Polymer mother liquor preparation process and liquid preparation device

Abstract

This invention discloses a polymer mother liquor preparation process and apparatus. The process includes: S1, water and dry powder are initially mixed under the action of high-speed turbulence in an ejector; S2, the mixed solution is progressively refined by a grinding assembly with decreasing grinding gaps; S3, the solution is transferred between multiple homogenizing tanks via air pressure to achieve shear-free mixing; S4, a aging tank is evacuated to eliminate microbubbles; S5, an injection assembly injects the solution downhole. The apparatus includes a dry powder wetting and dispersing assembly, a grinding assembly, a dissolving assembly, an aging assembly, and an injection assembly. The grinding assembly uses an adjustable-gap grinding disc design, the dissolving assembly uses multiple homogenizing tanks to achieve efficient mixing via air pressure transfer, and the aging assembly is connected to a vacuum negative pressure device to eliminate microbubbles. This invention effectively protects the polymer chain structure, improves the viscosity of the mother liquor and the oil displacement efficiency through progressive grinding, shear-free mixing, and vacuum defoaming technologies, while avoiding equipment blockage, demonstrating significant economic and practical advantages.

Description

Technical Field

[0001] This invention belongs to the field of oil displacement agent dispersion and formulation technology, and particularly relates to a polymer mother liquor preparation process and preparation device. Background Technology

[0002] In the tertiary oil recovery stage of oil extraction, polymer flooding is a key technology for enhancing oil recovery. Its core involves mixing dry polymer powder (such as HPAM) with water to prepare a high-viscosity mother liquor. Currently, the mainstream preparation processes employ hydraulic jet dispersion and grinding pump grinding, but significant drawbacks remain: First, in the grinding stage, the existing grinding pumps grind too violently, breaking up undissolved particulate materials instantly. The materials are subjected to severe shearing, which affects the subsequent oil displacement effect.

[0003] Secondly, in the homogenization stage, the intense mechanical shear force applied by existing homogenization equipment (such as high-shear pumps) to break up particles will severely sever the polymer molecular chains, leading to a decrease in molecular weight and loss of solution viscosity, which directly affects the final oil displacement effect. Summary of the Invention

[0004] To address the problems in the background art, this invention provides a polymer mother liquor preparation process and dispensing device, making significant innovations in the grinding and homogenization stages. In the grinding stage, the gap between the grinding surfaces of the grinding disc gradually decreases from the center to the edge. The material is fed in from the center, initially broken into larger particles, and then gradually and gently refined as it moves towards the edge, avoiding sudden and violent shearing. In the homogenization stage, air pressure is used to achieve the transfer and mixing of the solution in the homogenizing tank. The shearing force during the transfer and mixing process is minimal, resulting in very little damage to the polymer molecular chains.

[0005] The technical solution provided by this invention is: a polymer mother liquor preparation process, comprising the following steps; S1. Water and dry powder undergo first-stage forced mixing under the high-speed turbulence of the jet injector, initially forming a mixed solution; S2. The pre-mixed solution is fed into the crushing and grinding assembly for grinding: the grinding gap of the crushing and grinding assembly gradually decreases, so that the shear force on the material increases gradually and the particles are gently and gradually refined, avoiding the adverse damage to the material caused by violent grinding. S3. The solution obtained in S2 is fed into homogenizing tanks at intervals. At this time, one of the two adjacent homogenizing tanks is empty and the other is filled with solution. Air pressure is introduced into the homogenizing tank filled with solution. Under the action of pressure, the solution is transferred to the adjacent empty homogenizing tank. Then, the action of introducing air pressure into the homogenizing tank containing solution is repeated. This realizes the continuous transfer and mixing of solution between homogenizing tanks. The transfer and mixing process is basically unaffected by shear force, which can increase the homogenization effect and improve the homogenization speed. S4. The solution obtained in S3 is sent into the maturation tank. A vacuum device is connected to the upper end of the maturation tank. The maturation tank is evacuated by the vacuum device to reduce the micro bubbles and foam in the solution in the maturation tank. S5. Use the injection assembly to inject the matured polymer solution downhole.

[0006] A further technical solution is that, in S2, the grinding gap can be adjusted for polymer dry powders with different particle sizes and different solubility characteristics.

