CA1117409A - Deep well pumping system - Google Patents
Deep well pumping systemInfo
- Publication number
- CA1117409A CA1117409A CA000333734A CA333734A CA1117409A CA 1117409 A CA1117409 A CA 1117409A CA 000333734 A CA000333734 A CA 000333734A CA 333734 A CA333734 A CA 333734A CA 1117409 A CA1117409 A CA 1117409A
- Authority
- CA
- Canada
- Prior art keywords
- fluid
- pumping
- downhole
- deep well
- pumping system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
- F04D15/0066—Control, e.g. regulation, of pumps, pumping installations or systems by changing the speed, e.g. of the driving engine
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
- F04D15/02—Stopping of pumps, or operating valves, on occurrence of unwanted conditions
- F04D15/0209—Stopping of pumps, or operating valves, on occurrence of unwanted conditions responsive to a condition of the working fluid
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Control Of Non-Positive-Displacement Pumps (AREA)
- Control Of Positive-Displacement Pumps (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
IMPROVED DEEP WELL PUMPING SYSTEM
(D#74,736-F) ABSTRACT OF THE DISCLOSURE
A deep well pumping system. It employs a variable speed electric motor driving a centrifugal pump located down hole. There is means to control the speed of the pump drive depending upon the static head of fluid in the hole being pumped, in order to maintain the pumping rate the same as the rate of produced fluid in the hole.
I
(D#74,736-F) ABSTRACT OF THE DISCLOSURE
A deep well pumping system. It employs a variable speed electric motor driving a centrifugal pump located down hole. There is means to control the speed of the pump drive depending upon the static head of fluid in the hole being pumped, in order to maintain the pumping rate the same as the rate of produced fluid in the hole.
I
Description
lil740~
BACKGROU~ID OF THE INVENTION
Field of the Invention This invention concerns oil well pumping systems in general. More specifically, it relates to an improved deep well down hole pumping system that employs a con-tinuous centrifugal pumping arrangement with an electric motor drive.
Descri~tion of the Prior Art For various reasons, including the wide variation in actual condltions in regard to oil wells that must be pumped for producing the fluid therefrom, the most widely used arrangement for carrying out the pumping is the longstanding surface controlled and powered reciprocating-type of pumping. It has a string of so-called sucker rods which are connected from a surface structure and extend downhole to actuate a reciprocating pump. Such an arrangement has practical problems, particularly where the well is deep, which means the string of sucker rods must be very long and heavy.
While, heretofore, attempts have been made to employ down hole electrical submergible pumping systems, these have been applied particularly to wells which are considered high volume producers. So that, even though the principle of using submergible electrical pumping systems with high-volume fluid pumping at substantial depths has been known, it has been found as a practical matter that such systems are lacking in production flexibility once they have been installed. Thus, a submergible pump system that is designed to match a particular production rate of fluid, will not retain the 1117~09 matching characteristics as tlle production of the well changes.
Consequently, such systems are subject to failure under pump-off conditions and have not been found economically feasible.
Heretofore, there has been a suggestion for pumping of deep oil wells. It is United States Patent No. 1,957,320 to Coberly et al, issued May 1, 1934. That system employs a hydraulic-type of fluid driven motor located down hole and power-ing a down hole pump. There are controls applied to an electric motor located at the surface. The motor drives a surface hydraulic pump that applies hydraulic fluid pressure to actuate the down hole fluid motor. That system has quite apparently not been found particularly practical.
Thus, it is an object of this invention to provide a deep well pumping system. It employs a centrifugal pump down hole and includes flexible controls to vary the pumping rate in accordance with the static fluid head down hole.
SUMMARY OF THE INVENTION
The present invention provides an improved deep well pumping system. It comprises in combination a tubing string for carrying pumped fluid from down hole to the surface, and a submergible pumping unit operatively connected to said tubing string at the down hole end thereof, The said pumping unit comprises a three-phase AC electric motor connected for driving a centrifugal pump. The pumping system also comprises means for sensing static pressure of said fluid down hole, and speed control means for automatically controlling the speed of said motors depending upon said static pressure, in order to regulate the pumping rate for maintaining the fluid level down hole within predetermined limits. The said speed control means comprises static type solid-state means for varying the frequency of said
BACKGROU~ID OF THE INVENTION
Field of the Invention This invention concerns oil well pumping systems in general. More specifically, it relates to an improved deep well down hole pumping system that employs a con-tinuous centrifugal pumping arrangement with an electric motor drive.
