CN102817602B - Online Profile Control Method and Device for Polymer Flooding Oilfield - Google Patents

Abstract

An on-line profile control method and device for a polymer flooding field, wherein the on-line profile control device for the polymer flooding field comprises: a polymer solution injection line having an inlet end and an outlet end; the annular liquid mixer is connected with the polymer solution injection pipeline in parallel, a liquid inlet bell mouth and a liquid outlet bell mouth are respectively arranged at two ends of the annular liquid mixer, the liquid inlet bell mouth and the inlet end are respectively connected with a polymer solution liquid inlet pipeline, and the liquid outlet bell mouth and the outlet end are respectively connected with a mixed liquid outlet pipeline; and the cross-linking agent solution liquid inlet pipeline is connected to the inner annular wall of the annular liquid mixer, and one end of the cross-linking agent solution liquid inlet pipeline, which extends into the annular liquid mixer, is opposite to the liquid inlet bell mouth. The polymer flooding oil field on-line profile control method and the polymer flooding oil field on-line profile control device can improve the polymer flooding effect of the polymer flooding oil field, realize the on-line profile control treatment of the polymer flooding oil field, and effectively prevent the viscosity of a polymer solution from being reduced due to the shearing action.

Description

Online Profile Control Method and Device for Polymer Flooding Oilfield

technical field

The invention relates to an oilfield profile control method and device, in particular to an online profile control method and device for polymer flooding oilfields used in the technical field of oil and gas field development engineering to improve the oil recovery rate of polymer flooding oilfields.

Background technique

At present, my country's large-scale oil fields, such as Daqing Oilfield, Shengli Oilfield and other eastern oilfields, have entered the final stage of development, and their output has declined to varying degrees, while the increase in new reserves is getting slower and slower, and the cost and difficulty of exploration are also increasing. Therefore, controlling the water cut, stabilizing the current crude oil output, maximizing the ultimate recovery rate, and economically and rationally utilizing and developing it play a decisive role in the entire oil industry, and the tertiary oil recovery technology is so far able to meet this requirement Among the tertiary oil recovery technologies, the chemical flooding technology occupies the most important position, and among the chemical flooding, the polymer flooding technology is the most mature and effective. The mechanism of polymer flooding is to add polymers to the injected water to increase the viscosity of the displacement phase, adjust the water absorption profile, and increase the swept volume of the displacement phase, thereby increasing the ultimate recovery.

In polymer flooding oil fields, due to the large well spacing, thick oil layers, many layers, and serious heterogeneity, the polymer solution escapes into the oil well along the high permeability layer, resulting in low sweep coefficient, which reduces the development effect of polymer flooding. To fundamentally solve this problem, the method of profile control and water plugging must be adopted to improve the water absorption profile and increase the water flooding sweep coefficient, that is, to mix the polymer solution and the cross-linking agent solution, and inject the mixed solution into the oil layer In order to carry out high-dose deep profile control.

In the prior art, it is necessary to inject a certain amount of polymer solution into the water injection well first, and then inject a certain amount of plugging agent (that is, a mixture of polymer solution and crosslinking agent solution) into the water injection well according to the actual displacement effect. , using this injection method, it is necessary to stop the injection of the polymer solution injected first, and then inject the plugging agent. The disadvantage is that the purpose of online injection of the plugging agent cannot be achieved. To achieve the purpose of deep profile control or flood control; on the other hand, due to the mixer for mixing the polymer solution and the cross-linking agent solution, the polymer solution is mainly controlled by multiple guide vanes arranged on the inner peripheral wall of the mixing drum. Mixing with the crosslinking agent solution, due to the large difference in viscosity between the polymer solution and the crosslinking agent solution (the viscosity of the polymer solution is usually 100 to 200 times that of the crosslinking agent solution), when the two go down the mixing drum When flowing, the flow rate of the polymer solution and the crosslinking agent solution are different, and it is difficult for the two to fully and uniformly mix in the mixing drum; in addition, the polymer solution is in a state of turbulent flow, and its flow rate is relatively fast. The guide vanes will have a certain shearing effect on the mixture of the polymer solution and the crosslinking agent solution, and the viscosity of the mixture of the polymer solution and the crosslinking agent solution will decrease due to the shearing effect, resulting in the final prepared mixture The profile control effect of the liquid on the oil layer is not ideal.

