U.S. patent application number 13/698841 was filed with the patent office on 2013-03-14 for mating unit enabling the deployment of a modular electrically driven device in a well.
The applicant listed for this patent is Philip Head. Invention is credited to Philip Head.
Application Number | 20130062050 13/698841 |
Document ID | / |
Family ID | 44992387 |
Filed Date | 2013-03-14 |
United States Patent
Application |
20130062050 |
Kind Code |
A1 |
Head; Philip |
March 14, 2013 |
MATING UNIT ENABLING THE DEPLOYMENT OF A MODULAR ELECTRICALLY
DRIVEN DEVICE IN A WELL
Abstract
An electric pump assembly is provided in a well, the pump
comprising an electric motor module having a first outer housing
and a first mating means, an electric pump module having a pump
inlet and a pump outlet, and a second outer housing and a second
mating means. In one aspect, the electric motor module and electric
pump module are capable of being reversibly joined together by the
first and second mating means, as the electric motor module
includes a first rotating member that is capable of rotating
relative to the first outer housing, and the electric pump module
includes a second rotating member that is capable of rotating
relative to the second outer housing. In this way, the first
rotating member and second rotating member can transfer torque when
the electric motor module and electric pump module are joined. In
another aspect, a flowpath is provided in each module, the
flowpaths fluidly communicating when the modules are joined.
Inventors: |
Head; Philip; (Egham,
GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Head; Philip |
Egham |
|
GB |
|
|
Family ID: |
44992387 |
Appl. No.: |
13/698841 |
Filed: |
May 19, 2011 |
PCT Filed: |
May 19, 2011 |
PCT NO: |
PCT/ZA11/00035 |
371 Date: |
November 19, 2012 |
Current U.S.
Class: |
166/105 |
Current CPC
Class: |
E21B 43/128 20130101;
F04D 13/10 20130101; E21B 17/028 20130101 |
Class at
Publication: |
166/105 |
International
Class: |
E21B 43/12 20060101
E21B043/12 |
Foreign Application Data
Date |
Code |
Application Number |
May 18, 2010 |
GB |
1008278.2 |
Oct 7, 2010 |
GB |
1016910.0 |
Claims
1. An electric pump assembly in a well, comprising an electric
motor module having an first outer housing and a first mating
means, an electric pump module having a pump inlet and a pump
outlet, a second outer housing and a second mating means, the
electric motor module and electric pump module capable of being
reversibly joined together by the first and second mating means,
the electric motor module includes a first rotating member that is
capable of rotating relative to the first outer housing, and the
electric pump module includes a second rotating member that is
capable of rotating relative to the second outer housing, such that
the first rotating member and second rotating member can transfer
torque when the electric motor module and electric pump module are
joined.
2. An assembly according to any previous claim wherein the electric
motor module is deployed on an electric cable.
3. An assembly according to claim 2, wherein a conductive member or
members of the electric cable carries both the weight of itself and
the weight of the electric motor module.
4. An assembly according to claim 2, wherein the first rotating
member and second rotating member are joined by interlocking
splines.
5. An assembly according to claim 1, comprising two or more pump
modules, and/or two or more electric motor modules.
6. An assembly according to claim 1, comprising a tube expansion
module that may be releasably attached to and driven by the motor
module.
7. An electric motor module according to claim 1.
8. A pump module according to claim 1.
9. An tube expansion module according to claim 6.
10. An electric pump assembly in a well, comprising an electric
motor module having an first outer housing and a first mating
means, an electric pump module having a pump inlet and a pump
outlet, a second outer housing and a second mating means, the
electric motor module and electric pump module capable of being
reversibly joined together by the first and second mating means,
the electric motor module including a first flowpath inside the
first outer housing, the electric motor module including a second
flowpath inside the second outer housing, such that the first and
second flowpaths are brought into fluid communication when the
electric motor module and electric pump module are joined.
11. An assembly according to claim 10, wherein the electric motor
module includes a first rotating member that is capable of rotating
relative to the first outer housing, and the electric pump module
includes a second rotating member that is capable of rotating
relative to the second outer housing, such that the first rotating
member and second rotating member can transfer torque when the
electric motor module and electric pump module are joined.
