Gel breaking activator, fracturing fluid containing gel breaking activator, and preparation method and application of gel breaking activator

Abstract

The invention belongs to the technical field of oil and gas field fracturing fluid gel breaking, and relates to a gel breaking activator, a fracturing fluid containing the gel breaking activator, and a preparation method and application of the gel breaking activator. The gel breaking activating agent is prepared from the following components in percentage by mass: 3.3 percent to 7.13 percent of triethanolamine, 6.7 percent to 8.58 percent of D-sodium erythorbate, 3.3 percent to 7.13 percent of tea polyphenol, 6.7 percent to 8.58 percent of sodium dehydroacetate, 8.58 percent to 20 percent of ethylene glycol and the balance of water. The invention also discloses a preparation method of the gel breaking activator, the raw materials are physically blended, the preparation process is simple, and the gel breaking activator can be prepared on site and is convenient to use. The invention further discloses fracturing fluid containing the gel breaking activator and application, the dosage of the gel breaking activator is small and only needs 1%-3%, and the gel breaking performance at the temperature of 20-50 DEG C is good. The problem that gel breaking of fracturing fluid is difficult when the formation temperature is lower than 50 DEG C can be solved.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas development technology, specifically relating to a colloid activator, a fracturing fluid containing the same, its preparation method, and its application. Background Technology

[0002] There are currently three methods for breaking up plant-based gum fracturing fluids: The first method uses enzyme-based breaker, but this must be used at a low pH. Enzyme activity is generally highest at pH 6.0, and completely lost at pH above 9.0. Currently used plant-based gum fracturing fluids have a pH between 8 and 10, making them alkaline. Some specific enzymes can maintain over 60% activity within a pH range of 6.0-10.0, but these are costly, difficult to operate in the field, and have limited application conditions. The second method involves adding substances that slowly generate acid to lower the pH of the fracturing fluid in the formation, disrupting the cross-linked structure and polymer backbone to achieve breaking up the fluid. However, this method still suffers from drawbacks such as high cost, difficulty in control, and compatibility issues. The third method uses peroxides (such as ammonium persulfate and potassium persulfate) to achieve rapid breaking up.

[0003] Currently, ammonium persulfate (APS) is mainly used as a breaker in oilfield plant gum fracturing fluids. For example, patent document CN102352233A discloses a low-damage, small-molecule guar gum fracturing fluid. Its breaker process involves: at a certain temperature, the acid generated by the hydrolysis reaction of persulfate lowers the pH value of the gel, and the oxygen free radicals generated by the self-decomposition reaction oxidize and degrade the acetal bonds of the guar gum, jointly destroying the gel structure. Therefore, the breaker rate depends on the decomposition rate of persulfate. Studies have shown that the decomposition of persulfate is a first-order reaction; at 70℃, the half-life of ammonium persulfate is over 8 hours. At 50℃, the half-life is 152 hours, indicating very slow decomposition. Below 50℃, the breaker ability of persulfate decreases rapidly.

[0004] When the formation temperature is below 50°C, conventional fracturing fluid breaker (mainly peroxides, such as ammonium persulfate and sodium persulfate) cannot obtain sufficient activation energy at low temperatures, so it cannot generate enough oxygen free radicals and acids through self-decomposition reaction. Oxygen free radicals and acids are the key basis for fracturing.

[0005] In recent years, researchers have begun to study improving the gel-breaking ability of fracturing fluids under low-temperature conditions, mainly focusing on the effects of different gel-breaking aids on gel-breaking performance. The main methods used include: 1. Adding reducing agents such as RA (inorganic salt) and Fe(II). The main problem with this method is the Fe produced by the APS / Fe(II) reaction. 3+Precipitation occurs at pH ≥ 3, resulting in a high residue content and causing formation damage. 2. Adding a complexing activator that inhibits iron ion precipitation to a certain concentration of ferrous iron salt (Fe(II)) synergistically promotes the decomposition of APS breaker. Compared with using ferrous iron salt (Fe(II)) alone as an additive, this method requires less dosage and accelerates the fracturing fluid breaking speed. Its chelating effect on iron ions accelerates the reaction. The main problem with this method is that the breaking speed is too fast, making it unsuitable for on-site construction conditions.

