Energy-increasing, plug-removing, viscosity-reducing and discharge-aiding composite integrated agent for oil layer as well as preparation method and application of composite integrated agent

Abstract

The invention discloses an energy-increasing, plug-removing, viscosity-reducing and discharge-assisting composite integrated agent for an oil layer and a preparation method and application thereof.The composite integrated agent comprises an agent A, an agent B, an agent C and an agent D. The agent A comprises urea, urease and sodium bicarbonate according to the mass ratio of (4.5-5.5): (0.8-1.2): (3.5-4.5); the agent B comprises the following components: p-aminobenzene sulfonic acid, ethylenediamine tetramethylenephosphonic acid and polydimethylsiloxane in a mass ratio of (8-10): (0.8-1): (1-1.2); the agent C comprises the following components: sodium dodecyl sulfate and diethylenetriamine, and the mass ratio of the sodium dodecyl sulfate to the diethylenetriamine is (0.8-1): (1.8-2.2); and the agent D comprises the following components: polyvinylpyrrolidone and lauryl sodium sulfate in a mass ratio of (1-1.2): (2-3). According to the invention, the reaction is carried out under the oil layer condition to form a high-pressure multi-phase foam system, a high-permeability layer is temporarily blocked and sealed, and potential tapping of a high-permeability layer and a low-permeability layer is carried out in sequence, so that the effects of various yield increasing measures of an oil well are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of oilfield exploitation. Specifically, the present invention relates to an integrated agent for enhancing reservoir energy, removing plugging, reducing viscosity and assisting drainage of oil layers, and a preparation method and application thereof. Background Art

[0002] With the continuous development of oilfields and the continuous production of reservoir fluids (oil, gas, water), the energy of the reservoir decreases in a "gradient" manner. When the formation energy drops to a certain extent, due to the "capillary flow resistance", the existing formation energy cannot drive the "formation fluid", resulting in a sharp drop in the produced fluid volume. In some cases, due to the difference in the mobility ratio of oil and water, although the fluid volume does not decrease significantly, the water cut increases significantly. That is to say, due to the decrease in formation energy, the originally flowing pores are blocked, or due to the decrease in formation pressure, the droplet diameter that originally matched the formation pore diameter no longer matches, thereby causing damage to the oil layer and significantly reducing the production capacity.

[0003] Meanwhile, during the displacement and production of crude oil, the relatively light components in the crude oil flow and are produced preferentially. The longer the production time, the greater the degree of retention and deposition of the relatively heavy components in the crude oil near the wellbore during the flow and production of the fluid (such as "dead oil" near the wellbore), causing "secondary" damage to the oil well. In addition, the damage caused during the drilling, completion, and perforation processes when the oil layer is opened is also one of the main reasons for the decline in the production capacity of the oil well. Moreover, during the development of oilfields, the entry of incompatible well fluids is likely to generate various scales (inorganic scales such as calcium, magnesium, and iron, and organic scales such as asphaltene, resin, and wax) that block the reservoir and reduce the production capacity of the oil well.

[0004] It can be seen that the decline in reservoir production capacity, the difficulty of flowing thick oil, and various blockages are the key factors causing the decline in oil well production and the real root cause of oil well blockage. To fundamentally remove various blockages in oil wells and restore and increase the oil well production, the key is to conduct technical research on restoring reservoir energy, reducing crude oil viscosity, reducing oil flow resistance, and removing various blockages in the oil layer, so as to fundamentally restore the oil well production and ultimately improve the crude oil recovery rate and the degree of production. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems in the related technologies to some extent. To this end, the present invention provides an integrated agent for enhancing reservoir energy, removing plugging, reducing viscosity and assisting drainage of oil layers, and a preparation method and application thereof.

[0006] The present invention adopts the following technical solutions: In the first aspect, The present invention provides an integrated agent for enhancing reservoir energy, removing plugging, reducing viscosity and assisting drainage of oil layers, including: Agent A: The components are urea, urease, and sodium bicarbonate, and the mass ratio is (4.5 - 5.5):(0.8 - 1.2):(3.5 - 4.5); Agent B: The components are sulfanilic acid, ethylenediaminetetramethylenephosphonic acid and polydimethylsiloxane, and the mass ratio is (8 - 10):(0.8 - 1):(1 - 1.2); Agent C: The components are sodium dodecyl sulfonate and diethylenetriamine, and the mass ratio is (0.8 - 1):(1.8 - 2.2); Agent D: The components are polyvinylpyrrolidone and sodium dodecyl sulfate, and the mass ratio is (1 - 1.2):(2 - 3).

[0007] In some embodiments, the oil reservoir energy - enhancing, plug - removing, viscosity - reducing and flow - assisting composite agent includes: Agent A: The components are urea, urease and sodium bicarbonate, and the mass ratio is 5:1:4; Agent B: The components are sulfanilic acid, ethylenediaminetetramethylenephosphonic acid and polydimethylsiloxane, and the mass ratio is 8:1:1; Agent C: The components are sodium dodecyl sulfonate and diethylenetriamine, and the mass ratio is 1:2; Agent D: The components are polyvinylpyrrolidone and sodium dodecyl sulfate, and the mass ratio is 1:2.5.

