Information
-
Patent Grant
-
6298917
-
Patent Number
6,298,917
-
Date Filed
Monday, August 3, 199825 years ago
-
Date Issued
Tuesday, October 9, 200122 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Fletcher, Yoder & Van Someren
-
CPC
-
US Classifications
Field of Search
US
- 166 384
- 166 385
- 166 651
- 166 2421
- 166 105
- 166 380
- 166 2422
- 166 369
-
International Classifications
- E21B2300
- E21B1922
- E21B4300
-
Abstract
A coiled tubing system deploys an electric submergible pump system within a wellbore. The coiled tubing system includes an internal power cable for providing power to a submergible motor. Additionally, a control line, such as a hydraulic line, is disposed within the hollow interior of the coiled tubing to provide an input to the submergible pumping system. The control line is preferably routed through an interior space of a connector unit disposed between the coiled tubing and the submergible motor.
Description
FIELD OF THE INVENTION
The present invention relates generally to submergible pumping systems for raising fluids from wells and, particularly, to a coiled tubing system that integrates combined conductors for providing power to a submergible electric motor of the pump system and at least one other control line to provide other input to the system.
BACKGROUND OF THE INVENTION
In producing petroleum and other useful fluids from production walls, it is generally known to provide a submergible pumping system for raising the fluids collected in a well. Production fluids enter a wellbore via perforations formed in a well casing adjacent a production formation. Fluids contained in the formation collect in the wellbore and may be raised by the submergible pumping system to a collection point above the earth's surface.
In a conventional bottom intake electric submergible pumping system, the system includes several components, such as a submergible electrical motor that supplies energy to a submergible pump. The system may further include a motor protector for isolating the motor from well fluids. A motor connector may also be used to provide a connection between the electrical motor and an electrical power supply. These and other components may be combined in the overall submergible pumping system.
Conventional submergible pumping systems are suspended within a wellbore by support tubing or by a cable. Power is supplied to the submergible electric motor by a power cable that is banded to the cable or support tubing. The banding is required because otherwise the unsupported weight of the power cable can damage or break the power cable. Coiled tubing is also used to install electric submergible pumping systems into a well. Coiled tubing provides a relatively fast and uninterrupted method for installation and retrieval of the pumping system. With coiled tubing, the power cable is either banded to the outside of the coiled tubing or disposed internally within the hollow interior formed by the coiled tubing.
Existing power cables may contain conductors for powering the motor, typically three conductors. Any other inputs to the electric submergible pumping system must be provided by a separate line, typically banded to the outside of the tubing, support cable, or coiled tubing. This, of course, leaves the additional input or control line susceptible to damage due to its location external to the submergible pumping system and system support, e.g., coiled tubing. Consequently, it would be advantageous to combine coiled tubing with an internal power cable and additional control line or control lines disposed within the hollow interior of the coiled tubing. The control line could be used to supply hydraulic fluid for the control of devices, such as a hydraulically actuated integral packer. It also could be used to supply chemical treatments into the production fluid, such as corrosion control or scale inhibitor fluids, or to provide electrical or optical inputs to additional devices or sensors within the submergible pumping system.
SUMMARY OF THE INVENTION
The present invention features a coiled tubing system for use in deploying a submergible pump system. The submergible pump system includes a motor and a pump that are disposed within a wellbore of a well containing production fluids. The system comprises an outer coiled tubing having a longitudinal hollow interior. A power cable is disposed within the longitudinal hollow interior and includes a plurality of conductors. The conductors are disposed within an insulative core and an outer armor layer wrapped about the insulative core. The plurality of power conductors are adapted to provide power to the submergible motor. Additionally, a control line is disposed within the outer armor layer and runs along the length of the power cable to provide a desired control input to the submergible pump system.
According to another aspect of the present invention, a submergible pumping system is designed for deployment by coiled tubing within a wellbore. The submergible pumping system includes a connector assembly, a submergible motor, and a submergible pump. The connector assembly, submergible motor, and submergible pump are combined in a submergible pumping system for deployment in the wellbore. The pumping system also comprises a coiled tubing system that extends between the connector assembly and a position proximate a surface outlet of the wellbore. The coiled tubing system has outer coiled tubing forming a generally hollow interior. A plurality of conductors extend through the hollow interior and into the connector assembly for connection to the submergible motor. Additionally, a tubular member extends through the hollow interior to supply a desired fluid to the submergible pumping system.
