second pump for pumping said gas through said coiled tubing into said well
wherein said spool, injector, flameless heating unit and first pump are
supported on
a single platform for transportation and use.
-14-

25. The hybrid rig of claim 24 wherein said second pump additionally pumps
said
liquified gas through said flameless heating unit.
26. The hybrid rig of claims 24 or 25 wherein said source of heat additionally
includes a second heat exchanger for extracting heat from said prime mover's
coolant.
27. The hybrid rig of claim 26 wherein said first pump circulates at least a
portion
of said heat exchanging fluid through said water brake and another portion of
said
fluid through said second heat exchanger.
28. The hybrid rig of any one of claims 24 to 27 wherein said flameless
heating
unit additionally comprises:
a supply line providing fluid communication between said first pump and a
first
inlet into said water brake;
a valve in said supply line, said valve allowing said heat exchanging fluid to
flow into said first inlet of said water brake when open and stopping said
flow when
closed;
an airline connected to said supply line between said water brake and said
valve for the flow of pressurized air into said first inlet;
a one way check valve in said airline to prevent the reverse flow of said heat
exchanging fluid therethrough;
a return line providing fluid communication between an outlet from said water
brake and said reservoir; and
an expansion tank for said pressurized air connected above said reservoir in
fluid communication therewith, whereby opening said valve allows said heat
exchanging fluid to flow through said water brake and closing said valve
allows said
pressurized air to flow into said water brake for purging said heat exchanging
fluid
therefrom.
-15-

29. The hybrid rig of any one of claims 24 to 28 wherein said source of heat
includes a third heat exchanger for extracting heat from hydraulic fluid used
for
actuating said first and second pumps.
30. The hybrid rig of any one of claims 24 to 29 wherein said water brake
additionally comprises:
a hardened housing;
bearings;
fluid seals; and
one or more additional inlets for said heat exchanging fluid to cool said
bearings and seals, whereby said hardened housing and said fluid cooled
bearings
and seals allow said water brake to run when said valve is closed for
unloading said
prime mover without disconnecting said water brake therefrom.
31. The hybrid rig of any one of claims 24 to 30 wherein said coiled tubing is
directly coupled to said flameless heating unit.
32. The hybrid rig of any one of claims 24 to 31 wherein said liquified gas is
liquid
nitrogen.
33. The hybrid rig of any one of claims 24 to 32 wherein said heat exchanging
fluid
is water, glycol or a mixture thereof.
34. The hybrid rig of any one of claims 24 to 33 additionally comprising a
hydraulically actuated boom.
35. The hybrid rig of any one of claims 24 to 34 wherein said prime mover
provides power for actuation of said spool, tubing injector and boom.
36. A method for the servicing of a bore hole in the earth by injecting a
pressurized
gas thereinto, comprising the steps of supporting a first sub-assembly adapted
for the
insertion and removal of a continuous length of coiled tubing into and from
said bore
-16-

hole on a platform; and supporting a second sub-assembly adapted for the
vaporization of liquified gas and the pumping of the resulting gas through
said coiled
tubing to said bore on said same platform, said vaporization of said liquified
gas
comprising the additional steps of circulating said liquified gas through a
heat
exchanger in which said liquified gas is vaporized by heat transferred from a
heat
transferring fluid and heating said heat transferring fluid by the circulation
thereof
through a water brake drivingly connected to a prime mover.
-17-

Description

Note: Descriptions are shown in the official language in which they were submitted.


