Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
  • B04C5/00—Apparatus in which the axial direction of the vortex is reversed
  • B04C5/24—Multiple arrangement thereof
  • B04C5/28—Multiple arrangement thereof for parallel flow
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/34—Arrangements for separating materials produced by the well
  • E21B43/38—Arrangements for separating materials produced by the well in the well
  • E21B43/385—Arrangements for separating materials produced by the well in the well by reinjecting the separated materials into an earth formation in the same well
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
  • B04C5/00—Apparatus in which the axial direction of the vortex is reversed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
  • B04C5/00—Apparatus in which the axial direction of the vortex is reversed
  • B04C5/08—Vortex chamber constructions
  • B04C5/081—Shapes or dimensions

Definitions

• the present invention relates to apparatus and methods for the separation of liquids of differing densities in production streams from underground wells. More particularly, the invention relates to the downhole hydrocyclonic separation of a oil
• Hydrocyclones are compact, centrifugal separators with no moving parts
• plurality of hydrocyclones are typically mounted within a pressure vessel assembly.
• Such an assembly resembles a shell-and-tube heat exchanger, in that the
• hydrocyclones are mounted to tube sheets which are sandwiched between flanges in the pressure vessel.
• the complete pressure vessel assembly typically has a single
• dry oil stream will typically contain about 50 per cent water, by volume, and may
• Multi-stage separator assemblies including multiple hydrocyclones
• Hydrocyclones are also useful for making a preliminary separation of oil from
• the production liquids may comprise about 70 per cent, or more, water. Conventionally, this water must be transported above
• PCT International Application WO 94/13930 discloses a
• each hydrocyclone extending through the wall of the housing and having an opening external of the
• the present invention overcomes the deficiencies of the prior art.
• a downhole separation assembly comprising an axially elongate tubular housing defining an internal chamber, and having at least one inlet which is arranged to allow production fluid to
• At least one hydrocyclone separator is contained in the chamber and has an inlet open to the chamber so that the production fluid in the chamber enters each separator.
• An overflow outlet and an underflow outlet are provided for
• each separator and are connected to pipes which lead out of the chamber.
• the walls of the housing and the well casing can be reduced to only that which is
• the well casing may be used as the housing, in which case the
• chamber is defined by the well casing and a pair of axially spaced packers which are
• the separation apparatus preferably
• a pumping unit which pumps production liquids into the chamber.
• a second pumping unit may also be provided, if necessary, to transport the dry oil stream to the surface. If, on the other hand, the pressure in the well bore is sufficiently high that no upstream pumping is required, the housing can be provided with a plurality of
• the size of the apertures may be smaller than the size of any of the passages within the housing and separators), to avoid a flow blockage of the separators) by any solid matter in the production fluid.
• a plurality of axially spaced separators are disposed in the chamber.
• the overflow stream will leave the chamber at one end
• each hydrocyclone separator may be limited, because the head by its nature is the widest part of a hydrocyclone separator. At such locations,
• the pipe may be formed with a non-circular cross section having substantially the same cross-sectional area as do the adjacent portions of the pipe.
• the pipe may be formed with a non-circular cross section having substantially the same cross-sectional area as do the adjacent portions of the pipe.
• non-circular cross section may be substantially kidney-shaped.
• Figure 1A is a schematic which depicts a down hole hydrocyclone separator assembly in accordance with the present invention shown in a simplified axial cross-
• Figure 1B is a schematic illustration of the embodiment of the invention depicted in Figure 1A, in radial cross-section taken through section 1B-1 B;
• Figure 2A depicts a schematic representation of an embodiment of the present
• Figure 2B depicts in axial cross-section a schematic representation of a first
• Figure 2C depicts in axial cross-section a schematic representation of a second sub in accordance with the embodiment of the invention illustrated in Figure 2A;
• Figure 2D depicts in axial cross-section a schematic representation of a third sub in accordance with the embodiment of the invention illustrated in Figure 2A;
• Figures 3A and 3B are each broken axial section views of portions of a down
• Figure 4A, 4B, and 4C are each broken axial section views of portions of a
• Figure 4D is a radial cross-section view of the embodiment illustrated in Figure
• Figure 4E is a radial cross-section view of the embodiment illustrated in Figure 4B taken through section B-B.
• the separator assembly preferably comprises a housing 10, a hydrocyclone 2, and an internal chamber 20 defined by the inside diameter of housing
• upper and lower support plates 3 and 4, respectively, may be
• manifold 7 and an underflow manifold 8 extend through chamber 20 and are
• Manifolds 7 and 8 are both firmly affixed to both support plates 3 and 4.
• Hydrocyclone 2 is preferably of a well known de-oiling configuration such as
• An underflow pipe 6 is hydraulically connected to the underflow outlet 19 of the hydrocyclone separator
• outlet pipe 5 is connected to the overflow outlet 15 of hydrocyclone separator 2, and
