Downhole floating coalescence enhanced oil-water cyclone separation device

Abstract

The application relates to a downhole floating coalescence reinforced oil-water cyclone separation device for the same well injection and recovery, which is composed of an oil-water coalescence module and an oil-water two-phase separation module, and the oil-water mixed liquid is coalesced in the oil-water coalescence module and then is separated in the oil-water two-phase separation module; the oil-water coalescence module comprises a primary spiral flow channel, an upper oil pipe coupling and an upper sleeve, the overflow passage lower end of the primary spiral flow channel is fixedly connected with a sectional flow pipe, a plurality of annular channels are arranged at the lower part of the primary spiral channel and outside the sectional flow pipe in intervals, and the adjacent two annular channels are fixedly connected through a connecting sleeve; a flow stabilizing ball is slidably connected outside the sectional flow pipe between the adjacent two annular channels. The oil droplets pass through the annular channels and change the oil droplet migration track, the oil droplet collision and gathering probability is increased, the oil droplets are coalesced, small oil droplets are coalesced into large oil droplets, the flow stabilizing ball between every two annular channels stabilizes the flow, the oil droplet collision is increased, and the flow stabilization, coalescence and cyclone integration are realized.

Description

Technical Field

[0001] This invention relates to downhole oil-water separation technology in the petrochemical field, specifically a floating coalescence enhanced oil-water cyclone separator for injection and production in the same well. Background Technology

[0002] In oilfield development, high water-cut oilfields, with produced fluid water cut exceeding 98%, high liquid-to-oil ratios, high system back pressure, low gathering and transportation efficiency, and poor separation efficiency, require increased production capacity investment to ensure crude oil output. This necessitates long-distance circulation of produced water, increasing energy consumption in the gathering and transportation system. Stabilizing flow, coalescence, energy conservation, and efficiency improvement have become major challenges in enhancing the economic benefits of high water-cut oilfields. Currently, in same-well injection and production technologies, uncertainties arising from complex downhole conditions, such as gas-bearing conditions, make it difficult to improve oil-water separation efficiency. Therefore, the development of equipment that can mitigate the impact of turbulence, stabilize flow rate, increase oil droplet collisions, coalescence separation, achieve integrated swirl flow, and improve oil-water separation efficiency is essential.

[0003] Chinese utility model patent: A multi-inlet, multi-outlet high-efficiency oil-water separator hydrocyclone, patent number: ZL202120814893.9. While this patented device increases throughput by adding inlets and outlets and improves separation efficiency to some extent by adding a flow stabilizer to the cylindrical section's inner cavity, it still has several shortcomings. Firstly, its structure is too simple, offering little innovation compared to traditional oil-water separators, resulting in only a minor improvement in separation efficiency. Secondly, the patent simply adds a flow stabilizer, which does not effectively promote the separation of fine oil droplets, leading to limited economic benefits. Therefore, a downhole floating coalescing enhanced oil-water hydrocyclone separator is needed to achieve efficient downhole oil-water separation. Summary of the Invention

[0004] The purpose of this invention is to provide a floating coalescing enhanced oil-water cyclone separator for injection and production in the same well. This floating coalescing enhanced oil-water cyclone separator for injection and production in the same well is used to solve the problem that existing oil-water separators are not sufficient to separate fine oil droplets.

