Downhole oil-water separation reinjection tubular column capable of being adjusted while being measured

Abstract

The invention discloses an underground oil-water separation reinjection pipe column capable of adjusting while measuring, which comprises a sleeve, and the inside of the sleeve is connected with a perforated pipe, a canning cylinder and a steady flow suspension device through a reinjection oil pipe; an oil phase outlet channel, a test channel and a rotary water phase outlet channel are formed in the steady flow suspension device, and an oil-rich inlet connected with an underground oil-water separator is formed in the lower end of the oil phase outlet channel; an oil-rich outlet connected with a lifting oil pipe is formed in the upper end of the oil phase outlet channel; the upper end of the test channel is communicated with the lifting oil pipe, and the lower end is communicated with the rotary water phase outlet channel; a reinjection water inlet connected with an underground oil-water separator is formed in one side of the rotary water phase outlet, and a reinjection water outlet connected with a reinjection oil pipe is formed in the lower end of the rotary water phase outlet channel; and a water injection working barrel capable of measuring and adjusting water is connected in the canning barrel, and is communicated with the casing annulus through a water nozzle. According to the invention, monitoring of underground oil-water separation reinjection water and adjustment while measurement can be realized, the split ratio is effectively adjusted, and the oil-water separation efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil production equipment, and in particular relates to a downhole oil-water separation and measurement-adjustment reinjection pipe column. Background Art

[0002] When oil fields enter the medium-high water content period, the water content of the produced fluid increases significantly, and the cost of lifting and treating the produced water is high. Some oil fields are limited by the capacity of surface water treatment equipment, which restricts the continuous stable production of oil fields. Therefore, the demand for downhole oil-water separation technology increases. Various forms of downhole oil-water separation technology have always received much attention and continued development, but there are many supporting technologies that have always restricted the large-scale promotion of downhole oil-water separation, such as the regulation of diversion ratio and the monitoring of downhole reinjection water.

[0003] At present, wireline operations are usually used to cast and fish mechanical water nozzles to control the amount of reinjection water, thereby adjusting the diversion ratio. It is necessary to calculate the size of the reinjection water nozzle in conjunction with the operating conditions of the electric pump and the injection and production parameters, and repeatedly cast and fish to replace the water nozzles to adjust the optimal diversion ratio. Another type of underground permanent cable reinjection water monitoring and control device has high cost, and there is a risk of failure of the cable being pre-placed underground for a long time, resulting in the inability to effectively control the diversion ratio, low underground oil-water separation efficiency, and poor results. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a downhole oil-water separation and measurement and adjustment reinjection string, which is intended to realize the monitoring and measurement and adjustment of downhole oil-water separation reinjection water, effectively adjust the diversion ratio, and improve the oil-water separation efficiency.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a downhole oil-water separation and measurement and adjustment reinjection string, characterized in that it includes a casing, the inside of the casing is connected to a perforated pipe, a canned cylinder and a flow-stabilizing suspension device from bottom to top through a reinjection oil pipe; wherein the flow-stabilizing suspension device is a three-way structure, that is, an oil phase outlet channel, a test channel and a rotational water phase outlet channel are formed inside the flow-stabilizing suspension device, an oil-rich inlet is formed at the lower end of the oil phase outlet channel, and the oil-rich inlet is connected to the oil flow pipeline of a downhole oil-water separator, and the downhole oil-water separator is connected to an electric submersible pump; an oil-rich outlet is formed at the upper end of the oil phase outlet channel, and the oil-rich outlet is connected to a lifting oil pipe; the measurement channel is connected to the oil flow pipeline of a downhole oil-water separator, and the downhole oil-water separator is connected to an electric submersible pump; an oil-rich outlet is formed at the upper end of the oil phase outlet channel, and the oil-rich outlet is connected to a lifting oil pipe; The test channel and the rotary water phase outlet channel are both arranged on the same side of the oil phase outlet channel, the upper end of the test channel is connected to the lifting oil pipe, and the lower end of the test channel is connected to the rotary water phase outlet channel; a reinjection water inlet is formed on the side of the rotary water phase outlet channel close to the oil phase outlet channel, the reinjection water inlet is connected to the water flow pipeline of the downhole oil-water separator, and a reinjection water outlet is formed at the lower end of the rotary water phase outlet channel, and the reinjection water outlet is connected to the reinjection oil pipe; the inside of the canned barrel is connected with a measuring and adjusting water injection working cylinder, and the measuring and adjusting water injection working cylinder is connected to the annulus of the casing and the reinjection oil pipe through a water nozzle, and the water nozzle is an adjustable structure; During production, a production plug is put into the test channel to plug the test channel, and the production fluid enters the electric submersible pump through the annulus between the casing and the reinjection oil pipe, and then is lifted and the oil-water two-phase separation is completed in the downhole oil-water separator. After separation, the oil-rich production fluid enters the lifting oil pipe through the oil phase outlet channel, and the low-oil-content wastewater enters the reinjection oil pipe through the rotary water phase outlet channel; During the test, the production plug in the test channel is first taken out, and then the test plug carrying the measuring and adjusting instrument is lowered into the matching position of the flow-stabilizing suspension device through the upper test cable operation. The measuring and adjusting instrument is lowered into the canned cylinder and docked with the measuring and adjusting water injection working cylinder. The measuring and adjusting instrument is controlled by the test cable to adjust the size of the water nozzle of the measuring and adjusting water injection working cylinder, thereby changing the amount of water injection to achieve the target diversion ratio. After the adjustment is completed, the test cable operation takes out the measuring and adjusting instrument, thus completing the regulation of the downhole oil-water separation diversion ratio and the reinjection water volume, and the production plug is put back into operation for downhole oil-water separation and reinjection production.

