Abstract:
An orbital downhole separator for separating well fluids into constituents of different specific gravities. Specifically, it is designed to separate water from oil or gas. The apparatus comprises a housing with a rotating member therein driven by a motor in the housing. Well fluid flows through the rotating member and is subjected to centrifugal force to separate the components. A flow conditioner is used to facilitate separation. The invention includes several different versions of the flow conditioner including an impeller, a stator and controllers for controlling the speed of the motor in response to signals related to the amount of petroleum in the water.

Description:
BACKGROUND  
       [0001]     This invention relates to downhole separators used in oil and gas wells, and in particular, to an orbital downhole separator driven by an internal motor and having a flow conditioner to improve fluid separation and control systems for such separators.  
         [0002]     Oil and/or gas wells quite often pass through a productive strata the yield of which includes oil, gas and other valuable products but also includes undesirable and unwanted constituents such as salt water. In oil well production operations, relatively large quantities of water are frequently produced along with the valuable petroleum products. This is particularly true during the latter stages of the producing life of a well. Bringing this water to the surface and handling it there represents a significant expense in lifting, separation and disposal.  
         [0003]     Various methods have been employed for extracting the valuable petroleum yield from the unwanted constituents. Some have involved the pumping of the total yield of the well to the surface and then using various methods for separating the valuable products from the unwanted portion. In addition, the unwanted portion of the yield, after having been pumped to the well surface and separated, often has been pumped downwardly again through a remote wellbore into a disposal layer. This, of course, also increases expenses.  
         [0004]     In some oil wells, the unwanted constituents can amount to as much as 80% to 90% of the total formation yield. Accordingly, to obtain a given volume of valuable petroleum from the well fluid, eight or nine times the volume of the petroleum must first be pumped to the surface and then separated from the unwanted portion. As already noted, this process can be very slow and expensive. Although the problem of producing substantially water-free oil from the well reservoir may occur at any stage in the life of an oil well, the proportion of water to valuable yield generally increases with time as the oil reserves decline. Ultimately, when the lifting cost of the combined petroleum and water constituents exceeds the value of the recovered oil, abandonment of the well becomes the only reasonable alternative.  
         [0005]     Many procedures have been tried for producing water-free oil from a formation that has a large quantity of water. For example, the oil and water produced are pumped or otherwise flowed together to the surface where they are treated to separate the petroleum from the water. Since the volume of water is usually much greater than that of the oil, the separator must handle large volumes of fluid and therefore is correspondingly large and expensive. Moreover, the water produced contains mineral salts which are extremely corrosive, particularly in the presence of air. Also, flowing the oil and water together upwardly through the well sometimes forms emulsions that are difficult to break. Such emulsions frequently must be heated in order to separate them even when in the presence of emulsion-treating chemicals. The heating of the large amount of water, as well as the small amount of oil requires an expenditure of large amounts of energy, reducing the net equivalent energy production from the well.  
         [0006]     Water produced from deep formations within the earth frequently contains large amounts of natural salts. For this reason, the salt water brought to the surface cannot be disposed of by allowing it to flow into surface drains or waterways. Relatively small amounts of salt water can sometimes be disposed of by draining into a slush pit or evaporation tank. The normally required disposal method for large volumes of salt water, however, is to introduce the water into a subsurface formation. This requires a disposal well for receiving the produced salt water.  
         [0007]     By returning the water to the same formation in this manner, the water is disposed of and also acts as a re-pressurizing medium or drive to aid in maintaining the bottomhole pressure for driving the well fluids toward the producing well. But, in those areas where producing wells are widely separated, the cost of drilling disposal wells for each producing well is often prohibitive. In such instances, it is necessary to lay a costly pipeline-gathering network to bring all of the produced water to a central location, or alternatively, to transport the produced water by trucks or similar vehicles. Regardless of the method for transporting the waste salt water from a producing well to a disposal well, the cost of the disposal can be, and usually is, prohibitive. Furthermore, fluids from subterranean reservoirs can have undesirable characteristics such as creating excessive pressure and super-heating of the fluids. If excessive pressure is present, then surface equipment, such as a choke manifold, must be installed to choke the flow pressure down to about 2,000 psi, a manageable pressure. If a highly pressurized fluid depressurizes within a short period of time, then a large portion of the gas is “flashed”. This reaction adversely affects the desirable petroleum from the formation yield. In general, both well seals and surface equipment suffer in the presence of excessive fluid pressure and heat. This equipment is expensive in terms of maintenance and capital costs. Thus, it is highly desirable to minimize these undesirable characteristics of the well flow before being brought to the surface.  
