1. The high-efficiency multifunctional scale inhibitor for oilfield flooding is characterized by having a structure shown in a formula I:

wherein the value range of y is 5-10, and R₁And R₂Independently is H or-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x(ii) a Wherein n is 1 or 2, x is 1 or 2, and m is 1, 2 or 3;

the R is₁And R₂Not H at the same time.

2. The high-efficiency multifunctional scale inhibitor for oilfield flooding as defined in claim 1,

the R is₁Is H, R₂is-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x；

And/or said R₁is-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x，R₂is-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x；

Wherein n is 1, x is 1, and m is 1.

3. The preparation method of the high-efficiency multifunctional scale inhibitor for oilfield flooding, which is disclosed by claim 1 or 2, is characterized by comprising the following steps of:

mixing sodium tetrahydroxy succinate and metal sodium, and performing neutralization reaction to obtain a product system containing a compound with a structure shown in formula 1;

reacting the product system containing the compound with the structure shown in the formula 1 with Cl_nC_mH_2m-x-n+2(PO₃H₂)_xMixing, and carrying out substitution reaction to obtain a product system containing a compound with a structure shown in a formula 2; wherein n is 1 or 2, x is 1 or 2, and m is 1, 2 or 3;

mixing the product system containing the compound with the structure shown in the formula 2 with concentrated sulfuric acid, and carrying out etherification dehydration reaction to obtain the efficient multifunctional scale inhibitor for oilfield flooding;

m in formula 1₁And M₂Independently is H or Na, and the M₁And M₂Not H at the same time;

r in formula 2₁And R₂Independently is H or-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x(ii) a Wherein n is 1 or 2, x is 1 or 2, and m is 1, 2 or 3;

the R is₁And R₂Not both can be H.

4. The method of claim 3, wherein the molar ratio of sodium tetrahydroxysuccinate to sodium metal is 1: (1-2).

5. The method of claim 3, wherein the compound having the structure of formula 1 and Cl are present in the product system comprising the compound having the structure of formula 1_nC_mH_2m-x-n+2(PO₃H₂)_xThe molar ratio of (1-1.2): 1.

6. the method according to claim 3 or 5, wherein the temperature of the substitution reaction is 60 to 70 ℃ and the time is 1 hour.

7. The method according to claim 6, wherein the rate of temperature increase to the temperature of the substitution reaction is 1 to 2 ℃/min.

8. The method according to claim 3, wherein the ratio of the total mass of the compound having the structure represented by formula 2 and concentrated sulfuric acid to the mass of the concentrated sulfuric acid in the product system comprising the compound having the structure represented by formula 2 is 100: (10-15).

9. The preparation method according to claim 3, wherein the temperature of the etherification dehydration reaction is 70 to 90 ℃;

the temperature rise rate of raising the temperature to the temperature of the etherification dehydration reaction is 0.5-1.5 ℃/min.

10. The application of the efficient multifunctional scale inhibitor for oilfield flooding, which is prepared by the preparation method of any one of claims 1 and 2 or 3-9, in the field of oilfield flooding scale inhibition.

Background

The scale inhibitor on the market at present generally has stronger pertinence to the scale inhibition of single agent calcium carbonate, calcium sulfate or barium sulfate, so the complex scale inhibitor is required to be compounded when the comprehensive scale inhibitor is required on the oilfield site to realize the comprehensive scale inhibition performance. However, after the injection into the formation, because the formation adsorbs different chemical agents differently and the flow rate ratios of different substances in the formation are different, the solution composition of the formation in a certain section is different from the actual original formulation, and the difference causes the difference of the actual effect in the using process. Meanwhile, the concentration of the common scale inhibitor is lower, generally between 30% and 50%, and after compounding, the actual effective content of the common scale inhibitor is lower, so that the common scale inhibitor can be used at a higher concentration in an oil field construction site.