Therefore, it is necessary to provide a new polymer flooding oil field profile control method and device to overcome the above-mentioned defects.

Contents of the invention

The object of the present invention is to provide an online profile control device for polymer flooding oil field, which can improve the effect of polymer flooding in polymer flooding oil field, realize the online profile control treatment of polymer flooding oil field, and effectively prevent the The cutting effect reduces the viscosity.

Another object of the present invention is to provide an online profile control method for polymer flooding oil fields, which can effectively improve the polymer flooding effect of polymer flooding oil fields, realize online profile control processing for polymer flooding oil fields, and effectively prevent polymerization The viscosity of the solution is reduced by shearing.

Above-mentioned purpose of the present invention can adopt following technical scheme to realize:

The invention provides an online profile control device for a polymer flooding oil field. The online profile control device for a polymer flooding oil field includes:

a polymer solution injection line having an inlet port and an outlet port;

An annular liquid mixer, which is arranged in parallel with the polymer solution injection pipeline, the two ends of the annular liquid mixer are respectively provided with a liquid inlet bell mouth and a liquid outlet bell mouth, and the liquid inlet bell mouth and the inlet port are respectively connected to the A polymer solution inlet pipeline is connected, and the outlet bell mouth and the outlet port are respectively connected with a mixed solution outlet pipeline;

The cross-linking agent solution inlet line is connected to the inner ring wall of the annular mixer, and the end of the cross-linking agent solution inlet line extending into the annular mixer is opposite to the inlet bell mouth.

In a preferred embodiment, the annular mixer has an annular accommodation chamber, and one end of the crosslinking agent solution inlet line extending into the annular accommodation chamber is connected to a shower head, and the shower head is opposite to the inlet bell mouth .

In a preferred embodiment, the shower head is a spherical shower head, and a plurality of liquid outlet through holes are opened on the side of the shower head opposite to the liquid inlet bell mouth.

In a preferred embodiment, the diameter of the outlet through hole is 1-2 mm.

In a preferred embodiment, the polymer solution inlet line is connected with a polymer solution flow meter and a liquid inlet one-way stop valve.

In a preferred embodiment, the inlet bell mouth of the annular liquid mixer is connected to the polymer solution inlet pipeline through a polymer solution one-way stop valve, and the liquid outlet bell mouth of the annular liquid mixer is connected through a mixed liquid single The stop valve is connected with the mixed liquid outlet pipeline.

In a preferred embodiment, a one-way stop valve is connected to the polymer solution injection pipeline.

In a preferred embodiment, a liquid outlet one-way stop valve is connected to the mixed liquid outlet pipeline.

In a preferred embodiment, a cross-linking agent solution one-way stop valve, a cross-linking agent solution flow meter and a high-pressure resistant metering pump are connected to the cross-linking agent solution inlet line.

In a preferred embodiment, a sampling and detection pipeline is connected to the outlet pipeline of the mixed solution.

The present invention also provides an online profile control method for a polymer flooding oil field, the online profile control method for a polymer flooding oil field includes the following steps:

a) Provide a polymer solution injection pipeline and an annular mixer, the polymer solution injection pipeline and the annular mixer are arranged in parallel, and the two ends of the annular mixer are respectively provided with a liquid inlet horn and an outlet horn mouth, the inlet port of the inlet bell mouth and the polymer solution injection pipeline is connected with a polymer solution inlet pipeline respectively, and the outlet end of the outlet bell mouth and the polymer solution injection pipeline is connected with a polymer solution injection pipeline respectively. The mixed liquid outlet line is connected, and the inner ring wall of the annular liquid mixer is connected with a crosslinking agent solution inlet line, and one end of the crosslinking agent liquid inlet line extending into the annular liquid mixer is connected with the liquid inlet. The bell mouth is opposite;

b) Inject the polymer solution into the polymer solution inlet line, during the process of injecting the polymer solution, the annular mixer is in a closed state, and the polymer solution flows into and mixes through the polymer solution injection line The liquid comes out of the liquid pipeline, and then injected into the water injection well;

c) Open the annular mixer, close the polymer solution injection line, inject the cross-linking agent solution into the cross-linking agent solution inlet line, the polymer solution and the cross-linking agent solution are in the Mix in the annular liquid mixer, and the mixed liquid generated after the two are mixed is injected into the water injection well from the mixed liquid outlet line;

d) Close the annular liquid mixer, open the polymer solution injection pipeline, and perform normal polymer flooding production.