         [0008]     Downhole separation of water from oil in a well is a desirable approach for disposal of formation water in the well. It eliminates or reduces the excessive costs discussed above required to pump the water to the surface and dispose of it. Furthermore, the greatly reduced environmental impact of the produced water is another factor in making this approach attractive.  
         [0009]     Earlier downhole separators are shown in U.S. Pat. Nos. 5,156,586; 5,484,383; and 6,367,547.  
         [0010]     The use of downhole separators eliminates or reduces the excessive costs discussed above to pump the water and dispose of it. Furthermore, the greatly reduced environmental impact of the produced water is another factor in making this approach attractive.  
         [0011]     Improvements of prior art separators are desirable to further improve efficiency. The present invention includes a separator with a rotating cylinder and a variety of flow conditioners to increase the efficiency of the separator. One embodiment of the present invention adds an impeller to pump the fluid into an annulus to increase tangential fluid velocities. In another, a stator is used to orient the fluid to enter the impeller with a minimum of shearing action. In still another, baffles are positioned in an annular space in the rotor to force the fluid to rotate at the shaft velocity which will improve the separation efficiency.  
         [0012]     In another embodiment, a multi-lip cup designed to facilitate multi-density substances so that they are separated into different conduits is used.  
         [0013]     In another embodiment, a smart controller is used to control the speed of the motor to modulate the oil concentration in the outlet water. This control function is achieved without the use of a sensor for oil-concentration feedback by measuring the voltage and the current of the motor. The voltage is a measure of the rotor speed, and the current is a function of the applied torque. The torque in turn varies with the water-cut (the ratio of water to oil). By establishing the relationship between the torque and the water-cut and the speed, the motor speed can be adjusted to operate at the desired set point.  
         [0014]     A further embodiment utilizes a speed control which has an oil-in-water concentration sensor feedback in conjunction with a conventional PID controller or an adaptive controller for the control function. The motor speed is adjusted to achieve the oil concentration in the out fluid stream on the water side. One way of doing this includes using a valve on the downstream side of the water side which is modulated to achieve the quality of the water to be re-injected. A conventional controller is used to regulate the valve in response to the operating conditions to obtain a desired set-point of the oil content in the re-injection water. An adaptive controller can also be used to control the speed of the motor or the position of the valve using an adaptive algorithm for the controller to drive the concentration of the oil to the desired value.  
       SUMMARY  
       [0015]     The present invention is a downhole separator designed to separate components of well fluids within the well without the necessity of pumping the fluids to the surface first. The separator may be said to comprise a housing adapted for connection to a tool string for use in a well, a cylinder rotatably disposed in the housing and defining a flow passage therein, and a motor disposed in the housing for rotating the cylinder, whereby fluid flowing through the housing enters the flow passage and is subjected to centrifugal force such that the fluid is separated into different components having different specific gravities. The separator may further comprise a flow conditioner for facilitating the separation of the fluids. The invention includes several different flow conditioners.  
         [0016]     One version of the flow conditioner comprises an impeller adjacent to the inlet of the cylinder for pumping fluid into the flow passage. The impeller is preferably attached to the cylinder.  
         [0017]     In another embodiment, the flow conditioner comprises a baffle disposed in the flow passage in the cylinder to reduce slippage of fluid in the rotating cylinder. Preferably, the baffle is one of a plurality of angularly spaced baffles which extend longitudinally through the cylinder.  
         [0018]     In another embodiment, the cylinder defines an oil port and a sand port therein, and the flow conditioner comprises a cup disposed adjacent to an end of the cylinder. The cup has a first lip adjacent to the oil port and a second lip adjacent to the sand port. The first and second lips define an annular water passage therebetween, wherein the first lip directs separated oil through the oil port, the second lip directs separated sand and water mixture through the sand port, and water is directed through the water passage. The first and second lips are preferably substantially concentric.  
         [0019]     In another embodiment, the motor is a variable speed motor, and the flow conditioner comprises an oil-in-water sensor in communication with separated water discharged from the cylinder, the sensor generating an oil concentration signal in response to a concentration of oil in the discharged water, and a controller connected to the motor for varying the speed of the motor in response to the oil concentration signal compared to a predetermined desired oil concentration in the discharged water. The controller may be, for example, an adaptive controller or a PID controller.  
