阅读说明：本技术 一种三元复合驱用驱油剂及三元复合驱油体系 (Oil displacement agent for ternary combination flooding and ternary combination flooding system ) 是由 朱焱 赵嵩 吴昊 刘红娟 陈思安 于 2020-06-17 设计创作，主要内容包括：本发明公开了一种三元复合驱用驱油剂及三元复合驱油体系,其中,所述三元复合驱用驱油剂,包括表面活性剂、聚丙烯酰胺及碱,其特征在于：所述碱中加入盐；所述盐,用于降低垢质的生成；所述三元复合驱油体系,包括所述的三元复合驱用驱油剂；解决现有复合驱生产成本高的问题。(The invention discloses an oil displacement agent for ternary combination flooding and a ternary combination oil displacement system, wherein the oil displacement agent for ternary combination flooding comprises a surfactant, polyacrylamide and alkali, and is characterized in that: adding a salt to the base; the salt is used for reducing the generation of scaling substances; the ternary complex oil displacement system comprises the oil displacement agent for ternary complex flooding; the problem of current combination flooding high in production cost is solved.)

1. An oil displacement agent for three-element composite flooding, which comprises a surfactant, polyacrylamide and alkali, and is characterized in that:

adding a salt to the base;

the salt is used for reducing the generation of scaling substances.

2. The oil displacement agent for three-element composite flooding according to claim 1, characterized in that:

the salt is sodium chloride.

3. The oil displacement agent for three-element composite flooding according to claim 2, characterized in that:

the alkali is sodium hydroxide and/or sodium carbonate;

the weight ratio of the sodium chloride to the sodium hydroxide and/or sodium carbonate is 5: 1-9: 1.

4. the oil displacement agent for three-element composite flooding according to claim 3, characterized in that:

the surfactant comprises aryl tertiary fatty amine and petroleum sulfonate.

5. The oil displacement agent for three-element composite flooding according to claim 4, characterized in that:

the aryl tertiary fatty amine is represented by the formula (I):

wherein: m is 7 or 8, n is 7 or 8, m + n is 15, R1, R2 are each independently H or C₁-C₂Alkyl of R₃、R₄Independently of one another are methyl.

6. The oil displacement agent for three-element composite flooding according to claim 5, characterized in that:

the weight ratio of the aryl tertiary fatty amine to the petroleum sulfonate is 3: 1-7: 1.

7. the oil displacement agent for three-element composite flooding according to any one of claims 1 to 6, characterized by comprising:

the polyacrylamide is alkali-resistant polyacrylamide.

8. The oil displacement agent for three-element composite flooding according to claim 7, characterized in that:

the alkali-resistant polyacrylamide comprises the following components in parts by weight: 100-200 parts of acrylamide, 10-30 parts of acrylic acid, 5-12 parts of nonionic monomer, 5-20 parts of AMPS, 400 parts of water and 0.01-0.04 part of disodium ethylene diamine tetraacetate;

the preparation method comprises the following steps:

(1) mixing acrylamide, acrylic acid, a nonionic monomer, AMPS and water, uniformly stirring, adjusting the pH value to 7-7.5 by using a sodium hydroxide solution with the mass percentage concentration of 10%, adding disodium ethylene diamine tetraacetate, and uniformly stirring;

(2) adding the solution prepared in the step (1) into a reactor, controlling the stirring speed at 680-720r/min, controlling the temperature of a reaction system at 8-12 ℃, introducing nitrogen for 20min, adding 0.03-0.06 part by weight of a 1# initiator, adding 0.01-0.04 part by weight of a 2# initiator and 0.01-0.04 part by weight of a 3# initiator after 10min, stopping introducing nitrogen after the temperature of the system is raised to 2 ℃, curing for 4 hours after the temperature is raised to the highest temperature, and cooling to room temperature;

(3) granulating, drying, crushing and screening the polymer obtained in the step (2) to obtain a finished product;

wherein the 1# initiator is one or more of azobisisobutyronitrile, azobisisoheptonitrile or azobisisobutylamidine hydrochloride;

the 2# initiator is one or more of ammonium persulfate, potassium persulfate or sodium persulfate;

the 3# initiator is one or more of sodium bisulfite, sodium thiosulfate or triethanolamine.

9. A ternary complex flooding system is characterized in that:

the oil displacement agent for the ternary combination flooding, which comprises the oil displacement agent for the ternary combination flooding, according to any one of claims 1 to 8.

10. The ternary complex flooding system of claim 9, characterized in that:

the mass concentration of the surfactant is 0.3%, and the mass concentration of the sum of the alkali and the salt is 1.2%.

Technical Field

The invention relates to the technical field of oilfield chemical flooding oil extraction, in particular to an oil displacement agent for oilfield compound flooding.

Background

The ASP flooding greatly improves the recovery ratio and causes a plurality of problems in the production process, wherein, the highest difficulty of the popularization of the ASP flooding technology is caused by overhigh production cost, and the two main reasons of high production cost are caused by high medicament cost and extra maintenance cost caused by scaling.

(1) The alkali scaling brings a plurality of problems to the production

In the process of preparing the oil displacement agent for the ternary combination flooding, the sewage for preparation contains the scale-forming cation Ca²⁺、Mg^{2 +}Some blocks also contain Ba₂ ⁺(ii) a HCO in water₃ ^－、CO₃ ^2－After encountering high concentrations of base, HCO₃ ^－All converted to CO₃ ^2－(ii) a Simultaneously, a large amount of OH appears in the system^－， CO₃ ^2－And OH^－With Ca²⁺、Mg²⁺、Ba²⁺The combination produces water insoluble carbonates and hydroxides which deposit scale on pipelines, filters, valve blocks and wellbores. The formation of these scales is primarily responsible for the following problems in oilfield production:

firstly, the scale formation at both ends of injection and production is serious, and the cost for cleaning and preventing scale is high;

secondly, the oil well pump detection rate is increased due to scaling;

and the workload of scale removal and prevention is large, the environmental protection risk is increased, and the management difficulty is increased.