12. An assembly according to claim 10 wherein electric power is
supplied via a supply means situated on a well casing.
13. An assembly according to claim 12, wherein the first rotating
member and second rotating member are joined by means of
interlocking splines.
14. An assembly according to claim 10, comprising two or more pump
modules, and/or two or more electric motor modules.
15. An electric motor module according to claim 10.
16. A pump module according to claim 10.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a method of deploying a modular
electrical submersible powered fluid transducer system, such as a
gas compressor or an electrical submersible pump, generally known
as an ESP, in an oil and/or gas production well.
BACKGROUND OF THE INVENTION
[0002] The disposing in wells of electrical submersible systems has
been done for many years using jointed tubular conduits with an
electrical motor, and a fluid transducer connected to the bottom of
the jointed tubing. Consecutive joints of tubular conduits are
connected and lowered into a well with the assistance of a rig mast
and hoisting equipment, whilst unspooling and connecting to the
outer diameter of the tubing a continuous length of electrical
power transmission cable. This method of disposing the electrical
submersible fluid transducer system is well know to those familiar
with the art of producing non-eruptive sources of oil and gas from
the subterranean environment. The retrieval of these electrical
submersible fluid transducer systems is also commonly accomplished
by pulling the jointed tubing out of the well simultaneously with
the electrical submersible motor and fluid transducer system and
the electrical power transmission cable. The following prior art
references are believed to be pertinent to the invention claimed in
the present application: U.S. Pat. Nos. 3,939,705; 4,105,279;
4,494,602; 4,589,717; 5,180,140; 5,746,582 and 5,871,051;
International patent application No. WO98122692 and European patent
specifications Nos. 470576 and 745176. U.S. Pat. Nos. 3,835,929,
5,180,140 and 5,191,173 teach the art of deploying and retrieving
an electrical submersible system in oil wells using coiled or
continuous tubing. These coiled tubing disposal methods often use
large coiled tubing spool diameters owing to the radius of
curvature possible of the continuous tubing. Hence the surface
spooling devices that these systems require to inject and retrieve
the continuous tubing are cumbersome, and require special surface
and subterranean equipment for deployment and intervention.
[0003] Other previous art disclosed in the literature teaches the
disposal and retrieval of the subterranean electrical fluid
transducer system with wireline or wire rope as structural support
for simultaneously disposing the electrical power transmission
cable with the system. Hence these wireline methods and apparatus
involve the use of large and unique surface intervention equipment
to handle the weight and spool used for the electrical power cable
and the wire rope to be run in the well. U.S. Pat. No. 5,746,582
discloses the retrieval of a submersible pumps whilst leaving an
electrical motor and cable in a well. Hence the method of U.S. Pat.
No. 5,746,582 teaches the retrieval and deployment of the
mechanical portion of an electrical submersible fluid transmission
system whilst leaving the electrical motor and other component
parts of the electrical submersible system disposed in the disposal
of the electrical motor separately from the electrical power
transmission cable. In the case of artificially lifted wells
powered with electrical submersible motor systems, the current art
is to dispose the required transducer assembly, for example a pump
or compressor assembly, with an electrical motor and electrical
power cable simultaneously into the well with a supporting member.
This supporting member is jointed tubing from a surface rig, a
coiled tubing unit with continues tubing or braided cable. The
tubing or a braided cable is required as the electrical power cable
is not able to support its own weight in the well and hence must be
connected and disposed in the well with a structural member for
support. In the case of jointed pipe deployed from a rig, the power
cable is attached to the electrical motor on surface, and the cable
is attached to the tubing as the electrical motor, transducer, and
tubing are disposed into the well casing or tubing. The attachment
of the cable to the tube is done by the use of steel bands, cast
clamps, and other methods known to those familiar with the oil and
gas business. In other methods, the power cable is placed inside of
continuous tubing or attached to the outside of continuous tubing
with bands as taught by U.S. Pat. No. 5,191,173. This continuous
tubing is often referred to in the industry as coiled tubing. U.S.