Disclosure of Invention

The invention aims to provide an efficient multifunctional scale inhibitor for oilfield flooding and a preparation method thereof, wherein the scale inhibitor has good comprehensive scale inhibition performance, and has high scale inhibition rate when the use concentration is less than or equal to 30 ppm.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a high-efficiency multifunctional scale inhibitor for oilfield flooding, which has a structure shown in a formula I:

wherein the value range of y is 5-10, and R₁And R₂Independently is H or-Cl_n-1C_mH_2m-x-n(PO₃H₂)_x(ii) a Wherein n is 1 or 2, x is 1 or 2, and m is 1, 2 or 3;

the R is₁And R₂Not H at the same time.

Preferably, said R is₁Is H, R₂is-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x；

And/or said R₁is-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x，R₂is-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x；

Wherein n is 1, x is 1, and m is 1.

The invention also provides a preparation method of the efficient multifunctional scale inhibitor for oilfield flooding, which comprises the following steps:

mixing sodium tetrahydroxy succinate and metal sodium, and performing neutralization reaction to obtain a product system containing a compound with a structure shown in formula 1;

reacting the product system containing the compound with the structure shown in the formula 1 with Cl_nC_mH_2m-x-n+2(PO₃H₂)_xMixing, and carrying out substitution reaction to obtain a product system containing a compound with a structure shown in a formula 2; wherein n is 1 or 2, x is 1 or 2, and m is 1, 2 or 3;

mixing the product system containing the compound with the structure shown in the formula 2 with concentrated sulfuric acid, and carrying out etherification dehydration reaction to obtain the efficient multifunctional scale inhibitor for oilfield flooding;

m in formula 1₁And M₂Independently is H or Na, and the M₁And M₂Not H at the same time;

r in formula 2₁And R₂Independently is H or-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x(ii) a Wherein n is 1 or 2, x is 1 or 2, and m is 1, 2 or 3;

the R is₁And R₂Not both can be H.

Preferably, the mole ratio of the sodium tetrahydroxysuccinate to the metal sodium is 1: (1-2).

Preferably, the compound having the structure shown in the formula 1 and Cl in the product system comprising the compound having the structure shown in the formula 1_nC_mH_2m-x-n+2(PO₃H₂)_xThe molar ratio of (1-1.2): 1.

preferably, the temperature of the substitution reaction is 60-70 ℃ and the time is 1 h.

Preferably, the heating rate of heating to the temperature of the substitution reaction is 1-2 ℃/min.

Preferably, the ratio of the total mass of the compound having the structure shown in formula 2 and concentrated sulfuric acid to the mass of the concentrated sulfuric acid in the product system comprising the compound having the structure shown in formula 2 is 100: (10-15).

Preferably, the temperature of the etherification dehydration reaction is 70-90 ℃;

the temperature rise rate of raising the temperature to the temperature of the etherification dehydration reaction is 0.5-1.5 ℃/min.

The invention also provides the application of the high-efficiency multifunctional scale inhibitor for oilfield flooding in the technical scheme or the high-efficiency multifunctional scale inhibitor for oilfield flooding prepared by the preparation method in the technical scheme in the field of oilfield flooding scale inhibition.

The invention provides a high-efficiency multifunctional scale inhibitor for oilfield flooding, which has a structure shown in a formula I:

wherein the value range of y is 5-10, and R₁And R₂Independently is H or-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x(ii) a Wherein n is 1 or 2, x is 1 or 2, and m is 1, 2 or 3;

the R is₁And R₂Not both can be H.

The scale inhibitor provided by the invention has organic phosphate groups and carboxylic acid groups, and the organic phosphate groups and the carboxylic acid groups can generate a synergistic effect to effectively inhibit scale.

Detailed Description

The invention provides a high-efficiency multifunctional scale inhibitor for oilfield flooding, which has a structure shown in a formula I:

wherein the value range of y is 5-10, and R₁And R₂Independently is H or-Cl_n-1C_mH_2m-x-n(PO₃H₂)_x(ii) a Wherein n is 1 or 2, x is 1 or 2, and m is 1, 2 or 3;

the R is₁And R₂Not H at the same time.

