Note: Descriptions are shown in the official language in which they were submitted.
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BEPARATOP. BYBTEHB FOR WELL PRODUCTION FLUIDS
Field of the Invention
The present invention pertains to single and multi-stage
separator systems, particularly adapted to be interposed in
surface disposed flowlines for separating well production
fluids.
Background
The above-referenced patent application pertains to so-
called downhole, spiral or stationary auger type separator
devices, primarily adapted for separating gas from liquid
being produced from a hydrocarbon fluid production well. In
certain.wells which produce hydrocarbon fluids, for example,
both gas and liquids are produced simultaneously directly from
one or more production zones. Gas and liquid may also be
produced simultaneously from wells which utilize artificial
gas lift or which are producing oil which has been driven to
the production well by pressurized gas injection into the
subterranean reservoir. Accordingly, elaborate and expensive
separation and treatment facilities are usually required to
separate gas from production liquids. In some instances, it
is also desirable to separate more dense gasses or liquids
from less dense gasses or liquids in wells which are producing
various types of hydrocarbon fluids, such as both water and
crude oil, for example.
As well operating conditions change with respect to the
relative amounts of oil and gas being produced, or the
relative amounts of oil,-water and gas, it is often necessary
to modify the separator facilities. Still further, changing
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proportions of oil, water and gas, for example, can cause slug
flow in the fluid production flowlines, and can put undue
loading on all or portions of the existing separator facili-
ties. Moreover, if the separated gas is to be used for
reservoir injection or for artificial gas lift in other wells,
the remote location of conventional separator facilities
usually requires extensive piping to return the gas to the
injection wells or the wells using gas lift.
Downhole separation of gas from liquids can provide a
high pressure gas source for gas lift and for compression by
nearby disposed compressors for reinjection. Downhole
separation will usually also provide higher pressure gas at
the surface due to reduced pressure losses in the flow
conduits. However, insertion of and retrieval of a downhole
separator, such as the types described in the above-mentioned
patent application can be somewhat difficult and expensive to
accomplish. Moreover, changing flow conditions may dictate
a change in the separator position, size or other design
features, and premature wear due to abrasives in the fluid
flowstream may also require repair or replacement of the
separator. Accordingly, a downhole location of the separator
can require expensive and time consuming operations to replace
or repair the separator itself.
On the other hand, surface installation of an inline
spiral or so-called auger type separator may be easily
accomplished by inserting the separator structure in a
conventional flowline with minimal interruption of well
operations and with minimal expense with regard to equipment
costs. Existing valving and controls may be utilized to a
large extent in the flowlines, and no expensive installation
procedures or structures are required, such as support pads,
buildings or other enclosures usually necessary for conven-
tional separator systems. Still further, surface disposed
inline type separators may be arranged in multistage configu-
rations to obtain substantial gas-liquid separation, separa-
tion of gasses and/or liquids of different densities from each
other and/or separation of particulate solids from gas and/or
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liquids. Separation of gas at the surface and adjacent to the
fluid production well may also minimize piping requirements
if the separated gas is required for reservoir injection or
artificial gas lift. Certain processes may also favor sepa-
ration of water from oil and transport of these liquids in
= separate conduits to minimize corrosion problems. For
example, it may be advantageous to separate water or brine
from produced oil and conduct these fluids in separate
flowlines to a process facility and wherein certain corrosion
inhibitors may be injected into the oil or water flowlines to
minimize corrosion. Such arrangements would be beneficial
wherein, for example, the corrosion inhibitors would not be
suitable for mixing with one or the other of the fluids due
to its process requirements. Still further, a mechanically
simple, low cost separator which is at least capable of
partial gas-liquid separation or partial separation of fluids
of different densities is desirable and is particularly useful
for separating produced fluids in many hydrocarbon production
well operations and in other fluid process applications.
Summarv of the Invention
The present invention provides a unique surface flowline
or so-called inline type separator system, particularly
adapted for use in connection with fluid production wells for
separating fluids of different densities including separating
liquid from gas, separating liquids of different densities
from each other and separating particulate solids from a major
portion of a fluid flowstream.