Pat. No. 3,835,929 teaches the use of the continuous tubing with
the electrical power transmission cable inside of the tube. In all
cases where electrical submersible fluid transducers systems are
disposed and retrieved from wells the electric motor and electrical
power transmission cable are deployed or retrieved
simultaneously.
[0004] It is well known to those familiar with electrical
submersible power cable that the action of removing the cable from
the well can result in damage to the electrical power transmission
cable, in a variety of ways. The damage inflicted on the electrical
power cable can be due to bending stresses imposed on the cable
during the disposal and retrieval. The conventional electrical
power cable insulation, wrapping, and shields can develop stress
cracks from the spooling of the cable over sheaves and spools
devices used to deploy the cable. Another failure mode associated
with submersible power transmission cable is caused form impact
loads or crushing of the cable as it is disposed or retrieved in
the wells. It is also well known that gases found in subterranean
environments impregnated the permeability of the electrical power
transmission cable's insulation, wrapping and shields. This gas is
trapped in the permeability of the insulation at a pressure similar
to the pressure found inside the well. When the cable is retrieved
from the well the electrically powered transmission cable is
exposed to ambient pressures. This will create a pressure
differential between gas encapsulated in the cable insulation and
the ambient surface pressure conditions. The rate of impregnated
gas expansion from the higher pressure inside of the cable
insulation expanding towards the lower pressure of the ambient
conditions can sometimes exceed the cable insulation permeability's
ability to equalise the pressure differential. The result is a
void, or stressing of the insulation, and premature failure of the
cable. The requirement to retrieve and dispose the electrical power
transmission cable with the electrical submersible fluid traducer
system also requires the use of specialised surface intervention
equipment. This can require very large rigs, capable of pulling
tubing, electrical power transmission cable, and electrical
submersible fluid transducers. In the offshore environment these
well intervention methods require semi-submersible drill ships and
platforms. In the case of jointed conduit deployed in a plurality
of threaded lengths, normally 9-12 m each, the pulling equipment is
a drilling or pulling rig at surface. In the case that the
electrical power transmission cable and assembly are disposed
connected to or in continuous tubing, a specialised coiled tubing
rig is required at surface. This coiled tubing unit consisting of
an injector head, a hydraulic power unit, and a large diameter
spooling device containing the continuous coiled tubing all located
on the surface. This disposal and retrieval method requires
significant space at the earth's surface or sea floor. The reasons
for intervening in a well to retrieve or dispose an electrical
submersible transducer system are well know to those familiar with
the art of fluid removing fluids from wells. There are at least two
classical reasons for intervention in wells disposed with
electrical submersible fluid transducer systems. These include the
need to increase fluid production, or the need to repair the
disposed electrical submersible power system. The reason for
requiring increased fluid production is dependent on many factors
including but not limited to economical and reservoir management
techniques discussed in the literature. The reasons for intervening
for repair or to replace the electrical submersible fluid
transducer systems are due to normal equipment wear and the
subsequent loss of fluid production capacity, catastrophic
equipment failure, and changes in the fluid production capacity of
the subterranean fluid reservoir. The equipment failures can be
caused due to subterranean electrical failures in the electrical
motor windings, electrical motor insulation degradation due to heat
or mechanical wear, conductive fluid leaking into the motor, wear
or failure of the fluid transducer parts, wear of electrical motor
bearings, shaft vibrations, changes in inflow performance of the
reservoir, and other phenomena known to those familiar with the art
of fluid production from wells. Therefore, it is often required to
change out component parts of the electrical submersible fluid
transducer system, but not necessarily the electrical power
transmission cable. However, owing to prior art the power cable is
retrieved when the electrical motor or the motor seals fail.
SUMMARY OF THE INVENTION
[0005] According to the present invention, there is provided an
electric pump assembly as defined in the claims.
[0006] In a first aspect, an embodiment provides an electric pump
assembly in a well, comprising an electric motor module having an
first outer housing and a first mating means, an electric pump
module having a pump inlet and a pump outlet, a second outer
housing and a second mating means, the electric motor module and
electric pump module capable of being reversibly joined together by
the first and second mating means, the electric motor module
includes a first rotating member that is capable of rotating
relative to the first outer housing, and the electric pump module
includes a second rotating member that is capable of rotating
relative to the second outer housing, such that the first rotating
member and second rotating member can transfer torque when the
electric motor module and electric pump module are joined.