In the present invention, said R₁Preferably H, R₂Is preferably-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x；

And/or said R₁Is preferably-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x，R₂Is preferably-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x；

Wherein n is 1, x is 1, and m is 1.

The invention also provides a preparation method of the efficient multifunctional scale inhibitor for oilfield flooding, which comprises the following steps:

mixing sodium tetrahydroxy succinate and metal sodium, and performing neutralization reaction to obtain a product system containing a compound with a structure shown in formula 1;

reacting the product system containing the compound with the structure shown in the formula 1 with Cl_nC_mH_2m-x-n+2(PO₃H₂)_xMixing, and carrying out substitution reaction to obtain a product system containing a compound with a structure shown in a formula 2; wherein n is 1 or 2, x is 1 or 2, and m is 1, 2 or 3;

mixing the product system containing the compound with the structure shown in the formula 2 with concentrated sulfuric acid, and carrying out etherification dehydration reaction to obtain the efficient multifunctional scale inhibitor for oilfield flooding;

m in formula 1₁And M₂Independently is H or Na, and the M₁And M₂Not H at the same time;

r in formula 2₁And R₂Independently is H or-Cl_n-1C_mH_2m-x-n+2(PO₃H₂)_x(ii) a Wherein n is 1 or 2, x is 1 or 2, and m is 1, 2 or 3;

the R is₁And R₂Not both can be H.

In the present invention, all the starting materials for the preparation are commercially available products known to those skilled in the art unless otherwise specified.

The invention mixes tetrahydroxy sodium succinate and metallic sodium to generate neutralization reaction, and obtains a product system comprising a compound with a structure shown in a formula 1.

In the present invention, the molar ratio of the sodium tetrahydroxysuccinate to the metal sodium is preferably 1: (1-2).

The mixing process is not particularly limited, and may be performed by a method known to those skilled in the art.

In the invention, the temperature of the neutralization reaction is preferably room temperature, and the time of the neutralization reaction is preferably 2-6 h, more preferably 3-5 h, and most preferably 4 h.

In the present invention, the neutralization reaction is preferably carried out in a solvent, and the kind of the solvent is not particularly limited in the present invention, and those known to those skilled in the art can be used. In an embodiment of the invention, the solvent is in particular butane.

In the present invention, the volume ratio of the substance of sodium tetrahydroxysuccinate to the solvent is preferably 1 mol: (100 to 300) mL, more preferably 1 mol: 200 mL.

After obtaining a product system comprising the compound with the structure shown in the formula 1, the invention combines the product comprising the compound with the structure shown in the formula 1 and Cl_nC_mH_2m-x-n+2(PO₃H₂)_xMixing, and carrying out substitution reaction to obtain a product system containing a compound with a structure shown in a formula 2; wherein n is 1 or 2, x is 1 or 2, and m is 1, 2 or 3.

In the present invention, the mixing is preferably carried out by first warming the product system comprising the compound having the structure represented by formula 1 to the temperature of the substitution reactionAfter the reaction, Cl was added_nC_mH_2m-x-n+2(PO₃H₂)_x。

In the invention, the heating rate of the heating is preferably 1-2 ℃/min, more preferably 1.2-1.8 ℃/min, and most preferably 1.4-1.6 ℃/min.

In the present invention, the Cl is_nC_mH_2m-x-n+2(PO₃H₂)_xThe addition mode of (2) is preferably dropwise addition; the dropping rate is not particularly limited in the present invention, and may be a dropping rate well known to those skilled in the art. In a specific embodiment of the invention, the Cl_nC_mH_2m-x-n+2(PO₃H₂)_xThe dropping rate of (2) is specifically 5 mL/min.