[0005] The technical solution adopted by this invention to solve its technical problem is as follows: This downhole floating coalescing enhanced oil-water cyclone separator for injection and production consists of an oil-water coalescing module and an oil-water two-phase separation module. First, the oil-water mixture is coalesced in the oil-water coalescing module, and then separated in the oil-water two-phase separation module. The oil-water coalescing module includes a primary spiral channel, an upper tubing coupling, and an upper outer sleeve. The lower end of the overflow channel of the primary spiral channel is fixedly connected to a segmented flow pipe. Multiple annular channels are spaced apart at the lower part of the primary spiral channel and outside the segmented flow pipe. Adjacent annular channels are fixedly connected by a connecting sleeve. The upper end of the outer wall of the uppermost annular channel is connected to the upper outer sleeve. A sleeve; a flow stabilizing ball is slidably connected to the segmented flow tube between two adjacent annular channels; the upper end of the annular channel is trumpet-shaped, and the middle of the annular channel is cylindrical. Both the upper and lower ends of the annular channel have external threads. The flow stabilizing ball is elliptical and has a flow tube hole in its center. A spring is fixed at the lower end of the flow tube hole, and a protrusion is provided in the flow tube hole. The protrusion of the flow stabilizing ball is stuck in the groove of the segmented flow tube. The movement trajectory of oil droplets changes as they pass through the annular channel, increasing the probability of oil droplet collision and aggregation, causing small oil droplets to coalesce into large oil droplets. The flow stabilizing ball between every two annular channels can stabilize the flow rate, increase the collision of oil droplets, and achieve the integration of flow stabilization, coalescence, and swirling flow.

[0006] The oil-water two-phase separation module in the above scheme includes a secondary spiral flow channel, a secondary hydrocyclone sleeve, a lower outer sleeve, and a lower oil pipe coupling. The secondary spiral flow channel is connected to the segmented flow pipe by threads. The secondary hydrocyclone sleeve is connected to the outer wall of an adjacent annular channel by threads. The upper end of the lower outer sleeve is connected to the secondary hydrocyclone sleeve, and the lower end is connected to the oil pipe coupling by threads. The secondary spiral flow channel is located inside the secondary hydrocyclone sleeve, and the separated water phase is discharged from the water phase outlet of the oil-water separator hydrocyclone.

[0007] In the above scheme, the segmented flow passage is composed of flow passage No. 1, flow passage No. 2, and flow passage No. 3 connected sequentially; there are five annular channels and four interlocking sleeves, namely interlocking sleeve No. 1, interlocking sleeve No. 2, interlocking sleeve No. 3, and interlocking sleeve No. 4; there are four flow stabilizing balls, namely flow stabilizing ball No. 1, flow stabilizing ball No. 2, flow stabilizing ball No. 3, and flow stabilizing ball No. 4; the lower inner wall of the oil pipe coupling is threaded to the top cover of the hydrocyclone, and the lower outer wall of the top cover of the hydrocyclone is threaded to the upper outer sleeve; the uppermost annular channel The lower outer wall is threaded to the No. 1 interlocking sleeve. The upper and lower outer walls of the No. 2 interlocking sleeve, the upper and lower outer walls of the No. 3 interlocking sleeve, and the upper and lower outer walls of the No. 4 interlocking sleeve are respectively threaded between two adjacent annular channels. The upper end of the first-stage spiral flow channel is threaded to the top cover hole of the hydrocyclone. The lower end of the first-stage spiral flow channel is threaded to the No. 1 flow pipe. The lower end of the No. 1 flow pipe is threaded to the No. 2 flow pipe. The lower end of the No. 2 flow pipe is threaded to the No. 3 flow pipe.

[0008] In the above scheme, a groove is provided at the lower end of the overflow channel of the spiral flow channel, and the protrusion on the flow stabilizing ball is slidably connected in the groove. Beneficial effects

[0009] 1. This invention innovatively designs an annular channel for coalescing oil droplets, which reduces the area through which oil droplets pass during oil-water separation, making the oil droplets more concentrated under different passing areas for the same amount of oil droplets, and exhibiting extremely high oil droplet coalescing performance.

[0010] 2. This invention innovatively designs a flow-stabilizing sphere. Breaking through the traditional constraint of only being able to change the axial area, the flow-stabilizing sphere can alleviate the impact force brought by turbulence, stabilize the flow rate, increase the collision of oil droplets, and achieve more efficient flow stabilization and coalescence, realizing integrated swirling flow and enhancing the effect of oil-water separation.

