MXPA00010482A - Three-phase rotary separator - Google Patents

Abstract

The method of operating a rotating separator apparatus (32), to which fluid, including gas and liquids is supplied in a fluid jet via a nozzle, which includes separating the liquids from the gas, at a first zone within the rotating apparatus, and separating the liquids into liquids of differing density at a second zone within the apparatus. The separated liquids are removed via two open weirs (204, 207) which isolate the liquids in the separating zones from the shear forces from scoops (209, 210) within the weir passages. Longitudinal ribs may be provided for structural support, coalescence promotion and fluid recirculation inhibition.

Description

ROTATING SEPARATOR OF THREE PHASES BACKGROUND OF THE INVENTION This invention relates to the separation of a three-phase fluid -gas, oil and water and more particularly relates to the achievement of said separation using a rotating separator. In addition, the invention relates to methods of operation of the rotary separator in relation to dredging means immersed in an annular liquid in the rotating separator and to relief means for isolating fluid cutting forces produced by the dredging means from the separation of the portions of the rotary separator. The solids suspended in the flow must also be separated. In existing non-rotating methods, the use of a large gravity separation tank is required and only a partial separation of the water and oil phases is achieved. Therefore, an additional treatment is required for the separation of these constituents. Secondary treatment methods require the expenditure of large amounts of energy, such as via high-speed centrifuges. Another advantage is the size and weight of the containers required. For coastal gas and oil production, large separation containers require large and expensive structures to support their weight. There is a need for improved means to efficiently achieve separation of the three phases - gas, oil and water, furthermore, there is a need to achieve such separation in a mixture of such fluids passed through a nozzle, as in a jet stream. .

SUMMARY OF THE INVENTION It is a main object of the invention to provide a simple, effective method and apparatus that meets the above needs.

Basically, the above object is fulfilled by the operation of the rotating separator so that said fluid, including gas and liquids (such as oil and water mixed together) are supplied in a fluid jet, via a nozzle, the steps of the basic method include (a) separating the liquids from the gas in the stream in a first zone within the rotating apparatus and (b) providing relief structures operating to separate the liquids in the liquids of different density in a second zone within said apparatus. As will be apparent, the fluid jet has a moment that is used by the transfer of energy from the jet to the rotary separator. The energy can also be transferred from an external source to the rotary separator. It is another object to provide a method and apparatus for achieving complete separation of gas, oil, water and solids by employing a relief structure. It operates by using the energy of the two-phase fluid or by means of a supplementary motor drive. It has a self-regulation feature to maintain wide ranges of gas, oil and water with non-external controls. A further object relates to the removal of the fluid jet from the suspended solid particles, the method includes providing a solids removal passage in the rotary separator and includes the conduction of the particles that are separated by centrifugal force to the passage. Another object includes the provision in the rotary separator of a passage to receive a liquid A of higher density, an outlet for the liquid A is provided in the apparatus and an output for the liquid B of lower density, the liquids is provided in the apparatus. A and B have a stable interface location determined by the relative locations and operation of two reliefs defined by the relief structure and the passage, so that substantially complete separation of the flow of liquids A and B occurs for a relatively large range broad flows. At least one of the outlets may advantageously be in the form of a ladle immersed in at least one of the liquids flowing as an annular liquid relative to the ladle, with one of the reliefs located to control the flow of a liquid over relief of the ring. Typically, a barrier is provided between two such annular liquids defined by liquids A and B. A movable entrance barrier can be provided in association with the bucket to block the entry of gas thereinto. An additional object includes the support of the barrier for movement in response to changes in force applied to the barrier by at least one of the liquids flowing relative to the bucket. A further object includes providing one or more outlets in the rotary separator to have the shape of an open relief and for the liquid flowing via relief to a passage in which a ladle is immersed to remove the liquid as will be described. A further object is to employ two reliefs defined by the relief structure to control the flow of two such liquids at the outlet and thereby control the position of an interface defined by and between the two liquids. Finally, it is an object of the invention to provide for the outlet of the nozzle liquid, a jet that produces a pulse and includes the transfer of the pulse to the rotary separator. These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following description and drawings in which: DESCRIPTION OF THE FIGURES FIG. 1 is a sectional view, that is, an axial radial plane, of the three-phase rotating apparatus embodying the invention, wherein: G = Gas W = Water O = Oil Fig. 1a is a view similar to that of Fig. 1; Fig. 2 is a fragmentary section showing the details of a bucket having an entrance immersed in a rotating liquid ring and taken in a plane normal to the axis of rotation of the separator; Fig. 3 is a fragmentary section taken on lines 3-3 of Fig. 2; Fig. 4 is a view similar to that of Fig. 2 showing a modification; Fig. 5 is a view taken on lines 5-5 of Fig. 4; Fig. 6 is a fragmentary section showing two open relief outlets for the liquid buckets and Fig. 7 is a partial cross section taken on lines 7-7 of Fig. 1a.