In the invention, the product system comprising the compound with the structure shown in the formula 1 is prepared by reacting the compound with Cl and the compound with the structure shown in the formula 1_nC_mH_2m-x-n+2(PO₃H₂)_xThe molar ratio of (1) to (1.2): 1.

in the invention, the temperature of the substitution reaction is preferably 60-70 ℃, more preferably 62-68 ℃, and most preferably 64-66 ℃; the time for the substitution reaction is preferably 1 hour.

After the substitution reaction is finished, the method also preferably comprises a constant temperature process, wherein the constant temperature is preferably the same as the temperature of the substitution reaction; the constant temperature time is preferably 30 min.

Obtaining a product system comprising a compound with a structure shown in a formula 2; the product system containing the compound with the structure shown in the formula 2 is mixed with concentrated sulfuric acid to carry out etherification and dehydration reaction, so that the efficient multifunctional scale inhibitor for oilfield flooding is obtained.

The concentration of the concentrated sulfuric acid is not limited in any way, and the concentration of the concentrated sulfuric acid is known to those skilled in the art. In a specific embodiment of the present invention, the mass concentration of the concentrated sulfuric acid is specifically 98%.

In the present invention, the mixing is preferably performed by adding concentrated sulfuric acid to the product system comprising the compound having the structure represented by formula 2;

in the present invention, the adding manner of the concentrated sulfuric acid is preferably dropping, and the dropping rate is not limited in any way in the present invention, and can be a dropping rate well known to those skilled in the art.

After the mixing is finished, the temperature is preferably increased to the temperature of the etherification dehydration reaction at the temperature increase rate of 0.5-1.5 ℃/min, and the temperature increase rate is more preferably 1 ℃/min.

In the invention, the temperature of the etherification dehydration reaction is preferably 70-90 ℃, and more preferably 75-85 ℃; the time is preferably 1 h.

The invention also provides the application of the high-efficiency multifunctional scale inhibitor for oilfield flooding in the technical scheme or the high-efficiency multifunctional scale inhibitor for oilfield flooding prepared by the preparation method in the technical scheme in the field of oilfield flooding scale inhibition. In the invention, the use concentration of the efficient multifunctional scale inhibitor for oilfield flooding is less than or equal to 30 ppm.

The invention provides a high-efficiency multifunctional scale inhibitor for oilfield flooding and a preparation method thereof, which are described in detail with reference to the following examples, but the invention is not limited to the scope of the invention.

Example 1

Mixing 1mol of tetrahydroxy sodium succinate, 1mol of metal sodium and 100mL of solvent (the specific solvent is butane), carrying out neutralization reaction at room temperature for 120min, heating to 60 ℃ at the heating rate of 1.2 ℃/min, and dropwise adding 1mol of ClCH at the dropping rate of 5mL/min₂(PO₃H₂) Keeping the temperature for 30min after reacting for 1h, dripping 20mL of concentrated sulfuric acid with the mass concentration of 98%, heating to 70 ℃ at the heating rate of 1 ℃/min, and reacting for 1h to obtain the efficient multifunctional scale inhibitor for oilfield flooding (wherein R is₁Is H, R₂is-CH₂(PO₃H₂))。

Example 2

Mixing 1mol of sodium tetrahydroxysuccinate, 2mol of metal sodium and 100mL of solvent (specific solvent is butane), performing neutralization reaction at room temperature for 480min, and performing neutralization reaction at 1.8 deg.C/mThe temperature rise rate of in is increased to 70 ℃, and 1.2mol of LClCH is dripped at the dripping rate of 5mL/min₂(PO₃H₂) Keeping the temperature for 30min after reacting for 1h, dripping 20mL of concentrated sulfuric acid with the mass concentration of 98%, heating to 90 ℃ at the heating rate of 1 ℃/min, and reacting for 1h to obtain the efficient multifunctional scale inhibitor for oilfield flooding (wherein the scale inhibitor is R)₁is-CH₂(PO₃H₂)，R₂is-CH₂(PO₃H₂) And R₁Is H, R₂is-CH₂(PO₃H₂) Mixtures of) are used.