• assemblies 13 are run into the cased well bore with minimal clearance between the exterior wall of housing 10 and the interior wall of the well casing. Production fluid,
• hydrocyclone 2 In hydrocyclone
• the production fluid is separated into a clean water stream which flows to the underflow and a dry oil stream which flows to the overflow as is well known in the art.
• the clean water stream is enriched in water relative to the
• the underflow from the hydrocyclone separator 2 flows through the underflow outlet pipe 6 to underflow manifold 8, and is preferably transported downhole below assembly 13 for disposal or rei ⁇ jection into the formation.
• assemblies 13 are disposed between two axially spaced packers, a lower packer 93 and an upper packer 95.
• Upper packer 95 is optional. Upper packer 95 is used when
• disposal liquid such as water
• water is to be disposed above the separator assembly; or when it is desirable to prevent the production fluids from perforations 90 from flowing
• top separator assembly 13A Two such separator assemblies, top separator assembly 13A and bottom
• separator 13B are shown, although any number of separator assemblies 13 may be used without departing from the scope of the present invention. It should be appreciated that separator assemblies 13A and 13B are substantially the same as separator assembly 13 described with respect to Figure 1A, and like reference
• a production pump 31 is provided for pumping the production fluids and an
• overflow pump 32 is provided for pumping the overflow (dry oil) stream to the surface.
• Pumps 31 and 32 are driven by drive means such as one or more drive motors 30.
• pumps 31 and 32 may be electric
• Pumps 31, 32 and drive motor 30 are preferably disposed above separator assemblies 13A, 13B to simplify connection to a power source (not shown) which
• separator assemblies 13A and 13B illustrates only two separator assemblies 13A and 13B, any number of such assemblies may be used in conjunction with the apparatus described immediately below.
• Separator assemblies 13 are thus modular, and the number of such modules used should be determined in practice by the desired overall capacity, available
• a first or top sub 41 is preferably disposed
• Sub 41 preferably includes
• Passage 111 allows the production fluids from the
• a second or connecting sub 42 preferably is disposed between any two of separator assemblies 13, such as separator assemblies
• Sub 42 preferably includes a passage 211 for the pumped production fluids, an overflow passage 72, and an underflow passage 82. Passage 211 hydraulically interconnects
• Overflow passage 72 hydraulically interconnects the overflow manifolds 7A and 7B of any two separator assemblies 13 adjacent to sub 42, such as top separator assembly 13A and bottom
• a third or bottom sub 43 preferably is disposed between the bottom separator assembly 13B and lower packer 93.
• Sub 43 preferably is disposed between the bottom separator assembly 13B and lower packer 93.
• Underflow passage 83 hydraulically connects the underflow manifold 8B of
• production fluids are drawn into production pump 31 and pumped
• production fluids also pass through production passage 211 in second sub 42 and, as
• overflow pump 32 which then pumps the overflow through recovery pipe 74 extending to the surface. In wells with sufficient natural reservoir pressure, overflow pump 32 is not 0 required.
• any number of modular separator assemblies 13 may be used without o departing from the scope of the present invention.
• the separator assembly 113 comprises a housing 100 defining an internal chamber 120
• first sealing block 102 seals the lower end and second sealing block 103 seals the
• a production fluid inlet may be provided to separator assembly 113 in
• sealing block 102 is preferably provided through the appropriate sealing block.
• the housing 100 is preferably provided with a
• hydrocyclone 105 preferably are arranged in parallel within housing 100.
• separators 104 and 105 have a de-oiling configuration which is well known in the art. Both separators 104 and 105 have one or more tangential inlets 106 which are open to the interior of separators 104 and 105. Although the inlets are illustrated as being
• An underflow pipe 107 is connected to the underflow outlet 115 of the upper
• hydrocyclone separator 104 and leads down the chamber 120 past the lower
• first underflow outlet pipe is provided with a non-circular portion 107A which, in plan,
• the pipe underflow pipe 107 may have a substantially kidney-shaped cross section. This cross-sectional configuration ensures that the cross-sectional area of the pipe underflow pipe 107 remains substantially unchanged as the non-circular portion 107A of underflow pipe 107 passes the head of lower separator 105, despite the limited space available adjacent to the head 117 of the second separator 105.
• This cross-sectional configuration ensures that the cross-sectional area of the pipe underflow pipe 107 remains substantially unchanged as the non-circular portion 107A of underflow pipe 107 passes the head of lower separator 105, despite the limited space available adjacent to the head 117 of the second separator 105.
• non-circular portion 107A is not necessary, so long as the cross- sectional area of underflow pipe 107 is maintained substantially constant. It should
• non-circular portion 107A may include a plurality of pipes
• the underflow outlet pipe 107 leads to a manifold 108 which is shown as a part of the second
• the underflow outlet 119 of the lower separator 105 is also connected to manifold 108 so that the underflow streams from the two separators 104,
• an overflow outlet pipe 109 leads from the outlet 121 of lower separator 105 past the upper separator 104, and the overflow stream from lower
• separator 105 combines with the overflow stream from outlet 110 of the upper
• separator 104 in a manifold (not shown) similar to manifold 108, which then passes
• first sealing block 102 It should be appreciated that it is most desirable to maximize the size of the
