Cationic type gelled acid thickener and preparation method thereof

A cationic, gelled acid technology, applied in chemical instruments and methods, drilling compositions, etc., can solve the problems of inability to meet the requirements of high-temperature deep well acidizing fracturing, low efficiency of residual acid flowback, poor temperature resistance, etc. problems, to achieve the effects of high residual acid flowback efficiency, short swelling time, and good temperature resistance

CN106318369AActive Publication Date: 2017-01-11CHINA PETROLEUM & CHEM CORP +1
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2017-01-11

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Abstract

The invention relates to a cationic type gelled acid thickener. The gelled acid thickener is a copolymer comprising four monomers of acrylamide, a phosphorus-containing cationic monomer, dimethyl diallyl ammonium chloride and 2-acrylamido-2-methyl propanesulfonic acid. The invention also relates to a preparation method of the cationic type gelled acid thickener; the method selects the high-temperature-resistant phosphorus-containing cationic monomer, and adopts 'a two-step temperature control method' for preparing the gelled acid thickener, to improve the molecular weight of the product; the prepared cationic type gelled acid thickener has the advantages of short swelling time, good temperature resistant performance, high residual acid flow-back efficiency, little damage to a reservoir stratum and the like, and can meet the acidizing fracturing construction requirements on a 140-DEG C reservoir stratum.
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Description

technical field

[0001] The invention belongs to the technical field of oil and gas field acidizing and fracturing, in particular to a cationic gelling acid thickener and a preparation method thereof. Background technique

[0002] Acid fracturing is the main measure for increasing production and injection of carbonate reservoirs. The longer the acid-etched fractures formed during acid fracturing, the better the seepage capacity of formation fluids. However, conventional acidic liquids have small penetration depth, fast filtration rate and large loss, and the acidification effect is not good. Adding a thickener to the acid solution to form gelled acid can increase the viscosity of the acid solution, which can effectively reduce the rate of acid fluid loss and acid-rock reaction rate, thereby achieving the effect of increasing the length of acid-etched fractures. In the 1970s, xanthan gum (also known as xanthan gum) was widely used abroad as a gelling acid thickener. The resea...

Examples

Embodiment 1

[0041] Embodiment 1: Preparation of gelled acid thickener.

[0042] (1) Add 20% acrylamide, 1% methyltriphenylphosphine bromide, 1% dimethyl diallyl ammonium chloride, 1% 2-acrylamide to a certain amount of deionized water Base-2-methylpropanesulfonic acid, 0.01% ethylenediaminetetraacetic acid disodium salt and 0.05% urea were stirred evenly and filled with nitrogen for 20 minutes to prepare a comonomer mixture.

[0043] (2) Add 0.01% of the total mass of azobisisobutylamidine hydrochloride and 0.01% of the total mass of sodium bisulfite to the above-mentioned comonomer mixture for initiation, control the reaction temperature at 5° C., and react for 1 hour. Then the reaction container was transferred to a temperature-controlled environment of 40° C., and reacted for 2 hours to obtain a gel-like cationic gelling acid thickener.

[0044] (3) The gelled acid thickener is granulated, dried, pulverized and sieved to obtain dry cationic gelled acid thickener granules.

[0045] Af...

Embodiment 2

[0048] Embodiment 2: Preparation of gelled acid thickener.

[0049] (1) Add 25% acrylamide, 2% ethyltriphenylphosphine bromide, 2% dimethyl diallyl ammonium chloride, 2% 2-acrylamide to a certain amount of deionized water Base-2-methylpropanesulfonic acid, 0.05% ethylenediaminetetraacetic acid disodium salt and 0.06% urea were stirred evenly, and after being filled with nitrogen for 20 minutes, a comonomer mixture was obtained.

[0050] (2) Add 0.02% of the total mass of azobisisobutylimidazoline hydrochloride and 0.02% of the total mass of sodium bisulfite to the above-mentioned comonomer mixture for initiation, control the reaction temperature at 15°C, and react for 2 hours . Then the reaction container was transferred to a temperature-controlled environment of 50° C., and reacted for 2 hours to obtain a gel-like cationic gelling acid thickener.

[0051] (3) The gelled acid thickener is granulated, dried, pulverized and sieved to obtain dry cationic gelled acid thickener g...

Embodiment 3

[0055] Embodiment 3: Preparation of gelled acid thickener.

[0056] (1) Add 30% acrylamide, 3% allyl triphenylphosphine bromide, 3% dimethyl diallyl ammonium chloride, 3% 2-propene to a certain amount of deionized water Amido-2-methylpropanesulfonic acid, 0.08% ethylenediaminetetraacetic acid disodium salt and 0.08% urea were stirred evenly, and after being filled with nitrogen for 20 minutes, a comonomer mixture was prepared.

[0057] (2) Add 0.03% of the total mass of azobisisobutylamidine hydrochloride and 0.03% of the total mass of sodium sulfite to the above-mentioned comonomer mixture for initiation, control the reaction temperature at 20° C., and react for 3 hours. Then the reaction container was transferred to a temperature-controlled environment of 60° C., and reacted for 3 hours to obtain a gel-like cationic gelling acid thickener.

[0058] (3) The cationic gelling acid thickener is granulated, dried, crushed and sieved to obtain dry cationic gelling acid thickener ...