In accordance with one important aspect of the invention,
a separator system is provided for disposition in a surface
flowline between a wellhead and fluid processing or transport
facilities and which includes a so-called stationary auger or
spiral type baffle interposed in a casing in such a way as to
= provide separation of gas from liquid, separation of gasses
or liquids of different densities and separation of particu-
late solids and some fluid from other fluids, for example.
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The present invention is also characterized by a separa-
tor device wherein a spiral or helical type baffle is insert-
able in a casing comprising a portion of a flowline in such
a way as to induce generally spiral or helical flow of fluids
to effect separation of more dense fluids from less dense
fluids and wherein the less dense fluids flow along a general-
ly central flow path within the casing. The system may include
multiple stages of separator devices which are operable to
effect greater separation of gas from liquid, or separation
of gasses of different densities or liquids of different
densities from each other, as desired.
The present invention also provides a spiral, inline type
separator which is particularly adapted to be easily inserted
in a surface flowline leading from a production well or other
fluid source. The separator devices of the invention are
particularly compact and easy to insert in a production fluid
flow network, whether already existing or being newly de-
signed. Only minimal modification to the existing flow
distribution system is required. Moreover, in applications
for separating gas from oil and other liquids, at least
partial separation is easily obtained and the gas may be
routed directly back to an injection well or, in particular,
used for artificial gas lift without further separation steps
being required. If desired, however, the separators may be
easily staged to maximize separation of gas from liquid,
particulate solids from a major portion of the fluid flow-
stream or fluids of different densities from each other.
Still further, the present invention contemplates the
provision of single and multistage, inline, spiral-type
separator systems for fluid flowlines wherein the systems may
be controlled to minimize carryover of fluids into the
,flowline for the separated fluid.
Although the separator systems of the invention are
particularly useful in separating fluids in surface flowlines
leading from fluid production wells, the separator systems may
be utilized in other applications in conjunction with the
production and processing of hydrocarbon fluids as well as
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other fluid processes, inciuding disposition in fluid lines
ahead of flow metering devices.
Those skilled in the art will further appreciate the
above-mentioned features and advar-tages of the invention
together with other superior aspects thereof upon reading the
detailed description which follows in conjunction with the
drawing.
Brief Description of the Drawing
FIGURE 1 is a schematic diagram of a surface flowline
separator system for separating fluids from a production well
in accordance with the present invention;
FIGURE 2 is a schematic diagram of one embodiment of a
multistage separator system for separating fluids from a
production well flowstream;
FIGURE 3 is a longitudinal central section view of one
embodiment of a separator in accordance with the invention;
FIGURE 4 is a longitudinal central section view of an
alternate embodiment of an inline separator in accordance with
the present invention; and
FIGURE 5 is a schematic diagram of an alternate embodi-
ment of a multistage separator system in accordance with the
invention.
Description of Preferred Embodiments
In the description which follows, like elements are
marked throughout the specification and drawing with the same
reference numerals, respectively. The drawing figures are not
necessarily to scale in the interest of clarity and concise-
ness.
Referring to FIGURE 1 there is illustrated, in schematic
form, a hydrocarbon fluid production well 10 which may be
operating to produce a mixture of oil and gas and/or a mixture
of oil, gas and water, for example. The production well 10
has a conventional wellhead 12 and a production fluid flowline
14 connected to the wellhead for conducting the fluid mixture
described above to a suitable processing facility, not shown.
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In accordance with the invention, a unique so-called station-
ary auger or spiral type separator device 16 is connected to
the flowline 14 for receiving the fluid mixture being conduct-
ed therethrough. As shown, more than one production well may
be operably connected to the flowline 14. A second well l0a
is shown by way of example having a wellhead 12 and a produc-
tion fluid flowline 14a connected thereto and to the flowline
14. Those skilled in the art will appreciate that the fluid
stream flowing to the separator 16 may be from several wells,
from only one well, or from another source.