[0008] In the second aspect, The present invention also provides a preparation method of the above - mentioned oil reservoir energy - enhancing, plug - removing, viscosity - reducing and flow - assisting composite agent, including: Preparation of Agent A: First, add urea and sodium bicarbonate into the reaction kettle, stir at 23 - 27°C for 30 - 45 min, and the stirring speed is 30 - 60 r / min; then add urease into the reaction kettle and continue to stir at 23 - 27°C for 45 - 60 min to obtain Agent A; Preparation of Agent B: First, add sulfanilic acid into the reaction kettle, stir at 23 - 27°C for 30 - 45 min, and the stirring speed is 30 - 60 r / min; then add ethylenediaminetetramethylenephosphonic acid and polydimethylsiloxane into the reaction kettle and continue to stir at 23 - 27°C for 45 - 60 min to obtain Agent B; Preparation of Agent C: First, add sodium dodecyl sulfonate into the reaction kettle, stir at 45 - 55°C for 30 - 45 min, and the stirring speed is 30 - 60 r / min; then add diethylenetriamine into the reaction kettle and continue to stir at 45 - 55°C for 45 - 60 min, and cool to room temperature to obtain Agent C; Preparation of Agent D: First, add polyvinylpyrrolidone into the reaction kettle, stir at 45 - 55°C for 30 - 45 min, and the stirring speed is 30 - 60 r / min; then add sodium dodecyl sulfate into the reaction kettle and continue to stir at 45 - 55°C for 45 - 60 min, and cool to room temperature to obtain Agent D.

[0009] In some embodiments, the preparation method of the oil reservoir energy - enhancing, plug - removing, viscosity - reducing and flow - assisting composite agent includes: Preparation of Agent A: First, add urea and sodium bicarbonate into a reaction kettle, stir at 25°C for 30 min, and the stirring speed is 45 r / min; then add urease into the reaction kettle and continue to stir at 25°C for 45 min to obtain Agent A; Preparation of Agent B: First, add sulfanilic acid into a reaction kettle, stir at 25°C for 30 min, and the stirring speed is 45 r / min; then add ethylenediaminetetramethylenephosphonic acid and polydimethylsiloxane into the reaction kettle and continue to stir at 25°C for 45 min to obtain Agent B; Preparation of Agent C: First, add sodium dodecyl sulfonate into a reaction kettle, stir at 50°C for 30 min, and the stirring speed is 60 r / min; then add diethylenetriamine into the reaction kettle and continue to stir at 50°C for 45 min, and cool to room temperature to obtain Agent C; Preparation of Agent D: First, add polyvinylpyrrolidone into a reaction kettle, stir at 50°C for 30 min, and the stirring speed is 45 r / min; then add sodium dodecyl sulfate into the reaction kettle and continue to stir at 50°C for 45 min, and cool to room temperature to obtain Agent D.

[0010] In the third aspect, The present invention also provides an application method of the above - mentioned oil reservoir energy - enhancing, plug - removing, viscosity - reducing and flow - assisting composite agent. Among them, the mass ratio of Agent A, Agent B, Agent C, and Agent D used is (3 - 4):(3 - 4):(1.5 - 2.5):(1.5 - 2).

[0011] In some embodiments, the mass ratio of Agent A, Agent B, Agent C, and Agent D used is 3.5:3:2:1.5.

[0012] In some embodiments of the application method, Agent A is prepared into a 10% solution with water, that is, Solution A, for standby; Agent B is prepared into a 12% solution with water, that is, Solution B, for standby; Agent C is prepared into a 5% solution with water, that is, Solution C, for standby; Agent D is prepared into a 5% solution with water, that is, Solution D, for standby.

[0013] In some embodiments of the application, the application method includes: S1: Inject Solution A into the oil reservoir; S2: After the injection of Solution A is completed, inject a mixture of Solution B and Solution C into the oil reservoir. In the mixture, the dosage of Solution B is 50% of the total dosage of Solution B; S3: Continue to inject a mixture of Solution B and Solution D. In the mixture, the dosage of Solution B is 50% of the total dosage of Solution B.

[0014] In some embodiments of the application method, The preparation method of Solution A includes the following steps: Add part of the water into the mixing tank, keep the temperature constant at 25 - 28°C, preferably 25°C, add Agent A into the mixing tank at a feeding rate of 45 - 55 kg / min, preferably 50 kg / min, then add the remaining water to make the concentration of Agent A 10%, keep the temperature constant at 25 - 28°C, preferably 25°C, and stir at 45 - 65 r / min, preferably 60 r / min to obtain Solution A; The preparation method of Solution B includes the following steps: Add part of the water into the mixing tank, keep the temperature constant at 25 - 30°C, preferably 25°C, add Agent B into the mixing tank at a feeding rate of 45 - 55 kg / min, preferably 50 kg / min, then add the remaining water to make the concentration of Agent B 12%, keep the temperature constant at 25 - 30°C, preferably 25°C, and stir at 45 - 65 r / min, preferably 60 r / min to obtain Solution B; The preparation method of Solution C includes the following steps: Add part of the water into the mixing tank, keep the temperature constant at 25 - 30°C, preferably 25°C, add Agent C into the mixing tank at a feeding rate of 15 - 25 kg / min, preferably 20 kg / min, then add water to make the concentration of Agent C 5%, keep the temperature constant at 25 - 30°C, preferably 25°C, and stir at 45 - 65 r / min, preferably 60 r / min to obtain Solution C; The preparation method of Solution D includes the following steps: Add part of the water into the mixing tank, keep the temperature constant at 25 - 30°C, preferably 25°C, add Agent D into the mixing tank at a feeding rate of 10 - 15 kg / min, preferably 10 kg / min, then add water to make the concentration of Agent D 5%, keep the temperature constant at 25 - 30°C, preferably 25°C, and stir at 45 - 65 r / min, preferably 60 r / min to obtain Solution D.

[0015] In some application embodiments, the oil reservoir energy - enhancing, plug - removing, viscosity - reducing and flow - assisting composite agent is applicable to the exploitation of oil reservoirs in the middle and late stages of oilfield development. The oil reservoir energy - enhancing, plug - removing, viscosity - reducing and flow - assisting composite agent of the present invention is applied to the exploitation of low - production, low - efficiency and difficult - to - produce oil reservoirs in the middle and late stages of oilfield development, and still can achieve remarkable production - increasing effects.