[0011] 3. The present invention has a compact structure and achieves efficient separation of oil and water two-phase media in a small downhole space. It combines coalescence and flow stabilization to further improve the performance of oil-water separation.

[0012] 4. This invention features a novel structure and compact layout. Through the design of the annular channel and flow-stabilizing sphere, it mitigates the impact of turbulence, stabilizes the inlet flow rate, alters the oil droplet trajectory, and increases the probability of oil droplet collision and aggregation within the coalescing device. This enhances the coalescing effect of oil droplets within the pipeline, improves subsequent oil-water separation performance, and strengthens the oil-water separation effect. Simultaneously, this device is inexpensive, significantly improving economic efficiency. It is a high-efficiency oil-water separation device suitable for downhole applications.

[0013] 5. This invention can achieve fine separation of oil and water phases through annular channels and two-stage spiral flow channels. At the same time, it utilizes the coalescence and flow stabilization effects of the innovatively designed flow stabilizing ball to enhance the oil-water separation effect, achieving efficient separation of oil and water phases. The separated oil phase can be directly introduced into the oil pipeline, while the separated water phase can be reinjected underground.

[0014] 6. This invention has a compact structure and high separation efficiency. The flow stabilizing ball can automatically move up and down according to the flow rate, changing the radial area and overcoming the shortcomings of traditional methods that can only change the axial area. It can coalesce oil droplets, stabilize the flow rate, and achieve integrated vortex flow and efficient oil-water separation. Attached Figure Description

[0015] Figure 1 The figures are an overall appearance view (a) and a cross-sectional view (b) of the present invention.

[0016] Figure 2 This is an exploded view of the present invention.

[0017] Figure 3 The image shows the overall appearance of the oil-water coalescing module (a) and its cross-sectional view (b).

[0018] Figure 4 This is an exploded view of the oil-water coalescing module.

[0019] Figure 5 This is a view of the overall appearance of the flow stabilizer sphere and its cross-sectional view.

[0020] Figure 6 The images show the appearance of the annular channel and the flow tube.

[0021] Figure 7 The image shows the overall appearance of the oil-water two-phase separation module (a) and its cross-sectional view (b).

[0022] Figure 8 This is an exploded view of the oil-water two-phase separation module.

[0023] In the diagram: 1 - Oil-water coalescing module; 101 - Upper oil pipe coupling; 102 - Hydrocyclone top cover; 103 - Primary spiral flow channel; 104 - First flow passage pipe; 1041 - Groove; 105 - Second flow passage pipe; 106 - Third flow passage pipe; 107 - Annular channel; 108 - First flow stabilizer ball; 1081 - Protrusion; 109 - Second flow stabilizer ball; 110 - Third flow stabilizer ball; 111 - Fourth flow stabilizer ball. Flow ball, 112-upper outer sleeve, 1121-liquid inlet hole, 113-first ring sleeve, 114-second ring sleeve, 115-third ring sleeve, 116-fourth ring sleeve, 2-oil-water two-phase separation module, 201-secondary spiral flow channel, 202-secondary hydrocyclone sleeve, 2021-water phase outlet of oil-water separator hydrocyclone, 203-lower outer sleeve, 204-lower oil pipe coupling. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings:

[0025] The overall appearance and cross-sectional view of this downhole floating coalescence enhanced oil-water cyclone separator for simultaneous injection and production are shown below. Figure 1 As shown, the device is placed vertically and operates in a vertical configuration. It first coalesces the oil-water mixture, then separates the oil and water. The separated oil is discharged into the oil pipe, while the water is reinjected underground. An exploded view of a downhole floating coalescing enhanced oil-water cyclone separator is shown below. Figure 2 As shown, it mainly consists of an oil-water coalescence module 1 and an oil-water two-phase separation module 2.