In a preferred embodiment, a step c1) is further included between the step c) and the step d): closing the annular mixer, shutting down the water injection well and waiting for condensation.

In a preferred embodiment, the water injection well is shut down and waited for 5 days for solidification.

In a preferred embodiment, a sampling detection line is connected to the mixed liquid outlet line, and in the step c), the sampling detection line is opened, and the The mixed solution is sampled for detection.

In a preferred embodiment, the annular mixer has an annular accommodation chamber, and one end of the crosslinking agent solution inlet line extending into the annular accommodation chamber is connected to a shower head, and the shower head is opposite to the inlet bell mouth .

In a preferred embodiment, the shower head is a spherical shower head, and a plurality of liquid outlet through holes are opened on the side of the shower head opposite to the liquid inlet bell mouth.

In a preferred embodiment, the diameter of the outlet through hole is 1-2 mm.

In a preferred embodiment, a polymer solution flowmeter is connected to the polymer solution inlet pipeline, a crosslinking agent solution flowmeter is connected to the crosslinking agent solution inlet pipeline, and the polymer solution flowmeter The ratio of the reading to the reading of the crosslinker solution flowmeter is 10:1.

The characteristics and advantages of the polymer flooding oil field online profile control method and device of the present invention are: through the parallel arrangement of the polymer solution injection pipeline and the annular liquid mixer, the online profile control process of the polymer solution can be realized, that is, there is no need to stop the injection The polymer solution can be used to configure the mixed solution of the polymer solution and the cross-linking agent solution that needs profile control of the oil layer on-line, and the process is simple and the operation is convenient. In addition, because the end of the crosslinking agent solution inlet line extending into the annular mixer is opposite to the inlet horn, that is, the flow direction of the polymer solution injected from the inlet horn of the annular mixer is just in line with the direction of self-crosslinking. The flow direction of the cross-linking agent solution injected into the ring mixer by the agent solution inlet line is opposite, so the polymer solution and the cross-linking agent solution can be mixed at the inlet bell of the ring mixer, and the two are separated from the ring mixer. Further sufficient and uniform mixing can also be carried out during the flow from the inlet bell mouth of the liquid mixer to the liquid outlet bell mouth. The annular mixer can effectively prevent the viscosity of the polymer solution from being reduced due to shearing. The annular mixer is used to prepare The mixed solution can play a very good profile control effect on the oil layer.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

Fig. 1 is a structural schematic diagram of an online profile control device for a polymer flooding oil field according to the present invention.

Fig. 2 is a structural diagram of the annular liquid mixer of the polymer flooding oil field online profile control device of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Embodiment 1

As shown in FIG. 1 , the present invention provides an online profile control device for polymer flooding oil field, which includes a polymer solution injection pipeline 1 , an annular liquid mixer 2 and a crosslinking agent solution inlet pipeline 3 . Wherein: the polymer solution injection pipeline 1 has an inlet port 11 and an outlet port 12; the annular liquid mixer 2 is arranged in parallel with the polymer solution injection pipeline 1, and the two ends of the annular liquid mixer 2 are respectively provided with a liquid inlet bell mouth 21 and the liquid outlet bell mouth 22, the liquid inlet bell mouth 21 and the inlet port 11 are respectively connected with a polymer solution inlet pipeline 4, and the liquid outlet bell mouth 22 and the outlet port 12 are respectively connected with a mixed liquid The liquid outlet line 5 is connected; the cross-linking agent solution liquid inlet line 3 is connected on the inner ring wall of the annular liquid mixer 2, and the cross-linking agent solution liquid inlet line 3 extends into one end of the annular liquid mixer 2 and the Said inlet bell mouth 21 is relative.