CA 02457307 2004-03-08
HYBRID COILED TUBING/FLUID PUMPING UNIT
Field of the Invention
The present invention relates to a coiled tubing unit for use in the servicing
of oil
and gas welis and more particularly to a unit mounted on a single mobile
platform
capable of providing both coiled tubing and pressurized fluid injection with
non-fired heat
recovery.
Background
Well bores require periodic maintenance to remove for example accumulated
sediments or for a host of other reasons well known in the industry. When
maintenance
is required, it is the usual practice to remove existing pumping equipment
from the
wellhead, and to move in a service rig to maintain control over the well
during servicing
and to inject and remove the necessary tools and eqiuipment required to
complete the
maintenance or servicing operations.
For well servicing and workovers, the use of coiled tubing is preferred.
Coiled
tubing is a single length of continuous unjointed tubing spooled onto a reel
for storage
in sufficient quantity to exceed the maximum depth of the well being serviced.
Coiled
tubing is favoured because its injection and withdrawal from the well can be
accomplished more rapidly compared to conventional jointed pipe, and it is
particularly
well suited for use in underbalanced wells. However, as with conventional
pipe, service
fluids and wire lines for downhole tools and instruments pass through the
tubing's
interior. The tubing is wound on a reel or spool mounted on a wheeled trailer
or the
flatbed of a truck for transport. The coiled tubing unit will normally also
include an
injector for insertion and removal of the tubing from the wellbore and a
guidearch which
leads the tubing into the injector.
For a typical cleanout, the tubing is injected into the well and a pressurized
fluid
is pumped through the tubing to circulate the well contents out through the
annulus
-1-

CA 02457307 2004-03-08
between the tubing and the well bore. The fluid can be a liquid but is often
an inert gas
such as air, nitrogen or carbon dioxide.
As a cleanout fluid, air has the obvious advantage that it costs nothing and
it
works. reasonably well particularly in shallow wells of less than 1200 metres
in depth.
In shallow wells, the ratio of oxygen to hydrocarbons is not critical and
there is relatively
little risk of explosion: In deeper wells however, partial pressures increase,
and. the
concentration of oxygen and its reactiveness increase sharply. This creates a
real risk
of explosion and the oxygen's reactiveness can cause sever corrosion by the
oxidation
of metallic surfaces.
Another disadvantage to the use of air is that the equipment needed to
compress
and pump it adds substantially to the weight of a coiled tubing rig. A major
issue with
coiled tubing units is the amount of coil they can carry without exceeding
load limits on
both the trailer and public roadways. So called "bob tailed" coiled tubing
units
incorporate the air compressor. The compressors typically pump 300 to 650
standard
cubic feet per minute (scfm) at a maximum pressure of approximately 2000 psi.
This is
not sufficient in itself to blow sand from deeper wells. To add more lifting
capacity, soap
is added to the air stream which produces a foam. The soap is stored in a
tank, and the
tank and compressor combined weight approximately 7500 lbs. (approximately
3400 kg),
which reduces the amount of coil the unit can carry by the same amount. This
limits
deeper well applications.
These and other factors mitigate against the use of air for deep well
applications
and favour the use of nitrogen. Nitrogen is inert at all depths and creates a
safer
working environment around hydrocarbons. Its also non-corrosive. It is pumped
at a
volume of up to 1500 scfm at pressures up 5000 psi which is sufficient to blow
sediments
from the wellbore without the need for soap. .
To complete a job using nitrogen, both a coiled tubing unit and a nitrogen
unit are
required on location. The two units are rigged together at the well site and
as the coiled
tubing is run into the well, the nitrogen is pumped through the tubing to
extrude any fluids
and/or solids accumulated in the well.
-2-