The separator 16 is adapted to separate at least a
portion of the gas in the fluid mixture from the liquid for
discharge from the separator by way of a conduit 18. Liquid
separated from the gas is discharged from the separator 16 by
way of a conduit 20. The liquid conduit 20 is operable to
have a conventional emergency shutdown valve 22 interposed
therein as well as a conventional check valve 24 and a
controllable throttling valve 26 interposed in the conduit 20
downstream of the check valve 24. Fluid leaving the valve 26
may be conducted to a suitable common line, manifold or
processing facility, not shown.
Gas separated from the fluid stream in the separator 16
is conducted through the conduit 18, having a suitable
emergency shutdown.valve 28 interposed therein, and a manual
or motor controlled throttling valve 30 also interposed in the
conduit 18. A suitable pressure sensor and controller 32 is
operable to sense the pressure in the conduit 18 and control
the valve 26 to adjust the flow rate through the conduit 20
so that a suitable controlled flow rate of fluid is provided
through the separator 16. Moreover, the controllable throt-
tling valve or choke 30 is operable to partially throttle the
flow of gas separated in the separator 16 and flowing through
the conduit 18 during s.tartup of the system shown in FIGURE
1, or in response to any substantial changes in the flow rate
through the system.
FIGURE 1 illustrates one final use of the gas separated
from the flowstream in the separator 16. As shown, the
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separated gas may be conducted to a well 34 which is operating
on gas lift to produce fluids through a tubing string 36 in
a conventional manner. Gas may be conducted to the wellhead
38 of the well 34 and down through an annulus provided between
the tubing string 36 and a casing 37 for entry into the tubing
string by way of conventional gas lift valves, not shown.
Accordingly, if the gas leaving the separator 16 is at a
suitable pressure, it may be conducted directly to a gas lift
well, such as the well 34, or a gas injection well 39.
Alternatively, gas flowing in the conduit 18, if sufficiently
free of liquid, may be compressed before further processing,
such as injection into the wells 34 or the injection well 39.
Gas flowing through the conduit 18 may, of course, be conduct-
ed to other facilities for processing, as desired.
Referring now to FIGURE 3, a preferred embodiment of the
separator 16 is shown in detail. The separator 16 is prefera-
bly characterized by an elongated outer, generally cylindrical
casing part 40 having conventional conduit tee fittings 42 and
44 connected thereto at opposite ends. The conduit fitting
42 provides a fluid inlet port 46 and the fitting 44 has a
fluid discharge port 48 for the separator 16. The ports 46
and 48 are disposed, respectively, at 90 degrees or right
angles to the longitudinal central axis 49 of the casing part
40. .
Conventional pipe flanges 50 are suitably connected, such
as by welding, to the conduit fitting 42 and to the conduit
14 for coupling the conduit 14 to the separator 16. In like
manner, conventional pipe flanges 50 are also connected to the
conduit fitting 44 and the liquid discharge conduit 20 for
coupling the liquid discharge conduit to the separator 16.
Still further, conventional pipe flanges 50 are also connected
to the conduit fittings 42 and 44 at one end of the axial
branch of the fittings, respectively, as shown. A blind
flange 52 is connected to the flange 50 at the conduit fitting
42, forming a closure at the inlet end of the separator 16 and
a flange 54 is connected to the flange 50 at the conduit
fitting 44 to form a closure at the opposite end of the
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separator 16. A central axial gas discharge conduit 56
extends through a suitable bore in the flange 54 in fluid
tight engagement therewith and within the conduit fitting 44
and the outer casing 40, as illustrated. The gas discharge
conduit 56 is suitably connected to the conduit 18, as shown,
and to the flange 54.
The separator 16 is provided with an elongated stationary
spiral or helical baffle, generally designated by the numeral
58 extending through the conduit fitting 42, through the
casing 40 and terminating at a discharge end 60. The baffle
58 is formed of relatively thin, platelike, double helical
baffle flights 62 and 64 which are disposed around and formed
integral with or otherwise suitably secured to an elongated
cylindrical hub 66. The hub 66 extends coaxially from the
flange 52 through casing 40 and is connected to the gas
discharge conduit 56. The hub 66 is also suitably journalled
in a boss 70 supported on the flange 52. The term spiral as
used herein is to denote that the flow direction is progres-
sively along an axis, such as the axis 49, and in a somewhat
helical orbital path about such axis through passages 59, 59a,
which are in communication with passages 43 and 45 defined by
the fittings 42 and 44, respectively. The geometry of the
baffle 58 may be a constant or variable pitch helix of
constant or variable inner or outer diameter. The baffle 58
may also be formed of single or multiple flights.