Specifically, the inlet port 11 of the polymer solution injection line 1 is connected to the liquid inlet bell mouth 12 of the annular liquid mixer 2, and both are connected to the polymer solution inlet line 4; the outlet port 12 of the polymer solution injection line 1 is connected to the The liquid outlet bell mouth 22 of the annular liquid mixer 2 is connected, and both are connected with the mixed liquid outlet pipeline 5 together. The polymer solution flows into the polymer solution injection line 1 and the annular mixer 2 respectively through the polymer solution inlet line 4, the polymer solution flowing out from the outlet port 12 of the polymer solution injection line 1, and the polymer solution from the annular mixer 2 The mixed liquid flowing out from the liquid outlet bell mouth 22 can flow into the water injection well from the mixed liquid outlet pipeline 5 . The polymer solution injection pipeline 1 is used to provide the normal polymer flooding process in the polymer flooding oil field.

The annular liquid mixer 2 is generally in the shape of an elliptical ring, and the liquid inlet bell mouth 21 and the liquid outlet bell mouth 22 are set at the two ends of the long axis of the elliptical annular liquid mixer 2, and the annular liquid mixer 2 is arranged in parallel with the polymer solution injection pipeline 1 , the cross-linking agent solution inlet line 3 is connected to the inner ring wall of the annular mixer 2, the cross-linking agent solution is injected into the annular mixer 2 through the cross-linking agent solution inlet line 3, and is connected with the polymer solution inlet line 4 The polymer solution injected into the annular mixer 2 is mixed to generate a mixed solution for profile control of the oil layer, and the mixed solution flows into the mixed solution outlet pipeline 5 from the outlet bell mouth 22 of the annular mixer 2 and flow into injection wells.

When the present invention carries out polymer flooding to the oil layer, first, open the polymer solution injection pipeline 1, at this moment, the annular liquid mixer 2 is in a closed state, inject the polymer solution into the polymer solution inlet pipeline 4, and the polymer solution starts from The polymer solution inlet pipeline 4 flows into the polymer solution injection pipeline 1, and then flows out from the mixed solution outlet pipeline 5 and injects it into the water injection well; The solution is injected into the pipeline 1. At this time, the crosslinking agent solution is injected into the crosslinking agent solution inlet pipeline 3. Because the polymer solution injection pipeline 1 and the annular mixer 2 are set in parallel, after the polymer solution injection pipeline 1 is closed, it will automatically The polymer solution flowing in the polymer solution inlet line 4 will flow into the annular mixer 2, and mix with the crosslinking agent solution injected into the annular mixer 2 from the crosslinking agent solution inlet line 3, and the polymer solution Fully mix with the cross-linking agent solution at the liquid inlet bell mouth 21 of the ring mixer 2, and flow through the ring mixer 2 for uniform mixing, and finally flow into the mixed liquid outlet pipeline 5 from the outlet bell mouth 22 and then inject In the water injection well, the profile control treatment of the downhole oil layer is completed.

The polymer flooding oil field online profile control device of the present invention can realize the online profile control process of the polymer solution through the parallel arrangement of the polymer solution injection pipeline 1 and the annular liquid mixer 2, that is, it is not necessary to stop injecting the polymer solution. On-line configuration of the mixed solution of polymer solution and cross-linking agent solution that requires profile control of the oil reservoir is simple in process and convenient in operation. In addition, because the end of the crosslinking agent solution inlet line 3 extending into the annular mixer 2 is opposite to the inlet horn 21, that is, the flow direction of the polymer solution injected from the inlet horn 21 of the annular mixer 2 Just opposite to the flow direction of the cross-linking agent solution injected into the annular mixer 2 from the cross-linking agent solution inlet line 3, therefore, the polymer solution and the cross-linking agent solution can pass through the liquid inlet bell mouth 21 of the annular mixer 2 The two are mixed at the liquid inlet bell mouth 21 of the annular liquid mixer 2 to the liquid outlet bell mouth 22, and the two can also be further fully and uniformly mixed. The annular liquid mixer 2 can effectively prevent the polymer solution from being sheared. The viscosity is reduced due to the action of the annular liquid mixer 2, and the mixed liquid prepared by the annular liquid mixer 2 can have a good profile control effect on the oil layer.

