A self-demulsifying heavy oil viscosity reducer and its preparation method and application

Abstract

The invention relates to a self-demulsification heavy oil viscosity reducer as well as a preparation method and application thereof. The preparation method is characterized in that the self-demulsification heavy oil viscosity reducer is prepared by taking acrylamide, sodium p-styrenesulfonate and octadecyl acrylate as main raw materials; the selected raw materials have low cost and can be preparedinto the self-demulsification heavy oil viscosity reducer by adopting a simple traditional preparation process; meanwhile, an obtained product has high yield and has great advantages in a productionlink of a product; besides, the self-demulsification heavy oil viscosity reducer disclosed by the invention has the advantages of excellent viscosity reduction capability, good temperature and salt resisting effects, more outstanding viscosity reduction effect of extra-heavy oil and self-demulsification performance; integration of viscosity reduction and demulsification can be realized, and efficient oil extraction is realized.

Description

technical field [0001] The invention relates to a self-demulsifying heavy oil viscosity reducer and its preparation method and application, belonging to the technical field of heavy oil viscosity reducer for petroleum exploitation. Background technique [0002] Heavy oil refers to the crude oil whose viscosity exceeds 100mPa·s at the temperature of the oil reservoir, and the density is greater than 0.92g / cm 3 , when the viscosity exceeds 50000mPa·s, it is called super heavy oil, and the density is greater than 0.98g / cm 3 . my country is rich in heavy oil resources, but it is difficult to exploit heavy oil reservoirs by conventional mining methods. In order to meet the increasing oil demand of the society, it is imminent to overcome the technical problems of heavy oil mining. Heavy oil contains a large amount of bitumen, colloids and solid hydrocarbons, hydrogen bonds are formed between atoms, and aromatic condensed rings are stacked on the plane. The interaction forces wor...

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Problems solved by technology

For example, Chinese patent document CN102719234A discloses a thick oil viscosity reducer and its preparation method and application. Terpolymer or tetrapolymer formed by radical copolymerization of acrylate, maleic anhydride, styrene and acrylamide with a chain length of C18-C22 and alkyl primary amines with a chain length of C12-C18 It is obtained by aminolysis reaction; the invention adds 500-1000ppm viscosity reducer, so that the viscosity reduction rate of heavy oil with a viscosity of 14000-24000mPas at 50°C can reach up to 85%; but the invention uses more raw materials, the steps are cumbersome, and the cost Higher, and the viscosity reduction rate is limited, the subsequent demulsification is more troublesome

As another example, Chinese patent document CN103450868A discloses a kind of temperature-resistant and salt-resistant water-soluble amphiphilic polymer composite heavy oil viscosity reducer, which is composed of two components A and B; component A is composed of acrylamide, hydrophobic Amphiphilic polymer formed by tetrapolymerization of alkyl acrylamide, acrylamido alkyl ammonium chloride quaternary ammonium salt and non-ionic polyether acrylate; component B is a small molecule surfactant; the viscosity reducer is The viscosity reduction rate of low-viscosity heavy oil exceeds 95%, and the viscosity reduction rate of medium-high-ultra-high-viscosity heavy oil reaches more than 85%. However, the invention uses more raw materials, the steps are cumbersome, the cost is high, and the subsequent demulsification is more troublesome

[0004] The oil-soluble viscosity reducer is polymerized with styrene as a monomer, but most oil-soluble viscosity reducers face the disadvantages of strong selectivity, poor viscosity reduction effect, and high cost.

Nonionic viscosity reducers represented by alkylphenol polyoxyethylene ethers are easy to break emulsion, but have poor temperature resistance; anionic viscosity reducers have strong temperature and salt resistance, but poor adsorption capacity; nonionic viscosity reducers - Although the ionic viscosity reducer has the advantages of the former two, it has the disadvantages of high cost and difficult preparation

Among many surfactants, polyacrylamide is recognized as the most effective and promising polymer, but the structure of polyacrylamide copolymers is prone to change under the conditions of high temperature, high heat and the presence of bacteria, making the relative molecular Decreased quality, hydrolysis of amide groups and changes in molecular morphology, resulting in changes in performance, which is not conducive to viscosity reduction of heavy oil

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