[0006] Preferably, an isolation packer for separating the water injection layer and the liquid production layer is provided in the casing at the connection between the perforated pipe and the reinjection oil pipe, and the isolation packer is connected to a top packer provided above the water injection layer through a screen pipe.

[0007] Preferably, a positioning insert seal is provided on the oil reinjection pipe located above the isolation packer, and the positioning insert seal is inserted into the isolation packer.

[0008] Preferably, a cable packer is provided on the upper part of the casing, and the power cable passes through the cable packer and is connected to the electric submersible pump.

[0009] As a preference, it also includes a sampling pipeline, which passes through the cable packer and is connected to the reinjection oil pipe, and is used to sample and test the oil content in the reinjection water after separation. The present invention has the following advantages due to the adoption of the above technical solution: 1. During production, the downhole oil-water separation and measurement-adjustment reinjection string provided by the present invention completes the lifting and reinjection functions of the separated oil and water phases through the specially designed internal channel of the flow-stabilizing suspension device, and the string structure is simple and reliable.

[0010] 2. When testing the downhole oil-water separation and measurement-and-adjustment reinjection string provided by the present invention, the downhole oil-water separation diversion ratio and reinjection water volume can be regulated by lowering a measurement and adjustment instrument. The downhole pressure and flow data can be directly read on the ground to achieve ground measurement and adjustment synchronization. The measurement and adjustment efficiency and injection accuracy are high, the operation is simple, the cost is low, and the measurement and adjustment instrument can be reused without adding a long-term electric control adjustment device, thereby reducing the operation cost and the risk of failure of the electric control and reinjection water device.

[0011] 3. The present invention can realize the monitoring and simultaneous adjustment of the oil-water separation reinjection water in the well through a cable operation, effectively adjust the diversion ratio, and improve the oil-water separation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings: Figure 1 A schematic diagram of the state of the downhole oil-water separation and measurement and adjustment re-injection string test provided by the present invention; Figure 2 A schematic diagram of the state of the downhole oil-water separation and measurement-adjustment reinjection string during production provided by the present invention.

[0013] 1. Casing; 2. Perforated pipe; 3. Positioning and inserting seal; 4. Reinjection oil pipe; 5. Canned barrel; 6. Water injection working barrel for measuring and adjusting; 6-1. Water nozzle; 7. Measuring and adjusting instrument; 8. Measuring and adjusting cable; 9. Submersible pump; 10. Downhole oil-water separator; 11. Multifunctional steady flow suspension device; 11-1. Oil phase outlet channel; 11-2. Test channel; 11-3. Rotary water phase outlet channel; 12. Test plug; 13. Lifting oil pipe; 14. Power cable; 15. Cable packer; 16. Sampling pipeline; 17. Production plug; 18. Isolation packer; 19. Screen pipe; 20. Top packer. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical scheme and advantages of the present invention clearer, the specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0015] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0016] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0017] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0019] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0020] The present invention provides a downhole oil-water separation and measurement and adjustment reinjection string, comprising a casing, wherein the casing is connected with a perforated pipe, a canned barrel and a flow-stabilizing suspension device through a reinjection oil pipe; an oil phase outlet channel, a test channel and a rotational water phase outlet channel are formed in the flow-stabilizing suspension device, and the lower end of the oil phase outlet channel forms an oil-rich inlet connected to the downhole oil-water separator; the upper end of the oil phase outlet channel forms an oil-rich outlet connected to the lifting oil pipe; the upper end of the test channel is connected to the lifting oil pipe, and the lower end is connected to the rotational water phase outlet channel; a reinjection water inlet connected to the downhole oil-water separator is formed on one side of the rotational water phase outlet, and a reinjection water outlet connected to the reinjection oil pipe is formed at the lower end of the rotational water phase outlet; a measurement and adjustment water injection mandrel is connected inside the canned barrel, and the measurement and adjustment water injection mandrel is connected to the casing annulus through a water nozzle. The present invention can realize the monitoring and measurement and adjustment of reinjection water for downhole oil-water separation, effectively adjust the diversion ratio, and improve the oil-water separation efficiency.