According to one embodiment of the present invention, as shown in FIG. 2 , the annular mixer 2 has an annular chamber 23, and one end of the crosslinking agent solution inlet line 3 extending into the annular chamber 23 is connected to a shower head 31 , the shower head 31 is opposite to the liquid inlet bell mouth 21 . In this embodiment, the shower head 31 is a spherical shower head, and a plurality of liquid outlet through holes 311 are opened on the side of the shower head 31 opposite to the liquid inlet bell mouth 21, that is, the spherical shower head 31 is opposite to the liquid inlet bell mouth 21. One side of the hemispherical surface is provided with a plurality of liquid outlet through-holes 311, the advantage of such arrangement is that the cross-linking agent solution can be discharged from a plurality of liquid outlets on the side of the hemispherical surface of the spherical shower head 31 facing the direction of the liquid inlet bell mouth 21. The through hole 311 is sprayed out, and the injection of the crosslinking agent solution is radial, so that the crosslinking agent solution and the polymer solution can be fully mixed, and the mixing degree of the two is improved. In this embodiment, the liquid outlet through hole 311 The diameter is 1-2 mm.

When carrying out the mixing of polymer solution and cross-linking agent solution, at first, polymer solution is injected in the circular mixer 2 from polymer solution inlet line 4, and cross-linking agent solution is injected from cross-linking agent solution inlet line 3 In the annular liquid mixer 2, since the diameter of the inlet bell mouth 21 gradually increases along the flow direction of the polymer solution (the direction indicated by the arrow in Figure 2), the flow rate of the polymer solution gradually slows down at the inlet bell mouth 21 At this time, the cross-linking agent solution injected into the shower head 31 through the cross-linking agent solution inlet line 3 is ejected radially from a plurality of liquid outlet through holes 311 on the shower head 31, because the polymer solution and the cross-linking agent solution The flow direction is opposite, and the polymer solution and the crosslinking agent solution can be fully mixed at the liquid inlet bell mouth 21 of the annular mixer 2, and then flow into the annular accommodation chamber 23, and further mix evenly through buffering and speed reduction until reaching the outlet. When the liquid bell mouth 22 is located, the polymer solution and the crosslinking agent solution can have sufficient time to mix uniformly, and finally flow out of the annular liquid mixer 2 through the liquid outlet bell mouth 22 .

The present invention mixes the polymer solution and the cross-linking agent solution through the annular mixer 2, and the polymer solution and the cross-linking agent solution are statically mixed at a reduced speed in the annular chamber 23, and the two can be mixed in the annular mixer 2. Fully and evenly mixed inside, effectively preventing the polymer solution from reducing the viscosity due to shearing.

According to one embodiment of the present invention, the polymer solution inlet line 4 is connected with a polymer solution flow meter 41 and a liquid inlet one-way stop valve 42 . The polymer solution flow meter 41 is used to measure the flow rate of the polymer solution injected from the polymer solution inlet line 4 , and the liquid inlet one-way stop valve 42 is used to open or close the polymer solution inlet line 4 .

Further, the liquid inlet bell mouth 21 of the annular liquid mixer 2 is connected to the polymer solution inlet pipeline 4 through a polymer solution one-way stop valve 24, and the liquid outlet bell mouth 22 of the annular liquid mixer 2 is passed through a mixing The liquid one-way stop valve 25 is connected with the mixed liquid outlet pipeline 5 . The polymer solution one-way stop valve 24 and the mixed solution one-way stop valve 25 are used to open or close the channels at the liquid inlet bell mouth 21 and the liquid outlet bell mouth 22 of the annular mixer 2 .

According to one embodiment of the present invention, the polymer solution injection pipeline 1 is connected with a one-way shut-off valve 13 , and the one-way shut-off valve 13 is used to open or close the polymer solution injection pipeline 1 . Further, the liquid outlet one-way stop valve 51 is connected to the mixed liquid outlet line 5 , and the liquid outlet one-way stop valve 51 is used to open or close the mixed liquid outlet line 5 . In addition, a crosslinking agent solution one-way stop valve 32, a crosslinking agent solution flow meter 33 and a high-pressure resistant metering pump 34 are connected to the crosslinking agent solution inlet line 3, and the crosslinking agent solution one-way stop valve 32 is used to open Or close the cross-linking agent solution inlet line 3 , and the cross-linking agent solution flowmeter 33 is used to measure the flow rate of the cross-linking agent solution injected from the cross-linking agent solution inlet line 3 . In one embodiment, the ratio of the reading of the polymer solution flowmeter 41 connected to the polymer solution inlet line 4 to the reading of the crosslinking agent solution flowmeter 33 connected to the crosslinking agent solution inlet line 3 is 10:1, that is, the volume of the polymer solution injected into the annular mixer 2 is 10 times the volume of the crosslinking agent solution injected into the annular mixer 2 .

