Online biological polysaccharide mixing and injecting device and method for microbial oil recovery

Abstract

The invention belongs to the technical field of microbial oil recovery, and particularly relates to an online biological polysaccharide mixing and injecting device and method for microbial oil recovery. The device comprises a premixing unit, an electromagnetic dissociation unit, a spiral stretching unit, a mixing injection unit and an automatic control unit, and the premixing unit, the electromagnetic dissociation unit, the spiral stretching unit and the mixing injection unit are sequentially connected. The automatic control unit is connected with the premixing unit, the electromagnetic dissociation unit, the spiral stretching unit and the mixing injection unit in a wired or wireless mode. The device can realize quick and uniform mixing of biological polysaccharide and injected water, release and maintain the viscosity of a polysaccharide system, reduce the residence time and equipment investment, avoid bacterial pollution and guarantee the effect of a microbial oil recovery process.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial oil recovery, and in particular relates to an online mixing and injection device and method for biopolysaccharide for microbial oil recovery. Background Art

[0002] As oilfield development enters the middle and late stages, microbial oil recovery has become the most promising technology for improving oil recovery due to its low cost and environmental friendliness. Biopolysaccharides are a type of biopolymer produced by microbial metabolism, also known as bio-gum. Currently, the main industrialized products include xanthan gum, blue gum, and curdlan gum. Because of its certain molecular weight and intermolecular hydrogen bonds, it has a certain viscosity. It plays an important role in adjusting the water absorption profile of water injection wells and activating oil recovery functional microorganisms in deep reservoirs. At the same time, because of its advantages such as temperature resistance and salt resistance, it has been continuously promoted and applied in improving oil recovery in high-temperature and high-salt reservoirs in Shengli Oilfield in recent years. At present, the preparation of biopolysaccharides mainly follows the method and process of preparing polymers, that is, the dispersion-maturation-dilution-injection process is adopted. The aging process usually adopts a conventional stirring tank and intermittent production. The aging time generally takes 2.0-2.5h, which has a large footprint and high equipment investment. At the same time, because biopolysaccharides have certain biodegradability, the aging time is too long, which is easy to cause the growth of harmful bacteria and affect the viscosity of the preparation system.

[0003] In order to shorten the aging time, researchers have tried to use static mixers and dynamic mixers to promote the dissolution of polymers for the preparation of conventional polymers. Although certain effects have been achieved, they all have limitations to varying degrees. Static mixers mainly rely on the fluid passing through the filling internal components, and the flow direction of the liquid changes continuously. They are suitable for mixing liquids with good water solubility, such as adding bactericides, corrosion inhibitors, scale inhibitors and other water-soluble additives to water. When used for mixing biopolysaccharides, uneven mixing is prone to occur, which affects the injection performance of the polysaccharide solution system; dynamic mixers mainly rely on rotors of different structures driven by motors to produce strong shearing effects, so that two viscous materials or viscous materials and powders are strongly mixed. Although the materials can be mixed evenly, it is easy to cause molecular breakage of the polysaccharide system, affecting the viscosity of the system, and then affecting the oil recovery effect. The above two mixing methods have problems such as poor mixing effect or too strong shearing affecting the viscosity of the system, and are not suitable for online mixing of biopolysaccharides for microbial oil recovery.

[0004] CN205330642U discloses a device for injecting a microbial oil recovery solid activator on-site, comprising a solid activator preparation part, an activator buffer part, an injection part, an automatic control part, a high-pressure valve and a high-pressure pipeline, wherein the solid activator preparation part is composed of a feed tank, a stirring tank, a stirring motor, a stirring paddle, a filter and a feeding pump; wherein the feed tank is a funnel-shaped structure, located between the water main line and the stirring tank; the stirring tank is a cylindrical structure, and its volume is 5 to 8 m 3 The stirring motor is located directly above the stirring tank; the stirring paddle is located inside the stirring tank and is 50 to 80 cm away from the bottom of the stirring tank; a filter and a feeding pump are installed on the outlet pipeline of the stirring tank in sequence, and the outlet of the feeding pump is connected to the activator buffer. The utility model has the advantages of simple injection process, low cost, safety and reliability, high degree of automation, and can realize on-site preparation and injection of solid activators.

