U.S. patent number 3,624,822 [Application Number 05/029,474] was granted by the patent office on 1971-11-30 for gas separator for a submersible oil pump.
This patent grant is currently assigned to Oil Dynamics, Inc.. Invention is credited to Joseph T. Carle, Charles L. Choate.
United States Patent |
3,624,822 |
Carle , et al. |
November 30, 1971 |
GAS SEPARATOR FOR A SUBMERSIBLE OIL PUMP
Abstract
A gas separator interposed between a submersible pump and
electric motor includes a plurality of flow diversion means
including a coaxial impeller for impelling well fluid through a
spiral gas separator chamber wherein entrained gas is centrifugally
separated from the well fluid. The disentrained gas is subsequently
returned to the well fluid basin while the well fluid passes from
the gas separator chamber into the inlet of a submersible pump.
Inventors: |
Carle; Joseph T. (Tulsa,
OK), Choate; Charles L. (Tulsa, OK) |
Assignee: |
Oil Dynamics, Inc. (Tulsa,
OK)
|
Family
ID: |
21849191 |
Appl.
No.: |
05/029,474 |
Filed: |
April 17, 1970 |
Current U.S.
Class: |
417/313; 55/472;
96/214; 96/217; 55/385.1; 166/105.5 |
Current CPC
Class: |
E21B
43/38 (20130101); F04D 9/002 (20130101) |
Current International
Class: |
E21B
43/38 (20060101); E21B 43/34 (20060101); F04D
9/00 (20060101); F04b 021/00 (); F28d 015/00 () |
Field of
Search: |
;417/313
;166/105.6,105.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Walker; Robert M.
Claims
What is claimed is:
1. A gas separator for a submersible well pump for pumping well
fluid from a well basin comprising:
a housing having at least one inlet adapted to admit well fluid
within the interior thereof and at least one outlet in
communication with the inlet of said submersible well pump;
a rotatable impeller within said housing and within the flow path
of said well fluid and adapted to assist said submersible pump in
transferring well fluid from said inlet to said outlet, said
impeller including means for imparting centrifugal force to said
well fluid during transfer thereof whereby gases entrained in said
well fluid are disentrained therefrom;
a cylindrical gas separator chamber disposed within said housing
between said impeller and said outlet and adapted to receive well
fluid from said impeller and conduct same to said inlet of said
pump; said gas separation chamber including an internal
gas-collecting receptacle in communication with the well fluid
basin and the output of said impeller for receiving gas
centrifugally separated from said well fluid; said gas separation
chamber further including outwardly of said gas-collecting
receptacle a spiraled passageway through which said well fluid
upwardly passes from said impeller to said pump unit; said
passageway being in communication with said gas-collecting
receptacle whereby gas disentrained from said well fluid during
passage therethrough enters said receptacle and subsequently back
into said well basin.
2. A gas separator as in claim 1 wherein said housing is comprised
of:
a plurality of cylindrical cups each including a downwardly
extending inset portion, said cups being longitudinally nested to
form said cylindrical longitudinal housing such that said inset
portions on each cup extend downwardly into the next lower cup;
each cup including at least one transverse aperture for admitting
well fluid within the interior of said housing whereby said well
fluid flows downwardly into the inlet of said impeller.
3. A gas separator of claim 2 wherein the transverse apertures of
each cup increase in area progressively upward.
Description
BACKGROUND OF THE INVENTION
This invention relates to gas separators and more particularly to a
gas separator for use with a submersible pump for oil and gas
wells.
In oil and gas well operation, it is common practice to utilize a
submersible pump having therebelow and coupled thereto an electric
driving motor.
In oil and/or gas wells in which the submersible pump is to be
installed, free and/or entrained gas is produced along with the
well fluid being pumped. If this gas enters the submersible pump
the volumetric and mechanical efficiency of the pump is reduced and
in some instances produces a gas lock of the pump.
It is therefore an object of this invention to present a gas
separator for use with a submersible pump which substantially
prohibits entrance of the gas into the inlet of the submersible
pump.
