Anhydrous fracturing fluid suitable for shale gas and preparation method of anhydrous fracturing fluid

Abstract

The invention belongs to the technical field of petrochemical engineering, and particularly relates to an anhydrous fracturing fluid suitable for shale gas and a preparation method of the anhydrous fracturing fluid. The anhydrous fracturing fluid suitable for shale gas is prepared from the following raw materials in percentage by mass: 0.5-2% of a crosslinking agent, 2-6% of a complex iron activator and the balance of a low carbon hydrocarbon; in a pressure vessel with a pressure of 0.8-3.0 MPa, the crosslinking agent is added into the low carbon hydrocarbon to be uniformly mixed, the complex iron activator is added to be stirred for 2-5 min, so that the anhydrous fracturing fluid suitable for shale gas is obtained; and the low carbon hydrocarbon is one or a mixture of more of propane, butane, n-hexane, n-heptane and kerosene. The anhydrous fracturing fluid suitable for shale gas easily flows back, has a good sand-carrying property, does not harm reservoirs, and can satisfy the needs of fracturing reconstruction of shale oil and gas and strong water-sensitive compact oil and gas reservoirs. A synthetic method is simple, and the content of an effective component dialkyl phosphate in a product is high, thereby facilitating the industrialization production of the anhydrous fracturing fluid.

Description

technical field

[0001] The invention belongs to the technical field of petrochemical industry, and in particular relates to an anhydrous fracturing fluid suitable for shale gas and a preparation method thereof. Background technique

[0002] In the development process of shale oil and gas, the method of volume fracturing is usually used for fracturing. According to statistics, each well needs to be fractured to consume millions of cubic meters of water, and the fracturing fluid contains a large amount of chemical substances, which are harmful to water. Both resources and the environment present enormous challenges. However, the method of waterless fracturing requires almost no water during the entire fracturing process, and has good compatibility with oil and gas reservoirs, and can almost 100% flow back.

[0003] For the study of shale gas fracturing fluid, the preparation of the thickener is the key, and the thickening effect of the thickener determines the performance of ...

Examples

Embodiment 1

[0015] The anhydrous fracturing fluid suitable for shale gas is made of the following raw materials in mass percentage: 1.5% crosslinking agent, 4.0% complex iron activator, and the rest are low-carbon hydrocarbons.

[0016] Described low carbon hydrocarbon is the mixture of propane and butane;

[0017] Described linking agent is alkyl phosphate, and the content of dialkyl phosphate in alkyl phosphate is 65.8%, and the synthetic method of alkyl phosphate comprises the following steps:

[0018] (1) First by P 2 o 5 React with triethyl phosphate at 80°C for 2 hours, and react with a feed molar ratio of 1:1 to obtain a polyphosphate intermediate.

[0019] (2) Add mixed alcohol to the polyphosphate intermediate described in step (1), mixed alcohol and P 2 o 5 The molar ratio is 3:1, react at 80°C for 4h to obtain alkyl phosphate. The mixed alcohols include ethanol, n-butanol, n-octanol and dodecanol, and the molar ratio between the alcohols is 1:1:1:1. The content of dialkyl...

Embodiment 2

[0023] Anhydrous fracturing fluid suitable for shale gas, made of the following raw materials in mass percentage: 1.8% crosslinking agent, 5% complex iron activator, and the rest are low-carbon hydrocarbons;

[0024] Described low carbon hydrocarbon is the mixture of propane and butane;

[0025] The cross-linking agent is an alkyl phosphate, and the content of dialkyl phosphate in the alkyl phosphate is 68.8%, and the synthetic method of the alkyl phosphate comprises the following steps:

[0026] (1) First by P 2 o 5 React with triethyl phosphate at 80°C for 2 hours, and react with a feed molar ratio of 1.3:1 to obtain a polyphosphate intermediate.

[0027] (2) Add mixed alcohol to the polyphosphate intermediate described in step (1), mixed alcohol and P 2 o 5 The molar ratio is 3:1, react at 90°C for 3h to obtain alkyl phosphate. The content of dialkyl phosphate is 68.8% measured by double indicator titration method.

[0028] Mixed alcohols include ethanol, propanol, n-...

Embodiment 3

[0032] Anhydrous fracturing fluid suitable for shale gas, made of the following raw materials in mass percentage: 0.5% crosslinking agent, 2% complex iron activator, and kerosene as the rest;

[0033] The cross-linking agent is an alkyl phosphate, and the content of dialkyl phosphate in the alkyl phosphate is 57.4%. The synthetic method of the alkyl phosphate comprises the following steps:

[0034] (1) First by P 2 o 5 React with triethyl phosphate at 80°C for 2 hours, and react with a feed molar ratio of 1.4:1 to obtain a polyphosphate intermediate.