DETAILED DESCRIPTION Figures 1 and 1a show versions of the structure of the three-phase rotary separator 32. A mixture of oil, gas and water is expanded in a nozzle 17. The resulting gas and the jet of liquid 1 is well aligned. The jet collides tangentially towards a (revolving) movement surface. 2. See in this regard the description in the U.S. Patent. 5,385,446 incorporated herein by reference. In the case shown, the surface is solid with grooves 3, to allow drainage of liquids and solids. The surface 2 is defined by the inner side of an annular rotating separator 2a connected by the rotor 8 and the structure 31 to a rotating shaft 19 of structure 32. The axle supports are shown in the locations 19a. The movement surface can alternatively be comprised of the separated liquid in which case the solid surface 2 is not required.

The centrifugal force field acting on the liquid and gas jet, when it hits the moving surface causes a radially immediate internal separation of the gas from the liquids. The separated gas flows through the gas vanes 9 in the rotor 8, transferring energy to the rotor and shaft 19. The gas exits through an outlet port 18. The vanes 9 are spaced apart from the axis of the rotor 19b . The oil and water and any solid particles flow in the space between the outer wall 20 and the separation surface 2, in the centrifugal force field. The higher density of the water causes a radial outward velocity and a separate form of the oil flow to be acquired. 4. The separated water is indicated at 5. Oil and separation water flow axially through the slots at location 8a in the rotor, towards the oil outlet 10 and towards the water outlet 13, respectively. If the tangential velocity of the gas and the jet of the liquid 1 colliding on the separation surface 2 is greater than the speed of the rotating surface, the liquids are retarded by the transfer energy of frictional forces to the separation surface and thus both the rotor and the shaft. If the tangential velocity of the jet is less than the speed of the desired rotating surface, the external energy must be transferred to the shaft and therefore to the rotor and to the separation surface to dredge the liquids more slowly up to the speed of the rotating surface. The energy can be transferred, for example, by a motor or by the shaft of another rotary separator. Solids that are heavier than water are thrown to the inside of the wall 20. The solids are collected at the farthest radial position 6 of that wall and flow in 21 with a small amount of water in a volute 22 of the which are downloaded. A barrier 12 for the balance of water and oil flowing to the right forces the flow of water through the passages defined in structure 23 located below (outside of) the water-oil interface 7, formed by the field of centrifugal force.