[0005] The on-site production injection process and device of microbial oil recovery disclosed in CN1431383A are suitable for oil reservoirs and blocks of microbial oil recovery in the petroleum industry. The process of the present invention is to place the screened or domesticated microorganisms in the fermentation tank of the bacterial seed station for fermentation production, and to establish a microbial bacterial liquid on-site production device and injection system at a water injection station near the target oil reservoir. The seed bacterial liquid in the fermentation tank of the bacterial station is transported to the bacterial liquid production device of the water injection station for continued fermentation production, and then injected into the formation. The device of the present invention has a batching facility, a jet pump, a bacterial liquid production tank and an injection pump, and the above equipment is connected to the water distribution system of the water injection station by a pipeline. The water injection station is used to build the station, which reduces the vehicle transportation cost. It avoids rebuilding the heating system and sterilization system, and the construction cost is low. In addition, the on-site operation and management are simple, the production cost is reduced, and the oil recovery effect is good.

[0006] The above-mentioned microbial oil recovery on-site injection device is not suitable for on-site injection of biopolysaccharides with a certain viscosity. Therefore, a new microbial oil recovery on-site injection device is needed for on-site injection of biopolysaccharides. Summary of the invention

[0007] The present invention aims to provide a biopolysaccharide online mixing and injection device and method for microbial oil recovery in view of the deficiencies of the prior art. The device can achieve rapid and uniform mixing of biopolysaccharides with injection water, release and maintain the viscosity of the polysaccharide system, reduce residence time and equipment investment, avoid bacterial contamination, and ensure the effect of microbial oil recovery process.

[0008] One of the purposes of the present invention is to disclose an online mixing and injection device for biopolysaccharides for microbial oil recovery, which includes a premixing unit, an electromagnetic dissociation unit, a spiral stretching unit, a mixing and injection unit and an automatic control unit, wherein the premixing unit, the electromagnetic dissociation unit, the spiral stretching unit and the mixing and injection unit are connected in sequence, and the automatic control unit is respectively connected to the premixing unit, the electromagnetic dissociation unit, the spiral stretching unit and the mixing and injection unit by wired or wireless means.

[0009] The premixing unit is composed of a polysaccharide feeding pump, a first solenoid valve, a first flowmeter, a second solenoid valve, a second flowmeter and an ejector, wherein the polysaccharide feeding pump is connected to the first solenoid valve and the first flowmeter in sequence; the second solenoid valve is connected to the second flowmeter and the ejector in sequence; the power fluid inlet and the suction port of the ejector are respectively connected to the outlets of the second flowmeter and the first flowmeter.

[0010] In the present invention, preferably, the polysaccharide feeding pump is one of a Roots pump, a screw pump, and a rotor pump, and more preferably a Roots pump with negative pressure capability, which is convenient for conveying polysaccharide fluid with higher viscosity; the displacement of the polysaccharide feeding pump is 1-5 cubic meters / h, and the head is 20-30m.

[0011] In the present invention, preferably, the first solenoid valve is of normally closed type, with a diameter of DN50 to DN80, a pressure rating of 1.6 MPa, and is made of stainless steel, preferably 316L.

[0012] In the present invention, preferably, the first flow meter is of electromagnetic type or elliptical gear type, with a measuring range of 1-10 cubic meters per hour, and is made of stainless steel, preferably 316L.

[0013] In the present invention, preferably, the second solenoid valve is of normally closed type, with a diameter of DN50 to DN80, a pressure rating of 25 MPa, and is made of stainless steel, preferably 316L.

[0014] In the present invention, preferably, the second flow meter is of electromagnetic type with a measuring range of 2-20 cubic meters per hour.

[0015] In the present invention, preferably, the ejector inlet and outlet diameters are DN50-DN80, the length is 600-800 mm, the power fluid flow rate is 5-20 cubic meters / h, and the nozzle diameter is 3-8 mm.

[0016] The electromagnetic dissociation unit is composed of an alternating power supply, a coil and an electromagnetic field chamber; wherein both ends of the alternating power supply are connected to the coil, the coil is wound around the outside of the electromagnetic field chamber, and the inlet of the electromagnetic field chamber is connected to the outlet of the ejector in the premixing unit through a pipeline.

[0017] In the present invention, preferably, the AC power input voltage is 220VAC, the frequency is 50Hz / 60HZ, the output frequency is a square wave of 10-50MHz, the length of the electromagnetic field chamber is 2-4m, the number of coil turns along the length direction is 100-400 turns / m; the cross section of the electromagnetic field chamber is circular or rectangular, and a circular shape is recommended, with a diameter of 20-200mm, and a width dimension of 20-200mm when it is rectangular. The flow rate of the fluid flowing through the electromagnetic field is controlled at 0.1-0.3m / s.