[0026] The oil-water coalescing module includes a primary spiral channel 103, an upper oil pipe coupling 101, and an upper outer sleeve 112. The lower end of the overflow channel of the primary spiral channel 103 is fixedly connected to a segmented flow pipe. Multiple annular channels 107 are spaced apart at the lower part of the primary spiral channel 103 and outside the segmented flow pipe. Adjacent annular channels are fixedly connected by a connecting sleeve. The upper outer sleeve 112 is connected to the upper end of the outer wall of the uppermost annular channel 107. A flow stabilizing ball is slidably connected to the outside of the segmented flow pipe between adjacent annular channels. The annular channels 107... The upper end is trumpet-shaped, and the middle of the annular channel is cylindrical. Both the upper and lower ends of the annular channel have external threads. The flow stabilizing ball is elliptical and has a flow passage hole in its center. A spring is fixed at the lower end of the channel hole, and the channel hole is equipped with a protrusion. The protrusion of the flow stabilizing ball is stuck in the groove of the segmented flow passage. The oil droplets change their movement trajectory as they pass through the annular channel, increasing the probability of oil droplet collision and aggregation, causing small oil droplets to coalesce into large oil droplets. The flow stabilizing ball between every two annular channels can stabilize the flow rate and increase the collision of oil droplets, realizing the integration of flow stabilization, coalescence, and swirling flow.

[0027] The oil-water coalescing module incorporates an annular channel and a flow-stabilizing sphere between the primary spiral channel 103 and the secondary spiral channel 201. The annular channel reduces the area through which oil droplets pass, enabling efficient coalescence. A flow-stabilizing sphere between every two annular channels stabilizes the flow rate, increases droplet collision, and further enhances flow stabilization and coalescence, achieving integrated swirling flow. The oil-water two-phase separation module primarily achieves efficient oil-water separation. The secondary spiral channel 201 strengthens the swirling field, facilitating the separation of the oil and water phases after droplet coalescence by the oil-water coalescing module. This integrated approach enhances droplet collision, flow stabilization, coalescence, and swirling flow, resulting in a more efficient swirling separation device. The annular channel and flow-stabilizing sphere further enhance the oil-water separation effect by coalescing the droplets.

[0028] In this embodiment, the segmented flow passage is formed by sequentially connecting flow passage 104, flow passage 105, and flow passage 106; there are five annular channels and four interlocking sleeves, namely interlocking sleeve 113, interlocking sleeve 114, interlocking sleeve 115, and interlocking sleeve 116; there are four flow stabilizing balls, namely flow stabilizing ball 108, flow stabilizing ball 109, flow stabilizing ball 110, and flow stabilizing ball 111.