• head 117 must accommodate not only underflow manifold 107 and overflow manifold 108 but must also leave adequate flow area for the production fluids flowing by head 117 to feed other separators in the assembly.
• separator assembly 113 (as well as separator assembly 13, Figure 1A) is preferably simplified by the use of many standard pipe
• the diametrical clearance may be as small as one sixteenth of an inch. No clearance is required for the flow of production fluids, as in the prior art, since chamber 20 is open to the flow of production fluids. Production fluids flood the
• T e production fluids in the internal chamber 120 which have been either pressurized by a pump or is naturally under pressure, enters the two separators 104, 105 through
• the clean water stream is enriched in
• underflow from the two separators flows through the second sealing block 103, and may then be transported downhole for disposal or reinjection via outlet 184.
• the dry oil stream from the overflow flows up through the first sealing block 102 and then to
• a common underflow outlet pipe is preferably progressively larger in cross-sectional area as it
• a common overflow outlet pipe is preferably progressively larger in cross-sectional area as it extends up the chamber, because the overflow outlet
• assemblies such as assembly 113 having two hydrocyclones in
• a capacity of up to 4,000 barrels of production fluid per day may be achieved with such a two hydrocyclone assembly.
• the cross-sectional area of the head of each hydrocyclone 104 and 105 may be one- half or greater than the cross-sectional area of the housing 100. II is preferable to maximize this ratio to maximize the capacity of the separator assembly.
• housing 100 is used for manifolds 107, 108 and the flow of production fluids.
• the separator assembly 313 comprises a tubular housing 300 defining an internal chamber 320 which is sealed at an upper end by a top adapter 310 and at a lower
• top adapter 310 and bottom adapter 380 are secured to housing 300 by threaded collars 311 and 321 , respectively.
• Separator assembly 313 may alternatively be reversed, so that adapter 310 is disposed at the lower end and adaptor 380 is disposed at the upper end.
• a production fluid inlet may be provided in either of two ways. First, if a
• production fluid pump is provided above the top adapter 310 (such as production
• chamber 320 is provided through the appropriate adapter, such as shown in adapter
• the housing 300 may be provided with a plurality of apertures, such as holes 361 B, or slots (not shown), or screened
• adapter 310 to the bottom adapter 380 by reference numerals 301 , 302, 303, 304, and 305, are preferably arranged in parallel within housing 300.
• hydrocyclone separators have a well known de-oiling configuration as is well known in
• Each of the separators has one or more tangential inlets (not shown, but
• An underflow pipe 360 connects each of the underflow outlets of the
• hydrocyclone separators 302, 303, and 304 to an underflow manifold 340.
• an underflow pipe 360A connects the underflow outlet of the top hydrocyclone 301 to underflow manifold 340.
• Underflow pipe 360A may vary slightly
• Underflow manifold 340 forms the top inlet of underflow manifold 340.
• Underflow manifold 340 extends down through the chamber 320 and past the lowest hydrocyclone 305, into bottom adapter 380.
• the underflow from hydrocyclone 305 also leads to bottom adapter 380, so that the underflow stream from all of the hydrocyclone separators 301 - 305 is
• bottom adapter 380 The underflow from hydrocyclone 305 communicates with the bore 381 of bottom adapter 380, as does
• manifold 340 may be provided with a non-circular portion 340A which, in plan, may
• non-circular portion 340A may have
• manifold 340 and overflow manifold 330 shown in Figure 4E adjacent head 117 of a separator may be cast into one piece which includes two flow passages therethrough,
• a one piece casting further reduces the cross-sectional area required to by-pass head 117 by manifolds 330, 340. If space
• non-circular portion 340A need not be provided.
• overflow outlet pipes 370 connect the overflow outlet of each of the
• overflow manifold assembly 330 is preferably substantially larger in cross-sectional area than that of overflow manifold
• the outside diameter of housing 300 is preferably less than the inside
• the well casing diameter may be measured prior to running the
• housing 300 may comprise the well casing itself, which further increases the diameter of separator assembly 313 and increases capacity.
• the specialty parts required may include the top adapter 310, bottom adapter 380, the non-circular portions 340A (if necessary) of underflow
• separator assembly 313 In use, the installation and operation of separator assembly 313 is as described above with reference to separator assembly 113, which is illustrated in Figures 3A and 3B. Separator assembly 313 is capable of substantially greater
• assemblies such as assembly 313 having five standard sized
• housing 300 is about 24 feet. Such an assembly is suitable for use in 7 inch well casing. A capacity of up to 10,000 barrels of production fluid per day can be
• housing 300 is about 0.3 or greater. This ratio is smaller than 0.5 because standard- sized hydrocyclones were used. It is preferable to maximize this ratio to maximize the

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• 1997
  • 1997-01-13 EP EP97900336A patent/EP0874694B1/de not_active Expired - Lifetime
  • 1997-01-13 AU AU13921/97A patent/AU1392197A/en not_active Abandoned
  • 1997-01-13 DE DE69700496T patent/DE69700496D1/de not_active Expired - Lifetime
  • 1997-01-13 WO PCT/GB1997/000087 patent/WO1997025150A1/en not_active Ceased
• 1998
  • 1998-07-10 NO NO19983185A patent/NO312086B1/no not_active IP Right Cessation

Non-Patent Citations (1)

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