[0006] In summary, none of the currently available breaker agents are suitable for fracturing fluid breaker operations at low temperatures. Summary of the Invention

[0007] The purpose of this invention is to provide a breaker activator, a fracturing fluid containing the breaker, a method for preparing the breaker, and its application, thereby solving the problem that existing breaker agents are not suitable for fracturing fluid breaker operations at low temperatures.

[0008] This invention is achieved through the following technical solution:

[0009] On one hand, the present invention discloses a gel-breaking activator, which comprises the following components by mass percentage:

[0010] Triethanolamine 3.3%–7.13%, D-isoascorbic acid sodium 6.7%–8.58%, tea polyphenols 3.3%–7.13%, sodium dehydroacetate 6.7%–8.58%, ethylene glycol 8.58%–20%, balance water.

[0011] On the other hand, the present invention discloses a method for preparing the gel-breaking activator, comprising the following steps:

[0012] Triethanolamine, sodium D-isoascorbate, tea polyphenols, sodium dehydroacetate, and ethylene glycol were mixed and stirred evenly, and then diluted with water to obtain a gelling activator.

[0013] On the other hand, the present invention discloses a fracturing fluid containing the aforementioned breaker activator.

[0014] Furthermore, the fracturing fluid comprises the following components:

[0015] Super guar gum, a demulsifier, a demulsifier, water, and the demulsifying activator as described in claim 1;

[0016] The amount of the breaker activator added is 1% to 3% of the total mass of the fracturing fluid.

[0017] Furthermore, the exhaust aid is a fluorocarbon surfactant, a compound of fluorocarbon surfactant and hydrocarbon surfactant, a compound of fluorocarbon surfactant and anionic surfactant, or a compound of nonionic amphoteric surfactant.

[0018] Furthermore, the demulsifier is at least one of alkyl sulfate, sulfonate, carboxyl compound, polyol, or a compound;

[0019] The compound is a mixture of polyalkylene glycol and ether.

[0020] On the other hand, the present invention discloses the application of the fracturing fluid in fracturing fluid degumming. After the fracturing fluid is prepared, a degumming agent and a crosslinking agent are added to the fracturing fluid. The fracturing fluid can degumme oil and gas reservoirs at 20-50°C.

[0021] The time for complete breakage of fracturing fluid is greater than the fracturing operation time, while the time for complete breakage of fracturing fluid is less than the blowout time.

[0022] Furthermore, in the application of the fracturing fluid in fracturing fluid debonding, the main debonding agent is peroxide.

[0023] Furthermore, in the application of the fracturing fluid in fracturing fluid gel breaking, the peroxide is ammonium persulfate.

[0024] Furthermore, in the application of the fracturing fluid in fracturing fluid gel breaking, the crosslinking agent is a borate, titanium compound, or zirconium compound.

[0025] Compared with the prior art, the present invention has the following beneficial technical effects:

[0026] This invention provides a debonding activator comprising triethanolamine, sodium D-isoascorbate, tea polyphenols, sodium dehydroacetate, and ethylene glycol. Triethanolamine acts as a reducing agent, while sodium D-isoascorbate and tea polyphenols act as antioxidants, forming a redox system. Since the main component of the debonding agent is ammonium persulfate, the free radicals generated by electron transfer between the oxidizing and reducing agents can be utilized to break the peroxy O-O groups of the persulfate ion, generating oxidative free radicals, which further react with water to produce hydroxyl free radicals. By establishing a redox system, the activation energy required to generate oxygen free radicals and acids is reduced, solving the problem of low-temperature debonding. This activator exhibits good wettability at the oil-water interface, good dispersibility in both oil and water phases, and excellent debonding performance, making it an excellent mixed-type debonding activator. The debonding activator prepared by this invention is stable at room temperature, can be stored for a long time, and has a simple formulation.

[0027] This invention also discloses a method for preparing a gel-breaking activator, which involves physically blending several raw materials. The preparation process is simple, can be prepared on-site, and is very convenient to use.