[0021] The downhole oil-water separation and measurement-while-adjustment reinjection string provided by the embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0022] See also Figure 1 The present embodiment provides a downhole oil-water separation and measurement and adjustment reinjection string, comprising a casing 1, wherein the casing 1 is connected from bottom to top through a reinjection oil pipe 4 to a perforated pipe 2, a canned barrel 5 and a flow-stabilizing suspension device 11, wherein the flow-stabilizing suspension device 11 is a three-way structure, i.e., an oil phase outlet channel 11-1, a test channel 11-2 and a rotational water phase outlet channel 11-3 are formed inside the flow-stabilizing suspension device 11, an oil-rich inlet is formed at the lower end of the oil phase outlet channel 11-1, and the oil-rich inlet is connected to the oil flow pipeline of a downhole oil-water separator 10, and the oil-water separator 10 is connected to an electric submersible pump 9; a rich oil inlet is formed at the upper end of the oil phase outlet channel 11-1. The oil-rich outlet is connected to the lifting oil pipe 13; the test channel 11-2 and the rotary water phase outlet channel 11-3 are both arranged on the same side of the oil phase outlet channel 11-1, the upper end of the test channel 11-2 is connected to the lifting oil pipe 13, and the lower end of the test channel 11-2 is connected to the rotary water phase outlet channel 11-3; the rotary water phase outlet channel 11-3 is formed with a reinjection water inlet on one side close to the oil phase outlet channel 11-1, and the reinjection water inlet is connected to the water flow pipeline of the downhole oil-water separator 10, and the lower end of the rotary water phase outlet channel 11-3 forms a reinjection water outlet, which is connected to the reinjection oil pipe 4. The inside of the canned barrel 5 is connected to the measuring and adjusting water injection working cylinder 6 through the upper end buckle, and the measuring and adjusting water injection working cylinder 6 is connected to the annulus of the casing 1 and the reinjection oil pipe 4 through the water nozzle 6-1, and the water nozzle 6-1 is an adjustable structure.

[0023] During production, the production plug 17 is inserted into the test channel 11-2 to plug the test channel 11-2 (see Figure 2 ), the produced liquid enters the electric submersible pump 9 through the annulus between the casing 1 and the reinjection oil pipe 4 for lifting, and then completes the oil-water two-phase separation in the downhole oil-water separator 10. After separation, the oil-rich produced liquid enters the lifting oil pipe 13 through the oil phase outlet channel 11-1, and the low-oil wastewater enters the reinjection oil pipe 4 through the rotary water phase outlet channel 11-3.

[0024] During the test, first take out the production plug 17 in the test channel 11-2, and then lower the test plug 12 carrying the test and adjustment instrument 7 through the upper test cable 8 to the matching position of the flow stabilizing suspension device 11 (see Figure 1), the measuring and adjusting instrument 7 is lowered into the downhole canned cylinder 5 and docked with the measuring and adjusting water injection working cylinder 6, and the measuring and adjusting instrument 7 is controlled by the test cable 8 to adjust the size of the water nozzle 6-1 of the measuring and adjusting water injection working cylinder 6, thereby changing the size of the water injection volume to achieve the target diversion ratio. After the adjustment is completed, the test cable 8 is operated to take out the measuring and adjusting instrument 7, that is, the downhole oil-water separation diversion ratio and the reinjection water volume are regulated, and then the production plug 17 is put into use to carry out downhole oil-water separation and reinjection production.

[0025] In the above embodiments, preferably, please refer to Figure 1 An isolation packer 18 for separating the water injection layer and the liquid production layer is arranged in the casing 1 at the connection between the perforated pipe 2 and the return oil pipe 4. The isolation packer 18 is connected to the top packer 20 arranged above the water injection layer through a screen pipe 19.

