Temperature-resistant and salt-resistant instant thickener for seawater-based fracturing fluid and preparation method thereof

Abstract

The invention discloses a temperature-resistant salt-resistant quick-dissolving thickening agent used for a seawater-based fracturing fluid and a preparation method thereof. The temperature-resistant salt-resistant quick-dissolving thickening agent comprises the following components in percentages by mass: 6% to 8% of acrylic acid, 5% to 6% of sodium hydroxide, 18% to 23% of acrylamide, 1% to 2% of an isolation monomer, 3% to 4% of a functional anion monomer, 3% to 5% of a functional cationic monomer, 4% to 6% of an association intermediate, and 0.4% to 0.8% of an ammonium persulfate-sodium bisulfite redox system or 0.6% to 1.0% of azobisisobutyronitrile which is used as an initiator, with the balance being deionized water. The preparation method for the temperature-resistant salt-resistant quick-dissolving thickening agent comprises the following steps: 1, synthesis of the association intermediate; 2, synthesis of a thickener colloid; and 3, colloid postprocessing. The thickening agent provided by the invention has the following advantages: salt resistance is excellent; the degree of mineralization of a solution has little influence on the rate of swelling; the viscosity-increasing capacity in seawater is strong; antibacterial stability of the solution is strong; the solution has excellent temperature resistance and shearing resistance; and the content of an insoluble substance is extremely small and can not be measured with a conventional method, so the damage of residues on reservoir strata is almost eliminated.

Description

technical field

[0001] The invention relates to the technical fields of fine chemistry and oilfield chemicals, in particular to a temperature-resistant and salt-resistant instant thickener for seawater-based fracturing fluid and a preparation method thereof. Background technique

[0002] With the deepening of oil and gas development, fracturing stimulation measures are widely used in the reservoir stimulation of oil and gas wells. For offshore oil and gas fields, due to the dependence on the freshwater-based fracturing fluid system and the many restrictions on the fresh water resources required for the preparation of fracturing fluids due to various factors such as space, construction scale, transportation, and cost, fracturing stimulation measures have become offshore. A "luxury" consumed by oil and gas fields. The root cause of this problem is the immaturity of seawater-based fracturing fluid technology, and the research on temperature-resistant and salt-resistant instant...

Examples

Embodiment 1

[0048] The synthetic optimization scheme of association intermediate provided by the present invention:

[0049] Add p-vinylbenzenesulfonic acid, NaOH, hydroquinone and deionized water to the monomer reactor in sequence, stir for 1.5h, then add NaHCO 3 , control the pH value to 8.5, then add allyl chloride dropwise to the solution, react for 8 hours after the dropwise addition, heat up to 90°C, react for 4 hours, cool to room temperature, filter to obtain a light yellow association intermediate, and store it for later use;

[0050] In the above reaction system, taking the total reaction system mass as 100%, p-vinylbenzenesulfonic acid accounts for 24% of the total mass, NaOH accounts for 6% of the total mass, hydroquinone accounts for 0.1% of the total mass, NaHCO 3 Accounting for 8% of the total mass, allyl chloride accounts for 8% of the total mass, and the rest is deionized water.

[0051] The performance of the product obtained by this synthesis scheme is excellent, so this...

Embodiment 2

[0053] Thickener colloid synthesis optimization scheme provided by the present invention:

[0054] Add acrylic acid, sodium hydroxide and deionized water to the polymerization reactor in sequence, mix and dissolve and neutralize the acrylic acid to a neutralization degree of 90%, then add acrylamide, maleic acid, 2-acrylamide-2 - Dimethylpropanesulfonic acid (AMPS), octadecyl methacrylate accounts for the total mass and the synthesized association intermediate, after controlling the temperature of the mixed reaction system at 20 ° C and feeding nitrogen into the reactor for 2 hours, Stop the nitrogen flow, and heat the reactor to increase the temperature of the reactant to 23°C, add the initiator, and react for 6 hours when the reactant starts to polymerize to obtain the colloid of the thickener.

[0055] In the above reaction system, taking the total reaction system mass as 100%, acrylic acid accounts for 6% of the total mass, sodium hydroxide accounts for 5% of the total mas...

