CN110903820A

CN110903820A - Shuangshuang synergistic cleanup additive and preparation method thereof

Info

Publication number: CN110903820A
Application number: CN201911075616.4A
Authority: CN
Inventors: 李伟; 王红科; 牛增前; 张雅静; 靳剑霞; 王越; 蔡景超; 徐昊垠; 郝鹏涛; 董丙响
Original assignee: CNPC Bohai Drilling Engineering Co Ltd
Current assignee: CNPC Bohai Drilling Engineering Co Ltd
Priority date: 2019-11-06
Filing date: 2019-11-06
Publication date: 2020-03-24

Abstract

The invention discloses a double-hydrophobic synergistic cleanup additive and a preparation method thereof, wherein the double-hydrophobic synergistic cleanup additive is prepared by the following method: adding cyclohexane and pentaerythritol into a reaction bottle, and stirring and mixing uniformly; slowly dropwise adding perfluorooctyl acyl chloride under the stirring condition, heating to 30-40 ℃ after dropwise adding, and reacting for 3-5 hours; cooling the reaction product to room temperature, and removing cyclohexane solvent to obtain the product; the amphiphobic synergistic cleanup additive is a nonionic fluorocarbon surfactant with four branched chains in a chemical structure, so that the amphiphobic synergistic cleanup additive has an amphiphobic effect, further effectively changes the wettability of the surface of a rock, and simultaneously has the effects of reducing the surface tension of a solid and a liquid and reducing the resistance of a capillary.

Description

Shuangshuang synergistic cleanup additive and preparation method thereof

Technical Field

The invention relates to the technical field of downhole operation of oil and gas fields, in particular to a dredging synergistic cleanup additive and a preparation method thereof.

Background

After fracturing construction, if the gel breaking liquid is too long in the reservoir, clay expansion is easy to occur, a channel is blocked, and even 'water lock damage' is caused, so that a cleanup additive needs to be added to reduce surface interfacial tension and capillary resistance, so that the gel breaking liquid is more quickly and thoroughly drained after fracturing.

Most of the conventional fracturing cleanup additives are surfactants, wherein fluorocarbon surfactants are more and more concerned due to higher cleanup performance, but have the defects of high cost, complex synthesis, need of compounding and the like.

Disclosure of Invention

The invention aims to provide a amphiphobic synergistic cleanup additive for solving the problems of high cost, complex synthesis, need of compounding and the like in the existing fluorocarbon cleanup additive

The invention also aims to provide a preparation method for preparing the amphiphobic synergistic cleanup additive.

Therefore, the technical scheme of the invention is as follows:

a amphiphobic synergistic cleanup additive has the following chemical structure:

a preparation method of a amphiphobic synergistic cleanup additive comprises the following specific steps: adding cyclohexane and pentaerythritol into a reaction bottle, and stirring and mixing uniformly; then heating to 30-40 ℃ under the stirring condition, dropwise adding perfluorooctyl acyl chloride into the reaction bottle, and continuing to react for 3-5 hours after dropwise adding; after the reaction product is cooled to room temperature, removing the solvent cyclohexane to obtain a cleanup additive product; wherein the feeding molar ratio of the pentaerythritol to the perfluorooctyl acyl chloride is 1 (4.1-4.4).

Preferably, the addition amount of the cyclohexane is 60 to 65 percent of the total weight of the cyclohexane, the pentaerythritol and the perfluorooctyl acyl chloride.

Compared with the prior art, the amphiphobic synergistic cleanup additive is a nonionic fluorocarbon surfactant with four branched chains in a chemical structure, so that the amphiphobic synergistic cleanup additive has an amphiphobic effect, further effectively changes the wettability of the surface of a rock, and simultaneously has the effects of reducing the surface tension of solid and liquid and reducing capillary resistance.

Detailed Description

The present invention will be further described with reference to the following examples, which are not intended to limit the invention in any way.

Example 1

A amphiphobic synergistic cleanup additive is prepared by the following steps:

adding cyclohexane and pentaerythritol into a reaction bottle, and stirring and mixing uniformly; then heating to 30 ℃ under the condition of stirring, dropwise adding perfluorooctyl acyl chloride into the reaction bottle, and continuing to react for 3 hours after the dropwise adding is finished; and after the reaction is finished, removing the cyclohexane solvent by rotary evaporation to obtain the cleanup additive product.

Wherein the feeding molar ratio of pentaerythritol to perfluorooctyl acyl chloride is 1: 4.1; the amount of cyclohexane used was 65% by weight based on the total weight of cyclohexane, pentaerythritol and perfluorooctyl chloride.