According to another aspect of the present invention, a method is provided for communicating various inputs to a submergible pumping system having at least a connector assembly, a submergible motor, and a submergible pump. The method includes connecting a coiled tubing to the connector assembly of the submergible pumping system and suspending the pumping system within a wellbore via the coiled tubing. The method also includes deploying a power cable, having a plurality of conductors, within an interior hollow region of the coiled tubing and connecting the plurality of conductors to the submergible motor. The method further includes deploying a control line, independent of the plurality of conductors, through the interior hollow region of the coiled tubing.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
FIG. 1
is a front elevational view of a submergible pumping system positioned in a wellbore, according to a preferred embodiment of the present invention;
FIG. 2
shows a packer assembly, according to a preferred embodiment of the present invention, disposed within the string of submergible pumping system components;
FIG. 3
is a cross-sectional view of the packer assembly illustrated in
FIG. 2
, taken generally along its longitudinal axes;
FIG. 4
is a cross-sectional view of the packer mandrel taken generally along its longitudinal axis;
FIG. 5
is a cross-sectional view of a connector, according to a preferred embodiment of the present invention;
FIG. 6
is a cross-sectional view taken generally along line
6
—
6
of
FIG. 5
;
FIG. 7
is an alternate embodiment of the combined power cable and coiled tubing illustrated in
FIG. 6
;
FIG. 8
is an alternate embodiment of the combined power cable and coiled tubing illustrated in
FIG. 6
; and
FIG. 9
is an alternate embodiment of the combined power cable and coiled tubing illustrated in FIG.
6
.
DETAILED DESCRPITION OF THE PREFERRED EMBODIMENTS
Referring generally to
FIG. 1
, a bottom intake electric submergible pump system
10
is illustrated according to a preferred embodiment of the present invention. Submergible pump system
10
may comprise a variety of components depending on the particular application or environment in which it is used. However, system
10
typically includes at least a submergible pump
12
, submergible motor
14
, and an integral packer assembly
16
. The provision of integral packer assembly
16
, within submergible pumping system
10
, obviates the need for external seating shoes, running a separate liner, employing landing nipples, or deploying a separate packer prior to deployment of submergible pumping system
10
.
As illustrated, system
10
is designed for deployment in a well
18
within a geological formation
20
containing desirable production fluids, such as petroleum. In a typical application, a wellbore
22
is drilled and lined with a wellbore casing
24
. The submergible pumping system is then deployed within wellbore
22
to a desired location for retrieval of wellbore fluids. At this location, packer assembly
16
is set and sealed against an interior surface
26
of wellbore casing
24
. The production fluids may then be pumped from well
18
via pump
12
, powered by motor
14
, to a point above packer assembly
16
and discharged into the annulus
28
formed between submergible pumping system
10
and interior surface
26
of wellbore casing
24
. As the wellbore fluids are continually pumped into annulus
28
above packer assembly
16
, the fluid level rises to a point at or above the earth's surface where the production fluid is collected for further processing.
As illustrated, submergible pumping system
10
typically includes additional components, such as a thrust casing
30
, a pump intake
32
, through which wellbore fluids enter pump
12
, a protector
34
, that serves to isolate the well fluid from the motor oil, and an injection line
36
. Additionally, a connector
38
is used to connect motor
14
with a deployment system, such as tubing, cable or coil tubing. In the preferred embodiment, the deployment system is a coiled tubing system
40
utilizing a coiled tube
42
having a power cable
44
running through its hollow center as will be described in detail below.
Furthermore, a variety of motors
14
and pumps
12
can be used in submergible pumping system
10
. However, an exemplary motor
14
is a three-phase, induction-type motor, and exemplary pump
12
is a multi-staged centrifugal pump. Additionally, additional components can be added, components can be removed, or the sequence of components can be rearranged according to the desired application.
Referring now also to
FIGS. 2 and 3
, packer assembly
16
includes a discharge head or packer mandrel
46
and a packer
48
integrally mounted on packer mandrel
46
for movement with packer mandrel
46
and the rest of submergible pumping system
10
as it is deployed at a specific location within wellbore
22
or removed from wellbore
22
.
Packer
48
is illustrated in simplified form, because a variety of conventional packers can be adapted for use with this submergible pumping system
10
. For example, packer
48
may be a mechanically set packer, such as a “J” latch-type packer, a Swab Cup-type packer, or a hydraulic packer. Preferably, packer
48
is a hydraulic packer, such as the Camco HRP-1-SP hydraulic set packer available through Camco International, Inc. of Houston, Tex. A hydraulic set packer generally includes a plurality of slips
50
having friction blocks
52
and a sealing element
54
. Slips
50
and friction blocks
52
are deployed against interior surface
26
of casing
24
to hold packer assembly
16
at a given location within wellbore
22
. Sealing element
54
typically comprises an elastomeric element that expands to seal between packer mandrel
46
and casing
24
to support the column of production fluid within annulus
28
. The specific configuration of packer
48
will depend on the application and the desires of the submergible pumping system operator.