[0029] The overall appearance and cross-sectional view of the oil-water coalescing module are as follows: Figure 3As shown, the lower end sidewall of the upper oil pipe coupling 101 is connected to the hydrocyclone top cover 102 via a threaded connection. The lower end sidewall of the hydrocyclone top cover 102 is connected to the upper outer sleeve 112 via a threaded connection. The lower end sidewall of the upper outer sleeve is connected to the upper end sidewall of the annular channel 107 via a threaded connection. The lower end sidewall of the annular channel 107 is connected to the first interlocking sleeve 113 via a threaded connection. There are a total of five annular channels 107, and every two annular channels are connected by interlocking sleeves. The second interlocking sleeve 114 and the third interlocking sleeve 115 are also connected by interlocking sleeves. The upper and lower sidewalls of the fourth-order interlocking sleeve 116 are sequentially connected between the two annular channels by threads; the upper end of the first-order spiral channel is connected to the top cover hole 1021 of the hydrocyclone by threads; the lower end of the first-order spiral channel is connected to the first flow pipe 104 by threads; the lower end of the first flow pipe is connected to the second flow pipe 105 by threads; the lower end of the second flow pipe is connected to the third flow pipe 106 by threads; the protrusion 1081 on the flow stabilizing ball is stuck in the groove 1041 on the first flow pipe and can move up and down. The oil-water two-phase mixture enters the device through inlet 1121, flows through oil-water coalescing module 1, first passes through a primary spiral channel 103 to form a swirling flow field, then passes through an annular channel 107 to reduce the oil droplet passing area and make the oil droplets more concentrated; after passing through the flow stabilizing balls 108-111, which move up and down by the action of grooves 1041 and springs, changing the radial area and increasing the collision of oil droplets, thereby achieving the effect of efficient oil droplet coalescence. The coalesced oil-water two-phase mixture then enters module 2. Figure 4 This is an exploded view of the oil-water coalescing module. The oil-water coalescing module mainly consists of an upper oil pipe coupling 101, a hydrocyclone top cover 102, a primary spiral flow channel 103, a first flow passage pipe 104, a second flow passage pipe 105, a third flow passage pipe 106, an annular channel 107, a first flow stabilizing ball 108, a second flow stabilizing ball 109, a third flow stabilizing ball 110, a fourth flow stabilizing ball 111, an upper outer sleeve 112, a first interlocking sleeve 113, a second interlocking sleeve 114, a third interlocking sleeve 115, and a fourth interlocking sleeve 116. Figure 5 The image shows the appearance and cross-sectional view of the flow stabilizer ball. It can float up and down to change the radial area and coalesce oil droplets. It is held in the slot by the protrusion 1081. Figure 6 The diagram shows the appearance of the annular channel and the flow tube. The annular channel 107 changes the area through which the oil droplets pass, thereby achieving the coalescence of the oil droplets. The groove 1041 on the flow tube is used to fix the flow stabilizing ball and restrict its movement within a certain range. Figure 7The diagram shows the overall structure and cross-sectional view of the oil-water two-phase separation module. The secondary spiral flow channel 201 is threadedly connected to the lower end of the No. 3 flow pipe 106; the secondary hydrocyclone sleeve 202 is threadedly connected to the upper outer sleeve 112; the upper and lower ends of the lower outer sleeve 203 are threadedly connected to the secondary hydrocyclone sleeve 202 and the oil pipe coupling 204, respectively. After the oil and water phases have stabilized and coalesced, they enter module 2 and are enhanced by the swirling flow field through the secondary spiral flow channel 201 before entering the oil-water hydrocyclone separator. Utilizing the density difference between oil and water, and the centrifugal force generated by the swirling flow, the oil and water phases are separated, achieving efficient separation. The separated oil phase passes sequentially through the overflow channel in the middle of the secondary spiral flow channel 201, the No. 3 flow pipe 106, the No. 2 flow pipe 105, the overflow channel 104 of the No. 1 flow pipe, and the overflow channel in the middle of the primary spiral flow channel 103, and finally enters the upper oil pipe coupling 101, from which it flows directly out of the device. The separated water phase is discharged from the water phase outlet 2021 of the oil-water separator to the lower oil pipe coupling 204, and then leaves the device and is reinjected into the ground. Figure 8 This is an exploded view of the oil-water two-phase separation module, which mainly consists of a secondary spiral flow channel 201, a secondary hydrocyclone sleeve 202, a lower outer sleeve 203, and a lower oil pipe coupling 204.

[0030] This device features a compact design and reliable, stable operation. The oil-water mixture first passes through an oil-water coalescing module, where an innovatively designed annular channel and flow-stabilizing sphere achieve stable flow and enhance oil droplet collision, further coalescing the oil droplets. The coalesced oil and water phases then enter an oil-water separation module for efficient separation. The separated oil phase flows into the upper oil pipe coupling, while the separated water phase exits the device through the lower oil pipe coupling and is reinjected into the ground, thus achieving highly efficient oil-water separation. This invention integrates flow stabilization, oil droplet coalescence, and swirling flow to achieve highly efficient oil-water separation, resulting in high operating efficiency, excellent separation effect, and is beneficial for the sustainable development of oilfields, demonstrating high practicality.

