# Patent

## Title
Amphiphilic macromolecule and use thereof

## Abstract

Amphiphilic macromolecules having repeating structural units: structural units to adjust molecular weight and molecular weight distribution and charging property effects, high stereo-hindrance structural units, and amphiphilic structural units, and are suitable for fields such as oil field well drilling, well cementation, fracturing, oil gathering and transfer, sewage treatment, sludge treatment and papermaking, etc., and can be used as an oil-displacing agent for enhanced oil production, a heavy oil viscosity reducer, a fracturing fluid, a clay stabilizing agent, a sewage treatment agent, a papermaking retention and drainage aid or a reinforcing agent, etc.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national stage entry of PCT/CN2011/001579 filed Sep. 16, 2011, which claims priority to Chinese Patent Application No. 201110210362.X, filed on Jul. 26, 2011, said applications are expressly incorporated herein in their entirety.
TECHNICAL FIELD
This invention relates to an amphiphilic macromolecule and uses thereof, and this amphiphilic macromolecule is applicable to oilfield drilling, well cementing, fracturing, crude oil gathering and transporting, sewage treating, sludge treating and papermaking, and it can be used as intensified oil producing agent and oil displacing agent, heavy oil viscosity reducer, fracturing fluid, clay stabilizer, sewage treating agent, retention aid and drainage aid and strengthening agent for papermaking.
BACKGROUND OF THE INVENTION
Chemical flooding is one of the most effective and potential chemical technologies for Enhanced Oil Recovery, which is especially represented by polymer flooding. However, there arise some problems for conventional polymers along with the deep implementation of polymer flooding technology. Under reservoir conditions of high temperature and high salinity, the viscosifying capacity and thermal stability of the widely used polymer, partially hydrolyzed polyacrylamide (HPAM), reduces rapidly; in the meantime, HPAM does not have the surface/interfacial activity per se, and could not start the oil film effectively, so that its ability to mine the remaining oil is limited. The polymer-based binary-component composite system (polymer/surfactant) and triple-component system (polymer/surfactant/alkali) may enhance the stability of the emulsified produced fluid, resulting in increased difficulty in oil/water separation and sewage treatment, as well as the weakening of synergistic effect among the components of the system under reservoir conditions, and also it may damage the reservoir. The application of the composite system is thus restricted.
It has become a difficulty and key for many large oilfield developments to keep the viscosifying capacity and viscosity stability of the polymer solution, so as to achieve the strategic target of stabilization of oil production and water cut control.
Heavy oil is a collective name for unconventional oil, including heavy oil, high viscosity oil, oil sand, natural asphalt and etc., and they are also referred to as heavy oil, ultra-heavy oil, asphalt and etc. Among the approximate 10 trillion barrels of remaining oil resources around the world, more than 70% of which is heavy oil resource. Chinese onshore heavy oil and bitumen resources account for about more than 20% of their total oil resources. According to incomplete statistics, the proved and controlled heavy oil reserves in China reach 1600 million tons. Nowadays heavy oil resource has become one of the important strategic replacement resources in China; however, the exploitation of heavy oil is rather difficult. Chemical emulsification and viscosity reduction method has become an important exploitation technology.
Polymeric emulsification viscosity reducer usually refers to a polymeric surfactant with a relative molecular weight more than several thousands and significant surface activity; according to the ion types, it can be divided into four categories: anionic, cationic, zwitterionic and non-ionic polymeric surfactant. Polymeric surfactant usually has limited capacity to reduce surface tension and oil-water interfacial tension, but has excellent emulsification and dispersion capability for heavy oil, with advantages of small usage amount, high viscosity reduction rate, lower cost and simple implementation process. In recent years, this research especially attracts more and more attention in this field.
BRIEF DESCRIPTION OF THE INVENTION
In the following context of this invention, unless otherwise defined, the same variable group, and molecular and structural formula have the same definitions.
The instant invention relates to an amphiphilic macromolecule, this amphiphilic macromolecule has repeating units as described below: a structural unit A for adjusting molecular weight, molecular weight distribution and charge characteristics, a highly sterically hindered structural unit B and an amphiphilic structural unit C.
In an embodiment, the structural unit A for adjusting molecular weight, molecular weight distribution and charge characteristics comprises (meth)acrylamide monomer unit A1 and/or (meth)acrylic monomer unit A2. Preferably, the structural unit A includes (meth)acrylamide monomer unit A1 and/or (meth)acrylic monomer unit A2 simultaneously. In the art, the molecular weight of the amphiphilic macromolecule may be selected as needed, preferably, this molecular weight may be selected between 1000000-20000000.
Preferably, the (meth)acrylamide monomer unit A1 has a structure of formula (1):