CA 02457307 2004-03-08
Nitrogen is normally stored and transported to the site as a liquid in a
pressurized
container forming part of the nitrogen rig, which also includes a tractor for
moving the rig
from job to job, a pumping unit and a heating unit to vaporize the nitrogen
prior to
injection through the coiled tubing and into the welibore. The heater is
normally an open
flame unit and by regulation it must therefore be kept at a predetermined safe
distance
from the wellhead.
The above described setup has numerous disadvantages. Most obviousiy,
operating costs for two rigs are high because of the eAra personnel, fuel and
equipment
required. There is the added pollution and cost resulting from the use of two
tractor units .
and an open flame heater. The mandated separation of the nitrogen and coiled
tubing
units greatly enlarges the footprint at the well site which sometimes
necessitates
enlarging the site. The high pressure tubing delivering the nitrogen gas to
the coiled
tubing unit is a hazard and setup and breakdown tiimes before and after the
job are
increased.
Summary of the Invention
The present invention seeks to overcome the above disadvantages by providing
a hybrid coiled tubing/fiuid pumping unit. The hybrid unit consists of a
coiled tubing reel
and injector, together with a nitrogen rig on a single platform. The nitrogen
rig must have
a non-fired heat recovery system between the pump and the coiled tubing to
vaporize
20. the nitrogen prior to injection. The term "single platform" can include
both a single
supporting surface such as a single trailer or flatbed, or two or more
supporting surfaces
that when in use can be situated close enough to one another that enlargement
of the
work site is unnecessary.
In operation, the hybrid coil tubing/nitrogen rig is driven to the well site
requiring
service. The unit has the capability of towing a pup trailer supporting the
liquid nitrogen
reservoir. Once at the site, the coiled tubing is deployed according to
standard
procedures known in the art; the tubing is delivered over a guide arch into
the injector,
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CA 02457307 2005-06-15
and the injector then inserts the tubing into the bore. If the bore is
underbalanced, a
lubricator can be used in conjunction with the injector.
The outer end of the coiled tubing can be permanently connected to the
nitrogen
rig, thus eliminating the need to connect tubing which could potentially be a
weak spot
in a high pressure line. The permanent connection also limits the amount of
high
pressure tubing exposed at the work site, making for a safer environment.
Because the
heater used to vaporize the liquid nitrogen is non-fired, it can be deployed
on the hybrid
unit imrnediately adjacent the well bore, which greatly reduces the onsite
footprint.
According to the present invention then, there is provided apparatus for the
servicing of a bore hole in the earth, comprising a first sub-assembly adapted
for the
insertion and removal of a continuous length of coiled tubing into and from
said bore
hole; and a second sub-assembly adapted for the vaporization of liquified gas
and the
pumping of the resulting gas through said coiled tubing into said bore hole
said second
sub-assembly including first heat exchanger means for vaporization of said
liquified gas,
said heat exchanger means allowing heat transfer between a heat transferring
fluid and
said liquified gas, and means for loading an internal combustion engine to
produce heat
within said means for loading, wherein at least a portion of said heat
transferring fluid is
circulated through said means for loading for the transfer of said heat to
said fluid, said
means for loading having a first inlet for said heat transferring fluid and an
outlet for the
discharge thereof; and platform means adapted to support said first and second
sub-
assemblies thereon.
According to another aspect of the present invention, there is also provided a
hybrid coiled tubing and pumping rig for servicing a well comprising a coiled
tubing spool;
coiled tubing wound about said spool; a coiled tubing injector for injecting
said
coiled tubing into said well; a guide arch for guiding said coiled tubing into
said injector;
a flameless heating unit for heating a liquified gas to produce gas, said
flameless heating
unit including a heat exchanger for vaporizing said liquified gas by heat
transfer between
a heat e:xchanging fluid and said liquified gas; a source of heat for said
heat exchanging
fluid including a water brake drivingly connected to a prime mover; a first
pump for
pumping said heat exchanging fluid through said heat exchanger and said water
brake;
-4-

CA 02457307 2005-06-15
and a reservoir for said heat exchanging fluid wherein said heat exchanging
fluid is
circulated from said reservoir, through said second pump, said heat exchanger,
said
water brake and back to said reservoir; and a second pump for pumping said gas
through said coiled tubing into said well wherein said spool, injector,
flameless heating
unit and first pump are supported on a single platform for transportation and
use.
jkccording to yet another aspect of the present invention, there is also
provided
a method for the servicing of a bore hole in the earth by injecting a
pressurized gas
thereinto, comprising the steps of supporting a first sub-assembly adapted for
the
insertion and removal of a continuous length of coiled tubing into and from
said bore
hole on a platform; and supporting a second sub-assembly adapted for the
vaporization
of liquified gas and the pumping of the resulting gas through said coiled
tubing to said
bore on said same platform, said vaporization of said liquified gas comprising
the
additional steps of circulating said liquified gas through a heat exchanger in
which said
liquifiecl gas is vaporized by heat transferred from a heat transferring fluid
and heating
said heat transferring fluid by the circulation thereof through a water brake
drivingly
connected to a prime mover.
-4a-