         [0020]     In an additional embodiment where the motor is a variable speed motor, the flow conditioner comprises a valve in communication with oil discharged from the cylinder to control the flow of the oil, an actuator adapted for opening and closing the valve, an oil-in-water sensor in communication with separated water discharged from the cylinder wherein the sensor generates an oil concentration signal in response to a concentration of oil in the discharged water, and a controller connected to the actuator whereby the valve is actuated in response to the oil concentration signal compared to a predetermined desired oil concentration in the discharged water, such that the flow of oil from the cylinder is controlled to vary the time the fluid is in the cylinder and thereby correspondingly varying the amount of oil separated from the water.  
         [0021]     In still another embodiment, the motor is again a variable speed motor, and the flow conditioner comprises a smart controller connected to the motor for varying the speed of the motor in response to a function of voltage and current signals from the motor compared to a predetermined desired value of a function corresponding to the water-cut.  
         [0022]     Another version of the flow conditioner comprises a stator adjacent to an inlet end of the cylinder. The stator preferably comprises a plurality of vanes for starting rotation of the fluid as it enters the cylinder.  
         [0023]     In one more embodiment, the cylinder defines a first port and a second port therein, and the flow conditioner comprises a cup disposed adjacent to a discharge end of the cylinder. The cup has a first lip adjacent to the first port, a second lip adjacent to the second port, the first and second lips defining an annular passage therebetween. This flow conditioner also comprises a sensor disposed adjacent to the cup for measuring the capacitance of fluid flowing thereby such that an operator can determine the separation of the components of the fluid. Preferably, the sensor is a capacitance-type sensor disposed adjacent to the first lip and first port. One example of the sensor is a MEMS sensor embedded in a surface of the cup facing the annular passage. Capacitance data from the sensor may be transmitted wirelessly to the surface or downhole controller, using telemetry, such as EM telemetry.  
         [0024]     Stated in another way, the orbital downhole separator comprises a housing adapted for connection to a tool string for use in a well, a rotating member disposed in the housing, a motor disposed adjacent to the housing and connected to the rotating member whereby fluid flowing through the rotating member is subjected to centrifugal force such that the fluid is separated into heavier and lighter components, and a flow conditioner for facilitating the separation of the fluid in the rotating member.  
         [0025]     Numerous objects and advantages of the invention will be understood by those skilled in the art when the following detailed description of the preferred embodiments is read in conjunction with the drawings illustrating such embodiments.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]      FIGS. 1A and 1B  show a longitudinal cross section of an orbital downhole separator of the present invention.  
         [0027]      FIG. 2  illustrates an embodiment of an orbital downhole separator with a rotating cylinder having baffles therein.  
         [0028]      FIG. 3  is a cross-sectional view taken along lines  3 - 3  in  FIG. 2 .  
         [0029]      FIG. 4  illustrates the use of a multi-lip cup with the orbital downhole separator.  
         [0030]      FIG. 5  schematically shows how a feedback controller can be used to control the speed of a motor in the separator.  
         [0031]      FIG. 6  is a schematic of a valve-based speed control for the motor.  
         [0032]      FIG. 7  shows a schematic of a smart sensor system.  
         [0033]      FIG. 8  shows an embodiment having a stator to increase rotation of the fluid at the inlet of an impeller.  
         [0034]      FIG. 9  illustrates a sensor for determining oil-in-water concentration of the fluid.  
         [0035]      FIG. 10  is a cross section taken along lines  10 - 10  in  FIG. 1A .  
     
    
     DESCRIPTION  
       [0036]     Referring now to the drawings and more particularly to  FIGS. 1A and 1B , an orbital downhole separator of the present invention is shown and generally designated by the numeral  10 . Separator  10  generally comprises a housing  12  with a rotor  14  rotatably disposed therein. Rotor  14  is driven by an electric motor  16 .  
         [0037]     Housing  12  comprises an upper adapter  18  with a central opening  20  therethrough. Upper adapter  18  has an external thread  22  adapted for connection to an upper tool string portion  24 . Upper adapter  18  is attached to a tubular member  26  by a threaded connection  28 . A seal  30  provides sealing engagement between upper adapter  18  and tubular member  26 .  