The helical baffle 58 is disposed within an inner,
generally cylindrical tubular casing 72 and the radial
extremities of the helical flights 62 and 64 are preferably
contiguous with the inner wall of the casing 72 but not
necessarily connected thereto. The baffle 58 may be held
stationary with respect to casing parts 72 and 40 by its
connection to conduit 56 and/or the boss 70. The inner casing
72 is coaxially spaced from the casing 40 and is supported in
the casing 40 by opposed spaced apart cylindrical collars 74
at each end thereof to define a closed annular space 76
between the collars and between the casings 40 and 72. The
space 76 is operable to be in communication with a conduit 80
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which may be connected to a suitable pressure sensor 82 to
detect fluid pressure within the annular space 76 in the event
that the casing 72 should become eroded or corroded through.
Due to the high velocities of fluid flowing through the casing
72 and the induced spiral flow of the fluid, any particulate
solids entrained in the fluid flowstream may tend to erode the
conduit 72 to a point where fluid leakage therefrom may occur.
Accordingly, by monitoring fluid pressure in the annular space
76, failure of the casing 72 may be detected.
The operation of the separator 16 is believed to be
within the purview of one of skill in the art of fluid
separators from the foregoing description. However, briefly,
mixed phase fluid entering the separator 16 by way of the
conduit fitting 42 is induced to flow in the substantially
spiral or helical flowpaths 59, 59a through the inner casing
72 under the inducement of the baffle flights 62 and 64. The
spiral or helical flow induced in the fluid by the baffle 58
will cause the more dense fluids to flow toward the inner wall
73 of the casing 72 while less dense fluid, such as gas, will
flow along the spiral flow paths closer to the hub 66. As the
fluid flow discharges from the baffle 58, the less dense
fluid, such as gas, will flow through suitable ports 57 in the
gas discharge conduit 56 and then through the conduit 56 to
the conduit 18. More dense fluid, such as oil or a mixture of
oil and water, will flow into the conduit fitting 44 and then
through the discharge flow path provided by the port 48 and
conduit 20.
The orientation of the separator 16 may be either
substantially vertical, inclined or horizontal as regards the
attitude of the longitudinal central axis 49. As mentioned
previously, a particular advantage of the separator 16 is that
it may be easily interposed in a flowline from one or more
wells at any desired point since the separator 16 is
particularly compact and may comprise a section of the
flowline.
By way of example, a separator 16 having a baffle 58 of
about 140 mm (5.50 inches) outside diameter, a hub diameter of
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57 mm (2.25 inches), a helical pitch of about 152 mm (6.0
inches) and having an overall length of about 1.14 m(45.0
inches) is interposed in a conventional steel inner casing 72
which is disposed in an outer steel casing having a nominal
diameter of 203 mm (8.0 inches). The casing fittings 42 and 44
are formed of conventional steel pipe tee fittings of 203 mm
(eight inch) nominal diameter. The gas discharge conduit 56
is 63.5 mm (2.50 inch) diameter Schedule 160 Steel Pipe with
four 25:4 mm (1.0 inch) diameter openings comprising the gas
discharge openings 57.
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A separator 16 having the above-described dimensions was
tested for separating gas from oil wherein between at least
forty-four percent of the gas in the fluid mixture to as much
as ninety percent of the gas in the mixture was separated and
removed from the separator 16 through the conduit 56. The gas-
to-oil ratio in the fluid mixture entering the separator 16
ranged from 178 to 246 standard cubic meters per litre (10:1
to 13.8:1 (thousands of standard cubic feet per stock tank
barrel)), total gas flow rate ranged from 849 x 103 standard
cubic meters (30 million standard cubic feet) per day to 923 x
103 standard cubic meters (32.6 million standard cubic feet)
per day and the liquid flow rate ranged from 375 to 477 m3
(2,360 to 3,000 barrels) of crude oil per day. Operating
pressures ranged from 11.4 to 12.8 MPa (1650 psi to 1860 psi).