Descri~tion of the Prior Art For various reasons, including the wide variation in actual condltions in regard to oil wells that must be pumped for producing the fluid therefrom, the most widely used arrangement for carrying out the pumping is the longstanding surface controlled and powered reciprocating-type of pumping. It has a string of so-called sucker rods which are connected from a surface structure and extend downhole to actuate a reciprocating pump. Such an arrangement has practical problems, particularly where the well is deep, which means the string of sucker rods must be very long and heavy.
While, heretofore, attempts have been made to employ down hole electrical submergible pumping systems, these have been applied particularly to wells which are considered high volume producers. So that, even though the principle of using submergible electrical pumping systems with high-volume fluid pumping at substantial depths has been known, it has been found as a practical matter that such systems are lacking in production flexibility once they have been installed. Thus, a submergible pump system that is designed to match a particular production rate of fluid, will not retain the 1117~09 matching characteristics as tlle production of the well changes.
Consequently, such systems are subject to failure under pump-off conditions and have not been found economically feasible.
Heretofore, there has been a suggestion for pumping of deep oil wells. It is United States Patent No. 1,957,320 to Coberly et al, issued May 1, 1934. That system employs a hydraulic-type of fluid driven motor located down hole and power-ing a down hole pump. There are controls applied to an electric motor located at the surface. The motor drives a surface hydraulic pump that applies hydraulic fluid pressure to actuate the down hole fluid motor. That system has quite apparently not been found particularly practical.
Thus, it is an object of this invention to provide a deep well pumping system. It employs a centrifugal pump down hole and includes flexible controls to vary the pumping rate in accordance with the static fluid head down hole.
SUMMARY OF THE INVENTION
The present invention provides an improved deep well pumping system. It comprises in combination a tubing string for carrying pumped fluid from down hole to the surface, and a submergible pumping unit operatively connected to said tubing string at the down hole end thereof, The said pumping unit comprises a three-phase AC electric motor connected for driving a centrifugal pump. The pumping system also comprises means for sensing static pressure of said fluid down hole, and speed control means for automatically controlling the speed of said motors depending upon said static pressure, in order to regulate the pumping rate for maintaining the fluid level down hole within predetermined limits. The said speed control means comprises static type solid-state means for varying the frequency of said
- 2 -~1'7~09 three-phase AC supply to said electric motor.
BRIEF DESCRIPTION OF TIIE DRAWING
The foregoing and other objects and benefits of the invention will be more fully set forth below in connection with the best mode contemplated by the inventor of carrying out the invention, and in connection with which there is an illustration provided in the drawing, wherein:
The figure of drawing is a schematic illustration of a system for deep well down hole pumping, according to the invention.
c 11~7409 3ESCRIPTION OF THE ?REFERRED EMBODI~ENT
In spite of much technical information and equip-ment which has been available heretofore in relation to pumping o~ fluld from oil wells and the like, there has not been a successful system for using centrifugal pumping in a continuous manner that could maintain the pumping rate substantially in accordance with the produced fluid down hole. Thus, even though the problem has been recognized heretofore, the only known solution related to controlling the pumping in a periodic manner in turn related to the pumping down of the fluid level in the well so that the pumping was stopped until well fluid had time to rise again in the well bore.
A known tentative proposal dealt with an arrange-ment for varylng the speed of an electric motor located down hole with a submersible pump. However, that proposal would employ a surface motor-generator in order to obtain a variable frequency source of power for drivlng the ; down hole motor. Consequently, the cost of such an arrangement would be high.
A deep well pumping system according to the in-ventlon i8 illustrated in the figure of drawing. There is a well 11 that has casing 12 thereln, at least near the surface. The well 11 produces fluid 15 that must be pumped in order to have it reach the surface. The pumplng system accordlng to this invention includes a tubing string 16 that has a pumping unit 19 attached at the lower end thereof. The unlt 19 lncludes a centrifugal pump 20 which ls driven by a three-phase AC motor 23, attached therebeneath. There is, of course, an lntake 111740~
24 ~or permitting the well fluid 15 to flow into the pump and motor elements 20 and 23. It will be appreciated that t;he intake 24 may be located be~ween the motor 23 and the pump 20 so long as the motor 23 is able to maintain adequate heat dissipation. These elements, per se, are commercially available as will be indicated in greater detail hereafter.