         [0038]     Housing  12  further comprises a lower adapter  32  attached to tubular member  26  by a threaded connection  34 . A seal  36  provides sealing engagement between tubular member  26  and lower adapter  32 . Lower adapter  32  has an external thread  38  adapted for engagement with a lower tool string portion  40  if desired. Lower adapter  32  further defines a central opening  42  therethrough.  
         [0039]     Tubular member  26  defines a central opening  44  therethrough which is in communication with central opening  20  in upper adapter  18  and central opening  42  in lower adapter  32 .  
         [0040]     A first upper seal housing  46  is disposed in central opening  44  of tubular member  26  adjacent to upper adapter  18 . Below first upper seal housing  46  is a first upper bearing  48  and a second upper bearing  50  therein, and the first upper bearing  48  and second upper bearing  50  are separated by an upper spacer  52 . Below second upper bearing  50  is a second upper seal housing  53 .  
         [0041]     Upper spacer  52  defines an upper flow passage  54  therethrough.  
         [0042]     A lower bearing housing  56  is disposed in central opening  44  of tubular member  26  adjacent to lower adapter  32 . Lower bearing housing  56  has a first lower bearing  58  and a second lower bearing  60  therein, and the first lower bearing  58  and second lower bearing  60  are separated by a lower spacer  62 .  
         [0043]     Lower bearing housing  56  defines a lower flow passage  64  longitudinally therethrough.  
         [0044]     A bearing shaft  66  is disposed through, and supported by, first and second lower bearings  58  and  60 . Bearing shaft  66  defines a central opening  68  in an upper end thereof.  
         [0045]     Rotor  14  comprises a stub shaft  72 , a main shaft  74  and a rotating cylinder  76  positioned around the stub shaft  72  and main shaft  74 . Main shaft  74  and a rotating cylinder  76  form a rotating member within housing  12 .  
         [0046]     An upper end of main shaft  74  extends into, and is supported by, first upper bearing  48  and second upper bearing  50 . Seal  77  provides sealing engagement between main shaft  74  and first upper seal housing  46  above first upper bearing  48 , and seal  79  provides sealing engagement between main shaft  74  and second upper seal housing  53  below second upper bearing  50 .  
         [0047]     Stub shaft  72  extends into central opening  68  in bearing shaft  66  and is connected thereto by a spline  78 . Stub shaft  72  defines a central opening  80  therein into which a lower portion of main shaft  74  extends. Main shaft  74  is attached to stub shaft  72  by a threaded connection  82 . A seal  84  provides sealing engagement between stub shaft  72  and threaded connection  82 .  
         [0048]     Main shaft  74  defines a central opening  86  therethrough. A plurality of radially extending upper ports  88  are in communication with central opening  86 . A plurality of radially extending lower ports  90  are also in communication with central opening  86 .  
         [0049]     Rotating cylinder  76  is attached to stub shaft  72  at press-fit connection  92 . By this connection and others previously described, it will be seen by those skilled in the art that bearing shaft  66 , stub shaft  72 , main shaft  74  and rotating cylinder  76  rotate together. Rotating cylinder  76  and main shaft  74  define an annular flow passage  94  therebetween.  
         [0050]     The present invention comprises a number of different flow conditioners to improve the efficiency of the separations of the fluids flowing therethrough. In  FIG. 1A , the flow conditioner is characterized by an impeller  96  at the upper end of rotating cylinder  76 . Impeller  96  is positioned in annular flow passage  94  and facilitates flow through the annular flow passage  94 , as will be further described herein.  
         [0051]     At least one inlet port  100  is defined in tubular member  26  adjacent to impeller  96 . Preferably, but not by way of limitation, inlet ports  100  are substantially tangentially disposed as best seen in  FIG. 10 .  
         [0052]     Stub shaft  72  has a plurality of longitudinally extending flow ports  102  therein which provide communication between lower flow passage  64  and annular flow passage  94 . A lower seal  104  provides sealing between rotating stub shaft  72  and stationary tubular member  26  of housing  12 .  
         [0053]     A seal adapter  106  is mounted on main shaft  74  adjacent to a shoulder  108  on the main shaft  74  below second upper seal housing  53 . An upper seal  110  provides sealing engagement between seal adapter  106  and tubular member  26 . Another seal  112  provides sealing engagement between seal adapter  106  and main shaft  74 .  
         [0054]     A channel  114  is formed in seal adapter  106  and is aligned, and in communication, with upper ports  88  in main shaft  74 . Channel  114  is also in communication with upper flow passage  54  in upper spacer  52 .  