[0007] In a second aspect, an embodiment provides an electric pump
assembly in a well, comprising an electric motor module having an
first outer housing and a first mating means, an electric pump
module having a pump inlet and a pump outlet, a second outer
housing and a second mating means, the electric motor module and
electric pump module capable of being reversibly joined together by
the first and second mating means, the electric motor module
including a first flowpath inside the first outer housing, the
electric motor module including a second flowpath inside the second
outer housing, such that the first and second flowpaths are brought
into fluid communication when the electric motor module and
electric pump module are joined.
[0008] Preferably, the electric motor module includes a first
rotating member that is capable of rotating relative to the first
outer housing, and the electric pump module includes a second
rotating member that is capable of rotating relative to the second
outer housing, such that the first rotating member and second
rotating member can transfer torque when the electric motor module
and electric pump module are joined.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Various illustrative embodiments of the invention will now
be described, purely by way of example and without limitation to
the scope of the claims, and with reference to the following
figures, in which:
[0010] FIGS. 1-3 show a side view of the production tubing, and of
the ESP modules, before and after installation;
[0011] FIG. 4 shows a side view of a module mating unit,
coupled;
[0012] FIG. 5 shows a side view of a module mating unit,
uncoupled;
[0013] FIG. 6 shows a cross sectional view of the electric
cable;
[0014] FIG. 7 shows a cross sectional view of one of the conductors
within the cable;
[0015] FIGS. 8 and 9 show a side view of another embodiment of the
motor and an expansion tube, and a side view of that embodiment in
operation in the production tubing;
[0016] and FIGS. 10-14 show further embodiments wherein:
[0017] FIG. 10 shows a side view of the production tubing,
electrical power cable, side pocket electrical connection are
installed permanently in an oil or gas well;
[0018] FIG. 11 shows a side view of the ESP modules;
[0019] FIG. 12 shows a side view of the production tubing,
electrical power cable, side pocket electrical connection are
installed permanently in an oil or gas well, with the ESP modules
in there final installed position;
[0020] FIG. 13 shows a side view of a module mating unit, coupled;
and
[0021] FIG. 14 shows a side view of a module mating unit,
uncoupled.
DETAILED DESCRIPTION OF THE EMBODIMENTS OF FIGS. 1-9
[0022] Referring to FIGS. 1 to 3, there is shown a well completion
with casing 1 cemented into the wellbore. A packer 2 with elastomer
seals 9 is set in the casing which includes a polished bore
receptacle (PBR) 3. The production tubing 4 stings into the PBR
with a stinger 5 and seal 6.
[0023] A no go landing feature 8 is included to provide a reference
stop point when installing the pump module 50.
[0024] Pump module 50 consists of a stinger and pump inlet 64, a
pump 66, and a pump outlet 67 and a mating unit 68.
[0025] Motor module 51 consist of a mating unit 69, a motor seal
70, a motor 67, and a sensor package 61 and umbilical interface
71.
[0026] To deploy the pump 50 and motor 51, the pump 50 is first
lowered down the well on a wireline, the wireline terminating in a
running tool that connects to the mating unit 68. The pump comes to
rest when the stinger 64 reaches the landing feature 8, the stinger
forming a seal against the polished bore receptacle inside stinger
5. When the surface operator detects that the pump has reached this
point (for example by monitoring the weight on the wireline or the
length of wireline deployed), the running tool is released and the
wireline extracted.
[0027] The motor module package 51 may then be deployed, the motor
51 being suspended on an umbilical cable 71. When the motor module
reaches the pump module, the motor module's mating unit 69 engages
with the pump module's mating unit 68.
[0028] As well as suspending the motor during deployment, the
umbilical 71 supplies the motor with electric power. Once installed
with the pump module, the motor can be operated from the surface,
the motor activating the pump so that well fluid from beneath the
pump inlet 64 is drawn up through the pump 66, and exits through
the pump outlet 67 and up through the production tubing 9 to the
surface.