There is a combined temperature and pressure sensing element 27 which is connected to the lower end o~
the unit l9. These provide control signals as part of the system to be more fully described hereafter.
Total depth of the well 11 is indlcated by an arrow 28, and it has been found that a system accordlng to the invention is applicable to a producing well having a depth on the order of 5000 ft. or more. At the surface, there is piping 31 which is schematically indicated. This carries the produced fluid 15 from the top of the tubing string 16 to storage, or for other utilization.
Other surface equipment is electrical and is in-dicated by a unit 32 that has the caption "pump motor controller". It will be observed that there are three electrical circuits indlcated schematically. One ls a source of electric power 35, and another ls a clrcuit 36 whlch delivers variable frequency power to the motor 23.
Also, there ls a third circuit 37 which carrles electrlcal signal information in connection with the pressure and temperature that are being measured in the element 27 down hole.
A preferred system employs a three phase AC
electric motor as the motor 23 down hole. This may be one such as a commercial motor designated by the tradename ~7~9 "Reda", manu~actured by T.R.W. Inc. Similarly, the pump 20 may be part of a commercial unit that incorporates a motor ln the unlt with the pump, and is supplied by the Reda Pump Company, which is a division of T.R.W. Inc., of Bartlesville, Oklahoma.
The motor 23 is controlled by the unit 32 at the surface. This unit 32 might take different forms, but preferably is a solid state AC to AC power converter, which transforms a constant voltage, fixed frequency power source into an ad~ustable voltage, ad~ustable fre-quency power supply. This element eliminates the need for rotating sur~ace machinery, such as the above indicated motor-generator combination. Thus, the element 32 may be in accordance with the principles described in a technical paper which was presented to the IEEE-IGA
Annual Meeting, at Cleveland, Ohio, October 18-21, 1971.
That paper was titled "Current Source Converter for AC
Motor Drlves", by Kenneth P. Phillips. Similarly, the element 32 may be a power converter like one which is described by a brochure of the Electric Machinery Manufacturing Company, Minneapolls, Mlnnesota, 55413, tltled "The E-M Ampll-Cycle". The brochure shows copyrlght 1971, Electrlc Machinery Manufacturing Company.
The speed of the motor 23 and the pump 20, and consequently the rate of pumping of the fluid 15, is controlled in accordance with the static pressure at the locatlon of the inlet 24, so that the fluid level of fluld 15 may be malntained wlthln predetermined llmits by pumping at a rate that ls comparable wlth the rate of production of the fluid. The element 27 provides for static pressure by having a pressure-sensitive element that develops electrical control signals 1n accordance ~i~h such pressure. A commercial unit for accomplishing this may be employed, e.g. one manufactured by Lynes Inc.
of PØ Box 12486, ln Houston, Texas, 77017. It may be noted that this same company manufactures a similar unit that develops signals in accordance with temperature.
Thus, both the pressure and the temperature down hole are measured with signals in accordance therewith and transmitted electrically up-hole over the circuit 37.
It may be noted that a pumping system according to this invention will operate in the absence of any temperature information, but it is deslrable to have a temperature signal which can be employed to shut down the pumping in case the temperature exceeds a safe level.
It may be observed that individual elements of the combination according to this invention have been proposed for various uses heretofore. However, a need for an efficient system of pumping fluid from deep wells that can maintain a variable pumping rate automatically over extended periods has existed for a long time and there has been no suggestion or solution to this problem heretofore. Also, it will be recognized that there are difficulties involved in connection with a deep well pumping system. Such difficulties are not only those generally indicated above in relation to reciprocating type pumping from the surface, but also in centriflcal pumping arrangements the requirements are quite exacting in regard to the necessary coollng of the pump itself, in addition to the motor drive therefor, and these 1~1740~
d~fficul~ies have now been overcome by this invention.
l,~hile a partlcular embodiment of the invention has been described above in considerable detail in accordance with the applicable statutes, this is not to be taken as in any way limiting the invention, but merely as being descriptive thereof.