CA 02457307 2004-03-08
Brief Description of the Drawings
Preferred embodiments of the present invention will now be described in
greater
detail and wiil be better understood when read in conjunction with the
following drawings,
in which:
Figure 1 is a perspective, partially schematical view of a well site set up
for
servicing using conventional nitrogen and coiled tubing units;
Figure 2 is a side elevational partially schematical view of a hybrid coil
tubing/pumping unit;
Figure 3 is a top plan view of a nitrogen rig forming part of the present
invention;
Figure 4 is a side elevational view of the nitrogen rig of Figure 3;
Figure 5 is a rear elevational view of the nitrogen rig of Figure 3;
Figure 6 is a schematic flow diagram of the nitrogen rig;
Figure 7 is a hydraulic schematic of the nitrogen rig; and
Figure 8 is a pictorial representation of a water brake forming part of the
nitrogen
rig.
Detailed Description of the Preferred Embodiments
Reference is now made to the drawings. Figure 1 shows prior art rigs and the
ways these rigs are used. In particular, Figure 1 shows a typicai setup for a
coil tubirig
unit 10 and a nitrogen rig 30.
Coil tubing unit 10 is situated adjacent to wellhead 5. The rig consists of a
mobile
tractor/trailer unit 9 fitted with a spool 12 for coiled tubing 14, a boom
mounted guide
arch 16 and a tubing injector 20 that inserts and removes the coiled tubing
from the well
bore. As will be appreciated, the tubing unit is shciwn in its working
position. For
transport and storage, the boom 18 is used to withdraw the guide arch and
injector into
a stored position on top of the trailer as best seen in Figure 2
A conventional stand-alone nitrogen rig 30 includes its own tractor trailer 31
with
the trailer supporting a tank 32 for liquid nitrogen, a flame fired heater 36
for vaporizing
-5-

CA 02457307 2004-03-08
the nitrogen and a high pressure pump 44 for pumping liquid nitrogen from tank
32 into
the heater and then into and through the tubing. The pump will normally use
the tractor's
motor for power via an intervening hydraulic pump.
As seen in Figure 1, the nitrogen rig is physically separated from the coiled
tubing
unit and the wellhead by the mandated distance required by law. The two units
are
rigged together using a high pressure line 38 to deliver= pressurized gas from
the pumper
into the coiled tubing for injection down the well bore. If additional
nitrogen is needed,
rig 30 can be outfitted with a pup trailer as known in the art.
Reference is now made to Figure 2 showing the hybrid unit 50 of the present
invention which provides both tubing and pumping operations from a single
platform. In
Figure 2, like numerals have been used to identify like elements.
The hybrid unit of the present invention includes all of the components of a
conventional coiled tubing unit including spool 12, guide arch 16, injector 20
and boom
18 to deploy the arch and injector from the storage position shown in Figure 2
to the
operational position shown in Figure 1. Unlike conventional rigs, however, the
present
unit also includes its own integrated nitrogen rig or skid 40 mounted on a sub-
frame 48
that can be conveniently and securely attached to the unit's trailer in any
known fashion.
In one embodiment constructed by the applicant, rig 40 weighs approximately
2650 lbs.
(approximately 1200 kg) compared to the 7500 lb. (approximately 3400 kg)
weight of a
combined air compressor and soap tank. The nitrogen rig will be described in
greater
detail below but it generally comprises the nitrogen pump 44, a flameless heat
exchanger 46 for vaporizing the liquid nitrogen and a heat producing and
engine loading
device such as a water brake 47 used to ioad the truck's engine for increased
heat
production used to vaporize the nitrogen. Heat exchanger 46 is flameless for
safety
reasons. As aforesaid, regulations require that no flame be present within a
predetermined distance of the wellhead. By using a flameless heater, hybrid
unit 50 can
be situated immediately adjacent the well in the same manner as a conventional
coiled
tubing unit.
The nitrogen is transported to the site as a compressed liquid which must be
vaporized prior to injection into the well for clean outs. Assuming that up to
90,000 cubic
-6-