According to an embodiment of the present invention, a sampling and detection pipeline 6 is connected to the mixed liquid outlet pipeline 5 . By opening the sampling detection pipeline 6, the mixed liquid flowing out from the annular liquid mixer 2 can be sampled and detected to simulate the formation temperature for gelation experiments.

Embodiment 2

The present invention also provides an online profile control method for a polymer flooding oil field, the online profile control method for a polymer flooding oil field includes the following steps:

a) Provide a polymer solution injection line 1 and an annular mixer 2, the polymer solution injection line 1 and the annular mixer 2 are arranged in parallel, and the two ends of the annular mixer 2 are respectively provided with liquid inlet horns Mouth 21 and outlet bell mouth 22, described inlet bell mouth 21 and the inlet end 11 of described polymer solution injection pipeline 1 are connected with a polymer solution inlet pipeline 4 respectively, described outlet bell mouth 22 and all The outlet end 12 of the polymer solution injection pipeline 1 is connected to a mixed liquid outlet pipeline 5 respectively, and a crosslinking agent solution inlet pipeline 3 is connected on the inner ring wall of the annular liquid mixer 2, and the crosslinking agent One end of the liquid inlet line 3 extending into the annular mixer 2 is opposite to the liquid inlet bell mouth 21;

b) Inject polymer solution into the polymer solution inlet line 4, during the process of injecting the polymer solution, the annular mixer 2 is in a closed state, and the polymer solution passes through the polymer solution injection line 1 flows into the liquid outlet pipeline 5 of the mixed liquid, and then injects it into the water injection well;

c) Open the annular mixer 2, close the polymer solution injection line 1, inject the cross-linking agent solution into the cross-linking agent solution inlet line 3, the polymer solution and the cross-linking agent solution Mix in the annular liquid mixer 2, and the mixed liquid generated after the two are mixed flows into the mixed liquid outlet pipeline 5 from the liquid outlet bell mouth 22 of the annular liquid mixer, and then injected into the water injection well;

d) Close the annular mixer 2, open the polymer solution injection pipeline 1, and perform normal polymer flooding production.

Specifically, the structure, working principle and beneficial effects of the polymer solution injection pipeline 1, the annular mixer 2 and the crosslinking agent solution inlet pipeline 3 mentioned in step a) are the same as those of the polymer solution injection pipeline in Embodiment 1 1. The annular mixer 2 is the same as the cross-linking agent solution inlet line 3, and will not be repeated here.

The above step b) is the process of polymer flooding the oil layer. First, the polymer solution injection pipeline 1 is opened. At this time, the annular mixer 2 is closed, and the polymer solution is injected into the polymer solution inlet pipeline 4. The polymerization The polymer solution flows from the polymer solution inlet line 4 into the polymer solution injection line 1, and then flows out from the mixed solution outlet line 5 and is injected into the water injection well.

When it is necessary to perform profile control treatment on the oil layer, step c) is performed, the annular liquid mixer 2 is opened, and the polymer solution injection pipeline 1 is closed. At this time, the crosslinking agent solution is injected into the crosslinking agent solution inlet pipeline 3. The polymer solution injection line 1 and the annular mixer 2 are arranged in parallel, therefore, after the polymer solution injection line 1 is closed, the polymer solution flowing in from the polymer solution inlet line 4 will flow into the annular mixer 2, and the The cross-linking agent solution injected into the cross-linking agent solution into the annular mixer 2 in the liquid inlet line 3 is mixed, and the polymer solution and the cross-linking agent solution are mixed at the liquid inlet bell mouth 21 of the annular mixer 2, and then pass through the annular mixer. The liquid mixer 2 is used for further uniform mixing, and finally the mixed liquid flows into the liquid outlet pipeline 5 from the liquid outlet bell mouth 22 of the annular liquid mixer 2 and then injected into the water injection well to complete the profile control treatment of the downhole oil layer.

In step d), after the profile control treatment of the oil layer is completed, the polymer solution injection pipeline 1 is opened, the annular liquid mixer 2 is closed, and the normal production of the polymer flooding is continued.