[0007] A further technical solution is to transfer the solution at least 60 times in step S3 to ensure homogeneity.

[0008] A polymer mother liquor preparation device includes a dry powder wetting and dispersion component, a crushing and grinding component, a dissolving component, a maturation component, and an injection component. The crushing and grinding component includes a screw conveyor and a grinding chamber. The output end of the screw conveyor is connected to the inlet of the grinding chamber. The grinding chamber contains a fixed grinding disc and a rotating grinding disc, with a grinding gap between them. The grinding gap continuously decreases from the center of the grinding disc towards its edge. The dissolving component includes a storage tank, a blower, and at least four [unclear - possibly referring to a specific type of equipment or component]. Several homogenizing tanks are provided, each connected to a blower at its top with a switch valve installed on the pipeline. A fluid transfer pipe is installed between every two adjacent homogenizing tanks, and another fluid transfer pipe is installed between the first and last homogenizing tanks. The fluid transfer pipe extends to the bottom of the homogenizing tank and is equipped with a switch valve. An exhaust pipe is installed above the homogenizing tank, with a switch valve installed on the exhaust pipe. A drain pipe is installed at the bottom of the homogenizing tank, with a switch valve installed on the drain pipe. A storage tank is connected to the top of the homogenizing tank, and a switch valve is installed on the connecting pipe.

[0009] Preferably, the ends of the two fluid transfer tubes inside the homogenizing tank are bent, and the two fluid transfer tubes are centrally symmetrical to each other.

[0010] Preferably, a distance adjustment mechanism is provided between the fixed grinding disc and the grinding box. The distance adjustment mechanism includes a grinding disc mounting plate and a lead screw. The fixed grinding disc is fixedly mounted on the grinding disc mounting plate, and the grinding disc mounting plate is in sliding sealing fit with the grinding box. The lead screw is threadedly connected to the grinding box. One end of the lead screw is connected to the grinding disc mounting plate. The lead screw can rotate relative to the grinding disc mounting plate but cannot move axially relative to the grinding disc mounting plate. The other end of the lead screw is fixedly connected to a gear. A worm is meshed with the outer side of the worm gear. When the worm rotates one revolution, the worm gear rotates one tooth.

[0011] Preferably, the curing component includes a curing tank, and a vacuum negative pressure device is connected to the upper end of the curing tank.

[0012] Preferably, the dry powder wetting and dispersing component includes an ejector, which includes an inlet pipe, a throat, and a connecting pipe. The inlet pipe is located on the left side of the connecting pipe, and the throat is located on the right side of the connecting pipe. The outer wall of the right end of the inlet pipe and the inner wall of the connecting pipe form a negative pressure zone. The powder pipe is connected to the connecting pipe corresponding to the negative pressure zone. An oblique hole is provided in the narrow diameter area of ​​the throat. The inlet pipe and the oblique hole are connected by an auxiliary pipe. The water sprayed through the oblique hole can help the mixture move to the right.

[0013] Preferred: Each homogenizing tank is equipped with a sampling tube.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In the crushing and grinding assembly of this invention, the gap between the fixed grinding disc and the rotating grinding disc gradually decreases from the center to the edge. The material is fed in from the center, first crushed into larger particles, and then gradually and gently refined as it moves towards the edge, avoiding sudden and violent shearing.

[0015] 2. The gap between the fixed grinding disc and the rotating grinding disc in the crushing and grinding assembly of the present invention is adjustable. The adjustable design allows a set of equipment to flexibly process a variety of materials. Different working conditions can be met by simply adjusting the gap, which improves the versatility and economy of the equipment.

[0016] 3. The process of transferring the solution between multiple homogenizing tanks in the dissolving component of this invention is as follows: Initially, homogenizing tanks No. 1 and No. 3 are filled with solution. The air pump is started to increase the pressure inside homogenizing tanks No. 1 and No. 3. Under the action of pressure, the solution in homogenizing tanks No. 1 and No. 3 flows out through the fluid transfer pipes respectively. The solution in homogenizing tank No. 1 flows into homogenizing tanks No. 2 and No. 4 respectively, and the solution in homogenizing tank No. 3 flows into homogenizing tanks No. 2 and No. 4 respectively. After completion, the air pressure in homogenizing tanks No. 2 and No. 4 is increased. Under the action of pressure, the solution in homogenizing tanks No. 2 and No. 4 flows into homogenizing tanks No. 1 and No. 3 respectively through the fluid transfer pipes. This process is repeated to realize the transfer and mixing of the solution between homogenizing tanks. During the transfer and mixing process, there is almost no shearing, which does not damage the polymer separation chain length and effectively ensures the viscosity of the final mother liquor, thereby improving the oil displacement efficiency.