[0028] This invention also discloses a fracturing fluid containing a breaker activator, which is stable at room temperature, can be stored for a long time, and has a simple formulation. The breaker activator is used in small amounts, only 1%–3%, and exhibits good breaker performance at low temperatures (20–50°C). The main component of the breaker is ammonium persulfate. At low temperatures, the breaker activator decomposes the ammonium persulfate, producing free oxygen and acid, which disrupts the cross-linked structure of the hydroxypropyl guar gum fracturing fluid, causing macromolecular degradation. This solves the problem of difficult breaker formation when the fracturing fluid temperature is below 50°C, resulting in good economic and environmental benefits. Attached Figure Description

[0029] like Figure 1 The image shows the fracturing fluid prepared by adding 1% (V / V) of breaker activator in Application Case 1 at 20°C.

[0030] like Figure 2 The image shows the fracturing fluid prepared at 20°C with 2% (V / V) breaker activator added in Application Case 1.

[0031] like Figure 3 The image shows the fracturing fluid prepared by adding 3% (V / V) breaker activator in Application Case 1 at 20°C.

[0032] like Figure 4 The image shows the fracturing fluid prepared by adding 1% (V / V) of breaker activator in Application Case 2 at 25°C.

[0033] like Figure 5 The image shows the fracturing fluid prepared by adding 2% (V / V) of breaker activator in Application Case 2 at 25°C.

[0034] like Figure 6 The image shows the fracturing fluid prepared by adding 3% (V / V) of breaker activator in Application Case 2 at 25°C.

[0035] like Figure 7 The image shows the fracturing fluid prepared by adding 1% (V / V) of breaker activator in Application Case 3 at 30°C.

[0036] like Figure 8 The image shows the fracturing fluid prepared by adding 2% (V / V) breaker activator in Application Case 3 at 30°C.

[0037] like Figure 9 The image shows the fracturing fluid prepared by adding 3% (V / V) breaker activator in Application Case 3 at 30°C.

[0038] like Figure 10The image shows the fracturing fluid prepared by adding 1% (V / V) breaker activator in Application Case 4 at 35°C.

[0039] like Figure 11 The image shows the fracturing fluid prepared by adding 2% (V / V) breaker activator in Application Case 4 at 35°C.

[0040] like Figure 12 The image shows the fracturing fluid prepared by adding 3% (V / V) of breaker activator in Application Case 4 at 35°C.

[0041] like Figure 13 The image shows the fracturing fluid prepared by adding 1% (V / V) of breaker activator in Application Case 5 at 40°C.

[0042] like Figure 14 The image shows the fracturing fluid prepared by adding 2% (V / V) breaker activator in Application Case 5 at 40°C.

[0043] like Figure 15 The image shows the fracturing fluid prepared by adding 3% (V / V) of breaker activator in Application Case 5 at 40°C.

[0044] like Figure 16 The image shows the fracturing fluid prepared by adding 1% (V / V) of breaker activator in Application Case 6 at 50°C.

[0045] like Figure 17 The image shows the fracturing fluid prepared by adding 2% (V / V) breaker activator in Application Case 6 at 50°C.

[0046] like Figure 18 The image shows the fracturing fluid prepared by adding 3% (V / V) of breaker activator in Application Case 6, and its breaker behavior at 50°C. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the present invention clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention; that is, the described embodiments are only a part of the embodiments of the present invention, and not all of them.

[0048] The components described and illustrated in the accompanying drawings and embodiments of this invention can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the invention provided in the following drawings is not intended to limit the scope of the claimed invention, but merely to illustrate one selected embodiment of the invention. All other embodiments obtained by those skilled in the art based on the accompanying drawings and embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0049] It should be noted that the terms “comprising,” “including,” or any other variations are intended to cover non-exclusive inclusion, such that a process, element, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to the process, element, method, article, or apparatus.

[0050] This invention discloses a gel-breaking activator, comprising the following components by mass percentage:

[0051] Triethanolamine 3.3%–7.13%, D-isoascorbic acid sodium 6.7%–8.58%, tea polyphenols 3.3%–7.13%, sodium dehydroacetate 6.7%–8.58%, ethylene glycol 8.58%–20%, balance water.