[0016] The oil reservoir energy - enhancing, plug - removing, viscosity - reducing and flow - assisting composite agent of the present invention, In solution A, under reservoir conditions, urea undergoes a chemical reaction with the aid of urease, generating gas to supplement the energy of the reservoir. Usually, the decomposition rate of urea with the aid of urease is slow under reservoir conditions, and the amount of gas generated is very small. Therefore, it is not obvious to achieve the effect of supplementing the reservoir volume and enhancing oil displacement to improve the recovery rate. The main reason is that urease is difficult to maintain a high activity under reservoir conditions, and its activity is greatly affected by the environmental pH value. The present invention creatively adds sodium bicarbonate and regulates the ratio of urea, urease, and sodium bicarbonate to make the pH within the optimal range of 6.8 - 7.8, so as to maintain the highest activity of urease under reservoir conditions and improve the energy enhancement and oil displacement and production effects.

[0017] The reaction mechanism involved in agent A is as follows: Under the condition of pH 6.8 - 7.8, urea decomposes with the aid of urease to generate CO2, H2O, N2, and NO2.

[0018] In solution B, sulfanilic acid corrodes reservoir rocks (such as carbonate rocks and clay minerals) to improve the permeability. Sulfanilic acid forms surfactants with the aromatic components (furan and ketone) of crude oil to reduce the oil flow resistance; sulfanilic acid disperses and dissolves the clay minerals in the reservoir to prevent the damage (blockage) caused by clay swelling and migration; ethylenediaminetetramethylenephosphonic acid complexes iron, magnesium, and calcium ions to prevent acid sensitivity damage (blockage); polydimethylsiloxane disperses and dissolves asphaltenes, resins, and waxes to remove organic blockages. The three work together to form a protection closed-loop for different types of reservoir damage. The plugging removal and surface activity effect (sulfanilic acid), complexation effect (ethylenediaminetetramethylenephosphonic acid), and dispersion and dissolution effect (polydimethylsiloxane) jointly improve the properties of the oil-water-rock interface, coordinate the fluid flow channels, reduce the flow resistance, and improve the productivity of the reservoir.

[0019] In solution C, through the surface activity of sodium dodecylsulfonate, the crude oil in the reservoir is dispersed and dissolved, enabling the molecular chains of the crude oil to fully stretch, exposing more metal ion binding sites. With the aid of the complexation of diethylenetriamine with transition metal ions, the content of target elements (such as nickel) in the molecular structure of the crude oil is reduced. After the removal of transition metal ions, the cross-linking effect between crude oil molecules weakens, and sodium dodecylsulfonate is more likely to penetrate and disperse the remaining molecular clusters, ultimately changing the occurrence state of crude oil molecules and reducing the number of single molecules aggregated by crude oil molecular clusters, thereby reducing the viscosity of the crude oil.

[0020] In solution D, with the aid of the driving force, a low-density foam system (0.65 - 0.85 g / cm 3 ) is formed. After the measure is taken and the well is opened, the production rate and the recovery degree are increased.

[0021] The present invention has the following advantages and beneficial effects; The energy - enhancing, plug - removing, viscosity - reducing and drainage - assisting composite agent of the present invention can be widely applied to the whole process of oilfield development, relieve the damage (blockage) of the oil reservoir in each link, and increase the single - well production; by virtue of the comprehensive characteristics of the agent, it can exploit and tap the potential of the blocked "target layer", fundamentally solve the technical problems of "difficulty in entering the target layer, low reaction degree, and inability to discharge the reaction products", and maximize the effect of production increase by measures.

[0022] The energy - enhancing, plug - removing, viscosity - reducing and drainage - assisting composite agent of the present invention reacts under reservoir conditions to form a high - pressure multiphase foam system, temporarily plugs and seals the high - permeability layer with channeling, and successively exploits and taps the potential of the sub - high - permeability layer and the low - permeability layer, improving the effect of various production - increasing measures for oil wells. Specifically, the multiphase foam plugging and channeling - sealing effect has the following remarkable characteristics: First, the foam has good fluidity and can penetrate into every corner of the oil reservoir to ensure the plugging effect; Second, the multiphase foam system has strong stability and can maintain long - term effectiveness under the formation temperature, high pressure and high salinity environment; Finally, after the measures, the temporary plugging effect of the multiphase foam is easy to remove and will not cause permanent blockage to the oil well, giving full play to the potential of the oil reservoir. Brief Description of the Drawings

[0023] Figure 1 It is for the diffusion situation when the liquid drop of Experimental Example 5 - 1 is dropped into the beaker; Figure 2 It is for the reaction degree 15 minutes after the liquid drop of Experimental Example 5 - 1 is dropped into the beaker; Figure 3 It is for the diffusion situation when the liquid drop of Experimental Example 5 - 2 is dropped into the beaker; Figure 4 It is for the reaction degree 15 minutes after the liquid drop of Experimental Example 5 - 2 is dropped into the beaker. Detailed Embodiments

[0024] The embodiments of the present invention will be described in detail below. The following described embodiments are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0025] The experimental methods used in the following embodiments are all conventional methods unless otherwise specified.

[0026] The materials, reagents, devices, etc. used in the following embodiments can be obtained from commercial channels or prepared according to the methods in the published literature unless otherwise specified.

[0027] In this article, when a value is described as a range, it should be understood that this disclosure includes the disclosure of all possible sub - ranges within the range, as well as the specific values falling within the range, regardless of whether the specific values or specific sub - ranges are explicitly indicated.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the meanings commonly understood by those of ordinary skill in the art to which this invention belongs.

[0029] In this article, unless otherwise specified, the solutions mentioned are aqueous solutions, and the concentrations mentioned are mass concentrations.