[0017] 4. In the jet ejector of the present invention, the inlet pipe and the throat are connected by a thin tube, so that a portion of the liquid enters the throat directly through the thin tube, impacting the material that is about to be blocked or has already been blocked in the throat, thus preventing polymer clusters from clogging the throat.

[0018] 5. The curing tank of the present invention is connected to a vacuum negative pressure device, which purifies the curing tank to effectively eliminate stable foam and microbubbles that are difficult to eliminate in the curing tank, thus avoiding affecting the efficiency of the subsequent injection pump (such as a plunger pump). Attached Figure Description

[0019] Figure 1 This is a simplified structural diagram of the entire invention.

[0020] Figure 2 This is a schematic diagram of the jet ejector in this invention.

[0021] Figure 3 This is a schematic diagram of the crushing and grinding component in this invention.

[0022] Figure 4 This is a schematic diagram of the dissolution component in this invention.

[0023] Figure 5 This is a top view showing the positional relationship of the fluid transfer tube in the homogenizing tank in this invention.

[0024] In the diagram: 1. Ejector; 2. Crushing and grinding assembly; 3. Dissolving assembly; 4. Vacuum negative pressure device; 5. Maturation tank; 6. Injection pump; 101. Powder pipe; 102. Connecting pipe; 103. Water inlet pipe; 104. Auxiliary pipe; 105. Negative pressure zone; 106. Inclined hole; 107. Throat pipe; 201. Screw conveyor; 202. Grinding box; 203. Grinding disc mounting plate; 204. Fixed grinding disc; 205. Rotating grinding disc; 206. Grinding gap; 207. Lead screw; 208. Worm gear; 209. Worm; 301. Storage tank; 302. Homogenizing tank; 303. Fluid transfer pipe; 304. Sampling pipe; 305. Blower; 306. Exhaust pipe; 307. Drain pipe. Detailed Implementation

[0025] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0026] This embodiment describes a polymer mother liquor preparation process, including the following steps; S1. Water and dry powder undergo first-stage forced mixing under the high-speed turbulence of ejector 1, initially forming a mixed solution.

[0027] S2. The initially mixed solution is fed into the crushing and grinding component 2 for grinding: the grinding gap 206 of the crushing and grinding component 2 gradually decreases, so that the shear force on the material increases gradually and the particles are gently and gradually refined, avoiding the adverse damage to the material caused by violent grinding.

[0028] In this step, the grinding gap 206 is adjustable for polymer dry powders with different particle sizes and different solubility characteristics.

[0029] S3. The solution obtained in S2 is fed into homogenizing tank 302 at intervals. At this time, one of the two adjacent homogenizing tanks 302 is empty and the other is filled with solution. Air pressure is introduced into the homogenizing tank 302 filled with solution. Under the action of pressure, the solution is transferred to the adjacent empty homogenizing tank 302. Then, the action of introducing air pressure into the homogenizing tank 302 containing solution is repeated. This realizes the continuous transfer and mixing of solution between homogenizing tanks 302. The transfer and mixing process is basically unaffected by shearing, which can increase the homogenization effect and improve the homogenization speed.