[0029] Referring to FIGS. 4 and 5, this shows the mating unit in
more detail, the lower housing body 100 has an internal bore 101,
with a sealing surface 102 and internal spleens 103. On the upper
half of the mating unit the outer housing 104 has a reduced
diameter 105, and splines 106 at its lowest extreme end which
enables it to pass the seal diameter 102 and engage the splines 103
in the lower mating unit body 100. The seal 107 engages the bore
102 and seals the ID from the OD.
[0030] In the lower mating unit is a shaft 110, mounted in bearings
111 and 112 which transmits torque. Its upper end is pointed 113 to
enable engagement, and splined 114 to transmit the torque from the
shaft 120 in the upper mating unit. The internal splines 121 on the
upper shaft engage the spines 114 on the lower shaft. The upper
shaft is also mounted in bearings 111 and 112.
[0031] Internal flow path consisting of drilled holes 130 and 131
enable fluid to pass from the lower side of the mating unit to the
upper side of the mating unit when engaged. This enables the pump
discharge from the lower pump to enter the pump inlet of the upped
pump. If two pump modules are required and deployed separately. The
flow path is not required if the motor module is connected to the
pump module
[0032] Referring to FIG. 6, the umbilical 160 includes three
conductors 161 arranged (spirally wound) in a triangular formation,
held together in a insulating filler 162 (which may, for example,
be extruded around the conductive cables). The conductive cables
and filler are then surrounded by a composite fibre 164 such as
Kevlar.RTM.. The weight of the cable is supported by the conductors
161 themselves. The filler 162 and the composite fibre 164 do not
themselves provide any significant load bearing characteristics.
The composite fibre 164 does though protect the body of the cable
from damage from friction or pressure from other components as it
is deployed down the well. Further, the spirally wound cabel
arrangement results in a torque in the cable. The composite fibre
164 may be wound so as to provide a torque reaction to this.
[0033] Referring to FIG. 7, a single conductor in this arrangement
comprises a central steel core 168 clad in a copper layer 167,
which is coated in a primary insulator 166 (for example Kapton
Tape.RTM.) having a high dielectric coefficient, and a secondary
insulator 165 which can provide mechanical protection, and a
further metal layer, such as a stainless steel layer 169 around the
secondary insulator 165. This layer is seam welded and is a snug
fit around the insulation 165. The additional stainless steel layer
169 may not always be required, but can be used to provide a second
conductive path in the conductor 161, for telemetry or separate
power for sensor systems, or a shielding layer to reduce the
electrical noise from the power cable. Also, each conductive
element could be stranded or further comprised of a plurality of
steel conductors each clad with a clad in a copper layer.
[0034] By deploying the pump module and motor module separately,
the weight of any one module is minimised. Further the pump, and
the motor, are both designed to be light weight; typically around
250-500 kg for the motor and connector, and 1000 kg for the pump. A
permanent magnet design for the motor is particularly suitable for
this purpose. By minimising the weight of the pump module, the
umbilical can be made thin enough, and therefore flexible enough to
pass over sheaf wheels rather than have to be injected into the
well using something like a CT injector
[0035] A modular arrangement also having a separate pump and motor
also has benefits in the event of the motor failing; many pump and
motor failures are due to electrical faults in the motor. In the
present system, the separate removal and replacement of the motor
is more convenient than the complete removal of a single combined
ESP unit.
[0036] Referring to FIGS. 8 and 9, the production tubing 4 may be
expanded in the region 4a where the motor 67 will be disposed, to
allow more room for the pumped fluid to flow past the motor after
exiting the pump outlet. A roller expander 80 assembly is attached
to the bottom of the motor seal 70, so that there is a torsional
link between the motor 67 and the roller expander assembly 80. The
roller expanded assembly 80 includes rollers 82 which may be
operated to move raidally outwards. The motor 67 and the roller
expander assembly 80 are deployed down the production tubing 4.
When the roller expander assembly reaches the region where the
motor is to be located, the rollers 82 are operated to move
radially outwards, causing the inner diameter of the production
tubing to expand, typically increasing the radius by 0.25 inches
(0.63 cm). The motor 67 then turns the roller expander assembly 80
so that the entire radius of the production tubing 4 is expanded
uniformly. The motor and roller expander assembly 80 is set to its
lowest point and pulled up the well during its expansion process.