[0030] Example 1

[0031] The oil reservoir energy-increasing, plugging removal, viscosity reduction and drainage assistance composite agent includes: Agent A: The components are urea, urease (Beijing Solarbio Science & Technology Co., Ltd., urease activity: ≥50 u / mg), and sodium bicarbonate, and the mass ratio is 5:1:4; Agent B: The components are sulfanilic acid, ethylenediaminetetramethylenephosphonic acid, and polydimethylsiloxane, and the mass ratio is 8:1:1; Agent C: The components are sodium dodecyl sulfonate and diethylenetriamine, and the mass ratio is 1:2; Agent D: The components are polyvinylpyrrolidone and sodium dodecyl sulfate, and the mass ratio is 1:2.5.

[0032] The oil reservoir energy-increasing, plugging removal, viscosity reduction and drainage assistance composite agent includes: Preparation of Agent A: First, add urea and sodium bicarbonate to the reaction kettle, stir at 25°C for 30 min, and the stirring speed is 45 r / min; then add urease to the reaction kettle and continue to stir at 25°C for 45 min to obtain Agent A; Preparation of Agent B: First, add sulfanilic acid to the reaction kettle, stir at 25°C for 30 min, and the stirring speed is 45 r / min; then add ethylenediaminetetramethylenephosphonic acid and polydimethylsiloxane to the reaction kettle and continue to stir at 25°C for 45 min to obtain Agent B; Preparation of Agent C: First, add sodium dodecyl sulfonate to the reaction kettle, stir at 50°C for 30 min, and the stirring speed is 60 r / min; then add diethylenetriamine to the reaction kettle and continue to stir at 50°C for 45 min, and cool to room temperature to obtain Agent C; Preparation of Agent D: First, add polyvinylpyrrolidone to the reaction kettle, stir at 50°C for 30 min, and the stirring speed is 45 r / min; then add sodium dodecyl sulfate to the reaction kettle and continue to stir at 50°C for 45 min, and cool to room temperature to obtain Agent D.

[0033] Example 2

[0034] Application method of the oil reservoir energy-increasing, plugging removal, viscosity reduction and drainage assistance composite agent, wherein the mass ratio of Agent A: Agent B: Agent C: Agent D is 3.5:3:2:1.5. Among them, Agent A, Agent B, Agent C, and Agent D are all prepared in Example 1.

[0035] Preparation of Solution A: Add 3 m 3 of water to the mixing tank, keep the temperature at 25°C, add 350 kg of Agent A to the mixing tank at a feeding rate of 50 kg / min, and add water until the volume reaches 3.5 m 3 . Keep the temperature at 25°C and the stirring speed at 60 r / min to prepare a 10% Solution A (input into the storage tank) with a volume of 3.5 m 3 .

[0036] Preparation of Solution B: Add 2.5 m 3 of water to the mixing tank, keep the temperature at 25°C, evenly add 360 kg of Agent B to the mixing tank at a feeding rate of 50 kg / min; add water until the volume reaches 3 m 3 . Keep the temperature at 25°C and the stirring speed at 60 r / min; prepare a 12% Solution B (input into the storage tank) with a volume of 3 m 3 .

[0037] Preparation of Solution C: Add 1.5 m 3 of water to the mixing tank, keep the temperature at 25°C, evenly add 100 kg of Agent C to the mixing tank at a feeding rate of 20 kg / min; add water until the volume reaches 2 m 3 . Keep the temperature at 25°C and the stirring speed at 60 r / min; prepare a 5% Solution C (input into the storage tank) with a volume of 2 m 3 .

[0038] Preparation of Solution D: Add 1 m 3 of water to the mixing tank, keep the temperature at 25°C, evenly add 75 kg of Agent D to the mixing tank at a feeding rate of 10 kg / min; add water until the volume reaches 1.5 m 3 . Keep the temperature at 25°C and the stirring speed at 60 r / min; prepare a 5% Solution D (input into the storage tank) with a volume of 1.5 m 3 .

[0039] When adding to the oil layer, S1: Inject Solution A into the oil layer. A large amount of Agent A enters the high-permeability layer, and a small amount of Agent A enters the sub-high-permeability layer and the low-permeability layer.

[0040] S2: After the injection of Solution A is completed, a mixture of Solution B and Solution C is injected into the oil layer. In the mixture, the dosage of Solution B is 50% of the total dosage of Solution B. The same large amounts of Agent B and Agent C preferentially enter the high-permeability layer. After the mixing of Agent A, Agent B, and Agent C, a large amount of gas is released by the reaction of Agent A, forming a high-pressure multiphase foam system. The high-permeability layer generates a large amount of gas and has a large pressure increase amplitude, forcing the subsequent injected Solution B and Solution C to enter the sub-high-permeability layer and the low-permeability layer, greatly improving the degree of production and potential tapping of the sub-high-permeability layer and the low-permeability layer. At the same time, during the injection of Solution A, a small amount enters the sub-high-permeability layer and the low-permeability layer. After mixing with the subsequent injected Solution B and Solution C, during the process of gas generation by the reaction of Agent A, it plays a role of dynamic stirring, improving the reaction degree, and finally achieving the purpose of temporarily plugging the high-permeability layer and tapping the potential of the low-permeability layer.

[0041] S3: Continue to inject a mixture of Solution B and Solution D. In the mixture, the dosage of Solution B is 50% of the total dosage of Solution B. Give full play to the composite characteristics of the integrated agent to maximize the single-well oil production of the oil well and provide strong technical support for the high-quality, high-efficiency, and sustainable development of the oilfield.