[0026] In the above embodiments, preferably, please continue to refer to Figure 1 A positioning insert seal 3 is provided on the oil reinjection pipe 4 located above the isolation packer 18 , and the positioning insert seal 3 is inserted into the isolation packer 18 .

[0027] In the above embodiments, preferably, please continue to refer to Figure 1 A cable packer 15 is arranged on the upper part of the casing 1 , and the power cable 14 passes through the cable packer 15 and is connected to the electric submersible pump 9 .

[0028] In the above embodiments, preferably, please continue to refer to Figure 1 , and also includes a sampling pipeline 16, which passes through the cable packer and is connected to the reinjection oil pipe 4, and is used to sample and test the oil content in the reinjection water after separation.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A downhole oil-water separation and measurement and adjustment re-injection string, characterized in that: It comprises a casing, wherein the inside of the casing is connected with a perforated pipe, a canned cylinder and a flow stabilizing suspension device from bottom to top through a return oil pipe; Wherein, the flow-stabilizing suspension device is a three-way structure, that is, an oil phase outlet channel, a test channel and a rotational water phase outlet channel are formed inside the flow-stabilizing suspension device, an oil-rich inlet is formed at the lower end of the oil phase outlet channel, and the oil-rich inlet is connected to the oil flow pipeline of the downhole oil-water separator, and the downhole oil-water separator is connected to the electric submersible pump; an oil-rich outlet is formed at the upper end of the oil phase outlet channel, and the oil-rich outlet is connected to the lifting oil pipe; the test channel and the rotational water phase outlet channel are both arranged on the same side of the oil phase outlet channel, the upper end of the test channel is connected to the lifting oil pipe, and the lower end of the test channel is connected to the rotational water phase outlet channel; a reinjection water inlet is formed on the side of the rotational water phase outlet channel close to the oil phase outlet channel, and the reinjection water inlet is connected to the water flow pipeline of the downhole oil-water separator, and a reinjection water outlet is formed at the lower end of the rotational water phase outlet channel, and the reinjection water outlet is connected to the reinjection oil pipe; The inside of the canned cylinder is connected with a measuring and adjusting water injection working cylinder, and the measuring and adjusting water injection working cylinder is connected with the annulus of the casing and the return oil pipe through a water nozzle, and the water nozzle is an adjustable structure; During production, a production plug is put into the test channel to plug the test channel, and the production fluid enters the electric submersible pump through the annulus between the casing and the reinjection oil pipe, and then is lifted and the oil-water two-phase separation is completed in the downhole oil-water separator. After separation, the oil-rich production fluid enters the lifting oil pipe through the oil phase outlet channel, and the low-oil-content wastewater enters the reinjection oil pipe through the rotary water phase outlet channel; During the test, the production plug in the test channel is first taken out, and then the test plug carrying the measuring and adjusting instrument is lowered into the matching position of the flow-stabilizing suspension device through the upper test cable operation. The measuring and adjusting instrument is lowered into the canned cylinder and docked with the measuring and adjusting water injection working cylinder. The measuring and adjusting instrument is controlled by the test cable to adjust the size of the water nozzle of the measuring and adjusting water injection working cylinder, thereby changing the amount of water injection to achieve the target diversion ratio. After the adjustment is completed, the test cable operation takes out the measuring and adjusting instrument, thus completing the regulation of the downhole oil-water separation diversion ratio and the reinjection water volume, and the production plug is put back into operation for downhole oil-water separation and reinjection production.

2. The downhole oil-water separation and measurement-adjustment reinjection string according to claim 1 is characterized in that: An isolation packer for separating the water injection layer and the liquid production layer is arranged in the casing located at the connection between the perforated pipe and the return oil pipe. The isolation packer is connected to the top packer arranged above the water injection layer through a screen pipe.

3. The downhole oil-water separation and measurement-adjustment reinjection string according to claim 2 is characterized in that: A positioning insert seal is provided on the oil reinjection pipe located above the isolation packer, and the positioning insert seal is inserted into the isolation packer.

4. The downhole oil-water separation and measurement-adjustment reinjection string according to claim 1, characterized in that: A cable packer is arranged on the upper part of the casing, and a power cable passes through the cable packer and is connected to the electric submersible pump.

5. The downhole oil-water separation and measurement-adjustment reinjection string according to claim 4 is characterized in that: It also includes a sampling pipeline, which passes through the cable packer and is connected to the reinjection oil pipe for sampling and testing the oil content in the reinjection water after separation.

Images