[0030] For ease of explanation, the four homogenizing tanks 302 in this embodiment are named the first homogenizing tank, the second homogenizing tank, the third homogenizing tank, and the fourth homogenizing tank, respectively. First, the first and third homogenizing tanks are filled with a mixture, while the second and fourth homogenizing tanks are empty. Then, air pressure is applied to the first and third homogenizing tanks, increasing the internal pressure. For the first homogenizing tank, the mixture inside flows through the fluid transfer pipe 303 into the empty second and fourth homogenizing tanks, with each tank filled halfway. For the third homogenizing tank, the mixture inside flows through the fluid transfer pipe 303 into the second and fourth homogenizing tanks, with each tank also filled halfway. At this point, the second and fourth homogenizing tanks are full, while the first and third homogenizing tanks are empty. It should be noted that during this process, the mixture in the second homogenizing tank comes partly from the first homogenizing tank and partly from the third homogenizing tank, and the mixture in the fourth homogenizing tank also comes partly from the first homogenizing tank and partly from the third homogenizing tank. Therefore, mixing is achieved during the transfer process, and both transfer and mixing can increase the homogenization speed. Similarly, by introducing air pressure into the second and fourth homogenizing tanks, the same principle is used to transfer the mixture to the first and third homogenizing tanks. This continuous cycle ensures uninterrupted transfer and mixing of the mixture.

[0031] The solution is transferred no less than 60 times.

[0032] S4. The solution obtained in S3 is sent into the maturation tank 5. A vacuum device is connected to the upper end of the maturation tank 5. The maturation tank 5 is evacuated by the vacuum device. Under the action of vacuuming, the bubbles and foam in the mixture are forced to precipitate and collapse, so as to reduce the adverse effect on the efficiency of the injection pump 6 (such as a plunger pump).

[0033] S5. Use the injection assembly to inject the matured polymer solution downhole.

[0034] like Figure 1-5 As shown, a polymer mother liquor preparation device is disclosed, including a dry powder wetting and dispersing component, a crushing and grinding component 2, a dissolving component 3, a maturation component and an injection component.

[0035] The main innovation of the polymer mother liquor preparation device is that the crushing and grinding component 2 includes a screw conveyor 201 and a grinding box 202. The output end of the screw conveyor 201 is connected to the inlet of the grinding box 202. The grinding box 202 is equipped with a fixed grinding disc 204 and a rotating grinding disc 205. A grinding gap 206 is left between the fixed grinding disc 204 and the rotating grinding disc 205. The grinding gap 206 decreases continuously from the center of the grinding disc to the edge of the grinding disc.

[0036] The initial mixed polymer solution from the dry powder wetting and dispersing component is drawn in through the inlet of the screw conveyor 201. Utilizing the constant volume conveying characteristics of the screw, the high-viscosity material is continuously and stably pushed towards the maximum gap at the center of the grinding disc for initial crushing. Under centrifugal force or pushing action, the material moves towards the edge of the grinding disc, experiencing a gradual decrease in gap and a gradual increase in shear force, resulting in progressively finer particles until the target particle size is reached and discharged through the outlet. In this embodiment, the grinding process is smoother and gentler, avoiding sudden and violent shearing.

[0037] A distance adjustment mechanism is provided between the fixed grinding disc 204 and the grinding box 202, such as... Figure 2 As shown, the distance adjustment mechanism includes a grinding disc mounting plate 203 and a lead screw 207. The fixed grinding disc 204 is fixedly mounted on the grinding disc mounting plate 203. The grinding disc mounting plate 203 and the grinding box 202 are in sliding and sealed fit. The lead screw 207 is threadedly connected to the grinding box 202. One end of the lead screw 207 is connected to the grinding disc mounting plate 203. The lead screw 207 can rotate relative to the grinding disc mounting plate 203 but cannot move axially relative to the grinding disc mounting plate 203. The other end of the lead screw 207 is fixedly connected to a gear. A worm 209 is meshed with the outer side of the worm gear 208. When the worm 209 rotates one revolution, the worm gear 208 rotates one tooth.

[0038] During operation, rotating the worm 209, the worm wheel 208, and the worm 209 together reduce speed. For every revolution of the worm 209, the worm wheel 208 rotates one tooth, and the corresponding lead screw 207 rotates only a very small angle. The distance that the lead screw 207 moves forward or backward relative to the grinding box 202 is very small, and the distance that it moves the grinding disc mounting plate 203 and the fixed grinding disc 204 is also very small. Therefore, this invention can achieve fine adjustments.