[0042] Experimental Example 1: Evaluation of the gas generation effect of urea under different conditions in the laboratory

[0043] Experimental instrument: TCY-WK1000 temperature and pressure reactor (pressure range 0.1 - 5.0 MPa, temperature range 0 - 350 °C, volume 1000 ml) Experimental Example 1-1: Weigh 100 ml of 10% urea solution and 200 ml of 1% urease solution, add them to the temperature and pressure reactor, set the temperature to 25 °C, measure the pH value, record the time taken for the pressure in the temperature and pressure reactor to rise to 0.5 MPa, and record the time from the start to the end of the reaction.

[0044] Experimental Example 1-2: Weigh 100 ml of 10% urea solution, 200 ml of 1% urease solution, and 160 ml of 5% sodium bicarbonate solution, add them to the temperature and pressure reactor, set the temperature to 25 °C, measure the pH value, record the time taken for the pressure in the temperature and pressure reactor to rise to 0.5 MPa, and record the time from the start to the end of the reaction.

[0045] Experimental Example 1-3: Weigh 100 ml of 10% urea solution, 200 ml of 1% urease solution, and 160 ml of 5% ammonium bicarbonate solution, add them to the temperature and pressure reactor, set the temperature to 25 °C, measure the pH value, record the time taken for the pressure in the temperature and pressure reactor to rise to 0.5 MPa, and record the time from the start to the end of the reaction.

[0046] Experimental Examples 1 - 4: Weigh 100 ml of 10% urea solution, 200 ml of 1% urease solution, and 160 ml of 5% potassium bicarbonate solution, add them to a temperature and pressure reactor, set the temperature to 25°C, measure the pH value, record the time taken for the pressure in the temperature and pressure reactor to rise to 0.5 MPa, and record the time taken from the start to the end of the reaction.

[0047] Experimental Example 1 - 5: Weigh 100 ml of 10% urea solution, 200 ml of 1% urease solution, and 160 ml of 5% calcium bicarbonate solution, add them to a temperature and pressure reactor, set the temperature to 25°C, measure the pH value, record the time taken for the pressure in the temperature and pressure reactor to rise to 0.5 MPa, and record the time taken from the start to the end of the reaction.

[0048] The evaluation results are shown in Table 1 below.

[0049] Table 1 Evaluation of the gas generation effect of urea decomposition under different conditions

[0050] It can be seen from Table 1 that: Under the conditions of urease and sodium bicarbonate solution, urea decomposes to produce gas at the fastest rate, with the largest amount of gas, and is most capable of meeting the actual application in oilfield development, while several other similar salts cannot meet the actual application in oilfield development.

[0051] Experimental Example 2: Evaluation experiment of viscosity reduction effect

[0052] Take the dehydrated oil samples from 3 well - times of Jin 45 - 2 - 7, Leng 37 - 10, and Du 32 - 1 - 3 respectively.

[0053] Keep the oil samples at a constant temperature of 50°C and measure the viscosity with reference to the petroleum industry standard SY / T0520 - 2008; Mix the oil samples with 1.0% EDTA solution, 1.0% sodium dodecyl sulfonate solution, 1.0% C solution, 1.0% C1 solution, 1.0% C2 solution, 1.0% C3 solution, and 1.0% C4 solution respectively, with a mixing volume ratio of 3:7. Keep the temperature at 50°C and measure the viscosity with reference to the petroleum industry standard SY / T0520 - 2008, and calculate the viscosity reduction rate. The results are shown in Table 2.

[0054] Table 2 Evaluation of the viscosity reduction effect of crude oil (heavy oil) with different reagents

[0055] Agent C in C solution: The components are sodium dodecyl sulfonate and diethylenetriamine, with a mass ratio of 1:2; Agent C1 in C1 solution: The components are sodium dodecyl sulfonate and diethylenetriamine, with a mass ratio of 1:1; Agent C2 in C2 solution: The components are sodium dodecyl sulfonate and diethylenetriamine, with a mass ratio of 2:1; C3 agent in C3 solution: The components are sulfanilic acid and diethylenetriamine, and the mass ratio is 1:2. C4 agent in C4 solution: The components are sodium dodecyl sulfonate and sodium diethyldithiocarbamate, and the mass ratio is 1:2.

[0056] As can be seen from Table 2, the C agent has the best viscosity reduction effect on crude oil, significantly better than that of other groups. It can be seen that the combination of sodium dodecyl sulfonate and diethylenetriamine with a mass ratio of 1:2 has the best viscosity reduction effect.

[0057] Experimental Example 3: Evaluation of the drainage aid effect

[0058] Measure 200 ml of 0.5% sodium dodecyl sulfonate solution, 0.5% polyvinylpyrrolidone solution, 0.5% D agent solution, 0.5% D1 agent solution, 0.5% D2 agent solution, 0.5% D3 agent solution, 0.5% D4 agent solution, and 0.5% D5 agent solution respectively, and add them to the corresponding 1000 ml beakers. Place the beakers in a constant temperature water bath, stir at 30 r / min, keep the temperature constant at 50 °C, and after 24 h of constant temperature, measure the total foam volume according to the standard specification of ASTM D1173-07, and the evaluation results are shown in Table 3.

[0059] Table 3 Evaluation of the drainage aid effect of different agents

[0060] D agent in D solution: The components are polyvinylpyrrolidone and sodium dodecyl sulfate, and the mass ratio is 1:2.5.

[0061] D1 agent in D1 solution: The components are polyvinylpyrrolidone and sodium dodecyl sulfate, and the mass ratio is 1:1.5.

[0062] D2 agent in D2 solution: The components are polyvinylpyrrolidone and sodium dodecyl sulfate, and the mass ratio is 1:1.

[0063] D3 agent in D3 solution: The components are polyvinylpyrrolidone and sodium dodecyl sulfate, and the mass ratio is 1.5:1.

[0064] D4 agent in D4 solution: The components are polyvinylpyrrolidone and sodium dodecyl sulfonate, and the mass ratio is 1:2.5.

[0065] D5 agent in D5 solution: The components are sodium diethyldithiocarbamate and sodium dodecyl sulfate, and the mass ratio is 1:2.5.

[0066] As can be seen from Table 3, the D agent has the best drainage aid effect, significantly better than that of other groups. It can be seen that when polyvinylpyrrolidone and sodium dodecyl sulfate are combined at a mass ratio of 1:2.5, the drainage aid effect is the best.

[0067] Experimental Example 4: Evaluation of Temporary Plugging Effect

[0068] Experimental Instruments and Equipment: Reciprocating Pump HA-P100: Flow rate 0.1 - 600 ml / min, pressure 0.1 - 10 MPa; Vacuum Drier: Temperature 20 - 100 °C, vacuum degree ≤ 100 Pa; Core Measuring Instrument: Temperature 20 - 100 °C, pressure 0.1 - 12 MPa; Preparation of Experimental Samples: 6 standard cores: Diameter × Length = 2.5 cm × 5 cm; 2 cores each with permeability of 500 mdc, 50 mdc, and 5 mdc; Prepare simulated formation water: Prepare an aqueous solution with a salinity of 5000 mg / L using sodium chloride: potassium chloride: sodium bicarbonate with a mass ratio of 1:1:1, which is the simulated formation water; Experimental Process and Steps: Experimental Example 4-1 (1) Evacuate and saturate 1 core of each of the above three types of permeable cores with simulated formation water; (2) Place the saturated cores into the core measuring instrument, keep the temperature constant at 25 °C for 30 min; (3) Displace with a reciprocating pump 10% BCD solution (B agent: C agent: D agent are mixed according to a mass ratio of 6:4:3 to form BCD agent, and then added to water to prepare a 10% BCD solution), and record the flow rates through different permeability ranges; (4) Calculate the proportion of flow rates through different permeability ranges.

[0069] Experimental Example 4-2 (1) Saturate 1 core of each of the above three types of permeable cores with 10% A solution; (2) Place the saturated cores into the core measuring instrument, keep the temperature constant at 25 °C for 30 min; (3) Displace with a reciprocating pump 10% BCD solution (B agent: C agent: D agent are mixed according to a mass ratio of 6:4:3 to form BCD agent, and then added to water to prepare a 10% BCD solution), and record the flow rates through different permeability ranges; (4) Calculate the proportion of flow rates through different permeability ranges.

[0070] The test results are shown in Table 4 below.

[0071] Table 4 Evaluation of the Effect of Agent A in Plugging High-Permeability Layers, Tapping Sub-High-Permeability Layers, and Low-Permeability Layers during Plug Removal

[0072] As can be seen from Table 4, Agent A has the effect of plugging and temporarily blocking the high-permeability layer (void layer), greatly improving the degree of Agent BCD entering the sub-high-permeability layer and low-permeability layer in sequence, fully tapping the potential of the "target layer", increasing the production increase range, and realizing the effective exploitation of low-yield, low-efficiency and difficult-to-produce oil layers in the middle and late stages of oilfield development.

[0073] Experimental Example 5 Evaluation Experiment on Improving Reaction Degree

[0074] Experimental Example 5-1 (1) Measure 200 ml of 0.3% partially hydrolyzed polyacrylamide (HPAM, molecular weight 2000) solution (viscosity at 50 °C is 50 mPa·s) and put it into a beaker. Place the beaker in a constant temperature water bath and keep the temperature at 50 °C for 30 min; (2) Add 2 drops of BCD solution to the beaker and observe the reaction diffusion situation during the falling process of the liquid drop.

[0075] Observe the diffusion situation when the liquid drop is dropped into the beaker and the reaction degree in the beaker after 15 min respectively. The results are as Figure 1 、 Figure 2 shown. It can be seen through Figure 1 that after the BCD solution is added, the diffusion is slow and the reaction degree is low. It can be seen through Figure 2 that the reaction degree basically remains unchanged after 15 min.

[0076] Experimental Example 5-2 (1) Measure 200 ml of the mixed solution of HPAM and Agent A (in the mixed solution, the proportion of HPAM is 0.3% and the proportion of Agent A is 10%) and put it into a beaker. Place the beaker in a constant temperature water bath and keep the temperature at 50 °C for 30 min; (2) Add 5 drops of BCD solution to the beaker and observe the reaction diffusion situation during the falling process of the liquid drop.

[0077] Observe the diffusion situation when the liquid drop is dropped into the beaker and the reaction degree in the beaker after 15 min respectively. The results are as Figure 3 、 Figure 4 shown. It can be seen through Figure 3 that after the BCD solution is added, it diffuses rapidly and the reaction degree is high. It can be seen through Figure 4 that it diffuses into the whole reaction system after 15 min, and the diffusion degree almost reaches 100%.

[0078] Through Figures 1 - 4 the observation results, it can be seen that when the oil layer energy-increasing, plugging-removing, viscosity-reducing and drainage-assisting composite agent of the present invention is used for plugging-removing and production-increasing measures, by virtue of the energy-increasing characteristic reaction of Agent A, a large amount of gas is released, which plays a role of dynamic stirring, greatly improving the reaction degree of the production-increasing agent, fundamentally solving the technical difficult problems of the production-increasing agent being difficult to "enter the target layer and have a low reaction degree", and realizing the maximization of the production-increasing effect.

[0079] Experimental Example 6 Acid Sensitivity Effect Evaluation Experiment

[0080] At room temperature, take vessels 1-1, 1-2, 2-1, 2-1, 3-1, and 3-2; Add 20 g of Zhoufu 60-46 core powder to vessel 1-1, and then add 100 ml of 10% hydrochloric acid solution. After the reaction ends, measure the pH value and observe the precipitation situation of the reaction solution; Add 20 g of Zhoufu 60-46 core powder to vessel 1-2, and then add 100 ml of 10% B solution. After the reaction ends, measure the pH value and observe the precipitation situation of the reaction solution; Add 20 g of Zhou 602-7 core powder to vessel 2-1, and then add 100 ml of 10% hydrochloric acid solution. After the reaction ends, measure the pH value and observe the precipitation situation of the reaction solution; Add 20 g of Zhou 602-7 core powder to vessel 2-2, and then add 100 ml of 10% B solution. After the reaction ends, measure the pH value and observe the precipitation situation of the reaction solution; Add 20 g of Zhao 33-Ping 28 core powder to vessel 3-1, and then add 100 ml of 10% hydrochloric acid solution. After the reaction ends, measure the pH value and observe the precipitation situation of the reaction solution; Add 20 g of Zhao 33-Ping 28 core powder to vessel 3-2, and then add 100 ml of 10% B solution. After the reaction ends, measure the pH value and observe the precipitation situation of the reaction solution.

[0081] The results are shown in Table 5.

[0082] Table 5 Acid Sensitivity Effect Evaluation Analysis

[0083] As can be seen from Table 5, when the B agent is used for production enhancement measures, even when implemented in reservoirs with a relatively high content of ferrochlorite (greater than 2.5%), iron ion precipitation will not occur, and acid sensitivity damage (blockage) to the reservoir will not be caused, improving the production enhancement effect of the measures.

[0084] Experimental Example 7 Conventional Vertical Well

[0085] After indoor analysis and evaluation diagnosis, Well Nan 208-286 has low formation energy and serious voidage; when incompatible fluids enter the reservoir, inorganic scale blockage is serious; blockage by organic substances such as asphaltene, resin, and wax is the main reason for the decline in reservoir energy. By using the oil reservoir energy enhancement, plugging removal, viscosity reduction, and drainage assistance integrated agent prepared in Example 2 of the present application for production enhancement measures, significant production enhancement effects can be achieved, as shown in Table 6 below.

[0086] Table 6 Analysis of the Production Enhancement Effect of the Energy Enhancement, Plugging Removal, Viscosity Reduction, and Drainage Assistance Integrated Agent Applied to Conventional Vertical Wells

[0087] Example 8 Horizontal Well

[0088] After indoor analysis, evaluation and diagnosis, Well 10H92 - A48 has low - permeability reservoir, low formation energy, serious voidage, serious inorganic scale plugging, high - viscosity oil, and plugging by organic substances such as asphaltene, resin and wax, which are the main reasons for the decline of reservoir energy. By adopting the stimulation measure of the integrated agent for enhancing reservoir energy, removing blockage, reducing viscosity and assisting fluid drainage prepared in Example 2 of the present application, significant production - increasing effects can be obtained, as shown in Table 7 below.

[0089] Table 7 Analysis of the production - increasing effect of the integrated agent for enhancing reservoir energy, removing blockage, reducing viscosity and assisting fluid drainage applied to horizontal wells

[0090] Example 9 Intermittent - production Well

[0091] After indoor analysis, evaluation and diagnosis, Well Nan 272 - P254 has low formation energy, serious voidage, intermittent production and poor liquid - supplying capacity, which are the main reasons for the decline of reservoir energy. By adopting the stimulation measure of the integrated agent for enhancing reservoir energy, removing blockage, reducing viscosity and assisting fluid drainage prepared in Example 2 of the present application, significant production - increasing effects can be obtained, as shown in Table 8 below.

[0092] Table 8 Analysis of the production - increasing effect of the integrated agent for enhancing reservoir energy, removing blockage, reducing viscosity and assisting fluid drainage applied to intermittent - production wells

[0093] In the present invention, the term "some embodiments" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment of the present invention. In this specification, the schematic representation of the above - mentioned term does not necessarily refer to the same embodiment. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments and the features of different embodiments described in this specification.

[0094] Although the embodiments of the present invention have been shown and described above, it can be understood that the above - mentioned embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above - mentioned embodiments within the scope of the present invention.

Claims

1. A composite integrated agent for enhancing reservoir energy, removing blockage, reducing viscosity and assisting drainage, characterized in that, Comprising: Agent A: The components are urea, urease and sodium bicarbonate, and the mass ratio is (4.5 - 5.5):(0.8 - 1.2):(3.5 - 4.5); Agent B: The components are sulfanilic acid, ethylenediaminetetramethylenephosphonic acid and polydimethylsiloxane, and the mass ratio is (8 - 10):(0.8 - 1):(1 - 1.2); Agent C: The components are sodium dodecyl sulfonate and diethylenetriamine, and the mass ratio is (0.8 - 1):(1.8 - 2.2); Agent D: The components are polyvinylpyrrolidone and sodium dodecyl sulfate, and the mass ratio is (1 - 1.2):(2 - 3).

2. The enhanced energy, plugging removal, viscosity reduction and drainage assistance composite agent for oil reservoirs according to claim 1, wherein The oil reservoir energy - enhancing, plug - removing, viscosity - reducing and drainage - assisting composite agent comprises: Agent A: The components are urea, urease and sodium bicarbonate, and the mass ratio is 5:1:4; Agent B: The components are sulfanilic acid, ethylenediaminetetramethylenephosphonic acid and polydimethylsiloxane, and the mass ratio is 8:1:1; Agent C: The components are sodium dodecyl sulfonate and diethylenetriamine, and the mass ratio is 1:2; Agent D: The components are polyvinylpyrrolidone and sodium dodecyl sulfate, and the mass ratio is 1:2.

5.

3. The preparation method of the composite integrated agent for enhancing reservoir energy, removing plugging, reducing viscosity and assisting drainage according to claim 1 or 2, characterized in that, Comprising: Preparation of Agent A: First, add urea and sodium bicarbonate into the reaction kettle, stir at 23 - 27°C for 30 - 45 min, and the stirring speed is 30 - 60 r / min; then add urease into the reaction kettle, and continue to stir at 23 - 27°C for 45 - 60 min to obtain Agent A; Preparation of Agent B: First, add sulfanilic acid into the reaction kettle, stir at 23 - 27°C for 30 - 45 min, and the stirring speed is 30 - 60 r / min; then add ethylenediaminetetramethylenephosphonic acid and polydimethylsiloxane into the reaction kettle, and continue to stir at 23 - 27°C for 45 - 60 min to obtain Agent B; Preparation of Agent C: First, add sodium dodecyl sulfonate into the reaction kettle, stir at 45 - 55°C for 30 - 45 min, and the stirring speed is 30 - 60 r / min; then add diethylenetriamine into the reaction kettle, and continue to stir at 45 - 55°C for 45 - 60 min, and cool to room temperature to obtain Agent C; Preparation of Agent D: First, add polyvinylpyrrolidone into the reaction kettle, stir at 45 - 55°C for 30 - 45 min, and the stirring speed is 30 - 60 r / min; then add sodium dodecyl sulfate into the reaction kettle, and continue to stir at 45 - 55°C for 45 - 60 min, and cool to room temperature to obtain Agent D.

4. The preparation method of the oil reservoir energy-increasing, plugging removal, viscosity reduction and drainage-aiding composite agent according to claim 3, characterized in that, Comprising: Preparation of Agent A: First, add urea and sodium bicarbonate into the reaction kettle, stir at 25°C for 30 min, and the stirring speed is 45 r / min; then add urease into the reaction kettle, and continue to stir at 25°C for 45 min to obtain Agent A; Preparation of Agent B: First, add sulfanilic acid into the reaction kettle, stir at 25°C for 30 min, and the stirring speed is 45 r / min; then add ethylenediaminetetramethylenephosphonic acid and polydimethylsiloxane into the reaction kettle, and continue to stir at 25°C for 45 min to obtain Agent B; Preparation of Agent C: First, add sodium dodecyl sulfate into the reaction kettle, stir at 50 °C for 30 min, and the stirring speed is 60 r / min; then add diethylenetriamine into the reaction kettle, continue to stir at 50 °C for 45 min, and cool to room temperature to obtain Agent C; Preparation of Agent D: First, add polyvinylpyrrolidone into the reaction kettle, stir at 50 °C for 30 min, and the stirring speed is 45 r / min; then add sodium dodecyl sulfate into the reaction kettle, continue to stir at 50 °C for 45 min, and cool to room temperature to obtain Agent D.

5. The application method of the composite integrated agent for enhancing energy, removing plugging, reducing viscosity and assisting drainage of the oil reservoir described in claim 1 or 2, characterized in that, The mass ratio of Agent A, Agent B, Agent C, and Agent D used is (3 - 4):(3 - 4):(1.5 - 2.5):(1.5 - 2).

6. The application method of the oil reservoir energy increasing, plugging removal, viscosity reduction and drainage assistance composite integrated agent according to claim 5, characterized in that The mass ratio of Agent A, Agent B, Agent C, and Agent D used is 3.5:3:2:1.

5.

7. The application method of the composite integrated agent for enhancing reservoir energy, removing plugging, reducing viscosity and assisting drainage according to claim 5 or 6, characterized in that Agent A is prepared into a 10% solution with water, namely Solution A, for standby; Agent B is prepared into a 12% solution with water, namely Solution B, for standby; Agent C is prepared into a 5% solution with water, namely Solution C, for standby; Agent D is prepared into a 5% solution with water, namely Solution D, for standby.

8. The application method of the oil reservoir energy increasing, plugging removal, viscosity reduction and drainage assistance composite agent according to claim 7, characterized in that The application method includes: S1: Inject Solution A into the oil layer; S2: After the injection of Solution A is completed, inject a mixture of Solution B and Solution C into the oil layer. In the mixture, the dosage of Solution B is 50% of the total dosage of Solution B; S3: Continue to inject a mixture of Solution B and Solution D. In the mixture, the dosage of Solution B is 50% of the total dosage of Solution B.

9. The application method of the oil layer energy enhancement, plugging removal, viscosity reduction, and drainage assistance composite integrated agent according to claim 8, characterized in that The preparation method of Solution A includes the following steps: Add part of the water into the mixing tank, keep the temperature constant at 25 - 28 °C, add Agent A into the mixing tank at a feeding speed of 45 - 55 kg / min, and then add the remaining water to make the concentration of Agent A 10%, keep the temperature constant at 25 - 28 °C, and stir at 45 - 65 r / min to prepare Solution A; The preparation method of Solution B includes the following steps: Add part of the water into the mixing tank, keep the temperature constant at 25 - 30 °C, add Agent B into the mixing tank at a feeding speed of 45 - 55 kg / min, and then add the remaining water to make the concentration of Agent B 12%, keep the temperature constant at 25 - 30 °C, and stir at 45 - 65 r / min to prepare Solution B; The preparation method of Solution C includes the following steps: Add part of the water into the mixing tank, keep the temperature constant at 25 - 30 °C, add Agent C into the mixing tank at a feeding speed of 15 - 25 kg / min, and then add water to make the concentration of Agent C 5%, keep the temperature constant at 25 - 30 °C, and stir at 45 - 65 r / min to prepare Solution C; The preparation method of Solution D includes the following steps: Add part of the water into the mixing tank, keep the temperature constant at 25 - 30 °C, add Agent D into the mixing tank at a feeding speed of 10 - 15 kg / min, and then add water to make the concentration of Agent D 5%, keep the temperature constant at 25 - 30 °C, and stir at 45 - 65 r / min to prepare Solution D.

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