CROSS REFERENCE TO RELATED APPLICATION(S)

This patent application claims the benefit and priority of Chinese Patent Application No. 202110206718.6, filed on Feb. 24, 2021, the disclosure of which is incorporated by reference herein in its entirety as part of the present application.

TECHNICAL FIELD

The present disclosure relates to a process for preparing a one-component type multi-functional fracturing fluid additive, and specifically relates to a one-component type multi-functional fracturing fluid additive and a process for preparing the same.

BACKGROUND ART

In recent years, fracturing technology has developed rapidly, and different fracturing systems have been developed and formulated according to different geological conditions to achieve the best fracturing and oil displacement effects.

Taking water-base fracturing systems as example, thickeners guar gum and acrylamide copolymers occupy above 90% of the market of fracturing fluid thickeners due to their advantages of mature construction technology, significant “antipolyelectrolyte effect” and wide pH application range. During the fracturing process, in addition to thickeners, suitable additives, such as clay stabilizers, drainage aids, drag reducers, emulsion inhibitors, filtrate reducers, corrosion inhibitors, fungicides, and the like, are also needed to formulate a fracturing fluid with excellent physical and chemical properties to ensure smooth construction and reduce reservoir damage. Processes for formulating water-base fracturing fluids at construction site mostly involve continuous mixing. When dry powder thickeners are used, there are disadvantages, such as high labor intensity, easy formation of dust, uneven mixing of thickeners, long dissolution time, difficulty in adding additives, etc. In recent years, emulsion-type fracturing fluids and oil dispersion-type fracturing fluids have been developed, but emulsion-type fracturing fluids has a low viscosity retention rate and low content in saline water, and the cost is high; oil dispersion-type fracturing fluids do not meet safety and environmental protection requirements because they contain a large amount of harmful organic solvents and cause serious pollution to formations. How to prepare a multi-functional fracturing fluid additive that meets safety and environmental protection requirements of oil and gas fields and has good performance has become a problem to be solved urgently.

SUMMARY

In order to address problems in the prior art, the present disclosure provides a one-component type multi-functional fracturing fluid additive and a process for preparing the same to overcome the disadvantages that the existing dry powder additives are prone to dust formation, uneven mixing, long dissolution time, difficult preparation of fluids, and the emulsion-type fracturing fluids and oil dispersion-type fracturing fluids cause serious pollution to formations, have poor functionality and involve complex flowback fluid treatment. A multi-functional fracturing fluid additive system is prepared, which is safe, environmentally friendly, temperature-resistant and shear-resistant, and has good performance.

In order to achieve the above objectives, the present disclosure uses the following technical means:

A process for preparing a one-component type multi-functional fracturing fluid additive, comprising the following steps:

Mixing ethylene glycol, isopropanol, 1-butanol, 1-hexanol and 1-octanol, and heating to uniformly disperse the mixture to obtain an aqueous dispersant;

Adding a high molecular polymer thickener and an auxiliary agent to the aqueous dispersant, and stirring the mixture at a high speed to obtain a suspension, wherein the auxiliary agent is one or more selected from clay stabilizers, drainage aids, drag reducers, emulsion inhibitors, filtrate reducers, corrosion inhibitors and fungicides;

Slowly stirring the suspension at a low speed, and cooling the suspension to room temperature to collect a sample of suspension.

As a further improvement of the present disclosure, the ethylene glycol, isopropanol, 1-butanol, 1-hexanol and 1-octanol are added in an amount of 20 to 40% wt, 20 to 40% wt, 1 to 10% wt, 0.1 to 5% wt, 0.1 to 5% wt of the total amount of the suspension.

As a further improvement of the present disclosure, the high molecular polymer thickener is added in an amount of 20 to 50% wt of the total amount of the suspension.