CA 02457307 2004-03-08
feet of nitrogen gas will be pumped per hour, approximately 1.7 million
British thermal
units (btu) of heat per hour will be required to vaporize this amount of
nitrogen. Some
of this heat can be obtained from the truck's engine up to approximately
250,000 btu's
with the bulk of the remaining heat being obtained fr-om water brake 47, with
perhaps
some additional heat being scavenged from the hydraulic fluid used
throughout.the unit.
Power for the hybrid rig is taken from the truck's engine. As will be known in
the
art, the truck's gearbox (not shown) will have at least two auxiliary power
take-offs. One
is used to drive the coiled tubing hydraulics including the injector and the
boom. This is
a conventional hookup and therefore will not be described in further detail.
The
gearbox's other power outlet is used to supply driving force to the nitrogen
rig through
for example a belt or chain drive 2.
The nitrogen rig includes its own gearbox 4 having two outlets 5 and 6 seen
most
clearly in Figures 3 to 5. Drive 2 is connected to gearbox 4 by a shaft 8 and
coupling 9.
Gearbox 4, which can be a John Deere FunkT"" model, distributes power between
outlets
5 and 6. Water brake 47 is mounted onto outlet 6 which couples it to the
truck's engine.
A hydraulic pump 41, such as a Kawasaki, is mounted onto outlet 5. Pump 41 is
used
to drive the skid's hydraulics which include the triplex nitrogen pump 44, a
boost pump
43 (shown schematically in Figure 6) which is sometimes used to boost pressure
to
pump 44's intake and a centrifugal pump 60 (also shown schematically in figure
6) which
circulates heated fluid through the heat exchange apparatus used to vaporize
the liquid
nitrogen as will now be described below with reference to Figure 6.
Pump 44 pumps liquid nitrogen from tank 32 through high pressure supply line
45 into heat exchanger 46. A smaller boost pump 43 between tank 32 and pump 44
is
actuated as required to ensure a continuous supply of liquid nitrogen at pump
44's intake
and to boost pressure at the intake. The liquid nitrogen is vaporized in the
heat
exchanger and the resulting gas flows through conduit 49 which can be
permanently or
semi-permanently coupled to the outer end of coiled tubing 14.
Heat exchanger 46 includes an inlet 52 for hot fluid, which can be water but
more
typically will be glycol or a water/glycol mixture, and an outlet 53 for cold
fluid. To heat
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CA 02457307 2004-03-08
the glycol, heat is derived from two principal sources, the truck's cooling
system and
water brake 47.
To maximize the production of heat from the truck engine's cooling system,
it's
preferred that the engine be fully loaded. Some of this load will come from
the engine's
peripherals such as the alternator, water pump and so forth, and some frorn
the power
required for the coiled tubing's hydraulics. These loads are not sufficient by
themselves
however to cause the engine to produce its maximum horsepower and heat output.
The
engine is therefore mechanically coupled to water brake 47 as described above
to
produce the required added load and to generate heat of its own.
Water brakes are well known in the art and therefore will not be described in
great
detail. Generally however they comprise a sealed chamber that is normally kept
full of
fluid. A plurality of radially extending, shaft mounted blades or
rotor/stators are disposed
to rotate within the chamber against the resistance of the fluid. The shaft is
rotated by
the motor being loaded. The mechanical energy from the spinning rotors is
converted
to heat energy in the fluid which is continuously circulated through the
chamber to cool
the water brake and its bearings and seals and to produce hot glycol for
circulation
through heat exchanger 46.
The present system incorporates a pump such as centrifugal pump 60 which
circulates the glycol throughout the system. The pump is connected at its
intake end to
two sources of hot glycol. The first is supply line 56 which delivers heat
extracted from
hot engine coolant circulated through hoses 57 into an engine coolant heat
exchanger
58. The second source is supply line 64 that delivers hot glycol from glycol
tank 65.
Pump 60 forces the hot glycol through a filter 66 following which the flow is
split
up to three different ways. Part of the glycol is deviated into inlet 52 of
heat exchanger
46. Another part is divided into feed line 69 that flows into water brake 47.
Feed line 69
is typically an inch in diameter but this can vary. A smaller portion is
diverted into 1/4
inch lines 71 and 72 that connect with secondary inlets such as 1/8 inch
orifices into the
water brake that divert glycol against the water brake's seals and bearings
when the
water brake runs empty as will be described below in greater detail. Glycol
entering the
-8-