[0018] The spiral stretching unit is composed of a shell, a rotating drum, a rotating shaft and a motor; wherein the shell is the outermost layer, the rotating drum is located inside the shell, fixed on the rotating shaft, connected to the motor, and driven by the motor.

[0019] In the present invention, preferably, the outer diameter of the drum is 400-1000mm, the surface of the drum is evenly distributed with circular protrusions, the height of the circular protrusions is about 1-2mm, the diameter is 10-20mm, the spacing is 30-100mm, the circular protrusions are 2-10mm away from the inner wall of the shell, and the circular protrusions are evenly distributed on the outer surface of the drum.

[0020] In the present invention, preferably, the motor is a speed-regulating motor with a rotation speed of 500-1500 r / min.

[0021] The mixing and injection unit is composed of a third solenoid valve, a third flowmeter, a mixer, and an injection pump; the third solenoid valve, the third flowmeter, and the mixer are connected in sequence, and the front and rear ends of the mixer are respectively connected to the outlet of the spiral stretching unit shell and the inlet of the injection pump; the outlet of the injection pump is injected into the formation through a pipeline.

[0022] In the present invention, preferably, the third solenoid valve is of normally closed type, with a diameter of DN50 to DN80, a pressure rating of 25 MPa, and is made of stainless steel, preferably 316L.

[0023] In the present invention, preferably, the third flow meter is of electromagnetic type with a measuring range of 1-10 cubic meters per hour and is made of stainless steel, preferably 316L.

[0024] In the present invention, preferably, the mixer can be a static mixer or a stirring tank, preferably a static mixer. When a static mixer is used, a spiral type with a diameter of 50-100 mm and a fluid flow rate of 1.0-1.5 m / s is preferably used; when a stirring tank is used, a spiral propulsion blade is preferably used, and the stirring residence time is 10-20 s.

[0025] In the present invention, preferably, the injection pump adopts a three-cylinder plunger pump with a displacement of 5-10 cubic meters / h and a pressure of 25 MPa.

[0026] The automatic control unit is composed of a PLC controller, a detection instrument, a driving device and a control device. The detection instrument includes a flow meter, and the driving device includes a pump and a driving motor.

[0027] On the other hand, the present invention discloses a method for online mixing and injection of biopolysaccharides for microbial oil recovery, wherein the method specifically comprises the following steps:

[0028] (1) high-pressure injection water enters the ejector after passing through the second solenoid valve and the second flowmeter, forms negative pressure after being ejected through the nozzle, and is premixed with the biopolysaccharide delivered by the polysaccharide feeding pump and sequentially passing through the first solenoid valve and the first flowmeter to form a heterogeneous fluid;

[0029] (2) The heterogeneous fluid enters the electromagnetic field chamber of the electromagnetic dissociation unit and passes through the coil under the action of an alternating power supply, forming an alternating electromagnetic field in the electromagnetic field chamber, causing induced polarization in the polysaccharide molecules in the heterogeneous fluid flowing through, generating positive and negative poles in the molecules, and under the action of the electromagnetic field, the polysaccharide molecules are arranged in an orderly manner with the same electrical polarity, dissociation occurs between the molecules, and the polysaccharide system changes from a tightly aggregated state to a discrete state;

[0030] (3) The discrete polysaccharide system enters the spiral stretching unit, and the motor drives the drum to rotate. Under the carrying effect of the circular protrusions, the polysaccharide molecules are further stretched in the gap between the drum and the shell to form a homogeneous fluid;

[0031] (4) The homogeneous fluid enters the mixing unit and is mixed with the injection water passing through the third solenoid valve and the third flow meter in a proportion through the mixer to form a uniform polysaccharide system solution, which is then transported out through a high-pressure injection pump and injected into the water well for oil production;

[0032] (5) The automatic control unit is connected to the polysaccharide feeding pump, the first solenoid valve, the first flowmeter, the second solenoid valve, the second flowmeter, the alternating power supply of the electromagnetic dissociation unit, the motor of the spiral stretching unit, the third solenoid valve, the third flowmeter and the injection pump of the mixing unit through the PLC controller; the injection water flow rate is set to Q through the PLC controller. 1 According to the detection result of the second flow meter, adjust the opening of the second solenoid valve to control the injection water flow rate at Q 1 Within ±5%, the polysaccharide flow rate Q is set by the PLC controller 2 According to the detection result of the first flow meter, the speed of the polysaccharide feeding pump and the opening of the first electromagnetic valve are adjusted to control the polysaccharide flow rate at Q 2 ±5%, the water injection flow rate Q is set by the PLC controller 3 According to the detection result of the third flow meter, adjust the opening of the third solenoid valve to control the injection water flow rate at Q 3 ±5%.