The online profile control method for polymer flooding oil field of the present invention can realize the online profile control process of the polymer solution through the parallel arrangement of the polymer solution injection pipeline 1 and the annular liquid mixer 2, that is, without stopping the injection of the polymer solution. On-line configuration of the mixed solution of polymer solution and cross-linking agent solution that requires profile control of the oil reservoir is simple in process and convenient in operation. In addition, because the end of the crosslinking agent solution inlet line 3 extending into the annular mixer 2 is opposite to the inlet horn 21, that is, the flow direction of the polymer solution injected from the inlet horn 21 of the annular mixer 2 Just opposite to the flow direction of the cross-linking agent solution injected into the annular mixer 2 from the cross-linking agent solution inlet line 3, therefore, the polymer solution and the cross-linking agent solution can pass through the liquid inlet bell mouth 21 of the annular mixer 2 The two are mixed at the liquid inlet bell mouth 21 of the annular liquid mixer 2 to the liquid outlet bell mouth 22, and the two can also be further fully and uniformly mixed. The annular liquid mixer 2 can effectively prevent the polymer solution from being sheared. The viscosity is reduced due to the action of the annular liquid mixer 2, and the mixed liquid prepared by the annular liquid mixer 2 can have a good profile control effect on the oil layer.

According to an embodiment of the present invention, a step c1) is further included between the step c) and the step d): closing the annular mixer 2, shutting down the water injection well and waiting for condensation, specifically, The water injection well needs to be shut down and wait for 5 days, so that after the well is shut down and waited for coagulation, the mixed solution of the polymer solution and the cross-linking agent solution can be fully applied in the downhole oil layer, and it can be used for the follow-up polymer flooding of the oil layer. The smooth progress of the process provides a prerequisite guarantee.

According to one embodiment of the present invention, a sampling detection line 6 is connected to the mixed liquid outlet line 5. In the step c), the sampling detection line 6 is opened, and the The mixed liquid prepared by the outlet bell mouth 22 is sampled and detected to simulate the temperature of the formation for gel experiments.

In one embodiment, the ratio of the reading of the flowmeter 33 connected to the crosslinking agent solution inlet line 3 to the reading of the flowmeter 41 connected to the polymer solution inlet line 4 is 10:1, that is, the injection The capacity of the polymer solution to the annular mixer 2 is 10 times the capacity of the cross-linking agent solution injected into the annular mixer 2, so that the mixed solution obtained after the polymer solution and the cross-linking agent solution are mixed Good profile control effect on oil layers.

The above are only a few embodiments of the present invention, and those skilled in the art can make various changes or modifications to the embodiments of the present invention according to the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims (18)