[0039] The dissolving component 3 includes a storage tank 301, a blower 305, and at least four even-numbered homogenizing tanks 302. The upper end of each homogenizing tank 302 is connected to the blower 305, and a switch valve is installed on the pipeline to control air intake. A fluid transfer pipe 303 is installed between every two adjacent homogenizing tanks 302, with one fluid transfer pipe 303 between the first and last homogenizing tank 302. The fluid transfer pipe 303 extends to the bottom of the homogenizing tank 302 and is equipped with a switch valve. To improve the mixing effect, such as... Figure 5 As shown, the ends of the two fluid transfer pipes 303 inside the homogenizing tank 302 are bent, and the two fluid transfer pipes 303 are centrally symmetrical to each other. In this way, the simultaneous liquid intake of the two fluid transfer pipes 303 forms a spiral flow. During the continuous liquid intake process, the two spiral flows achieve good mixing and improve the homogenization efficiency.

[0040] An exhaust pipe 306 is installed above the homogenizing tank 302, and a switch valve is installed on the exhaust pipe 306. If it is necessary to transfer the mixture from the first and third homogenizing tanks, the switch valve of the exhaust pipe 306 of the first and third homogenizing tanks needs to be closed to maintain the pressure inside the tank. If the second and fourth homogenizing tanks need to receive the mixture, the switch valve of the exhaust pipe 306 of the second and fourth homogenizing tanks needs to be opened to ensure that the tanks are open to the atmosphere.

[0041] A drain pipe 307 is installed at the lower end of the homogenizing tank 302. A switch valve is installed on the drain pipe 307. After homogenization is completed, the switch valve on the drain pipe 307 is opened, and the mixture will enter the maturation tank 5.

[0042] The upper ends of the storage tank 301 and the homogenizing tank 302 are connected. A switch valve is installed on the connecting pipe. When the mixture is transferred between the homogenizing tanks 302, all the switch valves between the storage tank 301 and the homogenizing tank 302 are closed.

[0043] The curing component includes a curing tank 5, and a vacuum negative pressure device 4 is connected to the upper end of the curing tank 5. The vacuum negative pressure device 4 can eliminate stable foam and microbubbles that are difficult to eliminate in the curing tank 5 to a certain extent, so as to avoid the bubbles from having an adverse effect on the subsequent injection pump 6.

[0044] like Figure 2As shown, the dry powder wetting and dispersing assembly includes an ejector 1, which includes an inlet pipe 103, a throat 107, and a connecting pipe 102. The inlet pipe 103 is located on the left side of the connecting pipe 102, and the throat 107 is located on the right side of the connecting pipe 102. The outer wall of the right end of the inlet pipe 103 and the inner wall of the connecting pipe 102 form a negative pressure zone 105. The powder pipe 101 is connected to the connecting pipe 102 corresponding to the negative pressure zone 105. An oblique hole 106 is provided in the narrow diameter area of ​​the throat 107. The inlet pipe 103 and the oblique hole 106 are connected by an auxiliary pipe 104. The water sprayed through the oblique hole 106 can help the mixture move to the right.

[0045] like Figure 4 As shown, each homogenizing tank 302 is equipped with a sampling tube 304.