         [0055]     Motor  16  is positioned in central opening  20  of upper adapter  18 . Motor  16  is adapted to drive a coupler shaft  120  which is connected to main shaft  74 . In other words, coupler shaft  120  interconnects motor  16  and rotor  14 . Wiring (not shown) connects motor  16  to a source of electrical power (not shown). When motor  16  is energized, coupler shaft  120  is rotated which causes main shaft  74  and the other components of rotor  14  to be rotated within housing  12 .  
         [0056]     A plurality of longitudinally extending holes  122  are defined through motor  16 , and it will be seen that these holes  122  are in communication with upper flow passage  54  in upper spacer  52 .  
         [0057]     In operation, separator  10  is made up on a tool string of which upper tool string portion  24  and lower tool string portion  40  are components. This tool string assembly is lowered to the desired location in the wellbore. When it is desired to start a separation process for fluid in the well, motor  16  is actuated. Well fluid enters separator  10  through inlet port  100 , and the fluid is forced into annular flow passage  94 . The rotation of rotating cylinder  76  applies centrifugal force to the fluid in annular flow passage  94 . This causes the heavier water to be separated from the lighter oil or gas. That is, the water and other higher density materials, such as sand, are forced radially outwardly in annular flow passage  94 , and the oil or gas (lighter components) stays to the inside.  
         [0058]     In the embodiment using impeller  96  as the flow conditioner, the impeller  96  acts to drive the fluid in a tangential direction. The pressure in the well annulus forces the oil or gas through lower ports  90  in main shaft  74  so that it enters central opening  86  in the main shaft  74 . The oil or gas is forced upwardly through central opening  86 , and it exits main shaft  74  through upper ports  88  therein. The oil or gas continues to flow upwardly through central opening  44  in tubular member  26 , upper flow passage  54 , holes  122 , central opening  20  in upper adapter  18  and on up through upper tool string portion  24  to the surface for recovery.  
         [0059]     Water is forced through flow ports  102 , central opening  44  below stub shaft  72 , lower flow passage  64 , central opening  42  in lower adapter  32  and on down through lower tool string portion  40  for disposal in the well.  
         [0060]     Referring now to  FIGS. 2 and 3 , a second flow conditioner in the form of an improved rotating cylinder is shown and designated by the numeral  76 ′. Rotating cylinder  76 ′ is similar to rotating cylinder  76  in that it has an outer cylinder  124  and an inner cylinder  126  which define the previously mentioned annular flow passage  94  therebetween. In improved rotating cylinder  76 ′, a plurality of longitudinal baffles  128  are disposed in annular flow passage  94  and extend the length thereof.  
         [0061]     The fluid may slip within rotating cylinder  76  (that is, it may not rotate with the rotating cylinder  76  as much as desired) because of the inertia of the fluid. In improved rotating cylinder  76 ′, the fluid is forced to rotate within the rotating cylinder  76 ′ because the fluid is held between inner cylinder  126  and outer cylinder  124  by baffles  128 , thus reducing the potential for fluid slip, and this improves the separation of the water from the oil or gas.  
         [0062]     Referring now to  FIG. 4 , a third flow conditioner is shown which provides for the separation of sand from at least some of the water. Again, most of the components are the same as in separator  10 . However, at the lower end of a modified rotating cylinder  76 ″, a multi-lip cup  130  is disposed in annular flow passage  94 .  
         [0063]     Cup  130  has an inner lip  132  adjacent to lower ports  90  and an outer lip  134  generally concentric with the inner lip  132 . An annular port  136  is defined between inner lip  132  and outer lip  134 . Rotating cylinder  76 ″ defines a plurality of radially disposed ports  138  therein adjacent to outer lip  134 .  
         [0064]     If there is sand in the fluid to be separated, it is sometimes desirable to separate this from the water and oil or gas. Cup  130  facilitates this separation. As the components of the fluid are subjected to the centrifugal force previously discussed, the water and sand are forced outwardly from the lighter oil or gas. Further, the sand will be forced outwardly against the wall of rotating cylinder  76 ″. As the separated fluid components flow downwardly though annular flow passage  94 , it will be seen that the oil or gas will flow inside inner lip  132  and out lower ports  90  as previously discussed. The sand, still mixed with some water, will flow outside of outer lip  134  and out ports  138  in rotating cylinder  76 ″. The bulk of the water, with the sand now separated therefrom, will flow downwardly through annular port  136 . Thus, the second embodiment allows handling of sand as well as water and oil or gas. It will be seen by those skilled in the art that this use of cup  130  could be used to accommodate fluids with other various density components and is not limited to just sand, water and oil or gas.  