1. An online profile control device for polymer flooding oil field, characterized in that, the online profile control device for polymer flooding oil field comprises: a polymer solution injection line having an inlet port and an outlet port; An annular liquid mixer, which is arranged in parallel with the polymer solution injection pipeline, the two ends of the annular liquid mixer are respectively provided with a liquid inlet bell mouth and a liquid outlet bell mouth, and the liquid inlet bell mouth and the inlet port are respectively connected to the A polymer solution inlet pipeline is connected, and the outlet bell mouth and the outlet port are respectively connected with a mixed solution outlet pipeline; The cross-linking agent solution inlet line is connected to the inner ring wall of the annular mixer, and the end of the cross-linking agent solution inlet line extending into the annular mixer is opposite to the inlet bell mouth. 2. The on-line profile control device for polymer flooding oil field according to claim 1, characterized in that, the annular liquid mixer has an annular accommodation chamber, and the crosslinking agent solution inlet line extends into one end of the annular accommodation chamber A shower head is connected, and the shower head is opposite to the liquid inlet bell mouth. 3. The on-line profile control device for polymer flooding oil field as claimed in claim 2, characterized in that, the shower head is a spherical shower head, and a plurality of liquid outlets are provided on the opposite side of the shower head to the inlet bell mouth through hole. 4. The on-line profile control device for polymer flooding oil field according to claim 3, characterized in that the diameter of the outlet through hole is 1-2 mm. 5. The on-line profile control device for polymer flooding oil field according to claim 1, characterized in that a polymer solution flow meter and a liquid inlet one-way stop valve are connected to the polymer solution inlet pipeline. 6. The on-line profile control device for polymer flooding oil field as claimed in claim 1, characterized in that, the inlet horn of the annular liquid mixer is connected with the polymer solution inlet pipeline through a polymer solution one-way stop valve , the bell mouth of the liquid outlet of the annular liquid mixer is connected with the liquid outlet pipeline of the mixed liquid through a one-way stop valve of the mixed liquid. 7. The on-line profile control device for polymer flooding oil field according to claim 1, characterized in that a one-way stop valve is connected to the polymer solution injection pipeline. 8 . The on-line profile control device for polymer flooding oil field according to claim 1 , wherein a one-way stop valve is connected to the mixed liquid outlet pipeline. 9 . 9. The on-line profile control device for polymer flooding oil field as claimed in claim 1, wherein a crosslinking agent solution one-way stop valve and a crosslinking agent solution flow meter are connected on the crosslinking agent solution inlet pipeline And high pressure metering pump. 10. The on-line profile control device for polymer flooding oil field according to claim 1, characterized in that a sampling and detection pipeline is connected to the outlet pipeline of the mixed fluid. 11. An online profile control method for a polymer flooding oil field, characterized in that, the online profile control method for a polymer flooding oil field comprises the following steps: a) Provide a polymer solution injection pipeline and an annular mixer, the polymer solution injection pipeline and the annular mixer are arranged in parallel, and the two ends of the annular mixer are respectively provided with a liquid inlet horn and an outlet horn mouth, the inlet port of the inlet bell mouth and the polymer solution injection pipeline is connected with a polymer solution inlet pipeline respectively, and the outlet end of the outlet bell mouth and the polymer solution injection pipeline is connected with a polymer solution injection pipeline respectively. The mixed liquid outlet line is connected, and the inner ring wall of the annular liquid mixer is connected with a crosslinking agent solution inlet line, and one end of the crosslinking agent liquid inlet line extending into the annular liquid mixer is connected with the liquid inlet. The bell mouth is opposite; b) Inject the polymer solution into the polymer solution inlet line, during the process of injecting the polymer solution, the annular mixer is in a closed state, and the polymer solution flows into and mixes through the polymer solution injection line The liquid comes out of the liquid pipeline, and then injected into the water injection well; c) Open the annular mixer, close the polymer solution injection line, inject the cross-linking agent solution into the cross-linking agent solution inlet line, the polymer solution and the cross-linking agent solution are in the Mix in the annular liquid mixer, and the mixed liquid generated after the two are mixed is injected into the water injection well from the mixed liquid outlet line; d) Close the annular liquid mixer, open the polymer solution injection pipeline, and perform normal polymer flooding production. 12. The online profile control method for polymer flooding oil field according to claim 11, characterized in that, between the step c) and the step d), a step c1) is further included: closing the annular liquid mixer, The water injection well is shut down and awaits condensation. 13. The online profile control method for polymer flooding oil field according to claim 12, characterized in that the water injection well is shut down and waited for 5 days for solidification. 14. The on-line profile control method for polymer flooding oil field according to claim 11, characterized in that a sampling and detection pipeline is connected to the outlet pipeline of the mixed liquid, and in the step c), the sampling and detection pipeline is opened , sampling and testing the mixed liquid flowing out from the liquid outlet horn of the annular liquid mixer. 15. The on-line profile control method of polymer flooding oil field as claimed in claim 11, characterized in that, the annular liquid mixer has an annular accommodation chamber, and the crosslinking agent solution inlet line extends into one end of the annular accommodation chamber A shower head is connected, and the shower head is opposite to the liquid inlet bell mouth. 16. The on-line profile control method for polymer flooding oil field as claimed in claim 15, characterized in that, the shower head is a spherical shower head, and a plurality of liquid outlets are provided on the opposite side of the shower head to the inlet bell mouth through hole. 17. The online profile control method for polymer flooding oil field according to claim 16, characterized in that the diameter of the outlet through hole is 1-2 mm. 18. The online profile control method of polymer flooding oil field as claimed in claim 11, characterized in that, a polymer solution flowmeter is connected to the polymer solution inlet pipeline, and a polymer solution flowmeter is connected to the crosslinking agent solution inlet pipeline. There is a crosslinker solution flow meter with a 10:1 ratio of the readings of the polymer solution flow meter to the reading of the crosslinker solution flow meter.