[0033] In the present invention, preferably, the ratio of the biopolysaccharide to the high-pressure injection water in step (1) is 1:2-5.

[0034] In the present invention, preferably, in step (2), the flow rate of the heterogeneous fluid flowing through the electromagnetic field chamber is controlled at 0.1-0.3 m / s, and the residence time is 1.5-2 min.

[0035] In the present invention, preferably, in step (3), the flow rate of the discrete polysaccharide system flowing through the cross section between the shell and the drum is 1-1.5 m / s.

[0036] In the present invention, preferably, in step (4), the residence time of the homogeneous fluid in the mixing unit is 10-30 s, and the injection pressure of the high-pressure injection pump is 15-25 MPa.

[0037] In the present invention, preferably, the Q in step (5) 1 =aQ 2 , where a=1-5.

[0038] In the present invention, preferably, the Q in step (5) 3 =bQ 2 , where b=1-5.

[0039] The device uses high-pressure water to generate negative pressure suction through an ejector to achieve premixing of biological polysaccharides and injection water, and then induces polarization through the electromagnetic field to generate two poles in the polysaccharide molecules, resulting in orderly arrangement of the polysaccharide molecules and achieving dissociation of the polysaccharide molecules. The rotating stretching effect of the drum then achieves uniform distribution of the polysaccharide molecules in the injection water. After mixing with the injection water, a polysaccharide system solution that meets the design requirements is formed, which is then injected into the oil layer through an injection pump to achieve online mixing and injection.

[0040] Compared with the prior art, the present invention has the following advantages:

[0041] (1) The process is simple, the unit process is mature, the overall process is stable, and the operation and management are convenient;

[0042] (2) Continuous mixing of biopolysaccharides is achieved, the residence time is shortened by 90%, the equipment investment is reduced by 80%, the equipment area is reduced by 90%, and the problem of harmful bacteria breeding caused by long residence time affecting the viscosity of the system is avoided;

[0043] (3) The viscosity release rate of the polysaccharide system reaches 100%, avoiding the problem of low viscosity release rate caused by insufficient mixing; the viscosity retention rate is above 95%, avoiding the problem of viscosity loss caused by strong shearing;

[0044] (4) The system has a high degree of automation and can realize unmanned operation and remote monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Schematic diagram of the online mixing and injection device for biopolysaccharides for microbial oil recovery. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] like Figure 1 As shown, the present invention discloses an online mixing and injection device for biopolysaccharide for microbial oil recovery, the device comprising a premixing unit 1, an electromagnetic dissociation unit 2, a spiral stretching unit 3, a mixing and injection unit 4 and an automatic control unit 5, wherein the premixing unit 1, the electromagnetic dissociation unit 2, the spiral stretching unit 3 and the mixing and injection unit 4 are connected in sequence, and the automatic control unit 5 is respectively connected to the premixing unit 1, the electromagnetic dissociation unit 2, the spiral stretching unit 3 and the mixing and injection unit 4 in a wired or wireless manner.

[0048] The premixing unit 1 consists of a polysaccharide feeding pump 11, a first solenoid valve 12, a first flowmeter 13, a second solenoid valve 14, a second flowmeter 15 and an ejector 16, wherein the polysaccharide feeding pump 11 is connected to the first solenoid valve 12 and the flowmeter 13 in sequence; the second solenoid valve 14 is connected to the second flowmeter 15 and the ejector 16 in sequence; the power fluid inlet and the suction port of the ejector 16 are respectively connected to the outlets of the second flowmeter 15 and the first flowmeter 13.

[0049] Preferably, the polysaccharide feeding pump 11 is one of a Roots pump, a screw pump, and a rotor pump, and more preferably a Roots pump with negative pressure capability, which is convenient for conveying polysaccharide fluid with higher viscosity; the displacement of the polysaccharide feeding pump 11 is 1-5 cubic meters / h, and the head is 20-30m.

[0050] Preferably, the first solenoid valve 12 is of normally closed type, with a diameter of DN50 to DN80, a pressure rating of 1.6 MPa, and is made of stainless steel, preferably 316L.

[0051] Preferably, the first flow meter 13 is of electromagnetic or elliptical gear type, with a measuring range of 1-10 cubic meters per hour, and is made of stainless steel, preferably 316L.