         [0065]     Referring now to  FIG. 5 a  fourth flow conditioner for downhole orbital separator is shown schematically to include a speed control  140  for a variable speed motor  16 ′. Speed control  140  comprises an oil-in-water sensor  142  in communication with the water discharged from separator  10  after separation of the water from the oil or gas. Sensor  142  sends an oil concentration signal to a feedback controller  144 . A conventional PID (proportional integral derivative) controller could also be used.  
         [0066]     The oil concentration signal is compared to a predetermined maximum desired oil concentration level. The speed of motor  16 ′ is adjusted to achieve the desired oil concentration level as necessary even though the mixture of water and oil or gas from the well may vary. The amount of centrifugal force applied to the fluid varies with the speed of motor  16 ′.  
         [0067]     Referring to  FIG. 6 , a fifth flow conditioner in the form of a valve-based control  150  for separator  10  is shown schematically. A valve  152  is used on the downstream side of the water side which is modulated to achieve the quality of the water to be re-injected into the well. A conventional controller  154  receives an oil concentration signal from an oil-in-water sensor  156  and compares it to a predetermined desired level. Controller  154  then sends an actuator signal to a valve actuator  158  to regulate valve  152  to vary the flow therethrough. Controlling the rate at which water is discharged from separator  10  affects how long it is subjected to the centrifugal force. Thus, the desired oil content in the water is achieved.  
         [0068]     It will be seen by those skilled in the art that speed control  140  can be combined with valve-based control  150  using an adaptive algorithm to control both the speed of motor  16 ′ and the actuation of valve  152 .  
         [0069]     Now referring to  FIG. 7 , a sixth flow conditioner characterized by a smart sensor/controller  160  is illustrated schematically for controlling separator  10 . Like speed control  140  of the third embodiment, smart sensor/controller  160  controls the speed of a variable speed motor  16 ′ in separator  10  to achieve the desired oil concentration level in the water. However, with smart sensor/controller  160  an oil-in-water sensor is not required. The voltage, V, and current, I, of motor  16 ′ are measured. The voltage, V, is a function of the speed of the rotor in the motor  16 ′, and the current, I, is a function of the applied torque on the rotor. The torque in turn varies with the amount of separation of water from the oil or gas (the water-cut). By establishing the relationship between the torque and the water-cut and the speed of motor  16 ′, the speed of the motor  16 ′ can be adjusted to operate at the desired speed.  
         [0070]     Referring now to  FIG. 8 , a seventh flow conditioner in a separator  10 ′″ is shown. Separator  10 ′″ is substantially the same as separator  10  except that a stationary stator  164  is used adjacent to a rotating cylinder  76 ′″. Stator  164  has a plurality of vanes  166  which direct flow to rotating cylinder  76 ′″ in a tangential direction to force the fluid to start rotating before it actually enters the rotating cylinder  76 ′″ which enhances fluid separation. In other words, stator  164  starts the fluid rotating before it enters rotating cylinder  76 ′″. Stator  164  could be used in conjunction with impeller  96 .  
         [0071]     Referring now to  FIG. 9  an eighth flow conditioner is shown using a sensor  170  to measure the capacitance of the fluid to determine the quality of the separation of the water from the oil or gas. Sensor  170  is used in conjunction with previously described cup  130 . Sensor  170  may be a capacitance-type sensor to measure the capacitance of the fluids in annular space  172  in cup  130 . Alternatively, a MEMS (micro electromechanical systems) sensor  174  may be embedded in surface  176  of cup  130  to measure the local capacitance of an oil film that forms there. The capacitance data may be transmitted wirelessly using EM telemetry or through some commutation scheme.  
         [0072]     Those skilled in the art will see that the different flow conditioners of the present invention can be combined in various ways to provide even more controlled separation.  
         [0073]     It will be seen, therefore, that the separator  10  of the present invention and the various flow conditioners thereof are well adapted to carry out the ends and advantages mentioned as well as those inherent therein. While preferred embodiments of the invention have been shown for the purposes of this disclosure, numerous changes in the arrangement and construction is well adapted to carry out the ends and advantages of parts may be made by those skilled in the art. All such changes are encompassed within the scope and spirit of the appended claims.