As a further improvement of the present disclosure, the clay stabilizers, drainage aids, drag reducers, emulsion inhibitors, filtrate reducers, corrosion inhibitors and fungicides in the auxiliary agent are added in an amount of 0 to 10% wt, 0 to 10% wt, 0 to 10% wt, 0 to 10% wt, 0 to 10% wt, 0 to 10% wt, 0 to 10% wt of the total amount of the suspension.

As a further improvement of the present disclosure, the high molecular polymer thickener is obtained by pulverizing high molecular polymer solids with a pulverizer and then sieving with an 80 to 140-mesh sieve.

As a further improvement of the present disclosure, the clay stabilizers, drainage aids, drag reducers, emulsion inhibitors, filtrate reducers, corrosion inhibitors and fungicides are obtained by separate grinding and then sieving with an 80 to 140-mesh sieve.

As a further improvement of the present disclosure, the high molecular polymer thickener is selected from hydrophobic acrylamide copolymers.

As a further improvement of the present disclosure, the clay stabilizer is selected from KCl, the drainage aid is selected from nonionic fluorine-containing surfactants, the drag reducer is selected from PVA, the emulsion inhibitor is selected from polyether DY202, and the filtrate reducer is selected from modified starch, the corrosion inhibitor is selected from quinolines, and the fungicide is selected from CuSO4.

As a further improvement of the present disclosure, the high speed is in the range of 5000 to 9000 r/min; the low speed is in the range of 1000 to 4000 r/min.

A one-component type multi-functional fracturing fluid additive, comprising the following raw materials in weight percentage:

Ethylene glycol 20 to 40% wt;

Isopropanol 20 to 40% wt;

1-Butanol 1 to 10% wt;

1-Hexanol 0.1 to 5% wt;

1-Octanol 0.1 to 5% wt;

High molecular polymer thickener 20 to 50% wt;

Clay stabilizer 0 to 10% wt;

Drainage aid 0 to 10% wt;

Drag reducer 0 to 10% wt;

Emulsion inhibitor 0 to 10% wt;

Filtrate reducer 0 to 10% wt;

Corrosion inhibitor 0 to 10% wt;

Fungicide 0 to 10% wt.

Compared with the prior art, the present disclosure has the following advantages:

The present disclosure provides a process for preparing a one-component type multi-functional fracturing fluid additive. The one-component type multi-functional fracturing fluid additive of the present disclosure uses ethylene glycol/isopropanol/1-butanol/1-hexanol/1-octanol as dispersant, and one or more of high molecular polymer thickeners/clay stabilizers/drainage aids/drag reducers/emulsion inhibitors/filtrate reducers/corrosion inhibitors/fungicides as dispersed substance; heated dispersants are mixed with dispersed substances and then subjected to high-speed stirring and low-speed low-temperature stirring to form a suspension of one-component type multi-functional fracturing fluid additive. The suspension is prepared based on the principle that the polymer dispersant in 1-butanol/1-hexanol/1-octanol is wrapped around the surface of solid particles, and then surrounded by the same series of low-molecular dispersants, and thereafter, dispersed in the same series of ethylene glycol/isopropanol aqueous dispersant with even lower molecular weight. According to the principle that similar substances are more likely to be dissolved by each other, the surrounded solid particles and the aqueous dispersant are two phases that are dispersed more uniformly and stably, thereby preparing novel environmentally friendly multi-functional water-dispersion oilfield chemical auxiliaries.

By observing the stability and flow state of the one-component type multi-functional fracturing fluid additive, the amount of dispersant used in the one-component type multi-functional fracturing fluid additive is optimized. The performance of the one-component type multi-functional fracturing fluid additive has been tested, and the results show that this auxiliary agent has good characteristics such as temperature resistance, shear resistance, salt resistance, and sand suspension. It solves the problems that the existing fracturing fluid systems cause serious pollution to the formation, are difficult to dissolve, and have limited function and poor performance, etc., and exhibits good use performance, environmental protection, and energy saving and consumption reduction characteristics, which can be used for the development of clean and environmentally friendly one-component type multi-functional fracturing fluid additives.