A control line
56
preferably is run from a location at the earth's surface to packer assembly
16
to “set” or engage packer
48
with wellbore casing
24
when desired. In the illustrated embodiment, control line
56
is a hydraulic line that supplies hydraulic fluid to packer
48
, thereby providing inputs to selectively set the packer.
Referring also to
FIG. 4
, packer mandrel
46
includes a housing
58
that has an upper connector end
60
and a lower connector end
62
. Upper connector end
60
is connected, for instance, to the lower portion of protector
34
while lower connector end
62
is connected to, for instance, the upper end of submergible pump
12
. Thus, packer mandrel
46
is disposed intermediate pump
12
and motor
14
with motor
14
being disposed above packer mandrel
46
within wellbore
22
while pump
12
is disposed below packer mandrel
46
in wellbore
22
.
Housing
58
includes an inlet
64
and a discharge end
66
having an outlet
68
. A fluid passage
70
connects inlet
64
and outlet
68
through the interior of housing
58
to permit the flow of wellbore fluids therethrough. Thus, wellbore fluids are taken in through intake
32
, pumped through the interior of submergible pump
12
and through fluid passage
70
before entering annulus
28
via outlet
68
.
A shaft
72
extends through the center of housing
58
generally along a longitudinal axis
74
to provide power from motor
14
to pump
12
. Preferably, shaft
72
extends through the center of fluid passage
70
. Bearings, and preferably a pair of bearings
76
, hold and support shaft
72
for rotation within housing
58
.
Housing
58
is designed to secure packer
48
thereto so that packer
48
is retained as an integral component of submergible pumping system
10
as it is deployed and moved within wellbore
22
. In other words, the various components, including packer
48
, may be assembled at the surface and deployed in wellbore
22
at any desired location without first deploying a separate packer in a preliminary step and/or without using any seating shoes, separate liners, or landing nipples that fix the location of submergible pumping system
10
at a specific location within wellbore
22
. Additionally, because packer
48
is independently controlled via control line
56
, it can be set at any time regardless of whether pump
12
has been started or any pumping action has occurred. Specifically, this allows packer
48
to be set at the desired location within wellbore
22
prior to initiation of any pumping action.
In the preferred embodiment, housing
58
includes an exterior surface
78
that forms an engagement region, preferably a recessed region
80
, for holding packer
48
, as best illustrated in FIG.
3
. In this embodiment, recessed region
80
is formed by an upper expanded region
82
of exterior surface
78
and a lower expanded region
84
of exterior surface
78
. Packer
48
is held within this recessed region
80
so that it is constrained to movement with packer mandrel
46
and thus submergible pumping system
10
. Packer
48
may, for instance, be assembled within recessed region
80
or packer mandrel
46
potentially can be formed as two or more components that are inserted into packer
48
and fastened together by, for instance, a weldment, bolts, or other fasteners. Additionally, packer
48
may be attached to housing
58
at additional points by additional fasteners, weldments, or splines to prevent any rotation of packer
48
with respect to housing
58
.
Referring generally to
FIG. 5
, a cross-sectional view of connector assembly
38
is taken generally along a longitudinal axis of connector assembly
38
. In the preferred embodiment, connector assembly
38
includes an outer housing
86
that has an interior hollow region
88
. Connector assembly
38
includes a lower mounting structure
90
by which it is connected to the next sequential component, preferably motor
14
, of submergible pumping system
10
. Lower mounting structure
90
may be designed for connection to motor
14
and housing
86
via a plurality of fasteners
92
, such as bolts.
In the illustrated embodiment, connector assembly
38
includes a head connector
94
that engages coiled tubing
42
. Opposite coiled tubing
42
, head connector
94
engages a housing connector
96
via a threaded region
98
and a sealing ring
100
. Housing connector
96
includes a radially outwardly extending flange
102
that abuts against a top portion of housing
86
. Housing connector
96
and housing
86
are held together by a union
104
that threadably engages housing
86
at a threaded region
106
to pull flange
102
tightly against the top of housing
86
, as illustrated in
FIG. 5. A
seal
108
is disposed between housing connector
96
and housing
86
.