The relative positioning of the oil outlet 10 in the oil collection area 10a and the water outlet 13, in the water collection zone 13a beyond the barrier 12 causes the oil-water interface 7a to form at a radially external location of the water outlet and the oil outlet, but which is radially internal to the passages of water 23. This location of the turning interface in 7a effects the separation of water and oil. Note that the interface 7a intersects the barrier 12 and that the zones 10a and 13a are on the opposite axial sides of the barrier 12. The radial location of the interface is determined by the following relationship, listing the dimensions as shown in Fig. 1a. The location of the interface is independent of the relative amounts of water and oil, so that the pressure drop of the liquid in the flow from the interface location to the outlet is small compared to the centrifugally induced higher head of the liquids rotating The liquid outlets are typically open ladles of the type shown in Figures 2, 3, 4 and 5. In Fig. 2, a rotary separator is shown at 110 and has an annular portion. 111 with a surface 111a radially inward towards the axis of the rotation separator 112 (the same axis 19b in Fig. 1). A liquid film or layer accumulates like a ring 113 on the rotating surface and shown with thickness "t". Such a liquid can typically be supplied in a jet, from a two-phase nozzle. The nozzle, the jet and the separator elements are shown schematically in Fig. 5. See also U.S. Pat. 5,385,446, incorporated herein by reference and wherein the moment of the jet is transferred to the separator on its inner surface 111a, inducing rotation. A ladle or diffuser structure is provided at 114 to remove the liquid in the ring 113. The ladle has an inlet 115 defined by the radially spaced outer and inner edges 115a and 115b presented to the relatively close liquid in the ring. The edge 115b is immersed in the annular liquid and the edge 115a is located radially inward of the inner surface 113a of the annular liquid. The annular liquid 113b radially internal from the edge of the ladle 115b enters the ladle at 113c and flows via a passage 116 in the ladle to the exit 117. The ladle is normally non-rotating, ie fixed or can rotate, but at a lower speed than the separator. The gas that has separated from the liquid and that accumulates as a layer 113 is collected inside the separator, as in 118. Since the edge 115a rests internally on the inner surface of the annular liquid 113a, there is a tendency to separate the gas at the entrance of the bucket in region 20, due to the dredging effect of the rotating annular liquid on the liquid surface of the adjacent gas 113a. The barrier structure is provided and located near the entrance of the bucket or entrance to block the gas outlet to the bucket. A structure of such a barrier is indicated at 121 and has a barrier surface 121a projecting radially outwardly from the inner edge of the bucket 115b, ie towards the annular liquid, whereby the liquid in the ring travels relatively past the surface barrier 121a to enter the bucket at its entrance. The barrier surface has a galvanic metal extension, indicated at 121 b, which controls the radial thickness at t2 of the annular liquid entering the ladle. In this regard, t2 is usually less than you. Galvanic metal extension 121 b is also usually of an amplitude (parallel to axis 112) close to the same as the ladle entry. It is shown that the barrier surface has an inclination in the direction of the relative stroke of the liquid entering the ladle and that the inclination is preferably convex to minimize or prevent the accumulation of the liquid in a turbulent path at the entrance of the ladle. Note in Fig. 3 that the amplitude w of the ladle entrance is smaller than the liquid in the ring, that is, the annular liquid exists side by side on the opposite sides of the ladle, as in 113e and 113f. Consequently, the separated gas is prevented or prevented substantially from the entry of the bucket to flow to the outlet and efficient gas-liquid separation is achieved. Another aspect relates to the provision of means for effecting the controllable displacement of the barrier structure towards the annular liquid, whereby the thickness t2 of the liquid layer entering the ladle is controlled. In the example of Fig. 2 and Fig. 3, said means for controlling the displacement of the barrier are shown in the form of a spring 125, positioned to drive the barrier structure towards the annular liquid. A balance is achieved between the force of the actuation of the spring to drive the barrier towards the annular liquid and the force of the liquid colliding on the convex surface 121a of the barrier to place the barrier radially as a function of the rotating speed of the separator, the rotational speed of the ring liquid and the viscosity of the liquid, whereby a controlled speed of the liquid intake in the ladle is achieved to correspond to the supply of the liquid to the ring and without air intake, that is, the inlet is opens to the left of the liquid flow but is blocked for gas. The guide structure is also provided to guide said displacement of the barrier structure as it moves in and out of the annular fluid. See for example the relatively coupled slidable surfaces 129 and 130 of the barrier and the rod of the ladle 131, attached to the ladle and sliding in the bore in the sleeve 129a attached to the ladle. A stop 134 in the rod engages the end 133a of the sleeve to radially limit the outward movement of the barrier structure and its galvanic metal end, as it was referred to. Figures 4 and 5 show the use of a sheet 40 or sheets immersed in the liquid and at an angle relative to the direction of travel of the annular liquid to receive the shock of liquid acting to produce a force component in a direction radially towards the outside (away from axis 12). That blade is connected to the barrier structure 121, via poles 42, to exert force on the barrier acting to move it in or toward the liquid.