[0035] (2) Add mixed alcohol to the polyphosphate intermediate described in step (1), mixed alcohol and P 2 o 5 The molar ratio is 3:1, react at 100°C for 4h to obtain alkyl phosphate. The content of dialkyl phosphate is 57.4% measured by double indicator titration method.

[0036] Mixed alcohols include n-butanol, n-octanol, tetradecyl alcohol, the molar ratio between alcohols is 1:1:2, mixed alcohols and P 2 o 5 The mol...

technical field

[0001] The invention belongs to the technical field of petrochemical industry, and in particular relates to an anhydrous fracturing fluid suitable for shale gas and a preparation method thereof. Background technique

[0002] In the development process of shale oil and gas, the method of volume fracturing is usually used for fracturing. According to statistics, each well needs to be fractured to consume millions of cubic meters of water, and the fracturing fluid contains a large amount of chemical substances, which are harmful to water. Both resources and the environment present enormous challenges. However, the method of waterless fracturing requires almost no water during the entire fracturing process, and has good compatibility with oil and gas reservoirs, and can almost 100% flow back.

[0003] For the study of shale gas fracturing fluid, the preparation of the thickener is the key, and the thickening effect of the thickener determines the performance of ...

Examples

Embodiment 1

[0015] The anhydrous fracturing fluid suitable for shale gas is made of the following raw materials in mass percentage: 1.5% crosslinking agent, 4.0% complex iron activator, and the rest are low-carbon hydrocarbons.

[0016] Described low carbon hydrocarbon is the mixture of propane and butane;

[0017] Described linking agent is alkyl phosphate, and the content of dialkyl phosphate in alkyl phosphate is 65.8%, and the synthetic method of alkyl phosphate comprises the following steps:

[0018] (1) First by P 2 o 5 React with triethyl phosphate at 80°C for 2 hours, and react with a feed molar ratio of 1:1 to obtain a polyphosphate intermediate.

[0019] (2) Add mixed alcohol to the polyphosphate intermediate described in step (1), mixed alcohol and P 2 o 5 The molar ratio is 3:1, react at 80°C for 4h to obtain alkyl phosphate. The mixed alcohols include ethanol, n-butanol, n-octanol and dodecanol, and the molar ratio between the alcohols is 1:1:1:1. The content of dialkyl...

Embodiment 2

[0023] Anhydrous fracturing fluid suitable for shale gas, made of the following raw materials in mass percentage: 1.8% crosslinking agent, 5% complex iron activator, and the rest are low-carbon hydrocarbons;

[0024] Described low carbon hydrocarbon is the mixture of propane and butane;

[0025] The cross-linking agent is an alkyl phosphate, and the content of dialkyl phosphate in the alkyl phosphate is 68.8%, and the synthetic method of the alkyl phosphate comprises the following steps:

[0026] (1) First by P 2 o 5 React with triethyl phosphate at 80°C for 2 hours, and react with a feed molar ratio of 1.3:1 to obtain a polyphosphate intermediate.

[0027] (2) Add mixed alcohol to the polyphosphate intermediate described in step (1), mixed alcohol and P 2 o 5 The molar ratio is 3:1, react at 90°C for 3h to obtain alkyl phosphate. The content of dialkyl phosphate is 68.8% measured by double indicator titration method.

[0028] Mixed alcohols include ethanol, propanol, n-...

Embodiment 3

[0032] Anhydrous fracturing fluid suitable for shale gas, made of the following raw materials in mass percentage: 0.5% crosslinking agent, 2% complex iron activator, and kerosene as the rest;

[0033] The cross-linking agent is an alkyl phosphate, and the content of dialkyl phosphate in the alkyl phosphate is 57.4%. The synthetic method of the alkyl phosphate comprises the following steps:

[0034] (1) First by P 2 o 5 React with triethyl phosphate at 80°C for 2 hours, and react with a feed molar ratio of 1.4:1 to obtain a polyphosphate intermediate.

[0035] (2) Add mixed alcohol to the polyphosphate intermediate described in step (1), mixed alcohol and P 2 o 5 The molar ratio is 3:1, react at 100°C for 4h to obtain alkyl phosphate. The content of dialkyl phosphate is 57.4% measured by double indicator titration method.

[0036] Mixed alcohols include n-butanol, n-octanol, tetradecyl alcohol, the molar ratio between alcohols is 1:1:2, mixed alcohols and P 2 o 5 The mol...

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