Compound type temperature-resisting viscoelastic self-diverting acid as well as preparation method and application thereof

Abstract

The invention relates to compound type temperature-resisting viscoelastic self-diverting acid as well as a preparation method and application thereof. The self-diverting acid is prepared from 1.0 to 7.5 weight percent of thickening agent A, 1.0 to 7.5 weight percent of thickening agent B, 32.2 to 75.5 weight percent of concentrated hydrochloric acid, 1.0 to 4.0 weight percent of corrosion inhibitor, 1.5 to 5.0 weight percent of ferric ion stabilizer, 1.5 to 4.0 weight percent of clay stabilizer and the balance of water; the thickening agent A is prepared from one or more of cocamidopropyl betaine, octadecyl dimethyl hydroxypropyl betaine and lauramidopropyl betaine; the thickening agent B is prepared from one or more of erucamide propyl betaine, docosyl dimethyl betaine and erucamide propylsulfobetaine. The self-diverting acid disclosed by the invention is suitable for a carbonate reservoir with the temperature of 80 to 120 DEG C.

Description

technical field

[0001] The invention relates to a composite temperature-resistant viscoelastic self-steering acid and a preparation method and application thereof, belonging to the technical field of oil and gas exploitation. Background technique

[0002] With the continuous exploration and development of oilfields at home and abroad, a large number of deep, low-permeability and heterogeneous oil reservoirs have been exploited. For low-permeability oil and gas fields that need to stimulate production, acidification is one of the commonly used measures to increase production. The acid solution reacts with the rock to dissolve the formation rock to produce acid-etched pores, which can allow oil and gas to flow into the production wellbore and improve the wellbore and the reservoir near the wellbore. connectivity to increase well productivity. In the reservoir with strong heterogeneity, the flow of acid liquid follows the principle of the lowest resistance. During the acidific...

Examples

Embodiment 1

[0108] This embodiment provides a compound high temperature resistant viscoelastic self-steering acid, in terms of mass percentage:

[0109] Thickener A: cocamidopropyl betaine 4wt.%;

[0110] Thickener B: erucamide propyl sulfobetaine 2wt.%;

[0111] 31wt.% concentrated hydrochloric acid: 48.4wt.%;

[0112] Corrosion inhibitor: Chloride-1,6-(α-octylpyridine) hexane 3.0wt.%;

[0113] Iron ion stabilizer: iron citrate ion stabilizer 4.5wt.%;

[0114] KCl: 3.5wt.%;

[0115] The balance is water.

[0116] The specific preparation process is:

[0117] According to the above ratio, add cocamidopropyl betaine to water at 25°C to fully dissolve, and cannot be dissolved in acid first, and erucamide propyl sulfobetaine is added to 31% concentrated hydrochloric acid to fully dissolve, cannot be dissolved first into water, then mix the two solutions, add pyridinium quaternary ammonium salt corrosion inhibitor -1,6-(α-octylpyridine) hexane chloride and ferric citrate ion stabilizer,...

Embodiment 2

[0123] This embodiment provides a composite temperature-resistant viscoelastic self-steering acid, in terms of mass percentage:

[0124] Thickener A: Cocamidopropyl Betaine 4wt.%;

[0125] Thickener B: erucamidopropyl betaine 2wt.%;

[0126] 31wt.% concentrated hydrochloric acid: 65.5wt.%;

[0127] Corrosion inhibitor: oleic acid imidazoline 3.5wt.%;

[0128] Iron ion stabilizer: edetate sodium salt iron ion stabilizer 4%;

[0129] KCl: 3.5wt.%;

[0130] The balance is water.

[0131] The specific preparation process is:

[0132] According to the above ratio, add cocamidopropyl betaine to water at 25°C to fully dissolve it, and cannot dissolve it in the acid solution first; add erucamide propyl betaine to 31% concentrated hydrochloric acid to fully dissolve it, and cannot dissolve it first In the water, mix the two solutions, add imidazoline corrosion inhibitor oleic acid imidazoline and ethylenediaminetetramate sodium salt iron ion stabilizer, stir evenly, and you can g...

Embodiment 3

[0138] The present embodiment provides a composite temperature-resistant viscoelastic self-steering acid, in mass percent:

[0139] Thickener A: octadecyldimethylhydroxypropyl sulfobetaine 3wt.%;

[0140] Thickener B: erucamidopropyl sulfobetaine 2wt.%;

[0141] 31wt.% concentrated hydrochloric acid: 48.4wt.%;

[0142] Corrosion inhibitor: chloride-1,6-(α-octylpyridine)hexane 3.0wt.%;

[0143] Ferric ion stabilizer: ferric citrate ion stabilizer 4.5wt.%;

[0144] KCl: 2.5wt.%;

[0145] The remainder is water.

[0146] The specific preparation process is:

[0147] According to the above ratio, at 25°C, octadecyldimethylhydroxypropyl sulfobetaine was added to water to fully dissolve, and erucamidopropyl sulfobetaine was added to 31% concentrated hydrochloric acid to fully dissolve. 1,6-(α-octylpyridine) hexane chloride and ferric citrate ion stabilizer are added, and the mixture is evenly stirred to obtain a composite high-temperature resistant viscoelastic Turn to acid f...

technical field

[0001] The invention relates to a composite temperature-resistant viscoelastic self-steering acid and a preparation method and application thereof, belonging to the technical field of oil and gas exploitation. Background technique

[0002] With the continuous exploration and development of oilfields at home and abroad, a large number of deep, low-permeability and heterogeneous oil reservoirs have been exploited. For low-permeability oil and gas fields that need to stimulate production, acidification is one of the commonly used measures to increase production. The acid solution reacts with the rock to dissolve the formation rock to produce acid-etched pores, which can allow oil and gas to flow into the production wellbore and improve the wellbore and the reservoir near the wellbore. connectivity to increase well productivity. In the reservoir with strong heterogeneity, the flow of acid liquid follows the principle of the lowest resistance. During the acidific...

Examples

Embodiment 1

[0108] This embodiment provides a compound high temperature resistant viscoelastic self-steering acid, in terms of mass percentage:

[0109] Thickener A: cocamidopropyl betaine 4wt.%;

[0110] Thickener B: erucamide propyl sulfobetaine 2wt.%;

[0111] 31wt.% concentrated hydrochloric acid: 48.4wt.%;

[0112] Corrosion inhibitor: Chloride-1,6-(α-octylpyridine) hexane 3.0wt.%;

[0113] Iron ion stabilizer: iron citrate ion stabilizer 4.5wt.%;

[0114] KCl: 3.5wt.%;

[0115] The balance is water.

[0116] The specific preparation process is:

[0117] According to the above ratio, add cocamidopropyl betaine to water at 25°C to fully dissolve, and cannot be dissolved in acid first, and erucamide propyl sulfobetaine is added to 31% concentrated hydrochloric acid to fully dissolve, cannot be dissolved first into water, then mix the two solutions, add pyridinium quaternary ammonium salt corrosion inhibitor -1,6-(α-octylpyridine) hexane chloride and ferric citrate ion stabilizer,...

Embodiment 2

[0123] This embodiment provides a composite temperature-resistant viscoelastic self-steering acid, in terms of mass percentage:

[0124] Thickener A: Cocamidopropyl Betaine 4wt.%;

[0125] Thickener B: erucamidopropyl betaine 2wt.%;

[0126] 31wt.% concentrated hydrochloric acid: 65.5wt.%;

[0127] Corrosion inhibitor: oleic acid imidazoline 3.5wt.%;

[0128] Iron ion stabilizer: edetate sodium salt iron ion stabilizer 4%;

[0129] KCl: 3.5wt.%;

[0130] The balance is water.

[0131] The specific preparation process is:

[0132] According to the above ratio, add cocamidopropyl betaine to water at 25°C to fully dissolve it, and cannot dissolve it in the acid solution first; add erucamide propyl betaine to 31% concentrated hydrochloric acid to fully dissolve it, and cannot dissolve it first In the water, mix the two solutions, add imidazoline corrosion inhibitor oleic acid imidazoline and ethylenediaminetetramate sodium salt iron ion stabilizer, stir evenly, and you can g...

Embodiment 3

[0138] The present embodiment provides a composite temperature-resistant viscoelastic self-steering acid, in mass percent:

[0139] Thickener A: octadecyldimethylhydroxypropyl sulfobetaine 3wt.%;

[0140] Thickener B: erucamidopropyl sulfobetaine 2wt.%;

[0141] 31wt.% concentrated hydrochloric acid: 48.4wt.%;

[0142] Corrosion inhibitor: chloride-1,6-(α-octylpyridine)hexane 3.0wt.%;

[0143] Ferric ion stabilizer: ferric citrate ion stabilizer 4.5wt.%;

[0144] KCl: 2.5wt.%;

[0145] The remainder is water.

[0146] The specific preparation process is:

[0147] According to the above ratio, at 25°C, octadecyldimethylhydroxypropyl sulfobetaine was added to water to fully dissolve, and erucamidopropyl sulfobetaine was added to 31% concentrated hydrochloric acid to fully dissolve. 1,6-(α-octylpyridine) hexane chloride and ferric citrate ion stabilizer are added, and the mixture is evenly stirred to obtain a composite high-temperature resistant viscoelastic Turn to acid f...

Images