[0052] The specific synthesis method of the de-gelling activator designed in this invention is as follows: triethanolamine (industrial grade), sodium D-isoascorbate (industrial grade), tea polyphenols (industrial grade), sodium dehydroacetate (industrial grade) and ethylene glycol (industrial grade) are mixed and stirred evenly in a reaction vessel at room temperature, and then diluted with domestic water to finally obtain the de-gelling activator.

[0053] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0054] Example 1

[0055] A debonding activator, by weight percentage, comprises the following components: 3.3% triethanolamine, 6.7% sodium D-isoascorbate, 3.3% tea polyphenols, 6.7% sodium dehydroacetate, 20% ethylene glycol, and 60% water; wherein triethanolamine, sodium D-isoascorbate, tea polyphenols, sodium dehydroacetate, and ethylene glycol are all industrial grade.

[0056] The specific preparation method of the gel breaking activator is as follows: triethanolamine, sodium D-isoascorbate, tea polyphenols, sodium dehydroacetate and ethylene glycol are mixed and stirred evenly in a reaction vessel at room temperature, and then diluted with domestic water.

[0057] Example 2

[0058] A debonding activator, by weight percentage, comprises the following components: 5% triethanolamine, 7.5% sodium D-isoascorbate, 5% tea polyphenols, 7.5% sodium dehydroacetate, 15% ethylene glycol, and 60% water; wherein triethanolamine, sodium D-isoascorbate, tea polyphenols, sodium dehydroacetate, and ethylene glycol are all industrial grade.

[0059] The specific preparation method of the gel breaking activator is as follows: triethanolamine, sodium D-isoascorbate, tea polyphenols, sodium dehydroacetate and ethylene glycol are mixed and stirred evenly in a reaction vessel at room temperature, and then diluted with domestic water.

[0060] Example 3

[0061] A debonding activator, by weight percentage, comprises the following components: 6% triethanolamine, 8% sodium D-isoascorbate, 6% tea polyphenols, 8% sodium dehydroacetate, 12% ethylene glycol, and 60% water; wherein triethanolamine, sodium D-isoascorbate, tea polyphenols, sodium dehydroacetate, and ethylene glycol are all industrial grade.

[0062] The specific preparation method of the gel breaking activator is as follows: triethanolamine, sodium D-isoascorbate, tea polyphenols, sodium dehydroacetate and ethylene glycol are mixed and stirred evenly in a reaction vessel at room temperature, and then diluted with domestic water.

[0063] Example 4

[0064] A debonding activator, by weight percentage, comprises the following components: 6.67% triethanolamine, 8.33% sodium D-isoascorbate, 6.67% tea polyphenols, 8.33% sodium dehydroacetate, 10% ethylene glycol, and 60% water; wherein triethanolamine, sodium D-isoascorbate, tea polyphenols, sodium dehydroacetate, and ethylene glycol are all industrial grade.

[0065] The specific preparation method of the compound decolloid activator is as follows: triethanolamine, sodium D-isoascorbate, tea polyphenols, sodium dehydroacetate and ethylene glycol are mixed and stirred evenly in a reaction vessel at room temperature, and then diluted with domestic water.

[0066] Example 5

[0067] A gelling activator comprising 7.13% triethanolamine, 8.58% sodium D-isoascorbate, 7.13% tea polyphenols, 8.58% sodium dehydroacetate, 8.58% ethylene glycol, and 60% water;

[0068] Triethanolamine, sodium D-isoascorbate, tea polyphenols, sodium dehydroacetate, and ethylene glycol are all industrial products.

[0069] The specific preparation method of the gel breaking activator is as follows: triethanolamine, sodium D-isoascorbate, tea polyphenols, sodium dehydroacetate and ethylene glycol are mixed and stirred evenly in a reaction vessel at room temperature, and then diluted with domestic water.

[0070] Fracturing fluid was prepared using the breaker activator configured in Examples 1-5 above. The fracturing fluid included 0.3% super guar gum, 1.0% flow aid, 1.0% demulsifier, 0.8% crosslinking agent, and 1%–3% breaker activator, with the remainder being the main breaker agent. The low-temperature breaker properties of the fracturing fluid were then evaluated.