This would be repeated several times to achieved the required
tubing expansion. The linkage between the motor 67 then turns the
roller expander assembly 80 may be similar to that between the
motor and pump shown in FIGS. 4 and 5.
[0037] After a suitable region 4a in the production tubing 4 has
been expanded, the rollers 82 are retracted into the roller
expander assembly 80, and then the motor 67 and roller expander
assembly 80 are raised through the production tubing on the
umbilicus 71. The pump module 50 and the motor module 67 may be
lowered in separate operations as previously described. This
particular method of installing an ESP is ideal for old production
wells, where the last remaining oil in place can be extracted, To
avoid the expense of a Rig to remove the production tubing 9 and
run a expanded section 4a, the in situ expanding method T would
obviates the need for the Rig.
DETAILED DESCRIPTION OF THE EMBODIMENTS OF FIGS. 10-14
[0038] Referring to FIGS. 10 to 12, there is shown a well
completion with casing 1 cemented into the wellbore. A packer 2 is
set in the casing which includes a polished bore receptacle (PBR)
3. The production tubing 4 stings into the PBR with a stinger 5 and
seal 6. The production tubing includes other features which enable
the electrical powered device to be installed and operated, these
will now be described.
[0039] A no go 7 landing feature is included to provide a reference
stop point when installing the first module 50. A locating B
profile 8 is included to provide an over pull for module 50, which
enables the electrical plug arm 61 to deploy and engage with its
matching half 62 mounted in an annular pocket 63. The permanently
installed wet connector 62 is supplied with electrical power via a
power cable 9 which penetrates the annular pocket via a bulk head
10.
[0040] Module 50 consists of a sensor package 64 which measures all
motor and well bore parameter, the orientation and plug arm
assembly 65, and motor and seal assembly 66, and the lower half of
a mating unit 67 described in more detail in FIGS. 13 and 14.
[0041] The next module to be installed consists of the upper half
of the mating unit 68, a pump inlet 69 and a pump 70, at the upper
end of this module is a further mating unit 67.
[0042] The next module to be installed consists of a further upper
mating unit 68, a pump and a upper lock down assembly and seal 71.
This keeps all the is modules compressed and locked together, while
the seal separates the pump inlet from the pump discharge.
[0043] Referring to FIGS. 13 and 14, this shows the mating unit in
more detail, the lower housing body 100 has an internal bore 101,
with a sealing surface 102 and internal splines 103. On the upper
half of the mating unit the outer housing 104 has a reduced
diameter 105, and splines 106 at its lowest extreme end which
enables it to pass the seal diameter 102 and engage the splines 103
in the lower mating unit body 100. The seal 107 engages the bore
102 and seals the ID from the OD.
[0044] In the lower mating unit is a shaft 110, mounted in bearings
111 and 112 which transmits torque and thrust. Its upper end is
pointed 113 to enable engagement, and splined 114 to transmit the
torque to the shaft 120 in the upper mating unit. The internal
splines 121 on the upper shaft engage the spines 114 on the lower
shaft. The upper shaft is also mounted in bearings 111 and 112.
[0045] Internal flow path consisting of drilled holes 130 and 131
enable fluid to pass from the lower side of the mating unit to the
upper side of the mating unit when engaged. This enables the pump
discharge from the lower pump to enter the pump inlet of the upped
pump.
[0046] In summary, an electric pump assembly is provided in a well,
the pump comprising an electric motor module having an first outer
housing and a first mating means, an electric pump module having a
pump inlet and a pump outlet, and a second outer housing and a
second mating means. In one aspect, the electric motor module and
electric pump module are capable of being reversibly joined
together by the first and second mating means, as the electric
motor module includes a first rotating member that is capable of
rotating relative to the first outer housing, and the electric pump
module includes a second rotating member that is capable of
rotating relative to the second outer housing. In this way, the
first rotating member and second rotating member can transfer
torque when the electric motor module and electric pump module are
joined. In another aspect, a flowpath is provided in each module,
the flowpaths fluidly communicating when the modules are
joined.
* * * * *