Embodiment 3

[0058] The post-treatment optimization scheme of the colloid provided by the invention:

[0059] After the step reaction in Example 2 is completed to generate the thickener colloid, the temperature of the reaction kettle is heated to 95°C and kept for 6 hours, and then the colloid is granulated, fluidized bed dried, and air-flow pulverized, and the thickened colloid with a size of 80 mesh or more is sieved. Agent granules, packaged to obtain a heat-resistant, salt-resistant instant thickener that can be used in seawater-based fracturing fluids.

[0060] The product obtained by this solution is in the form of white powder, with the best performance test. Therefore, this product is used as a temperature-resistant and salt-resistant instant thickener that can be used in seawater-based fracturing fluids. It will be replaced by the code BCG-HL below.

technical field

[0001] The invention relates to the technical fields of fine chemistry and oilfield chemicals, in particular to a temperature-resistant and salt-resistant instant thickener for seawater-based fracturing fluid and a preparation method thereof. Background technique

[0002] With the deepening of oil and gas development, fracturing stimulation measures are widely used in the reservoir stimulation of oil and gas wells. For offshore oil and gas fields, due to the dependence on the freshwater-based fracturing fluid system and the many restrictions on the fresh water resources required for the preparation of fracturing fluids due to various factors such as space, construction scale, transportation, and cost, fracturing stimulation measures have become offshore. A "luxury" consumed by oil and gas fields. The root cause of this problem is the immaturity of seawater-based fracturing fluid technology, and the research on temperature-resistant and salt-resistant instant...

Examples

Embodiment 1

[0048] The synthetic optimization scheme of association intermediate provided by the present invention:

[0049] Add p-vinylbenzenesulfonic acid, NaOH, hydroquinone and deionized water to the monomer reactor in sequence, stir for 1.5h, then add NaHCO 3 , control the pH value to 8.5, then add allyl chloride dropwise to the solution, react for 8 hours after the dropwise addition, heat up to 90°C, react for 4 hours, cool to room temperature, filter to obtain a light yellow association intermediate, and store it for later use;

[0050] In the above reaction system, taking the total reaction system mass as 100%, p-vinylbenzenesulfonic acid accounts for 24% of the total mass, NaOH accounts for 6% of the total mass, hydroquinone accounts for 0.1% of the total mass, NaHCO 3 Accounting for 8% of the total mass, allyl chloride accounts for 8% of the total mass, and the rest is deionized water.

[0051] The performance of the product obtained by this synthesis scheme is excellent, so this...

Embodiment 2

[0053] Thickener colloid synthesis optimization scheme provided by the present invention:

[0054] Add acrylic acid, sodium hydroxide and deionized water to the polymerization reactor in sequence, mix and dissolve and neutralize the acrylic acid to a neutralization degree of 90%, then add acrylamide, maleic acid, 2-acrylamide-2 - Dimethylpropanesulfonic acid (AMPS), octadecyl methacrylate accounts for the total mass and the synthesized association intermediate, after controlling the temperature of the mixed reaction system at 20 ° C and feeding nitrogen into the reactor for 2 hours, Stop the nitrogen flow, and heat the reactor to increase the temperature of the reactant to 23°C, add the initiator, and react for 6 hours when the reactant starts to polymerize to obtain the colloid of the thickener.

[0055] In the above reaction system, taking the total reaction system mass as 100%, acrylic acid accounts for 6% of the total mass, sodium hydroxide accounts for 5% of the total mas...

Embodiment 3

[0058] The post-treatment optimization scheme of the colloid provided by the invention:

[0059] After the step reaction in Example 2 is completed to generate the thickener colloid, the temperature of the reaction kettle is heated to 95°C and kept for 6 hours, and then the colloid is granulated, fluidized bed dried, and air-flow pulverized, and the thickened colloid with a size of 80 mesh or more is sieved. Agent granules, packaged to obtain a heat-resistant, salt-resistant instant thickener that can be used in seawater-based fracturing fluids.

[0060] The product obtained by this solution is in the form of white powder, with the best performance test. Therefore, this product is used as a temperature-resistant and salt-resistant instant thickener that can be used in seawater-based fracturing fluids. It will be replaced by the code BCG-HL below.

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