In formula (1), R1 is H or a methyl group; R2 and R3 are independently selected from the group consisting of H and a C1-C3 alkyl group; R2 and R3 are preferably H.
Preferably, the (meth)acrylic monomer unit A2 is (meth)acrylic acid and/or (meth)acrylate. Preferably the (meth)acrylate is sodium methacrylate.
Preferably, the molar percentage of (meth)acrylamide monomer unit A1 in the whole amphiphilic polymer repeat units is 70-99 mol %; preferably 70-90 mol %, more preferably 70-80 mol %.
Preferably, the molar percentage of (meth)acrylic monomer unit A2 in the whole amphiphilic polymer repeat units is 1-30 mol %; preferably 1-28 mol %, more preferably 20-28 mol %.
In another embodiment, the structural unit A for the regulation of molecular weight, molecular weight distribution and charge characteristics has a structure of formula (2):




wherein, R1 is H or a methyl group; R2 and R3 are independently selected from the group consisting of H and a C1-C3 alkyl group; R2 and R3 are preferably H; R4 is selected from H or a methyl group; Gr is —OH or —O−Na+; m and n represent the molar percentage of the structural units among the entire amphiphilic macromolecule repeating unit, and m is 70-99 mol %, preferably 70-90 mol %, more preferably 70-80 mol %; n is 1-30 mol %, preferably 2-28 mol %, more preferably 20-28 mol %.
In another embodiment, in formula (2), R1-R3 is preferably H, Gr is preferably —O−Na+.
In another embodiment, the highly sterically hindered structural unit B contains at least a structure G, wherein the structure G is a cyclic hydrocarbon structure formed on the basis of two adjacent carbon atoms in the main chain, or is selected from a structure of formula (3), and the highly sterically hindered structural unit B optionally contains a structure of formula (4):




In formula (3), R5 is H or a methyl group; preferably H; R6 is a radical selected from the group consisting of the structures of formulas (5) and (6).




In formula (5), a is an integer from 1 to 11; preferably 1-7;
In formula (4), R7 is H; R8 is selected from H, —SO3H and salts thereof, —(CH2)2CH3Cl, —CH2N+(CH3)2(CH2)ξCH3Cl− or —CH2N+(CH3)2(CH2)2N+(CH3)2(CH2)σCH32Cl−; ξ and σ are respectively integers from 1 to 15, preferably 1-11.
Preferably, the highly sterically hindered structural unit B comprises a structure G and a structure of formula (4).
In another embodiment, the cyclic hydrocarbon structure formed on the basis of two adjacent carbon atoms in the main chain is selected from the group consisting of:




Preferably, the molar percentage of structure G of the highly sterically hindered structural unit B in the entire amphiphilic macromolecule repeating units is 0.02-2 mol %; preferably 0.02-1.0 mol %, more preferably 0.05-0.5 mol %.
Preferably, the molar percentage of the structure of formula (4) of the highly sterically hindered structural unit B in the whole amphiphilic polymer repeat units is 0.05-5 mol %; preferably 0.1-2.5 mol %, more preferably 0.15-0.75 mol %.
In another embodiment, the highly sterically hindered structural unit B has a structure of formula (7):




In formula (7), the definition on G is as described above, preferably the structure of formula (3),




the definitions on R7 and R8 are as described in formula (4); x and y represent the molar percentages of the structures in the entire amphiphilic macromolecule repeating units, and x is 0.02-2 mol %, preferably 0.02-1.0 mol %, more preferably 0.05-0.5 mol %; y is 0.05-5 mol %, preferably 0.1-2.5 mol %, and more preferably 0.15-0.75 mol %.