SUMMARY OF THE INVENTION
Generally the gas separator of this invention is interposed between
a pump and the electric driving motor therefor and comprises a
housing containing within the interior thereof an impeller which
assists the propulsion of well fluid normally on its flow to the
pump intake through a separation chamber where gas is centrifugally
disentrained from the well fluid. The disentrained gas passes into
and through a gas-collecting receptacle and subsequently is
returned back into the well fluid basin while the well fluid
progresses from the gas separation chamber into the inlet of the
pump. The inlet to the impeller includes a plurality of vertically
nested inlet cylinders or cups through which the flow of fluids is
controlled.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 of the drawings is a partial cross-sectional view of the
lower segment of the gas separator of this invention showing the
same longitudinally disposed within a well casing.
FIG. 2 of the drawings is a partial cross-sectional view of an
intermediate portion of the gas separator.
FIG. 3 is a partial cross-sectional view of the upper portion of
the gas separator of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The gas separator of this invention generally denoted as the
numeral 10 is interposed between a pump designated as block 12 on
the drawings and pump-driving motor denoted as block 14. The pump
is driven by motor 14 through a coaxial shaft 16 extending
longitudinally through gas separator 10. Suitable splines 18 are
provided on shaft 16 for appropriate connections with the
respective shafts of the pump and motor.
The interconnected pump, gas separator 10, and pump driving motor
14, form an integral unit for insertion within the casing 20 of an
oil or gas well. When received within the well casing 20, the outer
wall of separator 10 is spaced relative to the inner wall of the
well casing so as to permit flow of well fluid 22 therebetween.
Well fluids may include oil, gas and water or combinations thereof.
In operation gas separator 10 is at least partially submerged in
the well fluid basin and preferably totally submerged therein.
The separator 10 is composed of a plurality of inlet cup members
coaxially assembled or nested. A base member 24 is provided at the
lower end thereof with a flange 26 for connection with a mating
flange on the housing of pump-driving motor 14 in a conventional
manner and includes a hollow interior within which shaft 16 is
splined or otherwise coupled to the shaft of motor 14.
The upper end of base member 24 is provided with an upstanding
circular flange having, in this instance, outer peripheral threads
for engaging the lower end of an elongated cylindrical housing 28
which terminates its upper end by connection with a tubular adapter
30 having a plurality of longitudinal fluid apertures 32. The
adapter 30 is outwardly notched to form a circular receiving
surface 34 which receives and carries the lower edge of a
cylindrical cup support 36. A plurality of transverse oval ports 38
are adjacent the upper end of support 36.
The upper peripheral edge of cup support 36 is flat to receive
longitudinally nested cylindrical cup members 40A, 40B, 40C, 40D
and 40E. Each cylindrical cup member includes an upper portion and
at the lower end thereof a downwardly projecting inset portion 42
with an interlocking surface 44 to receive the next adjacent cup
member therebetween.
Lip portion 42 of lowest cup member 40A projects downwardly into
the interior of cup support 36. The interlocking surface 44 of the
highest cup member 40E receives the lower end of a head member 46
which in turn is appropriately secured to the housing of pump 12.
Each of the cup members 42A-42E contains therein a plurality of
rectangular transverse inlet ports 48 providing access means for
well fluid 22 to enter the interior of gas separator 10.
Progressing upwardly from the lowest to the highest cup member the
area of ports on each succeeding cup member increases to that the
volume of well fluid 22 capable of entering the interior of the gas
separator through each of the ports also increases from the lowest
to the highest cup member.
Turning now to the internal components of gas separator 10,
coaxially received over the shaft 16 is a longitudinal sleeve 50,
which may be comprised of a plurality of separate nested
sleeves.
Secured to base member 24 by bolts and extending upwardly therefrom
is a coaxial impeller support 52 which rotatably carries an
impeller 54 coaxially affixed to shaft 18 for common rotation
therewith. Bearings 56 support the rotation of the impeller.