Housing
86
includes a collar connector
110
having threaded region
106
disposed along its upper portion. Collar connector
110
is connected to a lower housing connector
112
by a plurality of shear pins
114
and sealed thereto by a seal ring
116
. Thus, if submergible pumping system
10
becomes stuck within wellbore
22
, head connector
94
and collar connector
110
may be sheared away from lower housing connector
112
. Lower housing connector
112
includes a plurality of fishing teeth
118
to permit later retrieval of the remainder of submergible pumping system
10
, as is well known by those of ordinary skill in the art.
Housing
86
also includes a drain
120
for draining fluids, as necessary, from interior hollow region
88
. Specifically, drain
120
extends through housing
86
from interior hollow region
88
to wellbore
22
. Preferably, housing
86
further includes an outlet
122
that can be used to conduct control line
56
from interior hollow region
88
to annulus
28
between submergible pumping system
10
and wellbore casing
24
.
With additional reference to
FIG. 6
, the present invention preferably utilizes coiled tubing system
40
in which the outer coiled tubing
42
is connected to head connector
94
to suspend submergible pumping system
10
as it is deployed within wellbore
22
. Power cable
44
extends through a longitudinal hollow interior
124
of coiled tubing
42
. Power cable
44
extends into the interior of housing connector
96
and engages a penetrator
126
. Penetrator
126
conducts a plurality of motor conductors
128
to a lower portion of interior hollow region
88
of housing
86
. From this point, the individual motor conductors, typically three motor conductors
128
, are directed through lower mounting structure
90
for connection with motor
14
to provide appropriate electrical input thereto.
In the preferred embodiment, power cable
44
also includes, as an integral component, control line
56
. As illustrated best in
FIG. 6
, control line
56
may comprise an injection line having an outer wall
130
defining an interior fluid passage
132
for conducting, for instance, hydraulic fluid to packer
48
.
In the preferred embodiment illustrated in
FIGS. 5 and 6
, control line
56
is disposed generally at a central location between electrical motor conductors
128
within power cable
44
. The hydraulic control line is then routed through penetrator
126
and out of connector assembly
38
via outlet
122
, as illustrated best in FIG.
5
. From outlet
122
, control line
56
is routed along motor
14
and any other components of submergible pumping system
10
until it reaches packer
48
, where it may be connected in a conventional manner. Control line
56
may comprise multiple pieces and also may be held securely in place at outlet
122
by appropriate fasteners
134
.
In the preferred embodiment, power cable
44
includes control line
56
disposed generally along its longitudinal axis and through an insulative core
136
. Each of the three electrical motor conductors
128
is spaced radially outward from control line
56
and also runs through insulative core
136
. Each of the motor conductors
128
may be sheathed in an outer insulative layer
138
that is disposed through insulative core
136
, as is understood by those of ordinary skill in the art. Preferably, insulative core
136
is surrounded by an armor layer
140
, such as a metallic layer, for added strength and protection.
Although
FIG. 6
illustrates the preferred embodiment, a variety of alternate embodiments may be employed, such as those illustrated in
FIGS. 7-9
. For example, in
FIG. 7
, control line
56
is disposed through insulative core
136
at a position radially outward from the radial center of power cable
44
. In either of the embodiments illustrated in
FIG. 6
or
7
, control line
56
may comprise an injection line for carrying fluid, such as hydraulic fluid, to packer
48
or other components requiring independent input and actuation. When control line
56
is utilized as an injection line, it does not necessarily need to be used for powering the packer
48
of the preferred embodiment; it also could be used to inject chemical treatment into the production fluid for corrosion control, scale inhibition, etc.
In the alternate embodiment illustrated in
FIG. 8
, there are a plurality of control lines
56
for independently carrying hydraulic fluid, chemical treatment, or other fluids to various components or locations along submergible pumping system
10
. The multiple control lines potentially can be routed through connector assembly
38
or around connector assembly
38
along annulus
28
. As illustrated in
FIG. 9
, control line
56
also may comprise lines for carrying other types of inputs to submergible pumping system
10
. For example, control line
56
may comprise an electrical conductor, such as a twisted pair
142
and/or an optical fiber
144
for carrying inputs to selected components of submergible pumping system
10
, such as down hole sensors. Additionally, control line or lines
56
may comprise a mixture of control line types, e.g., hydraulic fluid injection lines, electrical conductors or optical fibers.
It will be understood that the foregoing description is of preferred embodiments of this invention, and that the invention is not limited to the specific forms shown. For example, a variety of packers and packer mandrel configurations may be adapted for use in a particular down hole environment; the submergible pumping system may incorporate a variety of additional or different components; the specific design of the connector assembly may incorporate different components and configurations; and the power cable may be constructed in various configurations of a variety of materials conducive for use in a down hole environment. These and other modifications may be made in the design and arrangement of the elements without departing from the scope of the invention as expressed in the appended claims.