CA 02457307 2004-03-08
water brake through lines 69 and 71 and 72 drains through line 75 which flows
the hot
fluid back into glycol tank 65.
The cold fluid leaving heat exchanger 46 is circulated through line 77 in
which it
can be delivered directly to engine heat exchanger 58 for recovery of waste
engine heat
prior to circulation back into pump 60. Or, if valve 80 is closed, the fluid
can be diverted
through hydraulic heat exchanger 84. This exchanger can be used to scavenge
heat
from hot hydraulic fluid from the skid's hydraulic pumps and motors circulated
through
the exchanger via inlet 85 and outlet 86.
The flow rate through heat exchanger 46 is approximately 295 gallons of glycol
per minute.
There are times when its unnecessary to operate the water brake. In
conventional systems, this requires that the gearbox be adapted to disengage
the brake
from the truck's engine. These gearboxes however are heavy and expensive. To
avoid
this, the present water brake in a preferred embodiment of the present
invention has
been adapted to run empty which otherwise would normally cause the brake and
its
seals to burn out.
In the present system, the brake's aluminum housing is hardened to 85
Rockwell,
and supply lines 71 and 72 continuously deliver a small amount of glycol to
1/8 inch
orifices which internally direct the glycol against the seals and/or bearings.
When valve
90 is closed to stop the delivery of glycol to the water brake, pressurized
air (7 to 10 psi)
from an expansion tank 94, arranged above and in fluid communication with
glycol tank
65 through a 2 inch connecting iine 97, flows through oneway check valve 98
and
through air hose 96 into line 69 to purge the fluid from the brake. Check
valve 98
prevents any reverse flow of glycol into the expansion tank when valve 90 is
open during
normal operation. Without fluid, the water brake simply spins without loading
the truck's
engine. The additional hardening of the water brake's housing and the
continuous flow
of glycol against the seals and bearings prevents burnout.
In operation, hybrid unit 50 can tow its own trailer supporting a liquid
nitrogen tank
32. At the well site, the trailer is disconnected from the iunit and
conveniently located for
connection to pump 44 and to boost pump 47 if one is needed.
-9-

CA 02457307 2004-03-08
Figure 7 is a schematic of the skid's hydraulic connections. Hydraulic fluid
from
reservoir 100 is drawn through filter 102, and is then pressurized by pump 41
for delivery
to centrifugal pump 60, boost pump 43 and triplex motor 44 through supply
lines 104,
105 and 106, respectively. Flow to boost pump 43 and motor 44 is regulated by
a
HaweT"~ valve 110 having two pressure compensated spools 111 and 112 to
maximize
flow to the boost pump at five gallons per minute and to the triplex motor at
60 gallons
per minute. Pressure compensated needle valve 118, such as a ParkerTM PMS 800,
regulates the flow of hydraulic fluid through pump 60. Any leakage from the
motors is
collected in lines 121, 122, 123 and 124 for drainage back to reservoir 101.
Return line
125 for fluid from the various pumps and motors can iriclude cooling unit 130
and a filter
132.
It is contemplated that the present rig can additionally incorporate an
exhaust gas
heat exchanger to recover even more engine waste heat for vaporizing the
nitrogen.
As will be appreciated from the foregoing, the hybrid unit is largely self-
contained,
quickly set up and broken down, occupies a small footprint, requires only one
crew, one
motor and enhances on-site safety.
The above-described embodiments of the present invention are meant to be
illustrative of preferred embodiments of the present invention and are not
intended to
limit the scope of the present invention. Various modifications, which would
be readily
apparent to one skilled in the art, are intended to be within the scope of the
present
invention. The only limitations to the scope of the present invention are set
out int the
following claims.
-10-

Representative Drawing
A single figure which represents the drawing illustrating the invention.
Administrative Status

2024-08-01:As part of the Next Generation Patents (NGP) transition, the Canadian Patents Database (CPD) now contains a more detailed Event History, which replicates the Event Log of our new back-office solution.

Please note that "Inactive:" events refers to events no longer in use in our new back-office solution.

For a clearer understanding of the status of the application/patent presented on this page, the site Disclaimer , as well as the definitions for Patent , Event History , Maintenance Fee  and Payment History  should be consulted.