Impeller 54 has therein a plurality of longitudinal openings 57
defining an impeller inlet and outlet.
Coaxially received over shaft 16 directly above impeller 54 is a
gas separation chamber 58 composed of an elongated core 60 and
possessing an internal gas annulus 62 which communicates with the
well basin through upper port 64, and with the outlet of impeller
54 through port 66.
Progressing horizontally outwardly and upwardly from the bottom of
the top of the outer wall of core 60 is an upwardly inclined
spiraled flange 68 the outer edge of which is bounded by a coaxial
encompassing member 70 sleeved thereover and extending downwardly
to rest on impeller support 52. The coaxial superpositioning of
encompassing member 70 over core 60 and flange 68 creates an
annular impeller outlet chamber 72 for accepting fluid expelled by
impeller 54 and a continuous enclosed upwardly spiraled passageway
74 through gas separation chamber 58 communicating at the lower end
thereof with impeller outlet chamber 72. Intermediate the
convolutions of flange 78 transverse ports 76 enable passageway 74
to communicate with gas receptacle 68 at a plurality of points.
Gas separation chamber 58 terminates with an upwardly progressing
circular flange 78 having the upper outer peripheral edge thereof
notched to engage the inner lower edge of tubular adapter 30.
Threadably received in the inner threads of adapter 30 is the lower
end of a tubular member 80 projecting upwardly through cup support
36 and cup members 40A-40E to threadably engage at the upper end
thereof the internal threads of head member 46. Tubular member 80
divides the upper portion of the gas separator into an elongated
annular well fluid outlet passageway 82 communicating with the
inlet of the pump and an elongated annular well fluid inlet
passageway 84 which communicates through apertures 32 in adapter 30
with the annular spacing between encompassing member 70 and cup
support 36 to provide a well fluid flow route to the inlet of
impeller 54.
As can be best seen by FIGS. 2 and 3 of the drawings ports 48 and
the lip portions 42 associated therewith form tributaries feeding
well fluid 22 into inlet passage 84. Thus well fluid entering
through inlet ports 48 in the cup members is channeled downwardly
into inlet passageway 84 and subsequently into the inlet of
impeller 54.
OPERATION
In operation, a stream of well fluid 22 along with any free and
entrained gas molecules enters the separator through inlet ports 48
in the longitudinal cup members 40A-40E (depending on the level)
and also through the ports 38 in cup supports 36. The fluid is then
channeled downwardly by lip portions 42 into well fluid inlet
passageway 84 and continues downwardly through the spacing between
the encompassing member 70 and the wall of cup support 36 to the
inlet of the impeller 54. During the downward flow of well fluid
22, a portion of the entrained gas molecules becomes disentrained
for which reason the receiving of the greatest volume of well fluid
in ports 48 in the upper cup members is desirable.
Impeller 54, rotating at same revolutions per minute as the shaft
16, creates a suction force of sufficient magnitude to reverse the
flow of well fluid 22 and to draw the same upwardly into the inlet
thereof. The well fluid exiting from the outlet of impeller 54 into
outlet chamber 72 has imparted thereto a centrifugal force which
frees an additional portion of the gas molecules entrained in the
well fluid and also drives well fluid 22 upwardly into spiraled
passageway 74. The freed gas molecules due to the high pressure
thereof pass through port 66 into gas receptacle 62 and from thence
through port 64 back into the well basin.
During the passage of well fluid through passageway 74 the
centrifugal force disentrains from the well fluid substantially all
of the remaining gas molecules which due to the high pressure
thereof pass through apertures 76 into gas receptacle 62 and
subsequently back into the well fluid basin.
Substantially gas-free well fluid 22 exits from spiraled passageway
74 into outlet passageway 82 where the suction of pump 12 draws the
well fluid into the pump inlet from whence the fluid is pumped into
fluid-gathering systems.
During the description of preferred embodiments specific language
has been used for the sake of clarity, however, it is to be
understood that the words used are not words of limitation and
include all equivalents which operate in a similar manner to
accomplish a similar purpose.
* * * * *