[0071] Comparative Example 1

[0072] 2% triethanolamine, 8.58% sodium D-isoascorbate, 7.13% tea polyphenols, 8.58% sodium dehydroacetate, and 8.58% ethylene glycol were mixed and stirred evenly in a reaction vessel at room temperature, and then diluted with domestic water to obtain a mixture.

[0073] Comparative Example 2

[0074] 8% triethanolamine, 9% sodium D-isoascorbate, 7.13% tea polyphenols, 8.58% sodium dehydroacetate, and 8.58% ethylene glycol were mixed and stirred evenly in a reaction vessel at room temperature, and then diluted with domestic water to obtain a mixture.

[0075] Comparative Example 3

[0076] 8% triethanolamine, 6.7% sodium D-isoascorbate, 3% tea polyphenols, 9% sodium dehydroacetate, and 25% ethylene glycol were mixed and stirred evenly in a reaction vessel at room temperature, and then diluted with domestic water to obtain a mixture.

[0077] Application Case 1:

[0078] The fracturing fluid is prepared by weight percentage, specifically comprising 0.3% super guar gum, 1.0% flow aid, 1.0% demulsifier, and 1% breaker activator, with the remainder being water. This fracturing fluid, breaker, and crosslinking agent are added to the oil and gas reservoir, and the fracturing is carried out at a breaker temperature of 20°C. Figure 1 As shown, when the amount of the gel-breaking activator prepared in Examples 1-5 is 1%, the oil and gas reservoir is completely gelled by the fracturing fluid and becomes transparent. The time for complete gel breaking by the fracturing fluid is greater than the fracturing operation time, but less than the blowout time, and the performance meets the requirements.

[0079] like Figure 2 and Figure 3 As shown above, when the gel breaking temperature is 20°C and the amount of gel breaking activator prepared in Examples 1-5 is adjusted to 2% and 3% respectively, the oil and gas reservoir is completely gelled by the fracturing fluid and becomes transparent.

[0080] When the gel breaking temperature is 20℃, and the amount of gel breaking activator prepared in Comparative Examples 1-3 is 1%-3%, the oil and gas reservoir is not completely gelled by the fracturing fluid within 8 hours and remains in a gel-like state.

[0081] Application Case 2:

[0082] The fracturing fluid is prepared by weight percentage, specifically comprising 0.3% super guar gum, 1.0% flow-out aid, 1.0% demulsifier, 0.8% crosslinking agent, and 1% breaker activator, with the remainder being water. This fracturing fluid, breaker, and crosslinking agent are added to the oil and gas reservoir at a breaker temperature of 25°C. Figure 4 As shown, when the amount of the gel-breaking activator added in Examples 1-5 is 1%, the time for complete gel breaking of the fracturing fluid is greater than the fracturing operation time, and the time for complete gel breaking of the fracturing fluid is less than the blowout time, thus meeting the performance requirements.

[0083] like Figure 5 and Figure 6 As shown, when the gel breaking temperature is 25°C and the amount of gel breaking activator prepared in Examples 1-5 is adjusted to 2% and 3%, the oil and gas reservoir is completely gelled by the fracturing fluid and becomes transparent.

[0084] When the gel breaking temperature is 25℃, and the amount of gel breaking activator prepared in Comparative Examples 1-3 is 1%-3%, the oil and gas reservoir is not completely broken by the fracturing fluid within 8 hours and remains in a gel-like state.

[0085] Application Case 3

[0086] The fracturing fluid was prepared by weight percentage, specifically comprising 0.3% super guar gum, 1.0% flow-out aid, 1.0% demulsifier, and 1% breaker activator, with the remainder being water. This fracturing fluid, breaker agent, and crosslinking agent were added to the oil and gas reservoir. The low-temperature breaker performance of the fracturing fluid was evaluated: the breaker temperature was 30°C. Figure 7 As shown, when the amount of the gel-breaking activator prepared in Examples 1-5 is 1%, the time for complete gel breaking of the fracturing fluid is greater than the fracturing operation time, and the time for complete gel breaking of the fracturing fluid is less than the blowout time, thus meeting the performance requirements.