Gas separation was controlled by controlling the flow rate of
gas through the discharge conduit 18 and setting a control
pressure with the sensor 32 and the associated controller for
the throttling valve 26. Operating conditions of the system
illustrated in FIGURE 1 are, thus, controlled by setting a
predetermined gas pressure in the conduit 18 and throttling
the flow of fluid leaving the separator through the conduit 20
to maintain the pressure in the conduit 18 at the set point.
Although partial separation of gas from liquid may be all
that is necessary in operations such as contemplated by the
arrangement of FIGURE 1, wherein the separated gas is used as
lift gas for the well 34, the unique separator 16 may also be
provided in multiple stages to provide more complete
separation of one fluid from another. Referring to FIGURE 2,
for example, there is illustrated a separator system 89
wherein a mixed phase, gas and liquid, fluid stream is being
produced from a well 90 by way of a surface flowline 92 to a separator
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16a. At least separation of gas from liquid in the flowstream
from the well 90 may be accomplished in the separator 16a
wherein a major portion of the gas is discharged from the
separator 16a by way of a discharge line 94 and a major
portion of the liquid is discharged from the separator 16a.
through a discharge line or conduit 96. The conduit 96 is
connected to the inlet casing fitting 42b of a second separa-
tor 16b wherein additional separation of gas from liquid may
occur and substantially gas free liquid may be discharged
through the fitting 44b of separator 16b to a liquid flowline
98. Simultaneously, gas is discharged from the second
separator 16b by way of a gas discharge flowline 100 which may
be connected to the gas discharge line 94 leading to a third
separator 16c which is receiving gas from the discharge line
94 at its inlet fitting 42c and is discharging substantially
gas-free liquid through a liquid discharge line 102. Discharge
line 102 may be connected to the liquid discharge line 98, as
shown.
In the arrangement illustrated in FIGURE 2, substantially
liquid-free gas is discharged from the separator 16c by way
of a discharge conduit 106. Suitable check valves 108 may be
interposed in the respective discharge conduits as illustrated
in FIGURE 2, to prevent reverse flow of fluids into the
respective separators 16a, .16b and 16c. Moreover, if the gas
discharged from the separator 16b is substantially liquid-
free, it may be conducted directly to the gas discharge
conduit 106 by way of a bypass conduit 110. Other series
arrangements of separators 16, 16a, 16b and 16c may be
provided depending on whether or not the respective fluids
being separated are required to be completely free of the
other fluids. The separators 16a, 16b and 16c are virtually
identical to separator 16 except they may be of different
sizes with respect to baffle diameter and pitch, for example,
to more effectively separate expected fluid volumetric flow
rates. Again, the unique advantages of the separator 16 are
applicable to various configurations of single and multistage
separator systems which will be appreciated by those skilled
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in the art from the description of the systems illustrated in
FIGURES 1 and 2.
Although the separators 16, 16a, 16b and 16c are particu-
larly adapted for and useful in separating gas from liquid in
hydrocarbon well production operations, these separators and
the systems disclosed herein may also be used in other fluid
process applications for separating single phase fluids of
different densities from each other and separating particulate
solids from a fluid flowstream by removing the solids from the
flowstream with a portion of a carrier fluid for the solids,
which fluid may be more dense than other fluids in the
flowstream. In other words, particulate solids may be
separated from a flowstream of a fluid of uniform density by
drawing off a portion of the fluid as a carrier for the
particulate solids and allowing substantially solids-free
fluid to flow through the discharge conduit 56 of the separa-
tor 16, for example. The separator system 89, for example,
may also be used to separate oil from water whereby separate
flowstreams of oil and water may be conducted from the system
by way of the conduits 106 and 98, respectively, assuming
water is the more dense fluid.