Example 2

A amphiphobic synergistic cleanup additive is prepared by the following steps:

adding cyclohexane and pentaerythritol into a reaction bottle, and stirring and mixing uniformly; then heating to 35 ℃ under the condition of stirring, dropwise adding perfluorooctyl acyl chloride into the reaction bottle, and continuing to react for 4 hours after the dropwise adding is finished; and after the reaction is finished, removing the cyclohexane solvent by rotary evaporation to obtain the cleanup additive product.

Wherein the feeding molar ratio of pentaerythritol to perfluorooctyl acyl chloride is 1: 4.2; cyclohexane was used in an amount of 62% by weight based on the total weight of cyclohexane, pentaerythritol and perfluorooctyl chloride.

Example 3

A amphiphobic synergistic cleanup additive is prepared by the following steps:

adding cyclohexane and pentaerythritol into a reaction bottle, and stirring and mixing uniformly; then heating to 40 ℃ under the condition of stirring, dropwise adding perfluorooctyl acyl chloride into the reaction bottle, and continuing to react for 5 hours after the dropwise adding is finished; and after the reaction is finished, removing the cyclohexane solvent by rotary evaporation to obtain the cleanup additive product.

Wherein the feeding molar ratio of pentaerythritol to perfluorooctyl acyl chloride is 1: 4.4; the amount of cyclohexane used was 60% by weight based on the total weight of cyclohexane, pentaerythritol and perfluorooctyl chloride.

Example 4

A amphiphobic synergistic cleanup additive is prepared by the following steps:

Wherein the feeding molar ratio of pentaerythritol to perfluorooctyl acyl chloride is 1: 4.3; the amount of cyclohexane used was 65% by weight based on the total weight of cyclohexane, pentaerythritol and perfluorooctyl chloride.

Example 5

A amphiphobic synergistic cleanup additive is prepared by the following steps:

Wherein the feeding molar ratio of pentaerythritol to perfluorooctyl acyl chloride is 1: 4.2; the amount of cyclohexane used was 60% by weight based on the total weight of cyclohexane, pentaerythritol and perfluorooctyl chloride.

And (3) performance testing:

the amphiphobic synergistic cleanup additive prepared in examples 1-5 is prepared into a 0.05 wt.% aqueous solution by adding water, and a surface interfacial tension test is carried out according to a standard SY/T5755-2016 cleanup additive performance evaluation method for fracture acidizing. The test results are shown in table 1 below.

Table 1: surface interfacial tension and interfacial tension test results

Numbering	Example 1	Example 2	Example 3	Example 4	Example 5
						Surface tension, mN/m	23.6	23.1	21.1	22.1	23.1
Interfacial tension, mN/m	1.25	1.17	0.98	1.02	1.09

As can be seen from table 1, when the amount of the amphiphobic synergistic cleanup additive in examples 1 to 5 added to the aqueous solution is 0.05 wt.%, the effective reduction of the surface interfacial tension can be achieved, and it can be seen that the amphiphobic synergistic cleanup additive can exhibit the effect of effectively reducing the surface interfacial tension of the solution at a small amount.

The amphiphobic synergistic cleanup additive prepared in examples 1-5 is further added with water to prepare a 0.05 wt.% aqueous solution, and a contact angle test is performed according to a standard SY/T5755-2016 cleanup additive performance evaluation method for fracture acidizing, and specific test results are shown in Table 2 below.

Table 2: contact Angle test results

Numbering	Example 1	Example 2	Example 3	Example 4	Example 5
						Contact angle, ° c	72.1	72.8	74.7	75.2	73.9

As can be seen from table 2, the contact angles of the 0.05 wt.% aqueous solutions of the amphiphobic synergistic cleanup additives of examples 1 to 5 are all greater than 70 ° through testing, and it can be seen that the amphiphobic synergistic cleanup additive can achieve better rock wettability change with a small addition amount.

Claims

1. The amphiphobic synergistic cleanup additive is characterized by having the following chemical structure:

2. a method for preparing the amphiphobic synergistic cleanup additive as recited in claim 1, comprising the following specific steps: adding cyclohexane and pentaerythritol into a reaction bottle, and stirring and mixing uniformly; then heating to 30-40 ℃ under the stirring condition, dropwise adding perfluorooctyl acyl chloride into the reaction bottle, and continuing to react for 3-5 hours after dropwise adding; after the reaction product is cooled to room temperature, removing the solvent cyclohexane to obtain a cleanup additive product; wherein the feeding molar ratio of the pentaerythritol to the perfluorooctyl acyl chloride is 1 (4.1-4.4).

3. The method for preparing the amphiphobic synergistic cleanup additive according to claim 2, wherein the amount of cyclohexane added is 60-65% of the total weight of cyclohexane, pentaerythritol and perfluorooctyl acyl chloride.