BRIEF DESCRIPTION OF TIIE DRAWING
The foregoing and other objects and benefits of the invention will be more fully set forth below in connection with the best mode contemplated by the inventor of carrying out the invention, and in connection with which there is an illustration provided in the drawing, wherein:
The figure of drawing is a schematic illustration of a system for deep well down hole pumping, according to the invention.
c 11~7409 3ESCRIPTION OF THE ?REFERRED EMBODI~ENT
In spite of much technical information and equip-ment which has been available heretofore in relation to pumping o~ fluld from oil wells and the like, there has not been a successful system for using centrifugal pumping in a continuous manner that could maintain the pumping rate substantially in accordance with the produced fluid down hole. Thus, even though the problem has been recognized heretofore, the only known solution related to controlling the pumping in a periodic manner in turn related to the pumping down of the fluid level in the well so that the pumping was stopped until well fluid had time to rise again in the well bore.
A known tentative proposal dealt with an arrange-ment for varylng the speed of an electric motor located down hole with a submersible pump. However, that proposal would employ a surface motor-generator in order to obtain a variable frequency source of power for drivlng the ; down hole motor. Consequently, the cost of such an arrangement would be high.
A deep well pumping system according to the in-ventlon i8 illustrated in the figure of drawing. There is a well 11 that has casing 12 thereln, at least near the surface. The well 11 produces fluid 15 that must be pumped in order to have it reach the surface. The pumplng system accordlng to this invention includes a tubing string 16 that has a pumping unit 19 attached at the lower end thereof. The unlt 19 lncludes a centrifugal pump 20 which ls driven by a three-phase AC motor 23, attached therebeneath. There is, of course, an lntake 111740~
24 ~or permitting the well fluid 15 to flow into the pump and motor elements 20 and 23. It will be appreciated that t;he intake 24 may be located be~ween the motor 23 and the pump 20 so long as the motor 23 is able to maintain adequate heat dissipation. These elements, per se, are commercially available as will be indicated in greater detail hereafter.
There is a combined temperature and pressure sensing element 27 which is connected to the lower end o~
the unit l9. These provide control signals as part of the system to be more fully described hereafter.
Total depth of the well 11 is indlcated by an arrow 28, and it has been found that a system accordlng to the invention is applicable to a producing well having a depth on the order of 5000 ft. or more. At the surface, there is piping 31 which is schematically indicated. This carries the produced fluid 15 from the top of the tubing string 16 to storage, or for other utilization.
Other surface equipment is electrical and is in-dicated by a unit 32 that has the caption "pump motor controller". It will be observed that there are three electrical circuits indlcated schematically. One ls a source of electric power 35, and another ls a clrcuit 36 whlch delivers variable frequency power to the motor 23.
Also, there ls a third circuit 37 which carrles electrlcal signal information in connection with the pressure and temperature that are being measured in the element 27 down hole.
A preferred system employs a three phase AC
electric motor as the motor 23 down hole. This may be one such as a commercial motor designated by the tradename ~7~9 "Reda", manu~actured by T.R.W. Inc. Similarly, the pump 20 may be part of a commercial unit that incorporates a motor ln the unlt with the pump, and is supplied by the Reda Pump Company, which is a division of T.R.W. Inc., of Bartlesville, Oklahoma.
The motor 23 is controlled by the unit 32 at the surface. This unit 32 might take different forms, but preferably is a solid state AC to AC power converter, which transforms a constant voltage, fixed frequency power source into an ad~ustable voltage, ad~ustable fre-quency power supply. This element eliminates the need for rotating sur~ace machinery, such as the above indicated motor-generator combination. Thus, the element 32 may be in accordance with the principles described in a technical paper which was presented to the IEEE-IGA
Annual Meeting, at Cleveland, Ohio, October 18-21, 1971.
That paper was titled "Current Source Converter for AC
Motor Drlves", by Kenneth P. Phillips. Similarly, the element 32 may be a power converter like one which is described by a brochure of the Electric Machinery Manufacturing Company, Minneapolls, Mlnnesota, 55413, tltled "The E-M Ampll-Cycle". The brochure shows copyrlght 1971, Electrlc Machinery Manufacturing Company.