Referring now to FIGURE 4, there is illustrated another
embodiment of a multistage separator system in accordance with
the invention, generally designated by numeral 112, and also
particularly adapted to separate fluids of various densities
and/or particulate solids from a fluid flowstream being
discharged from a source such as a hydrocarbon fluid produc-
tion well 120, for example. The separator system 112 includes
a multistage spiral baffle type separator 122 having an
elongated, generally cylindrical, tubular, outer casing
section 124, including a fluid inlet end 126 connected to a
suitable flanged inlet conduit 128. The conduit 128 is in
communication with a surface flowline 130 connected to a
conventional wellhead 121 of the well 120. The source
flowstream for the separator 122 may be one or more production
wells or the separator may be interposed elsewhere in a fluid
process flowstream.
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Referring further to FIGURE 4, the outer casing 124
includes a first support web portion 130 adjacent the inlet
end 126 and having plural fluid ports 132 formed therein. A
transverse end wall 134 is formed opposite the inlet end 126
and a fluid discharge port 136 extends generally normal to a
longitudinal central axis 138 of the outer casing 124. An
elongated, stationary multiple diameter baffle 140 is inter-
posed in the casing 124 and includes helical baffle flights
142 and 144 disposed around a generally cylindrical hub 146.
The hub 146 is supported at one end by the web 130, as shown,
extends toward the opposite end of the separator 122 and is
connected to a central axial discharge conduit 148 having
fluid inlet ports 150 formed therein.
The separator 122 includes a second stage defined in part
by a generally cylindrical tubular inner casing part 152
disposed within the casing 124 in concentric relationship
therewith. The 'casing part 152 is, as shown, of smaller
diameter than the diameter of an inner wall 125 of the casing
part 124 and is supported therein by a ported collar 127 and
by the end wall 134. An annular flow channel 156 is formed
between the casing parts 124 and 152 and which is in communi-
cation with the discharge port 136. The inner wall 153 of the
casing part 152 is of a diameter smaller than the diameter of
the baffles 142 and 144. Accordingly, a second stage spiral
baffle is formed having baffle flights 142a and 144a disposed
in the casing part 152 and being contiguous with but of
smaller outside diameter than the respective baffle flights
142 and 144. The casing part 152 has a transverse end wall
158 formed at an end opposite the ported collar 127 and a
transverse fluid discharge port 160 for discharging relatively
dense fluid separated in the separator section formed by the
baffle flights 142a and 144a and the casing part 152. The
port 160 defines a flow path extending generally normal to the
axis 138 also. The baffles 142, 142a, 144 and 144a define
spiral passages 145 and 145a in communication with the inlet
conduit 128 and discharge passages 137 and 161.
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The separator 122 is operable to separate fluids of at
least three different densities from each other and/or to
separate particulate solids from one or two fluids of differ-
ent densities flowing through the separator. A mixed phase
flowstream having fluids of different phases and different
densities, a single phase fluid flowstream having fluids of
different densities and/or a fluid flowstream having particu-
late solids entrained therein may undergo at least partial
separation in the separator 122. Fluid entering the inlet
conduit 128 will flow through the separator section defined
by the baffles 142 and 144 wherein the spiral flowpath induced
in the flowstream will cause the more dense fluid and particu-
late solids, for example, to move toward the inner wall 125
and enter the annular channel 156 at the inlet end of the
casing 152 through the ported collar 127. Lower density fluid
or fluid mixture will flow through the separator stage defined
by the baffles 142a and 144a wherein the more dense fluid of
such a mixture will flow along the wall 153 and the less dense
fluid of the mixture will tend to flow along the hub 146 and
enter the ports 150 of the discharge conduit 148. Fluid
flowing along or tending to move toward the wall 153 will flow
out of the separator through the discharge port 160.
By way of example, a multiphase fluid flowstream compris-
ing crude oil, water and natural gas may.be separated by the
separator 122 wherein water will be separated by the separator
stage defined by the baffles 142 and 144 to flow out of the
separator through the annular flowpath 156 and the discharge
port 136. A mixture of oil and gas will enter the separator
stage defined by the baffles 142a and 144a wherein separation
of gas from liquid will occur in the same manner as described
above for the separator 16 whereby gas will flow out of the
separator through the conduit 148 and liquid, such as crude
oil, will flow out of the separator through the discharge port
160.