[0087] like Figure 8 and Figure 9 As shown, the gel breaking temperature is 30℃. When the amount of gel breaking activator prepared in Examples 1-5 is adjusted to 2% and 3%, the oil and gas reservoir is completely gelled by the fracturing fluid and becomes transparent.

[0088] When the gel breaking temperature is 30℃, and the amount of gel breaking activator prepared in Comparative Examples 1-3 is 1%-3%, the oil and gas reservoir is not completely gelled by the fracturing fluid within 8 hours and remains in a gel-like state.

[0089] Application Case 4:

[0090] The fracturing fluid is prepared by weight percentage, specifically comprising 0.3% super guar gum, 1.0% flow-out aid, 1.0% demulsifier, and 1% breaker activator, with the remainder being water. This fracturing fluid, breaker, and crosslinking agent are then added to the oil and gas reservoir at a breaker temperature of 35°C. Figure 10 As shown, when the amount of the gel-breaking activator prepared in Examples 1-5 is 1%, the time for complete gel breaking of the fracturing fluid is greater than the fracturing operation time, and the time for complete gel breaking of the fracturing fluid is less than the blowout time, thus meeting the performance requirements.

[0091] like Figure 11 and Figure 12 As shown, when the gel breaking temperature is 35℃ and the amount of gel breaking activator prepared in Examples 1-5 is adjusted to 2% and 3%, the oil and gas reservoir is completely gelled by the fracturing fluid and becomes transparent.

[0092] When the gel breaking temperature is 35℃, and the amount of gel breaking activator prepared in Comparative Examples 1-3 is 1%-3%, the oil and gas reservoir is not completely broken by the fracturing fluid within 8 hours and remains in a gel-like state.

[0093] Application Case 5:

[0094] The fracturing fluid is prepared by weight percentage, specifically comprising 0.3% super guar gum, 1.0% flow-out aid, 1.0% demulsifier, 0.8% crosslinking agent, and 1% breaker activator, with the remainder being water. This fracturing fluid, breaker, and crosslinking agent are added to the oil and gas reservoir at a breaker temperature of 40°C. Figure 13 As shown, when the amount of the gel breaking activator is 1%-3%, the time for the fracturing fluid to completely break down is greater than the fracturing operation time, and the time for the fracturing fluid to completely break down is less than the blowout time, thus meeting the performance requirements.

[0095] like Figure 14 and Figure 15 As shown, when the breaking temperature is 40℃ and the amount of breaking activator is adjusted to 2% and 3%, the oil and gas reservoir is completely broken by the fracturing fluid and becomes transparent.

[0096] When the gel breaking temperature is 40℃, and the amount of gel breaking activator prepared in Comparative Examples 1-3 is 1%-3%, the oil and gas reservoir is not completely broken by the fracturing fluid within 8 hours and remains in a gel-like state.

[0097] Application Case 6:

[0098] The fracturing fluid is prepared by weight percentage, specifically comprising 0.3% super guar gum, 1.0% flow-out aid, 1.0% demulsifier, and 1% breaker activator, with the remainder being water. This fracturing fluid, breaker agent, and crosslinking agent are then added to the oil and gas reservoir at a breaker temperature of 50°C. Figure 16 As shown, when the amount of the gel breaking activator is 1%, the time for the fracturing fluid to completely break down is greater than the fracturing operation time, and the time for the fracturing fluid to completely break down is less than the blowout time, thus meeting the performance requirements.

[0099] like Figure 17 and Figure 18 As shown, when the breaking temperature is 50℃ and the amount of breaking activator is adjusted to 2% and 3%, the oil and gas reservoir is completely broken by the fracturing fluid and becomes transparent.

[0100] When the gel breaking temperature is 50℃, and the amount of gel breaking activator prepared in Comparative Examples 1-3 is 1%-3%, the oil and gas reservoir is not completely broken by the fracturing fluid within 8 hours and remains in a gel-like state.

[0101] In the above application examples, the discharge aids used are fluorocarbon surfactants, mixtures of fluorocarbon surfactants and hydrocarbon surfactants, mixtures of fluorocarbon surfactants and anionic surfactants, or mixtures of nonionic amphoteric surfactants.