Claims

1. A downhole floating coalescing enhanced oil-water cyclone separator for simultaneous injection and production, characterized in that: This downhole floating coalescing enhanced oil-water cyclone separator for simultaneous injection and production consists of an oil-water coalescing module and an oil-water two-phase separation module. The oil-water mixture is first coalesced in the oil-water coalescing module, and then separated in the oil-water two-phase separation module. The oil-water coalescing module includes a primary spiral channel, an upper tubing coupling, and an upper outer sleeve. The lower end of the overflow channel of the primary spiral channel is fixedly connected to a segmented flow pipe. Multiple annular channels are spaced apart at the lower part of the primary spiral channel and outside the segmented flow pipe. Adjacent annular channels are fixedly connected by a connecting sleeve. The upper outer sleeve is connected to the upper wall of the outermost annular channel, and the upper outer sleeve has an inlet hole at its upper part. A flow stabilizing ball is slidably connected to a segmented flow tube between two adjacent annular channels. The upper end of the annular channel is trumpet-shaped, and the middle of the annular channel is cylindrical. Both the upper and lower ends of the annular channel have external threads. The flow stabilizing ball is elliptical and has a channel hole in its center. A spring is fixed at the lower end of the channel hole, and a protrusion is set inside the channel hole. The protrusion of the flow stabilizing ball is stuck in the groove of the segmented flow tube. When oil droplets pass through the annular channel, the trajectory of the oil droplets is changed, increasing the probability of oil droplet collision and aggregation, causing small oil droplets to coalesce into large oil droplets. The flow stabilizing ball between every two annular channels can stabilize the flow rate, increase the collision of oil droplets, and achieve the integration of flow stabilization, coalescence, and swirling flow.

2. The downhole floating coalescing enhanced oil-water cyclone separator for injection and production according to claim 1, characterized in that: The oil-water two-phase separation module includes a secondary spiral flow channel, a secondary hydrocyclone sleeve, a lower outer sleeve, and a lower oil pipe coupling. The secondary spiral flow channel is connected to the segmented flow pipe by threads. The secondary hydrocyclone sleeve is connected to the outer wall of an adjacent annular channel by threads. The upper end of the lower outer sleeve is connected to the secondary hydrocyclone sleeve, and the lower end is connected to the lower oil pipe coupling by threads. The secondary spiral flow channel is located inside the secondary hydrocyclone sleeve, and the separated water phase is discharged from the water phase outlet of the oil-water separator hydrocyclone.

3. The downhole floating coalescing enhanced oil-water cyclone separator for injection and production according to claim 2, characterized in that: The segmented flow passage is composed of flow passage No. 1, flow passage No. 2, and flow passage No. 3 connected sequentially; there are five annular channels and four interlocking sleeves, namely interlocking sleeve No. 1, interlocking sleeve No. 2, interlocking sleeve No. 3, and interlocking sleeve No. 4; there are four flow stabilizing balls, namely flow stabilizing ball No. 1, flow stabilizing ball No. 2, flow stabilizing ball No. 3, and flow stabilizing ball No. 4; the lower inner wall of the upper oil pipe coupling is threaded to the top cover of the hydrocyclone, and the lower outer wall of the top cover of the hydrocyclone is threaded to the upper outer sleeve; the uppermost annular channel below The outer wall of the first-stage spiral channel is threaded to the No. 1 interlocking sleeve. The upper and lower outer walls of the No. 2, No. 3, and No. 4 interlocking sleeves are threaded to the adjacent two annular channels. The upper end of the first-stage spiral channel is threaded to the top cover hole of the hydrocyclone. The lower end of the first-stage spiral channel is threaded to the No. 1 flow pipe. The lower end of the No. 1 flow pipe is threaded to the No. 2 flow pipe. The lower end of the No. 2 flow pipe is threaded to the No. 3 flow pipe.

4. The downhole floating coalescing enhanced oil-water cyclone separator for injection and production according to claim 3, characterized in that: The overflow channel of the first-stage spiral flow channel has a groove at its lower end, and the protrusion on the flow stabilizing ball is stuck in the groove, and the protrusion is slidably connected to the groove.

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