Event History

Description Date
Time Limit for Reversal Expired 2014-03-10
Letter Sent 2013-03-08
Grant by Issuance 2008-02-12
Inactive: Cover page published 2008-02-11
Inactive: Final fee received 2007-11-21
Pre-grant 2007-11-21
Notice of Allowance is Issued 2007-05-23
Letter Sent 2007-05-23
Notice of Allowance is Issued 2007-05-23
Inactive: Approved for allowance (AFA) 2007-05-08
Amendment Received - Voluntary Amendment 2006-10-10
Inactive: S.30(2) Rules - Examiner requisition 2006-04-10
Inactive: IPC from MCD 2006-03-12
Amendment Received - Voluntary Amendment 2006-02-08
Letter Sent 2005-10-03
Letter Sent 2005-10-03
Inactive: Single transfer 2005-08-09
Inactive: S.30(2) Rules - Examiner requisition 2005-08-08
Inactive: S.29 Rules - Examiner requisition 2005-08-08
Amendment Received - Voluntary Amendment 2005-06-15
Letter Sent 2005-04-18
Inactive: Single transfer 2005-03-08
Inactive: S.30(2) Rules - Examiner requisition 2004-12-15
Amendment Received - Voluntary Amendment 2004-11-03
Application Published (Open to Public Inspection) 2004-05-15
Inactive: Cover page published 2004-05-14
Inactive: S.29 Rules - Examiner requisition 2004-05-03
Inactive: S.30(2) Rules - Examiner requisition 2004-05-03
Letter sent 2004-04-16
Advanced Examination Determined Compliant - paragraph 84(1)(a) of the Patent Rules 2004-04-16
Inactive: IPC assigned 2004-04-06
Inactive: First IPC assigned 2004-04-06
Inactive: IPC assigned 2004-03-24
Inactive: First IPC assigned 2004-03-24
Inactive: IPC assigned 2004-03-24
Inactive: Courtesy letter - Evidence 2004-03-16
Inactive: <RFE date> RFE removed 2004-03-15
Filing Requirements Determined Compliant 2004-03-15
Letter Sent 2004-03-15
Inactive: Filing certificate - RFE (English) 2004-03-15
Application Received - Regular National 2004-03-15
Inactive: Advanced examination (SO) fee processed 2004-03-08
Request for Examination Requirements Determined Compliant 2004-03-08
All Requirements for Examination Determined Compliant 2004-03-08

Abandonment History

There is no abandonment history.

Maintenance Fee

The last payment was received on 2007-02-26

Note : If the full payment has not been received on or before the date indicated, a further fee may be required which may be one of the following

  • the reinstatement fee;
  • the late payment fee; or
  • additional fee to reverse deemed expiry.

Please refer to the CIPO Patent Fees web page to see all current fee amounts.

Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
LEADER ENERGY SERVICES LTD.
Past Owners on Record
DOUGLAS COSTALL
ROBERT JOSEPH FOSTER
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
Documents

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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Abstract 2004-03-08 1 14
Description 2004-03-08 10 588
Claims 2004-03-08 7 293
Drawings 2004-03-08 5 195
Representative drawing 2004-03-26 1 23
Cover Page 2004-04-19 2 53
Drawings 2004-11-03 5 140
Description 2005-06-15 11 615
Claims 2005-06-15 7 254
Drawings 2005-06-15 6 101
Claims 2006-02-08 7 254
Claims 2006-10-10 7 249
Representative drawing 2007-05-08 1 14
Cover Page 2008-01-25 1 40
Acknowledgement of Request for Examination 2004-03-15 1 176
Filing Certificate (English) 2004-03-15 1 158
Request for evidence or missing transfer 2005-03-09 1 101
Courtesy - Certificate of registration (related document(s)) 2005-04-18 1 104
Courtesy - Certificate of registration (related document(s)) 2005-10-03 1 104
Courtesy - Certificate of registration (related document(s)) 2005-10-03 1 104
Reminder of maintenance fee due 2005-11-09 1 109
Commissioner's Notice - Application Found Allowable 2007-05-23 1 164
Maintenance Fee Notice 2013-04-19 1 171
Maintenance Fee Notice 2013-04-19 1 171
Correspondence 2004-03-15 1 25
Fees 2005-12-30 1 35
Fees 2007-02-26 1 60
Correspondence 2007-11-21 1 42
Fees 2008-03-10 1 56
Fees 2009-03-06 1 58
Fees 2010-03-08 1 58
Fees 2011-02-22 1 44
Fees 2012-02-09 1 45