[0052] Preferably, the second solenoid valve 14 is of normally closed type, with a diameter of DN50 to DN80, a pressure rating of 25 MPa, and is made of stainless steel, preferably 316L.

[0053] Preferably, the second flow meter 15 is of electromagnetic type with a measuring range of 2-20 m3 / h.

[0054] Preferably, the inlet and outlet diameters of the ejector 16 are DN50-DN80, the length is 600-800 mm, the power fluid flow rate is 5-20 cubic meters / h, and the nozzle diameter is 3-8 mm.

[0055] The electromagnetic dissociation unit 2 is composed of an alternating power supply 21, a coil 22 and an electromagnetic field chamber 23; wherein both ends of the alternating power supply 21 are connected to the coil 22, the coil 22 is wound around the outside of the electromagnetic field chamber 23, and the inlet of the electromagnetic field chamber 23 is connected to the outlet of the ejector 16 in the premixing unit 1 through a pipeline.

[0056] Preferably, the input voltage of the alternating power supply 21 is 220VAC, the frequency is 50Hz / 60HZ, the output frequency is a square wave of 10-50MHz, the length of the electromagnetic field chamber is 2-4m, the number of turns of the coil 22 along the length direction is 100-400 turns / m; the cross section of the electromagnetic field chamber is circular or rectangular, and it is recommended to adopt a circular shape with a diameter of 20-200mm, and when it is rectangular, the width direction dimension is 20-200mm. The flow rate of the fluid flowing through the electromagnetic field is controlled at 0.1-0.3m / s.

[0057] The spiral stretching unit 3 is composed of a shell 31 , a rotating drum 32 , a rotating shaft 33 and a motor 34 ; wherein the shell 31 is the outermost layer, the rotating drum 32 is located inside the shell, fixed on the rotating shaft 33 , connected to the motor 34 , and driven by the motor 34 .

[0058] Preferably, the outer diameter of the drum 32 is 400-1000 mm, and circular protrusions 321 are evenly distributed on the surface of the drum 32. The height of the circular protrusions 321 is about 1-2 mm, the diameter is 10-20 mm, the spacing is 30-100 mm, the circular protrusions 321 are 2-10 mm away from the inner wall of the shell 31, and the circular protrusions 321 are evenly distributed on the outer surface of the drum 32.

[0059] Preferably, the motor 34 is a speed-regulating motor with a rotation speed of 500-1500 r / min.

[0060] The mixing and injection unit 4 is composed of a third solenoid valve 41, a third flowmeter 42, a mixer 43, and an injection pump 44; the third solenoid valve 41, the third flowmeter 42 and the mixer 43 are connected in sequence, and the front and rear ends of the mixer 43 are respectively connected to the outlet of the spiral stretching unit 3 shell 31 and the inlet of the injection pump 44; the outlet of the injection pump 44 is injected into the formation through a pipeline.

[0061] Preferably, the third solenoid valve 41 is of normally closed type, with a diameter of DN50-DN80, a pressure rating of 25 MPa, and is made of stainless steel, preferably 316L.

[0062] Preferably, the third flow meter 42 is of electromagnetic type with a measuring range of 1-10 cubic meters per hour and is made of stainless steel, preferably 316L.

[0063] Preferably, the mixer 43 can be a static mixer or a stirring tank, preferably a static mixer. When a static mixer is used, a spiral type with a diameter of 50-100 mm and a fluid flow rate of 1.0-1.5 m / s is preferably used; when a stirring tank is used, a spiral propulsion blade is preferably used, and the stirring residence time is 10-20 s.

[0064] Preferably, the injection pump 44 is a three-cylinder plunger pump with a displacement of 5-10 cubic meters / h and a pressure of 25 MPa.

[0065] The automatic control unit 5 is composed of a PLC controller, a detection instrument, a driving device and a control device. The detection instrument includes a flow meter, and the driving device includes a pump and a driving motor.

