Thermally stable guar gum aqueous solution and preparation method and application thereof

Abstract

The invention relates to a thermally stable guar gum aqueous solution which comprises guar gum or derivatives of guar gum, water, a pH adjustor and an antioxidant, wherein the pH of the aqueous solution system ranges from 7 to 11 and the antioxidant is one of the following combinations: (1) sulfite and gallic acid; (2) sulfite and gallate; and (3) sulfite, gallic acid and gallate. At the temperature of 130 DEG C to 200 DEG C and under an air condition, the viscosity of the solution is still greater than 50MPa.S in two hours.

Description

technical field

[0001] The invention relates to a heat-stable guar gum aqueous solution, a preparation method and application thereof. Background technique

[0002] In recent years, with the rapid economic development, my country's demand for oil resources is also growing rapidly. However, oil and energy in the world are in a tense situation, and oil price fluctuations affect every corner of the world. Under the dual pressure of oil production reduction and strong domestic demand growth, my country's oil and gas development and exploration are facing severe tests. Since the 1940s, fracturing fluids have been used to stimulate production of oil production fractures. Since its development, fracturing fluid technology has also experienced significant progress. Since the late 1950s, guar gum and its derivatives fracturing fluids have been used in oil extraction. The fracturing fluid system currently used in China is mainly suitable for oil reservoirs with a temperature below 1...

Examples

preparation example 1

[0058] Preparation Example 1 Preparation of hydroxypropyl guar gum base liquid: Weigh 5.5 g of hydroxypropyl guar gum powder and dissolve it in 1000 ml of tap water, and stir for 15 minutes to fully swell the hydroxypropyl guar gum powder. Weigh 0.6g sodium hydroxide and 1.2g sodium carbonate, add sodium hydroxide and sodium carbonate to the hydroxypropyl guar gum solution respectively, continue to stir for 10min, wait for the guar gum solution to be stable, roughly measure its pH with pH test paper Value, make sure it is around pH=11. Then store the guar gum base solution at 25°C for at least 4 hours for later use.

Embodiment 1

[0059] Example 1 Weigh 0.20 g of sodium gallate, 0.12 g of sodium sulfite, and add 0.5 g of organoboron crosslinking agent BCL-61 into 100 g of the hydroxypropyl guar gum base liquid prepared in Preparation Example 1, and immediately stir in the same direction make it cross-linked. Wait until the mixture is ready to hang. Then the temperature resistance and shear resistance performance test of the obtained aqueous solution (also known as fracturing fluid) was carried out on a HAAKE RheoStress 6000 rheometer (test temperature: heating rate: 10°C / min, constant temperature after heating to 160°C, shear rate : 170S -1 ). The test results show that the viscosity of the fracturing fluid is still stable after being continuously sheared for 100 minutes, and after 126 minutes, the viscosity slightly decreases by about 50 MPa·s (see figure 1 ).

Embodiment 2

[0066] Example 2 Weigh 0.40g of sodium gallate, 0.24 of sodium sulfite, and 0.5g of organoboron crosslinking agent BCL-61 into 100g of hydroxypropyl guar base liquid, and immediately stir in the same direction to crosslink. Wait until the mixture is ready to hang. Then, the temperature resistance and shear resistance performance test of the obtained aqueous solution (also known as fracturing fluid) was carried out on a HAAKE RheoStress 6000 rheometer (test temperature: heating rate: 10°C / min, constant temperature after heating to 160°C, shear rate: 170S -1 ). The test results show that the fracturing fluid has been continuously sheared for 2 hours and has a viscosity of 120MPa·s.

technical field

[0001] The invention relates to a heat-stable guar gum aqueous solution, a preparation method and application thereof. Background technique

[0002] In recent years, with the rapid economic development, my country's demand for oil resources is also growing rapidly. However, oil and energy in the world are in a tense situation, and oil price fluctuations affect every corner of the world. Under the dual pressure of oil production reduction and strong domestic demand growth, my country's oil and gas development and exploration are facing severe tests. Since the 1940s, fracturing fluids have been used to stimulate production of oil production fractures. Since its development, fracturing fluid technology has also experienced significant progress. Since the late 1950s, guar gum and its derivatives fracturing fluids have been used in oil extraction. The fracturing fluid system currently used in China is mainly suitable for oil reservoirs with a temperature below 1...

Examples

preparation example 1

[0058] Preparation Example 1 Preparation of hydroxypropyl guar gum base liquid: Weigh 5.5 g of hydroxypropyl guar gum powder and dissolve it in 1000 ml of tap water, and stir for 15 minutes to fully swell the hydroxypropyl guar gum powder. Weigh 0.6g sodium hydroxide and 1.2g sodium carbonate, add sodium hydroxide and sodium carbonate to the hydroxypropyl guar gum solution respectively, continue to stir for 10min, wait for the guar gum solution to be stable, roughly measure its pH with pH test paper Value, make sure it is around pH=11. Then store the guar gum base solution at 25°C for at least 4 hours for later use.

Embodiment 1

[0059] Example 1 Weigh 0.20 g of sodium gallate, 0.12 g of sodium sulfite, and add 0.5 g of organoboron crosslinking agent BCL-61 into 100 g of the hydroxypropyl guar gum base liquid prepared in Preparation Example 1, and immediately stir in the same direction make it cross-linked. Wait until the mixture is ready to hang. Then the temperature resistance and shear resistance performance test of the obtained aqueous solution (also known as fracturing fluid) was carried out on a HAAKE RheoStress 6000 rheometer (test temperature: heating rate: 10°C / min, constant temperature after heating to 160°C, shear rate : 170S -1 ). The test results show that the viscosity of the fracturing fluid is still stable after being continuously sheared for 100 minutes, and after 126 minutes, the viscosity slightly decreases by about 50 MPa·s (see figure 1 ).

Embodiment 2

[0066] Example 2 Weigh 0.40g of sodium gallate, 0.24 of sodium sulfite, and 0.5g of organoboron crosslinking agent BCL-61 into 100g of hydroxypropyl guar base liquid, and immediately stir in the same direction to crosslink. Wait until the mixture is ready to hang. Then, the temperature resistance and shear resistance performance test of the obtained aqueous solution (also known as fracturing fluid) was carried out on a HAAKE RheoStress 6000 rheometer (test temperature: heating rate: 10°C / min, constant temperature after heating to 160°C, shear rate: 170S -1 ). The test results show that the fracturing fluid has been continuously sheared for 2 hours and has a viscosity of 120MPa·s.

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