The separator 122 may also operate to separate liquids
of different densities and separate particulate solids
entrained in the flowstream, which are likely, depending on
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their density, to migrate toward the wall 125 and be dis-
charged through the annular passage 156 and the discharge port
136 with some of the most dense carrier fluid in the mixture.
Accordingly, the multistage separator 122 may effectively
separate water, gas and oil at a point directly downstream of
a source of a mixture of these fluids, such as a hydrocarbon
fluid production well, for example. The separated oil, water
and gas may be conducted separately to disposal or to uses in
accordance with a system for handling these fluids without
requiring transport of the fluids long distances to more
elaborate separator facilities.
The configuration of the separator 122 is advantageous
in some respects in that the inlet conduit 128 is coaxial with
the baffle longitudinal axis, which axis is coincident with
the axis 138. on the other hand, the configuration of the
separator 16 is advantageous in that, by providing for the
inlet port 46 and outlet port 48 to be transverse to the axis
49, the baffle 58 may be removed from one end or the other of
the separator by removal of the flange 52 or 54, for example,
without disassembling the flowlines 14 or 20.
Referring now to FIGURE 5, a separator system 166 in
accordance with the invention is illustrated wherein a
multiphase fluid stream including entrained solids, for
example, is conducted to a first stage separator 16 by way of
a conduit 170. Gas is separated from the fluid stream in the
separator 16 and discharged by way of a discharge conduit 172
connected to the conduit 56. More dense fluid, such as liquid
together with entrained solids, is discharged from separator
16 through conduit 176. A suitable sensor 174 is interposed
in the conduit 172 which may comprise a densitometer or a
liquid droplet detector, for example. If excessive carryover
of liquid and/or entrained solids is occurring through the
conduits 56 and 172, the fluid stream being discharged
therethrough may be controlled by a motor operated throttling
valve 178 interposed in conduit 172 to control the amount of
gas flowing through the separator 16 that is removed by way
of the conduits 172 and 56. Alternatively, a sensor 174a may
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be interposed in conduit 176 also, and be operable to control
valve 178 if the composition of the fluid leaving the separa-
tor by way of conduit 176 is not in a desired range.
The conduit 176 is shown connected to the inlet port 180
of a second stage separator, generally designated by the
numeral 182. The separator 182 is similar in some respects
to the separator 16 except that the center conduit 56 is
removed and a transverse fluid discharge port 184 is provided
in a modified inner casing 186 similar to the inner casing 72
of the separator 16. However, the port 184 intersects the
flowpath of fluid flowing through the stationary spiral baffle
58 upstream of the discharge end 60 of the baffle. The outer
casing 40 is also modified to provide for the transverse
discharge port 184. The baffle 58 is supported in casing 186
and may be connected to a flange 52 at boss 70 by way of the
hub 66. The fluid taken off from the separator 182 through
the discharge port 184 is conducted through a conduit 190.
Fluid not taken off through the discharge port 184
progresses through an axial discharge port 194 downstream of
the baffle 58 to a discharge conduit 196 also having a
suitable sensor 198 interposed therein for detecting liquid
carryover, the composition of fluid flowing from the port 194
(such as a water-oil mixture) or the presence of solids in the
fluid flowstream. The sensor 198 is operably connected to a
controller for a motor operated valve 192 to control flow of
fluid through the discharge port 194 and the conduit 196 to
modify the carryover of the undesired component through the
discharge port 194. The port 194 is formed in back to back
flanges 50 suitably connected to casings 40 and 186 and also
forming a passage 195 in communication with port 194. The
axial passage 195 is also defined in part by the inner wall
187 of casing 186. Alternatively, as shown in FIGURE 5, a
sensor 198a may be interposed in the fluid discharge conduit
190 and responsive to the composition of the fluid flowing
therethrough to control the motor operated throttling valve
192. Accordingly, the sensors 174 and 198, or the sensors
174a and 198a, may be interposed in the separator system 166,
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as shown, and operate on the respective valves 178 and 192 to
prevent conduction of components of the fluid flowstream
through the respective conduits 172 and 196 that are unwanted
in these conduits.