Example 3

Mixing 1mol of tetrahydroxy sodium succinate, 1mol of metal sodium and 100mL of solvent (the specific solvent is butane), carrying out neutralization reaction at room temperature for 240min, heating to 70 ℃ at the heating rate of 1.5 ℃/min, and dropwise adding 1.2mol of LClCH at the dropping rate of 5mL/min₂(PO₃H₂) Keeping the temperature for 30min after reacting for 1h, dripping 20mL of concentrated sulfuric acid with the mass concentration of 98%, heating to 80 ℃ at the heating rate of 1 ℃/min, and reacting for 1h to obtain the efficient multifunctional scale inhibitor for oilfield flooding (wherein the scale inhibitor is R)₁is-CH₂(PO₃H₂)，R₂is-CH₂(PO₃H₂) And R₁Is H, R₂is-CH₂(PO₃H₂) Mixtures of) are used.

Example 4

Mixing 1mol of tetrahydroxy sodium succinate, 1mol of metal sodium and 200mL of solvent (the specific solvent is butane), carrying out neutralization reaction at room temperature for 240min, heating to 65 ℃ at the heating rate of 1.0 ℃/min, and dropwise adding 1.2mol of LClCH at the dropwise adding rate of 5mL/min₂(PO₃H₂) Keeping the temperature for 30min after reacting for 1h, dripping 20mL of concentrated sulfuric acid with the mass concentration of 98%, heating to 80 ℃ at the heating rate of 1 ℃/min, and reacting for 1h to obtain the efficient multifunctional scale inhibitor for oilfield flooding (wherein the scale inhibitor is R)₁is-CH₂(PO₃H₂)，R₂is-CH₂(PO₃H₂) And R₁Is H, R₂is-CH₂(PO₃H₂) Mixtures of) are used.

Test example

According to an evaluation method in the technical specification of the corrosion and scale inhibitor for water treatment of the Q/SY126-2014 oilfield, the high-efficiency multifunctional scale inhibitor for water injection of the oilfield, which is prepared in the embodiment 1-4, is prepared into a 1% solution for later use. The test results of the scale inhibition rates of barium sulfate, calcium carbonate and calcium sulfate are shown in tables 1-4:

table 1 example 1 scale inhibition rates for barium sulfate, calcium carbonate and calcium sulfate

Concentration of	Barium sulfate (%)	Calcium carbonate (%)	Calcium sulfate (%)
				10ppm	91.3	80.2	89.3
15ppm	93.3	92.3	92.3
				30ppm	96.3	96.3	95.7

Table 2 example 2 scale inhibition rates for barium sulfate, calcium carbonate and calcium sulfate

Concentration of	Barium sulfate (%)	Calcium carbonate (%)	Calcium sulfate (%)
				10ppm	87.3	83.2	87.3
15ppm	89.3	91.3	90.3
				30ppm	92.3	96.3	92.7

Table 3 example 3 scale inhibition ratio for barium sulfate, calcium carbonate and calcium sulfate

Table 4 example 4 scale inhibition ratio of barium sulfate, calcium carbonate and calcium sulfate

Concentration of	Barium sulfate (%)	Calcium carbonate (%)	Calcium sulfate (%)
				10ppm	95.3	90.2	93.3
15ppm	95.3	95.3	95.3
				30ppm	99.3	97.3	96.7

As can be seen from tables 1-4, the scale inhibitor has better comprehensive scale inhibition performance at lower concentration, and simultaneously meets the industrial standard with the scale inhibition rate of barium sulfate being more than or equal to 40% and the addition of the barium sulfate being 60ppm at the concentration of more than or equal to 15 ppm; the addition of calcium sulfate and calcium carbonate is 30ppm, and the scale inhibition rate is required to be more than or equal to 90 percent.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.