[0066] On the other hand, the present invention discloses a method for online mixing and injection of biopolysaccharides for microbial oil recovery, wherein the method specifically comprises the following steps:

[0067] (1) The high-pressure injection water enters the ejector 16 after passing through the second solenoid valve 14 and the second flowmeter 15, forms a negative pressure after being ejected by the nozzle, and is premixed with the biopolysaccharide delivered by the polysaccharide feeding pump 11 and sequentially passing through the first solenoid valve 12 and the first flowmeter 13 to form a heterogeneous fluid;

[0068] (2) The heterogeneous fluid enters the electromagnetic field chamber 23 of the electromagnetic dissociation unit 2, and passes through the coil 22 under the action of the alternating power supply 21, forming an alternating electromagnetic field in the electromagnetic field chamber, so that the polysaccharide molecules in the heterogeneous fluid flowing through are induced polarized, positive and negative poles are generated in the molecules, and under the action of the electromagnetic field, the polysaccharide molecules are arranged in an orderly manner with the same electrical polarity, and dissociation occurs between the molecules, and the polysaccharide system changes from a tightly aggregated state to a discrete state;

[0069] (3) The discrete polysaccharide system enters the spiral stretching unit 3, and the motor 34 drives the drum 32 to rotate. Under the carrying effect of the circular protrusion 321, the polysaccharide molecules are further stretched in the gap between the drum and the shell to form a homogeneous fluid;

[0070] (4) The homogeneous fluid enters the mixing unit 4, and is mixed with the injection water passing through the third solenoid valve 41 and the third flow meter 42 in proportion through the mixer 43 to form a uniform polysaccharide system solution, which is then transported out through the high-pressure injection pump 44 and injected into the water well for oil production;

[0071] (5) The automatic control unit 5 is connected to the polysaccharide feeding pump 11, the first electromagnetic valve 12, the first flowmeter 13, the second electromagnetic valve 14, the second flowmeter 15, the alternating power supply 21 of the electromagnetic dissociation unit, the motor 34 of the spiral stretching unit 3, the third electromagnetic valve 41, the third flowmeter 42 and the injection pump 43 of the mixing unit 4 through the PLC controller; the injection water flow rate is set to Q through the PLC controller. 1 According to the detection result of the second flow meter 15, the opening of the second solenoid valve 14 is adjusted to control the injection water flow rate at Q 1 Within ±5%, the polysaccharide flow rate Q is set by the PLC controller 2 According to the detection result of the first flow meter 13, the speed of the polysaccharide feeding pump 11 and the opening of the first electromagnetic valve 12 are adjusted to control the polysaccharide flow rate at Q 2 ±5%, the water injection flow rate Q is set by the PLC controller 3 According to the detection result of the third flow meter 42, the opening of the third solenoid valve 41 is adjusted to control the injection water flow rate at Q 3 ±5%.

[0072] Preferably, the ratio of the biopolysaccharide to the high-pressure injection water in step (1) is 1:2-5.

[0073] Preferably, in step (2), the flow rate of the heterogeneous fluid flowing through the electromagnetic field chamber is controlled at 0.1-0.3 m / s, and the residence time is 1.5-2 min.

[0074] Preferably, in step (3), the flow rate of the discrete polysaccharide system flowing through the cross section between the shell and the drum is 1-1.5 m / s.

[0075] Preferably, in step (4), the residence time of the homogeneous fluid in the mixing unit is 10-30 s, and the injection pressure of the high-pressure injection pump is 15-25 MPa.

[0076] Preferably, in step (5), Q 1 =aQ 2 , where a=1-5.

[0077] Preferably, in step (5), Q 3 =bQ 2 , where b=1-5.

[0078] Working principle of the present invention:

[0079] The biological polysaccharide and the injection water flow through the premixing unit, the electromagnetic dissociation unit, the spiral stretching unit and the mixing and injection unit in sequence. The polysaccharide and the injection water are mixed for the first time in the premixing unit, the induced polarization dissociation of the polysaccharide molecules is achieved in the electromagnetic dissociation unit, the polysaccharide molecules are evenly distributed in the injection water in the spiral stretching unit, and the polysaccharide solution and the injection water are mixed for the second time in the mixing and injection unit. Finally, a polysaccharide system that meets the design requirements is formed and external injection is achieved. The automatic control unit is used to adjust the flow balance of the biological polysaccharide and the injection water to achieve the stability of the polysaccharide content and injection flow in the injection system.

[0080] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change;

[0081] Secondly: In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0082] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A biopolysaccharide online mixing and injection device for microbial oil recovery, characterized in that: The device comprises a premixing unit, an electromagnetic dissociation unit, a spiral stretching unit, a mixing and injection unit and an automatic control unit, wherein the premixing unit, the electromagnetic dissociation unit, the spiral stretching unit and the mixing and injection unit are connected in sequence, and the automatic control unit is respectively connected to the premixing unit, the electromagnetic dissociation unit, the spiral stretching unit and the mixing and injection unit in a wired or wireless manner.

2. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 1, characterized in that: The premixing unit is composed of a polysaccharide feeding pump, a first solenoid valve, a first flowmeter, a second solenoid valve, a second flowmeter and an ejector, wherein the polysaccharide feeding pump is connected to the first solenoid valve and the first flowmeter in sequence; the second solenoid valve is connected to the second flowmeter and the ejector in sequence; the power fluid inlet and the suction port of the ejector are respectively connected to the outlets of the second flowmeter and the first flowmeter.

3. The on-line mixing and injection device for biopolysaccharide for microbial oil recovery according to claim 2, characterized in that: The polysaccharide feeding pump is one of a Roots pump, a screw pump and a rotor pump.

4. The on-line mixing and injection device for biopolysaccharide for microbial oil recovery according to claim 2 or 3, characterized in that: The polysaccharide feeding pump has a displacement of 1-5 cubic meters per hour and a head of 20-30 meters.

5. The on-line mixing and injection device for biopolysaccharide for microbial oil recovery according to claim 2, characterized in that: The first solenoid valve is of normally closed type, with a diameter of DN50 to DN80, a pressure rating of 1.6 MPa, and is made of stainless steel.

6. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 2, characterized in that: The first flow meter is of electromagnetic or oval gear type, with a measuring range of 1-10 cubic meters per hour and is made of stainless steel.

7. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 2, characterized in that: The second solenoid valve is of normally closed type, with a diameter of DN50 to DN80, a pressure rating of 25 MPa, and is made of stainless steel.

8. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 2, characterized in that: The second flow meter is of electromagnetic type with a measuring range of 2-20 cubic meters per hour.

9. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 2, characterized in that: The inlet and outlet diameters of the ejector are DN50-DN80, the length is 600-800mm, the power fluid flow rate is 5-20 cubic meters / h, and the nozzle diameter is 3-8mm.

10. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 1, characterized in that: The electromagnetic dissociation unit is composed of an alternating power supply, a coil and an electromagnetic field chamber; wherein both ends of the alternating power supply are connected to the coil, the coil is wound around the outside of the electromagnetic field chamber, and the inlet of the electromagnetic field chamber is connected to the outlet of the ejector in the premixing unit through a pipeline.

11. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 10, characterized in that: The alternating power supply has an input voltage of 220VAC, a frequency of 50Hz / 60HZ, and an output frequency of a square wave of 10-50MHz.

12. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 10, characterized in that: The length of the electromagnetic field chamber is 2-4m, and the number of coil turns along the length direction is 100-400 turns / m; the cross section of the electromagnetic field chamber is circular or rectangular.

13. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 12, characterized in that: The cross section of the electromagnetic field chamber is circular, with a diameter of 20-200 mm.

14. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 12, characterized in that: The electromagnetic field chamber has a rectangular cross section and a width dimension of 20-200 mm.

15. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 1, characterized in that: The spiral stretching unit is composed of a shell, a rotating drum, a rotating shaft and a motor; wherein the shell is the outermost layer, the rotating drum is located inside the shell, fixed on the rotating shaft, connected to the motor, and driven by the motor.

16. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 15, characterized in that: The outer diameter of the rotating drum is 400-1000 mm, and the surface of the rotating drum is evenly distributed with circular protrusions.

17. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 16, characterized in that: The height of the circular protrusions is about 1-2 mm, the diameter is 10-20 mm, the spacing is 30-100 mm, the distance between the circular protrusions and the inner wall of the shell is 2-10 mm, and the circular protrusions are evenly distributed on the outer surface of the drum.

18. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 15, characterized in that: The motor is a speed-adjustable motor with a rotation speed of 500-1500r / min.

19. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 1, characterized in that: The mixing and injection unit is composed of a third solenoid valve, a third flowmeter, a mixer, and an injection pump; the third solenoid valve, the third flowmeter, and the mixer are connected in sequence, and the front and rear ends of the mixer are respectively connected to the outlet of the spiral stretching unit shell and the inlet of the injection pump; the outlet of the injection pump is injected into the formation through a pipeline.

20. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 19, characterized in that: The third solenoid valve is of normally closed type, with a diameter of DN50-DN80, a pressure level of 25MPa, and is made of stainless steel.

21. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 19, characterized in that: The third flow meter is of electromagnetic type, has a measuring range of 1-10 cubic meters per hour, and is made of stainless steel.

22. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 19, characterized in that: The mixer is a static mixer or a stirring tank, and preferably a static mixer.

23. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 22, characterized in that: The static mixer is of spiral type, with a diameter of 50-100 mm and a fluid flow rate of 1.0-1.5 m / s.

24. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 22, characterized in that: The stirring tank adopts a spiral propulsion blade, and the stirring residence time is 10-20s.

25. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 19, characterized in that: The injection pump adopts a three-cylinder plunger pump with a displacement of 5-10 cubic meters / h and a pressure of 25MPa.

26. The biopolysaccharide online mixing and injection device for microbial oil recovery according to claim 1, characterized in that: The automatic control unit is composed of a PLC controller, a detection instrument, a driving device and a control device. The detection instrument includes a flow meter, and the driving device includes a pump and a driving motor.

27. A method for online mixing and injection of biopolysaccharides for microbial oil recovery, characterized in that: The method specifically comprises the following steps: (1) high-pressure injection water enters the ejector after passing through the second solenoid valve and the second flowmeter, forms negative pressure after being ejected through the nozzle, and is premixed with the biopolysaccharide delivered by the polysaccharide feeding pump and sequentially passing through the first solenoid valve and the first flowmeter to form a heterogeneous fluid; (2) The heterogeneous fluid enters the electromagnetic field chamber of the electromagnetic dissociation unit and passes through the coil under the action of an alternating power supply, forming an alternating electromagnetic field in the electromagnetic field chamber, causing induced polarization in the polysaccharide molecules in the heterogeneous fluid flowing through, generating positive and negative poles in the molecules, and under the action of the electromagnetic field, the polysaccharide molecules are arranged in an orderly manner with the same electrical polarity, dissociation occurs between the molecules, and the polysaccharide system changes from a tightly aggregated state to a discrete state; (3) The discrete polysaccharide system enters the spiral stretching unit, and the motor drives the drum to rotate. Under the carrying effect of the circular protrusions, the polysaccharide molecules are further stretched in the gap between the drum and the shell to form a homogeneous fluid; (4) The homogeneous fluid enters the mixing unit and is mixed with the injection water passing through the third solenoid valve and the third flow meter in a proportion through the mixer to form a uniform polysaccharide system solution, which is then transported out through a high-pressure injection pump and injected into the water well for oil production; (5) The automatic control unit is connected to the polysaccharide feeding pump of the premixing unit, the first solenoid valve, the first flowmeter, the second solenoid valve, the second flowmeter, the alternating power supply of the electromagnetic dissociation unit, the motor of the spiral stretching unit, the third solenoid valve, the third flowmeter and the injection pump of the mixing unit respectively through the PLC controller; the injection water flow rate is set to Q1 through the PLC controller, and the opening of the second solenoid valve is adjusted according to the detection result of the second flowmeter so that the injection water flow rate is controlled within Q1±5%, the polysaccharide flow rate Q2 is set through the PLC controller, and the rotation speed of the polysaccharide feeding pump and the opening of the first solenoid valve are adjusted according to the detection result of the first flowmeter so that the polysaccharide flow rate is controlled within Q2±5%, the injection water flow rate Q3 is set through the PLC controller, and the opening of the third solenoid valve is adjusted according to the detection result of the third flowmeter so that the injection water flow rate is controlled within Q3±5%.

28. The method for online mixing and injection of biopolysaccharides for microbial oil recovery according to claim 27, characterized in that: The ratio of the biopolysaccharide to the high-pressure injection water in step (1) is 1:2-5.

29. The method for online mixing and injection of biopolysaccharides for microbial oil recovery according to claim 27, characterized in that: In step (2), the flow rate of the heterogeneous fluid flowing through the electromagnetic field chamber is controlled at 0.1-0.3 m / s, and the residence time is 1.5-2 min.

30. The method for online mixing and injection of biopolysaccharides for microbial oil recovery according to claim 27, characterized in that: In step (3), the flow rate of the discrete polysaccharide system flowing through the cross section between the shell and the drum is 1-1.5 m / s.

31. The method for online mixing and injection of biopolysaccharides for microbial oil recovery according to claim 27, characterized in that: In step (4), the residence time of the homogeneous fluid in the mixing unit is 10-30s, and the injection pressure of the high-pressure injection pump is 15-25MPa.

32. The method for online mixing and injection of biopolysaccharides for microbial oil recovery according to claim 27, characterized in that: In step (5), Q1=aQ2, ​​wherein a=1-5.

33. The method for online mixing and injection of biopolysaccharides for microbial oil recovery according to claim 27, characterized in that: In step (5), Q3=bQ2, wherein b=1-5.

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