Said opposing force by the force exerted on the convex surface of the barrier, as referred to above and a balance is achieved, as referred to. No spring is used in this sample. The advantage of these types of outlets for the three-phase separator is that the major changes in the liquid flow velocity can be adjusted with only small changes in liquid elevation. This enables large changes in the flow of oil or in the flow of water to be removed by the outlet without large increases in pressure drop or in the location of the water-oil interface 7. Another type of output is shown in Fig. 6. The separated oil flows over a relief 204, positioned in such a way that the oil interface 201 is at a radius r0 of the centerline of the shaft. The relief 204 rotates with the rotor 13. The oil flows controllably in the relief 204 in a collection ring 205 in an oil passage 225 and from which it is removed by a ladle 209 immersed in the oil layer in 209a. The separated water 208 is retarded through the passage 203, formed by a space between the separating rotor 32 and the lower wall 206a of the dual relief structure 206. The water flows to the right under the action of the hydrostatic head and flows controllably in the relief 207. The water flows to a collection ring 214 in a water passage 224, from which it is removed by a ladle 210, immersed in the 210a water layer. The passages are separated by the relief barrier structure 206. The position of the two reliefs determines the location of the oil-water interface 202 (through the relationship on page 10). The walls of the relief structure 206 isolate the liquids in the separation zones from the cutting forces induced by the buckets. Fig. 7 is a partial cross section in lines 7-7 of Fig. 1a. The function of the reinforcements 230 in the rotary separator is shown. The nozzle 301, introduces a mixture of oil, gas and water 308 in the separation surface 2. The liquids drained through the holes 309 in a longitudinal passage 303 formed by longitudinal reinforcements 304. The reinforcements provide a joining surface for the falls as well as a structural support. They also have the function of inhibiting the secondary flows in the passages. The water and oil interface 307 is formed by the rotational gravity field and the location of the reliefs. The separated oil flows the upper part of the oil relief 305. The separated water flows through the passage 306 formed by the relief structure.

Claims (22)

1. An operating method of a rotary separating apparatus for which the fluid, including gas and liquids, is supplied in a fluid jet via a nozzle, comprising the steps of a) separating liquids from the gas in said stream, in a first zone within the rotary apparatus and b) provide relief structures operating to separate liquids in liquids of different density in a second zone within said rotating separator apparatus, c) and provide longitudinally extending reinforcements for the structural support of the separator apparatus rotary and to promote the union of the liquid supplied via said fluid jet.

2. The method according to claim 1, wherein the fluid jet has a moment and includes the transfer of energy from the jet to said rotary separator apparatus.

3. The method according to claim 1, which includes the transfer of energy from an external source to said rotating separating apparatus.

4. The method according to claim 1, wherein the stream of the jet contains solid particles and includes providing a solids removal passage in the rotating separator apparatus and includes the conduction of particles that are separated by the centrifugal force of said passage.

5. The method of operation of the rotating separating apparatus according to claim 1, for which the fluid, including the gas and the liquids are supplied in a fluid jet via a nozzle, comprising the steps of a) separating the liquids from the gas in said stream in a first zone within said rotating apparatus, b) providing relief structures operating to separate liquids in liquids of different density in a second zone of said rotating separator apparatus and c) providing in said apparatus rotary separator liquid discharges A and B in pressurized jets through pressures to produce the transfer thereof in said apparatus.

6. The method of operation of a rotary separating apparatus according to claim 1, comprising the steps of a) separating the liquids from the gas in said stream in a first zone within said rotating apparatus, b) providing relief structures operating for separating the liquids in liquids of different density in a second zone inside said rotary separating apparatus, c) providing in said apparatus an outlet for the flow of liquid A of higher density and providing in said apparatus an outlet for the flow of the liquid B of lower density, said liquids A and B have a stable interface location determined by the relative location and operation of two reliefs defined by such relief structures, so that the substantially complete separation of the flow of liquids A and B occurs with a relatively wide range of flows, d) and provide at least one of said output in the form of a dip dipper or in at least one such liquid that is collected as a centrifugally induced annular liquid traveling in relation to the bucket and locating one of said reliefs to control the flow of said liquid in a relief and for said annular liquid.

7. The method of operation of a rotary separating apparatus according to claim 1, wherein the fluid, including gas and liquids, is supplied in a fluid jet via a nozzle, comprising the steps of a) separating the liquids from the gas in said current, in a first zone within the rotating apparatus b) provide relief structures operating to separate the liquids in the liquids of different density in a second zone within said rotary separator apparatus, c) provide in said apparatus an outlet for the flow of liquid A of higher density and provide in said apparatus an outlet for the flow of liquid B of lower density, said liquids A and B have a stable interface location determined by the relative location and operation of two reliefs defined by said structures relief, so that the substantially complete separation of the flow of liquids A and B occurs for a relatively wide range of flows and d) provide these outputs in the form of two ladles immersed respectively in the liquids flowing to said outlets and which is collected as centrifugally induced annular fluids which travel relatively to the buckets and which locate such two reliefs to control the flow of said respective liquids for said respective annular fluids.