(2) The cost of the ternary composite flooding system agent is higher

The medicament cost accounts for more than 30 percent of the total production cost of the ASP flooding.

Disclosure of Invention

In view of the above, the invention provides an oil displacement agent for oilfield three-element composite flooding, which solves the problem of high production cost of the existing composite flooding.

In addition, the invention also provides a ternary complex oil displacement system.

In a first aspect, the oil displacement agent for three-component composite flooding comprises a surfactant, polyacrylamide and alkali, and is characterized in that:

adding a salt to the base;

the salt is used for reducing the generation of scaling substances.

Further, the salt is sodium chloride.

Further, the alkali is sodium hydroxide and/or sodium carbonate;

the weight ratio of the sodium chloride to the sodium hydroxide and/or sodium carbonate is 5: 1-9: 1.

Further, the surfactant includes an aryl tertiary fatty amine and a petroleum sulfonate.

Further, the aryl tertiary aliphatic amine is represented by the formula (I):

wherein: m is 7 or 8, n is 7 or 8, m + n is 15, R1, R2 are each independently H or C₁-C₂Alkyl of R₃、R₄Independently of one another are methyl.

Further, the weight ratio of the aryl tertiary fatty amine to the petroleum sulfonate is 3: 1-7: 1.

further, the polyacrylamide is alkali-resistant polyacrylamide.

Further, the alkali-resistant polyacrylamide comprises the following components in parts by weight: 100-200 parts of acrylamide, 10-30 parts of acrylic acid, 5-12 parts of nonionic monomer, 5-20 parts of AMPS, 400 parts of water and 0.01-0.04 part of disodium ethylene diamine tetraacetate;

the preparation method comprises the following steps:

(1) mixing acrylamide, acrylic acid, a nonionic monomer, AMPS and water, uniformly stirring, adjusting the pH value to 7-7.5 by using a sodium hydroxide solution with the mass percentage concentration of 10%, adding disodium ethylene diamine tetraacetate, and uniformly stirring;

(2) adding the solution prepared in the step (1) into a reactor, controlling the stirring speed at 680-720r/min, controlling the temperature of a reaction system at 8-12 ℃, introducing nitrogen for 20min, adding 0.03-0.06 part by weight of a 1# initiator, adding 0.01-0.04 part by weight of a 2# initiator and 0.01-0.04 part by weight of a 3# initiator after 10min, stopping introducing nitrogen after the temperature of the system is raised to 2 ℃, curing for 4 hours after the temperature is raised to the highest temperature, and cooling to room temperature;

(3) granulating, drying, crushing and screening the polymer obtained in the step (2) to obtain a finished product;

wherein the 1# initiator is one or more of azobisisobutyronitrile, azobisisoheptonitrile or azobisisobutylamidine hydrochloride;

the 2# initiator is one or more of ammonium persulfate, potassium persulfate or sodium persulfate;

the 3# initiator is one or more of sodium bisulfite, sodium thiosulfate or triethanolamine.

In a second aspect, a ternary complex flooding system is characterized in that:

the oil displacement agent for the ternary combination flooding comprises the oil displacement agent for the ternary combination flooding of the first aspect.

Further, the mass concentration of the surfactant is 0.3%, and the mass concentration of the sum of the alkali and the salt is 1.2%.

The invention has the following beneficial effects:

compared with the prior art, the oil displacement agent for the ternary combination flooding disclosed by the invention has the advantages that sodium chloride which cannot cause scaling is adopted to replace part of alkali (sodium hydroxide or sodium carbonate) to prepare the ternary system, and the scaling degree of the alkali is effectively reduced on the premise of meeting the basic performance of the ternary system and bearing the corrosion of the sodium chloride to metals, so that the extra maintenance cost caused by scaling is reduced, and the problem of high production cost of the existing combination flooding is solved.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

FIG. 1 is a comparison of the content of suspended matter in different salt/alkali pair sewage;

FIG. 2 is a graph of the effect of different salts/bases on corrosion of metal pipelines;

FIG. 3 is a graph of interfacial tension activity of a weak base ternary system as a blank comparison;

FIG. 4 is an interfacial tension activity diagram of the ternary complex flooding system in example 1 of the present invention;

FIG. 5 is an interfacial tension activity diagram of the ternary complex flooding system in example 2 of the present invention;

FIG. 6 shows the elasticity of the ternary complex flooding system in example 1 of the present invention;

FIG. 7 is a TSI chart of the ternary complex flooding system in example 2 of the present invention;

FIG. 8 is a chart of the adsorption resistance of the ternary complex flooding system in example 2 of the present invention;

Detailed Description

The present invention will be described below based on examples, but it should be noted that the present invention is not limited to these examples. In the following detailed description of the present invention, certain specific details are set forth. However, the present invention may be fully understood by those skilled in the art for those parts not described in detail.

Furthermore, those skilled in the art will appreciate that the drawings are provided solely for the purposes of illustrating the invention, features and advantages thereof, and are not necessarily drawn to scale.

Also, unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is, the meaning of "includes but is not limited to".