In another embodiment, the amphiphilic structural unit C has a structure of formula (8):




In formula (8), R9 is H or a methyl group; R10 is —O— or —NH—; R11 is a radical containing a straight-chain hydrocarbyl, a branched hydrocarbyl, a polyoxyethylene (PEO) group, a polyoxypropylene (PPO) group, an EO and PO block, a mono-quaternary ammonium salt, a multiple-quaternary ammonium salt or a sulfonic acid and salts thereof.
Preferably, the molar percentage of the amphiphilic structural unit C in the entire amphiphilic macromolecule repeating units is 0.05-10 mol %; preferably 0.1-5.0 mol %, more preferably 0.2-1.7 mol %.
In another embodiment, the structures consisted of R10 and R11 can be selected from —O(CH2)gN+(CH3)2(CH2)hCH3X−, —NH(CH2)iN+(CH3)2(CH2)jCH3X−, —O(CH2)kN+((CH2)fCH3)pX−, —O(CH2)qN+(CH3)2(CH2)αCH(SO3H) CH2(EO)β(PO)γ(CH2)δCH3X−, —NH(CH2)qN+(CH3)2(CH2)αCH(SO3H) CH2(EO)β(PO)γ(CH2)δCH3X−, —O(CH2)qN+(CH3)2(CH2)αCH(COOH) CH2(EO)β(PO)γ(CH2)δCH3X−, —NH(CH2)qN+(CH3)2(CH2)αCH(COOH) CH2(EO)β(PO)γ(CH2)δCH3X−, —O(CH2)2N+(CH3)2(CH2)εSO3—, —(OCH(CH2N+(CH3)2(CH2)ζCH3Cl−)CH2)ηO(CH2)θCH3, —(OCH(CH2N+((CH2)λCH3)3Cl−)CH2)τO(CH2)κCH3, —OCH(CH2N+(CH3)2(CH2)rCH3X−))2, —OCH(CH2N+((CH2)sCH3)3X−))2;
wherein, g, i, k and q are respectively integers of 1-6, preferably 2-4; h and j are respectively integers of 3-21, preferably 3-17; p is an integer of 3-9, preferably 3-5; α is an integer of 1-12, preferably 1-8; β and γ are respectively integers of 0-40, β is preferably 0-25, γ is preferably 0-15; δ is an integer of 0-21, preferably 0-17; ε is an integer of 4-18, preferably 4-12; ζ is an integer of 1-21, preferably 1-15; η and τ are respectively integers of 1-30, preferably 1-20; θ and κ are respectively integers of 3-21, preferably 3-17; λ is an integer of 0-9, preferably 0-5; r is an integer of 3-21, preferably 3-17; s is an integer of 3-9, preferably 3-5; and X− is Cl− or Br−.
In another embodiment, the amphiphilic macromolecule has a structure of formula (9):




In formula (9), the definitions on R4, m and n are as described in formula (2); the definitions on R7, R8, G, x and y are as described in formula (7); the definitions on R9, R10 and R11 are as described in formula (8); z represents the molar percentage of this structural unit in the entire amphiphilic polymer repeat unit, and z is 0.05-10 mol %, preferably 0.1-5.0 mol %, more preferably 0.2-1.7 mol %.
Specifically, this present invention provides a high molecular compound having a structure of formulas (I)-(X):













The molecular weight of the amphiphilic macromolecule described above is between 1,000,000 and 20,000,000; preferably between 3,000,000 and 14,000,000.
The measurement of the molecular weight M is as follows: The intrinsic viscosity [η] is measured by Ubbelohde viscometer as known in the art, then the obtained intrinsic viscosity [η] value is used in the following equation to obtain the desired molecular weight M:

M=802 [η]1.25 

The amphiphilic macromolecule according to this present invention can be prepared by known methods in the art, for example, by polymerizing the structural unit for adjusting molecular weight, molecular weight distribution and charge characteristics, the highly sterically hindered structural unit and the amphiphilic structural unit in the presence of an initiator. The polymerization process can be any type well known in the art, such as, suspension polymerization, emulsion polymerization, solution polymerization, precipitation polymerization, and etc.
A typical preparation method is as follows: the above monomers are each dispersed or dissolved in an aqueous system under stirring, the monomer mixture is polymerized by the aid of an initiator under nitrogen atmosphere to form the amphiphilic macromolecule. The so far existing relevant technologies for preparing an amphiphilic macromolecule can all be used to prepare the amphiphilic macromolecule of this invention.
All the monomers for preparing the amphiphilic macromolecule can be commercially available, or can be prepared on the basis of prior art technology directly; and some monomers' synthesis are described in details in specific examples.



DESCRIPTION OF FIGURES
FIG. 1 depicts the relationship of viscosity vs. concentration of the amphiphilic macromolecules obtained from examples 1-5 of the invention in saline having a degree of mineralization of 2×104 mg/L at a temperature of 80° C.
FIG. 2 depicts the relationship of viscosity vs. temperature of the amphiphilic macromolecules obtained from the examples 1-5 of the invention in saline having a degree of mineralization of 3×104 mg/L at the concentration of 1750 mg/L



DETAILED DESCRIPTION OF THE INVENTION
The present invention is further illustrated below by combining specific examples; however, this invention is not limited to the following examples.
EXAMPLE 1
This example synthesized the amphiphilic macromolecule of formula (I):




The synthesis of the amphiphilic macromolecule of this example was as follows:
Firstly, water, accounting for 3⁄4 of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for 1⁄4 of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 78%, 20%, 0.25%, 0.5%, 1% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 8, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 22° C.; after 5 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 1360×104.
EXAMPLE 2
This example synthesized the amphiphilic macromolecule of formula (II).




The synthesis route of the monomer




was as follows:





The synthesis of the amphiphilic macromolecule of this example was as follows:
Firstly, water, accounting for 3⁄4 of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for 1⁄4 of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 73%, 25%, 0.15%, 0.15%, 1.7% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 8, then nitrogen gas was introduced in for 40 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 25° C.; after 5 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 1010×104.
EXAMPLE 3
This example synthesized the amphiphilic macromolecule of formula (III):




The synthesis route of the monomer




was as follows:





The synthesis of the amphiphilic macromolecule of this example was as follows:
Firstly, water, accounting for 3⁄4 of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for 1⁄4 of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 75%, 24.5%, 0.15%, 0.15%, 0.2% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 9, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 25° C.; after 6 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 660×104.
EXAMPLE 4
This example synthesized the amphiphilic macromolecule of formula (IV):




The synthesis route of the monomer




was as follows:





The synthesis of the amphiphilic macromolecule of this example was as follows:
Firstly, water, accounting for 3⁄4 of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for 1⁄4 of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 75%, 23%, 0.05%, 0.5%, 1.45% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 9, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 25° C.; after 6 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 370×104.
EXAMPLE 5
This example synthesized the amphiphilic macromolecule of formula (V):




The synthesis route of the monomer




was as follows:





The synthesis of the amphiphilic macromolecule of this example was as follows:
Firstly, water, accounting for 3⁄4 of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for 1⁄4 of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 78%, 21%, 0.1%, 0.1%, 0.8% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 8, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 25° C.; after 6 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 450×104.
EXAMPLE 6
This example synthesized the amphiphilic macromolecule of formula (VI):




The synthesis of the amphiphilic macromolecule of this example was as follows:
Firstly, water, accounting for 3⁄4 of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for 1⁄4 of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 73%, 25%, 0.5%, 0.5%, 1% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 8, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 45° C.; after 3 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 640×104.
EXAMPLE 7
This example synthesized the amphiphilic macromolecule of formula (VII):