The system illustrated in FIGURE 5 may further comprise
a separator 16d similar to the separator 16 but having a
smaller diameter baffle 58d to accommodate the smaller
quantity of fluid being discharged from the separator 182 by
way of the conduit 196. The separator 16d may be operated to
separate liquids of two different densities, for example,
water from oil, wherein oil would flow from the separator 16d
by way of a discharge conduit 200, connected to a center
discharge conduit 56d, and the more dense fluid, typically
water, would flow out of 'the separator 16d through the
peripheral or transverse discharge port 48d and a discharge
conduit 202.
The separator system 166 illustrated in FIGURE 5 may be
operated in different modes. For example, assuming that a
fluid flowstream being conducted through the conduit 170
comprises a mixture of oil, water, gas and entrained particu-
late solids, separation of gas from the remainder of the
mixture may be accomplished in the separator 16 wherein
substantially all of the gas in the mixture is conducted
through the discharge conduit 172 and the more dense mixture
of oil, water and some entrained solids is discharged from the
separator 16 by way of the conduit 176. If the sensor 174
indicates that an excessive amount of liquid is being carried
over into the discharge conduit 172, the flow through the
valve 178 may be adjusted to modify this carryover flow.
Fluid discharged from the separator 16 by way of the
conduit 176 enters the separator 182 wherein, for example,
some liquid and entrained solids are likely to be centrifuged
to the periphery of the baffle 58 and flow out of the separa-
tor 182 by way of the discharge port 184 and the conduit 190.
If the sensor 198 indicates that excessive solids, or a water
and oil mixture, is being discharged through the passage 195
to conduit 196, the flow through the conduit 196 may be
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adjusted by the throttling valve 192. Assuming that entrained
solids are removed from the system 166 by way of the separator
182 and the conduit 190, a mixture of water and oil, for
example, may be discharged from the separator 182 by way of
conduit 196 which is connected to the inlet port 46d of
separator 16d. Separation of water from oil may occur in
separator 16d with water leaving the separator 16d by way of
conduit 202 and less dense oil by way of the center conduit
56d and discharge conduit 200 connected thereto.
The system 166 shown in FIGURE 5 may be operated in
another mode. Assuming that the fluid mixture entering the
separator 16 by way of conduit 170 is a mixture of gas and
liquid, the separator may operate to separate a sufficient
amount of gas to provide a substantially dry gas flowstream
leaving the separator 16 by way of the conduits 56 and 172
while some gas and all liquid will leave the separator 16 by
way of the port 48 and conduit 176. Accordingly, a two-phase,
gas and liquid mixture enters the separator 182 wherein
substantially gas-free liquid may be taken off from the
separator by way of the discharge port 184 and conduit 190
leaving a smaller flow rate two-phase mixture discharging from
the separator 182 by way of conduit 196. Finally, remaining
separation of gas from liquid could be effected in separator
stage 16d. With this type of operation, substantially liquid-
free gas is conducted from the system 166 by way of conduit
172 and substantially gas-free liquid is conducted from the
system by way of conduit 190.
Moreover, it is contemplated that one or more of the
separators and systems described above may be used to separate
liquids of two different densities, such as oil from water,
wherein a water-in-oil or oil-in-water emulsion has occurred,
for example. Such operation may be particularly beneficial for
well production operations wherein a water-oil emulsion is
being produced and otherwise requires rather elaborate
separation equipment and facilities to break the emulsion.
The separators 16, 16a, 16b, 16c, 16d, 122 and 182 may
be constructed using conventional engineering materials used
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in oil and gas processing equipment and facilities. The
operation of the separators described above is believed to be
within the purview of one skilled in the art from the forego-
ing description. Those skilled in the art will appreciate
that a particularly compact, mechanically uncomplicated and
easy to operate separator system can be provided utilizing the
separators 16, 16a, 16b, 16c, 16d, 122 and 182. These
separators may, as mentioned above, be arranged in different
configurations in parallel or series staging and the above-
described systems are exemplary but advantageous arrangements.
Although preferred embodiments of the invention have been
described in some detail herein, those skilled in the art will
recognize that various substitutions and modifications may be
made to the invention without departing from the scope and
spirit of the appended claims.
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