Claims

1. A process for preparing polymer mother liquor, characterized in that: Includes the following steps; S1. Water and dry powder undergo first-stage forced mixing under the high-speed turbulence of the jet injector (1), initially forming a mixed solution; S2. The solution after initial mixing is fed into the crushing and grinding assembly (2) for grinding: the grinding gap (206) of the crushing and grinding assembly (2) gradually decreases, so that the shear force on the material increases gradually and the particles are gently and gradually refined. S3. The solution obtained in S2 is fed into the homogenizing tank (302) at intervals. At this time, one of the two adjacent homogenizing tanks (302) is empty and the other is filled with solution. Air pressure is introduced into the homogenizing tank (302) filled with solution. Under the action of pressure, the solution is transferred to the adjacent empty homogenizing tank (302). Then, the action of introducing air pressure into the homogenizing tank (302) containing solution is repeated. This realizes the continuous transfer and mixing of solution between homogenizing tanks (302). The transfer and mixing process is basically unaffected by shearing, which can increase the homogenization effect and improve the homogenization speed. S4. The solution obtained in S3 is sent into the maturation tank (5). A vacuum device is connected to the upper end of the maturation tank (5). The maturation tank (5) is evacuated by the vacuum device to reduce the micro bubbles and foam in the solution in the maturation tank (5). S5. Inject the matured polymer solution downhole using the injection assembly; The polymer mother liquor preparation process employs a polymer mother liquor preparation device, which includes a dry powder wetting and dispersion component, a crushing and grinding component (2), a dissolving component (3), a maturation component, and an injection component. The dry powder wetting and dispersion component includes an ejector (1). The crushing and grinding component (2) includes a screw conveyor (201) and a grinding chamber (202). The output end of the screw conveyor (201) is connected to the inlet of the grinding chamber (202). The grinding chamber (202) is equipped with a fixed grinding disc (204) and a rotating grinding disc (205). A grinding gap (206) is left between the fixed grinding disc (204) and the rotating grinding disc (205). The grinding gap (206) decreases continuously from the center of the grinding disc to the edge of the grinding disc. The dissolving component (3) includes a storage tank (301) and a blower (305). The homogenizing tank (302) comprises an even number of homogenizing tanks (302) of no less than four. The upper end of each homogenizing tank (302) is connected to a blower (305) and a switch valve is installed on the pipeline. A fluid transfer pipe (303) is installed between every two adjacent homogenizing tanks (302). A fluid transfer pipe (303) is installed between the first homogenizing tank (302) and the last homogenizing tank (302). The fluid transfer pipe (303) extends to the lowest part of the homogenizing tank (302). A switch valve is installed on the fluid transfer pipe (303). An exhaust pipe (306) is installed above the homogenizing tank (302). A switch valve is installed on the exhaust pipe (306). A drain pipe (307) is installed at the lower end of the homogenizing tank (302). A switch valve is installed on the drain pipe (307). A storage tank (301) is connected to the upper end of the homogenizing tank (302). A switch valve is installed on the connecting pipe. The curing component includes a curing tank (5).

2. The polymer mother liquor preparation process according to claim 1, characterized in that: In S2, the grinding gap (206) is adjustable for polymer dry powders with different particle sizes and different solubility characteristics.

3. The polymer mother liquor preparation process according to claim 1, characterized in that: In step S3, the solution is transferred no less than 60 times.

4. The polymer mother liquor preparation process according to claim 1, characterized in that: The ends of the two fluid transfer tubes (303) inside the homogenizing tank (302) are bent, and the two fluid transfer tubes (303) are centrally symmetrical to each other.

5. The polymer mother liquor preparation process according to claim 1, characterized in that: A distance adjustment mechanism is provided between the fixed grinding disc (204) and the grinding box (202). The distance adjustment mechanism includes a grinding disc mounting plate (203) and a lead screw (207). The fixed grinding disc (204) is fixedly mounted on the grinding disc mounting plate (203). The grinding disc mounting plate (203) and the grinding box (202) are in sliding and sealed cooperation. The lead screw (207) is threadedly connected to the grinding box (202). One end of the lead screw (207) is connected to the grinding disc mounting plate (203). The lead screw (207) can rotate relative to the grinding disc mounting plate (203) but cannot move axially relative to the grinding disc mounting plate (203). The other end of the lead screw (207) is fixedly connected to a gear. A worm (209) is meshed with the outer side of the worm wheel (208). When the worm (209) rotates one revolution, the worm wheel (208) rotates one tooth.

6. The polymer mother liquor preparation process according to claim 1, characterized in that: The upper end of the curing tank (5) is connected to a vacuum negative pressure device (4).

7. The polymer mother liquor preparation process according to claim 1, characterized in that: The jet ejector (1) includes an inlet pipe (103), a throat pipe (107), and a connecting pipe (102). The inlet pipe (103) is located on the left side of the connecting pipe (102), and the throat pipe (107) is located on the right side of the connecting pipe (102). The outer wall of the right end of the inlet pipe (103) and the inner wall of the connecting pipe (102) form a negative pressure zone (105). The powder pipe (101) is connected to the connecting pipe (102) corresponding to the negative pressure zone (105). An oblique hole (106) is provided in the narrow diameter area of ​​the throat pipe (107). The inlet pipe (103) and the oblique hole (106) are connected by an auxiliary pipe (104). The water jetted through the oblique hole (106) can help the mixture move to the right.

8. The polymer mother liquor preparation process according to claim 1, characterized in that: Each homogenizing vessel (302) is equipped with a sampling tube (304).

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