8. The method according to claim 5, which provides a barrier between said liquids A and B after said liquids have flowed in such two respective reliefs and which have been collected as annular liquids, respectively.

9. The method of operation of a rotating separating apparatus according to claim 1, comprising the steps of a) separating the liquids from the gas in said stream in a first zone within said rotary apparatus b) providing relief structures for separating the liquids in liquids of different density in a second zone within said rotating separating apparatus, c) providing in said apparatus an outlet for the flow of liquid A of higher density and providing in said apparatus an outlet for the flow of liquid B of lower density , said liquids A and B have a stable interface location determined by the relative location and operation of the two reliefs defined by said relief structures, so that the substantially complete separation of the flow of liquids A and B occurs for a range relatively broad flows and d) provide a barrier between said liquids A and B after such liquid they have flown in such two respective reliefs and have been collected as annular fluids, respectively, and the flow of such fluids via such reliefs to the passages from which liquids are removed by ladles.

10. The method according to claim 6, which provides a movable entrance barrier to block gas entry in the bucket and support the barrier for movement in response to changes due to force applied to the barrier by at least one of said liquids flowing in relation to the ladle.

11. The method according to claim 9, wherein the liquid leaves the nozzle and forms a jet that produces a pulse and includes the transfer of said pulse to said rotary separating apparatus.

12. The method according to claim 1, wherein the vanes are provided by said rotary separating apparatus and includes the flow of the separated gas to the vanes to transfer the produced energy to the rotary separating apparatus.

13. The method according to claim 2, further comprising a rotating annular surface in which the liquids are separated from the gas.

14. The method according to claim 13, wherein said surface is provided by an annular region of the separator for passing liquids centrifugally apart from the gas.

15. The method according to claim 5, wherein said liquids are oil and water.

16. The method according to claim 15, which includes a rotating barrier structure between said outlets, said barrier structure having opposite sides and passage means for water to flow from one of said sides of the barrier structure to the other side of the barrier structure. said structure made said water outlet, the oil collecting on one side of said barrier structure and the water collecting on the other side of the barrier structure.

17. The method according to claim 9, including longitudinal protrusions for the structural support of the rotating separating apparatus and the promotion of liquid binding.

18. The rotating separating apparatus according to claim 1, comprising a) first means including reinforcing the liquid junction to separate the liquids from the gas in a first zone within said rotating separator apparatus and b) other means including the structure of relief and at least one ladle to separate the liquids in liquids of different density inside said rotating separating apparatus.

19. The combination of the means according to claim 18, wherein the fluid jet has a moment and includes means for transferring energy from the fluid jet to said rotating separator apparatus.

20. The combination of the means according to claim 18, wherein said rotating separating apparatus has an outlet for the flow of liquid A of higher density and an outlet for the flow of liquid B of lower density, said liquids A and B have a stable interface location determined by two reliefs defined by said relief structure, so that the substantially complete separation of the flow of liquids A and B occurs for a relatively wide range of flows.

21. The rotating separating apparatus according to claim 1, comprising a) first means for separating the liquids from the gas in a first zone within said rotary separating apparatus b) other means including the relief structure for separating the liquids in liquids of different density within said rotary separating apparatus, c) said rotating separating apparatus has an outlet for the flow of liquid A of higher density and an outlet of the flow of liquid B of lower density, said liquids A and B have a location of stable interface determined by two reliefs defined by said relief structure, so that the substantially complete separation of the flow of liquids A and B occurs for a relatively wide range of flows and d) one of said outputs comprises a ladle immersed in at least one of such liquids that are collected as a centrifugally induced annular fluid traveling in relation to The ladle, one such relief located to control the flow of said liquid in said relief for said annular liquid.

22. In the method of operation of the rotating separating apparatus according to claim 1, comprising the steps of a) separating the liquids from the gas in said stream, in a first zone in said rotating apparatus b) providing relief structures operating to separate the liquids in liquids of different density in a second zone within said rotating separating apparatus and c) the fluid jet has a moment and includes the energy transfer of the jet to said rotating separating apparatus.