The synthesis of the amphiphilic macromolecule of this example was as follows:
Firstly, water, accounting for 3⁄4 of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for 1⁄4 of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 75%, 23%, 0.25%, 0.5%, 1.25% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 9, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 55° C.; after 3 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 107×104.
EXAMPLE 8
This example synthesized the amphiphilic macromolecule of formula (VIII):




The synthesis of the amphiphilic macromolecule of this example was as follows:
Firstly, water, accounting for 3⁄4 of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for 1⁄4 of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 70%, 28%, 0.15%, 0.75%, 1.1% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 8, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 55° C.; after 3 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 310×104.
EXAMPLE 9
This example synthesized the amphiphilic macromolecule of formula (IX):




The synthesis of the amphiphilic macromolecule of this example was as follows:
Firstly, water, accounting for 3⁄4 of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for 1⁄4 of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 75%, 23.5%, 0.5%, 0.2%, 0.8% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 8, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 50° C.; after 2.5 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 720×104.
EXAMPLE 10
This example synthesized the amphiphilic macromolecule of formula (X):




The synthesis of the amphiphilic macromolecule of this example was as follows:
Firstly, water, accounting for 3⁄4 of the total weight of the reaction system, was charged into a reactor, then various monomers, totally accounting for 1⁄4 of the total weight of the reaction system, were charged into the reactor as well, and the molar percentages m, n, x, y, z for each repeating units were 75%, 23%, 0.5%, 0.5%, 1% in succession. The mixture was stirred until complete dissolution, and a pH adjusting agent was then added in to adjust the reaction solution to have a pH value of about 8, then nitrogen gas was introduced in for 30 minutes to remove oxygen contained therein. An initiator was added into the reactor under the protection of nitrogen gas, and nitrogen gas was further continued for 10 minutes, then the reactor was sealed. The reaction was conducted at a temperature of 50° C.; after 2 hours, the reaction was ended with a complete conversion. After the drying of the obtained product, powdered amphiphilic macromolecule was obtained. The molecular weight of the amphiphilic macromolecule was 520×104.
MEASUREMENT EXAMPLES
Measurement Example 1
Saline having a mineralization degree of 2×104 mg/L was used to prepare amphiphilic macromolecule solutions with different concentrations, and the relationship between the concentration, temperature and the viscosity of the solution was determined. The results were shown in FIG. 1 and FIG. 2.
The figures showed that the amphiphilic macromolecule solutions of examples 1-5 still have favorable viscosifying capacity under the condition of high temperature and high degree of mineralization. The highly sterically hindered unit in the amphiphilic macromolecule reduced the rotational degree of freedom in the main chain and increased the rigidity of the macromolecule chain, which made the macromolecule chain difficult to curl and tend to stretch out, thus enlarging the hydrodynamic radius of the macromolecule; in the meantime, the amphiphilic structural unit associated each other to form the microdomain by intramolecular- or intermolecular-interaction, thus enhancing the viscosifying capacity of the solution remarkably under the conditions of high temperature and high salinity.
Measurement Example 2
Testing method: Under a testing temperature of 25° C., 25 ml electric dehydration crude oil samples from three types of oilfields were added in a 50 ml test tube with a plug, then 25 ml aqueous solutions of amphiphilic macromolecule with different concentrations formulated with distilled water were added in. The plug of the test tube was tightened, then the test tube was shaken manually or by using an oscillating box for 80-100 times in horizontal direction, and the shaking amplitude should be greater than 20 cm. After sufficient mixing, the plug of the test tube was loosed. Viscosity reduction rate for crude oil was calculated according to the following equation:




  
    Viscosity
    ⁢
    
      
    
    ⁢
    reduction
    ⁢
    
      
    
    ⁢
    
      rate
      ⁡
      
        (
        %
        )
      
    
  
  =
  
    
      
        
          
            
              
                viscosity
                ⁢
                
                  
                