The speed of the motor 23 and the pump 20, and consequently the rate of pumping of the fluid 15, is controlled in accordance with the static pressure at the locatlon of the inlet 24, so that the fluid level of fluld 15 may be malntained wlthln predetermined llmits by pumping at a rate that ls comparable wlth the rate of production of the fluid. The element 27 provides for static pressure by having a pressure-sensitive element that develops electrical control signals 1n accordance ~i~h such pressure. A commercial unit for accomplishing this may be employed, e.g. one manufactured by Lynes Inc.
of PØ Box 12486, ln Houston, Texas, 77017. It may be noted that this same company manufactures a similar unit that develops signals in accordance with temperature.
Thus, both the pressure and the temperature down hole are measured with signals in accordance therewith and transmitted electrically up-hole over the circuit 37.
It may be noted that a pumping system according to this invention will operate in the absence of any temperature information, but it is deslrable to have a temperature signal which can be employed to shut down the pumping in case the temperature exceeds a safe level.
It may be observed that individual elements of the combination according to this invention have been proposed for various uses heretofore. However, a need for an efficient system of pumping fluid from deep wells that can maintain a variable pumping rate automatically over extended periods has existed for a long time and there has been no suggestion or solution to this problem heretofore. Also, it will be recognized that there are difficulties involved in connection with a deep well pumping system. Such difficulties are not only those generally indicated above in relation to reciprocating type pumping from the surface, but also in centriflcal pumping arrangements the requirements are quite exacting in regard to the necessary coollng of the pump itself, in addition to the motor drive therefor, and these 1~1740~
d~fficul~ies have now been overcome by this invention.
l,~hile a partlcular embodiment of the invention has been described above in considerable detail in accordance with the applicable statutes, this is not to be taken as in any way limiting the invention, but merely as being descriptive thereof.
Claims (2)
1. An improved deep well pumping system, com-prising in combination a tubing string for carrying pumped fluid from downhole to the surface, a submergible pumping unit operatively con-nected to said tubing string at the downhole and thereof, said pumping unit comprising a three-phase AC electric motor connected for driving a centrifugal pump, means for sensing static pressure of said fluid downhole, and speed control means for automatically con-trolling the speed of said motor depending upon said static pressure in order to regulate the pumping rate for main-taining the fluid level downhole within predetermined limits, said speed control means comprising static type solid-state AC to AC power converter means for varying the frequency and voltage of said three-phase AC supply to said electric motor.
2. An improved deep well pumping system accord-ing to Claim 1, also comprising means for sensing temperature of said fluid downhole in order to provide for shutdown in case of ex-cessive temperature rise.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US94079678A | 1978-09-07 | 1978-09-07 | |
| US940,796 | 1978-09-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1117409A true CA1117409A (en) | 1982-02-02 |
Family
ID=25475434
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000333734A Expired CA1117409A (en) | 1978-09-07 | 1979-08-14 | Deep well pumping system |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1117409A (en) |
| DE (1) | DE2934076A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3373326D1 (en) * | 1982-05-29 | 1987-10-08 | Jan Christlieb | Device for the control of a fluid pressure of a turbomachine engine |
| DE3220466A1 (en) * | 1982-05-29 | 1983-12-01 | Jan Dipl.-Ing. 2071 Todendorf Christlieb | Method and arrangement for the fluid-pressure-dependent control of the drive motor of a fluid kinetic machine, in particular of a pump |
| CH651111A5 (en) * | 1982-07-28 | 1985-08-30 | Cerac Inst Sa | PUMPING INSTALLATION AND METHOD FOR ACTIVATING THE SAME. |
| DE3642727A1 (en) * | 1986-12-13 | 1988-06-23 | Grundfos Int | Underwater motor-driven pump |
| JP3642578B2 (en) * | 1993-03-30 | 2005-04-27 | 株式会社荏原製作所 | Pump device |
-
1979
- 1979-08-14 CA CA000333734A patent/CA1117409A/en not_active Expired
- 1979-08-23 DE DE19792934076 patent/DE2934076A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| DE2934076A1 (en) | 1980-03-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |