Rapid viscosity breaker for surfactant fracturing fluid

Abstract

The invention provides a rapid viscosity breaker of a surfactant fracturing fluid. The viscosity breaker is composed of C6-16 alcohol, polyoxyethylene ether, saturated fatty acid, dehydrated sorbitol ester and water. According to the invention, the viscosity breaker can be used for rapid viscosity breaking of a clean fracturing fluid; and at the late stage of fracturing construction, the viscosity breaker is added by a gradient increasing supplementation manner, thus the clean fracturing fluid within a certain range of a well casing is subjected to rapid viscosity breaking, the time for viscosity breaking of the fracturing fluid by migration of formation water or oil to borehole is shortened, and the viscosity breaking effect is effectively improved.

Description

technical field

[0001] The invention relates to the field of gel breaking of clean fracturing fluid in oil-water well fracturing transformation, in particular to a rapid gel breaking agent for surfactant fracturing fluid. Background technique

[0002] At present, the fracturing fluids used in oilfield fracturing mainly include water-based fracturing fluids, oil-based fracturing fluids, clean fracturing fluids and other fracturing fluid systems. Clean fracturing fluid is a residue-free fracturing fluid system that has emerged in recent years. Its main components are cationic surfactants or anionic surfactants, which are mixed with additives such as inorganic salts and co-surfactants to form a viscoelastic fracturing fluid.

[0003] The gel-breaking effect of the fracturing fluid is related to the flowback of the gel-breaking fluid and the conductivity of the formation. In order to improve the effect of fracturing, the gel-breaking of the fracturing fluid should be as thoroug...

Examples

Embodiment 1

[0029] Take 5g of n-octanol, 20g of fatty alcohol polyoxyethylene ether (AEO3), 5g of octanoic acid, and 3g of sorbitan ester (span-20), and mix them with 67ml of water to form a gel breaker. Add the above gel breaker to the clean fracturing fluid in a water bath at 30°C. The weight of the gel breaker is 0.2% in the clean fracturing fluid. The gel can be broken within 20 minutes, and the viscosity drops to 3mPa .s.

Embodiment 2

[0031] Take 10g of lauryl alcohol, 20g of alkylphenol polyoxyethylene ether (OP-10), 15g of lauric acid, and 10g of sorbitan ester (span-60), and mix them with 45ml of water to form a gel breaker. Add the above gel breaker to the clean fracturing fluid in a water bath at 40°C. The weight of the added gel breaker accounts for 0.5% of the clean fracturing fluid. The gel can be broken within 13 minutes, and the viscosity will drop to 3mPa. .s.

Embodiment 3

[0033] Take 10g of cetyl alcohol, 30g of polyoxyethylene polyoxypropylene ether (L63), 30g of palmitic acid, and 5g of sorbitan ester (Tween-40), and mix them with 25ml of water evenly to form a gel breaker. Add the above gel breaker to the clean fracturing fluid in a water bath at 50°C, where the weight of the gel breaker is 1% in the clean fracturing fluid, and the gel will be broken within 2 minutes, and the viscosity will drop to 2mPa .s.

technical field

[0001] The invention relates to the field of gel breaking of clean fracturing fluid in oil-water well fracturing transformation, in particular to a rapid gel breaking agent for surfactant fracturing fluid. Background technique

[0002] At present, the fracturing fluids used in oilfield fracturing mainly include water-based fracturing fluids, oil-based fracturing fluids, clean fracturing fluids and other fracturing fluid systems. Clean fracturing fluid is a residue-free fracturing fluid system that has emerged in recent years. Its main components are cationic surfactants or anionic surfactants, which are mixed with additives such as inorganic salts and co-surfactants to form a viscoelastic fracturing fluid.

[0003] The gel-breaking effect of the fracturing fluid is related to the flowback of the gel-breaking fluid and the conductivity of the formation. In order to improve the effect of fracturing, the gel-breaking of the fracturing fluid should be as thoroug...

Examples

Embodiment 1

[0029] Take 5g of n-octanol, 20g of fatty alcohol polyoxyethylene ether (AEO3), 5g of octanoic acid, and 3g of sorbitan ester (span-20), and mix them with 67ml of water to form a gel breaker. Add the above gel breaker to the clean fracturing fluid in a water bath at 30°C. The weight of the gel breaker is 0.2% in the clean fracturing fluid. The gel can be broken within 20 minutes, and the viscosity drops to 3mPa .s.

Embodiment 2

[0031] Take 10g of lauryl alcohol, 20g of alkylphenol polyoxyethylene ether (OP-10), 15g of lauric acid, and 10g of sorbitan ester (span-60), and mix them with 45ml of water to form a gel breaker. Add the above gel breaker to the clean fracturing fluid in a water bath at 40°C. The weight of the added gel breaker accounts for 0.5% of the clean fracturing fluid. The gel can be broken within 13 minutes, and the viscosity will drop to 3mPa. .s.

Embodiment 3

[0033] Take 10g of cetyl alcohol, 30g of polyoxyethylene polyoxypropylene ether (L63), 30g of palmitic acid, and 5g of sorbitan ester (Tween-40), and mix them with 25ml of water evenly to form a gel breaker. Add the above gel breaker to the clean fracturing fluid in a water bath at 50°C, where the weight of the gel breaker is 1% in the clean fracturing fluid, and the gel will be broken within 2 minutes, and the viscosity will drop to 2mPa .s.