                ⁢
                of
                ⁢
                
                  
                
                ⁢
                crude
                ⁢
                
                  
                
                ⁢
                oil
                ⁢
                
                  
                
                ⁢
                sample
              
              -
            
          
        
        
          
            
              viscosity
              ⁢
              
                
              
              ⁢
              after
              ⁢
              
                
              
              ⁢
              mixing
            
          
        
      
      
        viscosity
        ⁢
        
          
        
        ⁢
        of
        ⁢
        
          
        
        ⁢
        crude
        ⁢
        
          
        
        ⁢
        oil
        ⁢
        
          
        
        ⁢
        sample
      
    
    ×
    100
  











TABLE 1







Experimental results of the heavy oil viscosity reduction of the 


amphiphilic macromolecule obtained from the example 6 to 


example 10 (oil-water ratio 1:1, 25° C.)













oil-water volume ratio








(1:1)
oil
viscosity
oil
viscosity
oil
viscosity


test temperature
sample
reduction
sample
reduction
sample
reduction


(25° C.)
1
rate (%)
2
rate (%)
3
rate (%)
















initial viscosity
900
—
7400
—
12000
—


(mPa · s)




















Example
 400 mg/L
405
55.00
1900
74.32
3300
72.50


6
 600 mg/L
320
64.44
1350
81.76
2450
79.58



 800 mg/L
275
69.44
1040
85.95
1250
89.58



1000 mg/L
245
72.78 
740
90.00
850
92.92



1200 mg/L
220
75.56
670
90.95
725
93.96


Example
 400 mg/L 
475
47.22
2100
71.62
3500
70.83


7
 600 mg/L 
375
58.33 
1750
76.35
2600
78.33



 800 mg/L
290
67.78
1475
80.07
1350
88.75



1000 mg/L
230
74.44 
1050
85.81
900
92.50



1200 mg/L
230
74.44
805
89.12
775
93.54


Example
 400 mg/L 
535
40.56
1690
77.16
3150
73.75


8
 600 mg/L 
460
48.89 
1100
85.14
1900
84.17



 800 mg/L
390
56.67
780
89.46
1125
90.63



1000 mg/L
350
61.11 
690
90.68
850
92.92



1200 mg/L
330
63.33
630
91.49
710
94.08


Example
 400 mg/L 
470
47.78
1800
75.68
3600
70.00


9
 600 mg/L 
390
56.67 
1480
80.00
2400
80.00



 800 mg/L
310
65.56 
975
86.82
1370
88.58



1000 mg/L
260
71.11 
675
90.88
1025
91.46



1200 mg/L
230
74.44 
580
92.16
840
93.00


Example
 400 mg/L 
505
43.89 
1600
78.38
3800
68.33


10 
 600 mg/L 
425
52.78
1150
84.46
2350
80.42



 800 mg/L
350
61.11
825
88.85
1275
89.38



1000 mg/L
315
65.00
695
90.61
1000
91.67



1200 mg/L
280
68.89 
625
91.55
825
93.13









Table 1 showed that the amphiphilic macromolecules of examples 6-10 had good effects for viscosity reduction as to all three oil samples. With the increase of the concentration of the amphiphilic macromolecule solution, the viscosity reduction rate increased. And, when the concentration of the amphiphilic macromolecule solution was the same, the viscosity reduction rate increased with the enhancing of the viscosity of the oil sample. It was believed that the amphiphilic macromolecule could reduce the viscosity of the crude oil remarkably via a synergetic effect between the highly sterically hindered structural unit and the amphiphilic structural unit, which could emulsify and disperse the crude oil effectively.
Industrial Application
The amphiphilic macromolecule of this invention can be used in oilfield drilling, well cementing, fracturing, crude oil gathering and transporting, sewage treating, sludge treating and papermaking, and it can be used as intensified oil producing agent and oil displacing agent, heavy oil viscosity reducer, fracturing fluid, clay stabilizer, sewage treating agent, retention aid and drainage aid and strengthening agent for papermaking.
The amphiphilic macromolecule of this invention is especially suitable for crude oil exploitation, for instance, it can be used as an intensified oil displacement polymer and a viscosity reducer for heavy oil. When it is used as an oil displacement agent, it has remarkable viscosifying effect even under the condition of high temperature and high salinity, and can thus enhance the crude oil recovery. When it is used as a viscosity reducer for heavy oil, it can remarkably reduce the viscosity of the heavy oil and decrease the flow resistance thereof in the formation and wellbore by emulsifying and dispersing the heavy oil effectively.

## Claims

1. An amphiphilic macromolecule comprising, as repeating units, a structural unit A for adjusting molecular weight, molecular weight distribution and charge characteristics, a sterically hindered structural unit B and an amphiphilic structural unit C, wherein the sterically hindered structural unit B comprises a structure G and a structure of formula (4), wherein the structure G is a cyclic hydrocarbon structure formed on the basis of two adjacent carbon atoms in the main chain, or is selected from a structure of formula (3):



wherein in formula (3), R5 is H or a methyl group; R6 is a radical selected from the group consisting of the structures of formula (5) and formula (6):




wherein in formula (5), a is an integer from 1 to 11,
wherein in formula (4), R7 is H; R8 is selected from the group consisting of H, —SO3H and salts thereof, —(CH2)2CH2Cl, —CH2N+(CH3)2(CH2)ξCH3Cl− and —CH2N+(CH3)2(CH2)2N+(CH3)2(CH2)σCH32Cl−; ξ and σ are respectively integers from 1 to 15.

2. The amphiphilic macromolecule as claimed in claim 1, wherein the structural unit A for adjusting the molecular weight, molecular weight distribution and charge characteristics comprises a (meth)acrylamide monomer unit A1 and a (meth)acrylic monomer unit A2.

3. The amphiphilic macromolecule as claimed in claim 1, wherein the amphiphilic structural unit C has a structure of formula (8):



wherein in formula (8), R9 is H or a methyl group; R10 is —O— or —NH—; R11 is a radical containing a straight-chain hydrocarbyl, a branched hydrocarbyl, a polyoxyethylene (PEO), a polyoxypropylene (PPO), an EO-PO block, a mono-quaternary ammonium salt, a multiple-quaternary ammonium salt, or a sulfonic acid and salts thereof.

4. The amphiphilic macromolecule as claimed in claim 2, wherein based on 100 mol % of the entire amphiphilic macromolecule repeating units, the molar percentage of the (meth)acrylamide monomer unit A1 is 70-99 mol %; and the molar percentage of the (meth)acrylic monomer unit A2 is 1-30 mol %.

5. The amphiphilic macromolecule as claimed in claim 1, wherein the molar percentage of the structure G in the entire amphiphilic macromolecule repeating unit is 0.02-2 mol %; and the molar percentage of the structure of formula (4) in the entire amphiphilic macromolecule repeating units is 0.05-5 mol %.

6. The amphiphilic macromolecule as claimed in claim 3, wherein based on 100 mol % of the entire amphiphilic macromolecule repeating units, the molar percentage of structure of formula (8) in the entire amphiphilic macromolecule repeating units is 0.05-10 mol %.

7. The amphiphilic macromolecule as claimed in claim 1, wherein the structural unit A for adjusting molecular weight, molecular weight distribution and charge characteristics has a structure of formula (2);



wherein in formula (2), R1 is H or a methyl group; R2 and R3 are independently selected from the group consisting of H and a C1-C3 alkyl group; R4 is selected from the group consisting of H and a methyl group; Gr is —OH or —O−Na+; m and n represent the molar percentage of the structural units in the entire amphiphilic macromolecule, and m is from 70 to 99 mol %; n is from 1 to 30 mol %.