[0102] In the above application examples, the demulsifier used is at least one of alkyl sulfate, sulfonate, carboxyl compound, polyol or compound; the compound is a compound of polyalkylene glycol and ether.

[0103] In the above application examples, the crosslinking agents used are borate series, titanium compounds, or zirconium compounds.

[0104] Comparative Example

[0105] As shown in Table 1, the fracturing fluid system includes super guar gum, flow aid, and demulsifier, but does not include the demulsifier activator of this invention. The main demulsifier is the traditional APS demulsifier.

[0106] Preparation of fracturing fluid:

[0107] The mass percentages of the materials are as follows: 0.3% super guar gum, 1.0% drainage aid, 1.0% demulsifier, and the remainder is domestic water.

[0108] Preparation of crosslinking solution: Take 10 mL each of crosslinking agent and crosslinking regulator (crosslinking agent: crosslinking regulator = 1:1), put them into a separate 50 mL beaker and stir well.

[0109] Preparation of fracturing fluid gel: Measure 100 mL of the prepared fracturing fluid and put it into a 250 mL beaker. Then, use a pipette to transfer 0.8 mL of crosslinking liquid (crosslinking ratio: 0.8%) into the fracturing fluid and stir continuously until it becomes fracturing fluid gel.

[0110] Table 1

[0111]

[0112] Table 2

[0113]

[0114] As shown in Table 2, the gel breaking activator prepared in this invention can be added to the system formed above, which can quickly break the gel.

[0115] As can be seen from the performance test results in Tables 1 and 2, the gel-breaking activator of this invention can solve the problem of difficulty in gel breaking of conventional fracturing fluids at a formation temperature of 30°C. The preparation method of this gel-breaking activator is simple, requires a small dosage, and has good prospects for widespread application.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A gel-breaking activator, characterized in that, By weight percentage, it includes the following components: Triethanolamine 3.3%–7.13%, D-isoascorbic acid sodium 6.7%–8.58%, tea polyphenols 3.3%–7.13%, sodium dehydroacetate 6.7%–8.58%, ethylene glycol 8.58%–20%, balance water.

2. The method for preparing the gel-breaking activator according to claim 1, characterized in that, The process includes the following: Triethanolamine, sodium D-isoascorbate, tea polyphenols, sodium dehydroacetate, and ethylene glycol were mixed and stirred evenly, and then diluted with water to obtain a gelling activator.

3. A fracturing fluid comprising the breaker activator of claim 1.

4. The fracturing fluid according to claim 3, characterized in that, The fracturing fluid comprises the following components: Super guar gum, a demulsifier, a demulsifier, water, and the demulsifying activator as described in claim 1; The amount of the breaker activator added is 1% to 3% of the total mass of the fracturing fluid.

5. The fracturing fluid according to claim 4, characterized in that, The exhaust aids are fluorocarbon surfactants, mixtures of fluorocarbon surfactants and hydrocarbon surfactants, mixtures of fluorocarbon surfactants and anionic surfactants, or mixtures of nonionic amphoteric surfactants.

6. The fracturing fluid according to claim 4, characterized in that, The demulsifier is at least one of alkyl sulfate, sulfonate, carboxyl compound, polyol or compound; The compound is a mixture of polyalkylene glycol and ether.

7. The application of the fracturing fluid according to any one of claims 3-6 in fracturing fluid rupture, characterized in that, After the fracturing fluid is prepared, a breaker and a crosslinking agent are added to the fracturing fluid; the fracturing fluid can break up the oil and gas reservoir at 20-50°C. The time for complete breakage of fracturing fluid is greater than the fracturing operation time, while the time for complete breakage of fracturing fluid is less than the blowout time.

8. The application of the fracturing fluid according to claim 7 in fracturing fluid rupture, characterized in that, The main de-gelling agent is peroxide.

9. The application of the fracturing fluid according to claim 8 in fracturing fluid rupture, characterized in that, The peroxide is ammonium persulfate.

10. The application of the fracturing fluid according to claim 7 in fracturing fluid rupture, characterized in that, The crosslinking agent is a borate, titanium compound, or zirconium compound.

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