Claims
- 1. A coiled tubing system for use in deploying a submergible pump system, including a motor and a pump, within a wellbore, comprising:an outer coiled tubing having a longitudinal hollow interior; a power cable disposed within the longitudinal hollow interior, the power cable including a plurality of conductors disposed within an insulative core and an outer armor layer disposed about the insulative core, the plurality of power conductors being adapted to provide power to the motor; a control line disposed within the outer armor layer; and a connector coupled to the outer coiled tubing and adapted for connection to the submergible pump system, the plurality of conductors and the control line extending at least partially through the connector, wherein the connector comprises a mechanism to selectively separate the coiled tubing from the submergible pump system while at a downhole location.
- 2. The coiled tubing system as recited in claim 1, wherein the control line includes an internal passageway for conducting a control fluid.
- 3. The coiled tubing system as recited in claim 1, wherein the control line comprises an electrical conductor.
- 4. The coiled tubing system as recited in claim 1, wherein the control line comprises an optical fiber.
- 5. The coiled tubing system as recited in claim 1, further comprising a connector assembly to which a terminal end of the outer coiled tubing is connected, the connector assembly including a connector housing and an internal passageway into which the plurality of conductors and the control line extend.
- 6. The coiled tubing system as recited in claim 5, wherein the connector assembly includes an outlet through which the control line is directed to the exterior of the connector housing.
- 7. The coiled tubing system as recited in claim 6, wherein the control line comprises an internal passageway for conducting a control fluid.
- 8. The coiled tubing system as recited in claim 7, wherein the control fluid is a hydraulic fluid.
- 9. The coiled tubing system as recited in claim 5, wherein the connector assembly includes an upper connector and a lower connector attached to one another by a shear mechanism that allows the upper connector to be sheared from the lower connector.
- 10. The coiled tubing system as recited in claim 5, further comprising a submergible motor to which the connector assembly is attached, wherein the plurality of conductors are connected to the submergible motor to supply power to the submergible motor.
- 11. A submergible pumping system for deployment by coiled tubing within a wellbore, comprising:a connector assembly; a submergible motor; a submergible pump, wherein the submergible motor and the submergible pump are combined in a submergible pumping system for deployment in the wellbore; and a coiled tubing system extending between the connector assembly and a position proximate the surface outlet of the wellbore, the coiled tubing system having an outer coiled tubing forming a generally hollow interior, a plurality of conductors extending through the hollow interior and into the connector assembly for connection to the submergible motor, and a tubular member extending through the hollow interior to supply a desired fluid to the submergible pumping system; wherein the connector assembly comprises a mechanism to selectively separate the coiled tubing system from the submergible pumping system while at a downhole location.
- 12. The submergible pumping system as recited in claim 1, wherein the tubular member comprises a hydraulic control line.
- 13. The submergible pumping system as recited in claim 11, wherein the plurality of conductors and the tubular member are held within an insulative core.
- 14. The submergible pumping system as recited in claim 13, wherein the insulative core is surrounded by an outer armor layer.
- 15. The submergible pumping system as recited in claim 14, wherein the plurality of conductors comprise three conductors and further wherein the tubular member substantially extends along an axial center of the insulative core and the three conductors extend through the insulative core at locations radially outward from the tubular member.
- 16. A method for communicating various inputs to a submergible pumping system having at least a connector assembly, a submergible motor and a submergible pump, comprising:connecting tubing to the connector assembly of the submergible pumping system; suspending the submergible pumping system within a wellbore by the tubing; deploying a premanufactured power cable, having a plurality of conductors and a control line, within an interior hollow region of the tubing; connecting the plurality of conductors to the submergible motor; and providing a mechanism for selectively separating the tubing from the submergible pumping system while at a downhole location.
- 17. The method as recited in claim 16, further comprising containing the plurality of conductors and the control line within an insulative core.
- 18. The method as recited in claim 17, further comprising surround the insulative core with an outer armor layer.
- 19. The method as recited in claim 18, wherein the step of deploying a control line includes deploying a fluid control line for carrying a control fluid.
- 20. The method as recited in claim 19, further comprising directing the fluid control line into an interior region of the connector assembly and then out of the connector assembly through an outlet.
US Referenced Citations (25)
Foreign Referenced Citations (3)
Number |
Date |
Country |
0 505 815 |
Sep 1992 |
EP |
0 565 287 |
Oct 1993 |
EP |
2 322 393 |
Aug 1998 |
GB |