8. The amphiphilic macromolecule as claimed in claim 1, wherein the cyclic hydrocarbon structure formed on the basis of the two adjacent carbon atoms in the main chain is selected from the group consisting of:

9. The amphiphilic macromolecule as claimed in claim 1, wherein the sterically hindered structural unit B has a structure of formula (7):



in formula (7), the definition of G is as described in claim 1; the definitions of R7 and R8 are as described in formula (4); x and y respectively represent the molar percentages of the structural units in the entire amphiphilic macromolecule, and x is from 0.02 to 2 mol %, y is from 0.05 to 5 mol %.

10. The amphiphilic macromolecule as claimed in claim 3, wherein R10 and R11 may be selected from —O(CH2)gN+(CH3)2(CH2)hCH3X−, —NH(CH2)iN+(CH3)2(CH2)jCH3X−, —O(CH2)kN+((CH2)pCH3)3X−, —O(CH2)qN+(CH3)2(CH2)αCH(SO3H)CH2(EO)β(PO)γ(CH2)δCH3X−, —NH(CH2)qN+(CH3)2(CH2)αCH(SO3H)CH2(EO)β(PO)γ(CH2)δCH3X−, —O(CH2)qN+(CH3)2(CH2)αCH(COOH)CH2(EO)β(PO)γ(CH2)δCH3X−, —NH(CH2)qN+(CH3)2(CH2)αCH(COOH)CH2(EO)β(PO)γ(CH2)δCH3X−, —O(CH2)2N+(CH3)2(CH2)εSO3−, —(OCH(CH2N+(CH3)2(CH2)ζCH3Cl−)CH2)ηO(CH2)θCH3, —(OCH(CH2N+((CH2)λCH3)3Cl−)CH2)τO(CH2)κCH3, —OCH(CH2N+(CH3)2(CH2)rCH3X−))2, —OCH(CH2N+((CH2)sCH3)3X−))2;
wherein g, i, k and q are respectively integers from 1 to 6; h and j are respectively integers from 3 to 21; p is an integer from 3 to 9; α is an integer from 1 to 12; β and γ are respectively integers from 0 to 40; δ is an integer from 0 to 21; ε is an integer from 4 to 18; ζ is an integer from 1 to 21; η and τ are respectively integers from 1 to 30; θ and κ are respectively integers from 3 to 21; λ is an integer from 0 to 9; r is an integer from 3 to 21; s is an integer from 3 to 9; and X− is Cl− or Br−.

11. The amphiphilic macromolecule as claimed in claim 1, wherein the amphiphilic macromolecule has a structure of formula (9):



wherein in formula (9), R4 is selected from the group consisting of H and a methyl group; m and n represent the molar percentages of the structural units in the entire amphiphilic macromolecule, and m is from 70 to 99 mol %; n is from 1 to 30 mol %; the definitions of G, R7, R8, x and y are as described in formula (7); R9 is H or a methyl group, R10 is —O— or —NH—; R11 is a radical containing a straight-chain hydrocarbyl, a branched hydrocarbyl, a polyoxyethylene (PEO), a polyoxypropylene (PPO), an EO-PO block, a mono-quaternary ammonium salt, a multiple-quaternary ammonium salt, or a sulfonic acid and salts thereof; z represents the molar percentage of the structural unit in the entire amphiphilic macromolecule, and z is from 0.05 to 10 mol %.

12. The amphiphilic macromolecule as claimed in claim 1, which is a compound of formulas (I)-(X):

13. The amphiphilic macromolecule as claimed in claim 1, wherein the amphiphilic macromolecule has a viscosity average molecular weight of between 1000000-20000000.

14. A method comprising: formulating the amphiphilic macromolecule as claimed in claim 1 into an aqueous solution: and
utilizing the aqueous solution in oilfield drilling, well cementing, fracturing, crude oil gathering and transporting, sewage treating, sludge treating and papermaking as intensified oil producing agent and oil displacing agent, or as a heavy oil viscosity reducer, fracturing fluid component, clay stabilizer, sewage treating agent, retention aid and drainage aid or strengthening agent for papermaking.

15. The amphiphilic macromolecule as claimed in claim 1, wherein R5 is H.