Anti-blocking fluid for resin cementing fluid as well as preparation method and use method of anti-blocking fluid

Abstract

The invention provides an anti-blocking liquid for a resin cementing fluid as well as a preparation method and a use method of the anti-blocking liquid. The anti-blocking liquid comprises the following components in parts by weight: 100 parts of water, 15-100 parts of an epoxy resin diluent, 5-15 parts of an emulsifier and 0-3 parts of a suspension stabilizer. The epoxy resin diluent and the epoxy resin have good compatibility and can delay the curing time of the epoxy resin, and the emulsifier can effectively reduce the interfacial tension of each component of a water-phase mixed system of the epoxy resin and the anti-blocking liquid and form a firm film on the surface of the epoxy resin microdroplet or form a double electric layer on the surface of the epoxy resin microdroplet. And while the uniform emulsion is kept, the epoxy resin is prevented from being gathered, cured and blocked. The suspension stabilizer enables the anti-blocking liquid to suspend the resin microdroplets better, and prevents the retained resin microdroplets from settling and gathering to hinder the gathering and curing of the epoxy resin.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield development cementing operations, and in particular relates to an anti-clogging liquid for resin cementing fluid and a preparation method and a use method thereof. Background Art

[0002] With the deepening of exploration and development, the number of casing damaged wells in various oil fields has increased year by year. Small casing cementing of casing damaged wells and side drilling of old wells are the main technical means to tap the potential of old wells and increase production. The cementing annulus gap of small casing cementing and side drilling is narrow and the cement annulus is thin; the traditional oil well cement-based materials are relatively brittle, the structural integrity of the cement annulus is easily damaged, and there are problems such as micro-gaps in the annulus, which lead to the failure of cement annulus sealing. The use of resin cementing fluid for cementing can effectively reduce the cementing construction pressure and improve the annulus sealing. However, during the small gap cementing construction process, the resin cementing fluid is not completely replaced due to the wear and tear of the rubber plug, resulting in cementing fluid retention; after the cementing is completed, the cementing fluid is not completely replaced and remains in the casing, accumulating and blocking the channel, resulting in the inability to log the bottom, and multiple trips of small drilling tools are required for well clearance or drilling plug treatment. It is difficult to handle the drilling plug for cementing small-sized casing, affecting the construction efficiency.

[0003] Patent number CN201310351101.9, patent name "Horizontal well cementing anti-plugging fluid and preparation method thereof" discloses a horizontal well cementing anti-plugging fluid and preparation method thereof. It mainly solves the technical problem that cement slurry is retained in the casing after the rubber plug is worn on one side, resulting in the inability to measure the bottom of the well logging. It is easy to configure on site, has good flow performance, and has a strong ability to suspend and disperse cement particles. It can prevent cement from clogging the passage in the casing due to deposition, and saves the construction procedures of drilling plugs with small drilling tools. However, the patented anti-plugging fluid only has a good effect on cement-based cementing fluid cementing anti-plugging, and is not suitable for anti-plugging use in resin-based cementing fluid systems. Summary of the invention

[0004] The purpose of the present invention is to provide an anti-clogging liquid for resin cementing fluid, which has low viscosity, good fluidity, is easily soluble in water and is easy to pump.

[0005] Another object of the present invention is to provide a method for preparing an anti-clogging fluid for resin cementing fluid.

[0006] Another object of the present invention is to provide a method for using an anti-clogging liquid for resin cementing fluid, which can effectively prevent the aggregation and deposition of resin droplets, prevent the resin cementing fluid from agglomerating and solidifying to form a plug, ensure the passage in the casing, and solve the difficult processing problem.

[0007] To this end, the technical solution provided by the present invention is as follows: An anti-clogging liquid for resin cementing fluid comprises the following components in parts by weight: 100 parts water; Epoxy resin diluent 15-100 parts; 5-15 parts of emulsifier; Suspension stabilizer 0-3 parts.

[0008] The epoxy resin diluent is one or more of polyol, N,N-dimethylformamide and acetone.

[0009] The emulsifier is one or more of Tween 60, emulsifier SR-10, and secondary alcohol AEO-9.

[0010] The suspension stabilizer is one or more of xanthan gum, carboxymethyl cellulose, hydroxyethyl cellulose and anionic polyacrylamide.

[0011] The polyol is ethylene glycol or butanediol.

[0012] The relative molecular weight of the carboxymethyl cellulose is 20,000-80,000, the relative molecular weight of the hydroxyethyl cellulose is 30,000-100,000, and the relative molecular weight of the anionic polyacrylamide is 3 million-6 million.

[0013] A method for preparing an anti-clogging liquid for resin cementing fluid comprises the following steps: Step 1) adding a formulated amount of suspension stabilizer to a formulated amount of water while stirring, stirring to dissolve evenly, and standing for 60-120 minutes to fully hydrate, to obtain a suspension stabilizer aqueous solution; Step 2) Add the epoxy resin diluent and emulsifier in the formula amount to the suspension stabilizer aqueous solution in sequence and stir for 30-60 minutes.

[0014] A method for using an anti-clogging liquid for resin cementing fluid. After the resin cementing fluid is pumped, the anti-clogging liquid is injected into the casing behind the rubber plug during displacement. The anti-clogging liquid is mixed with the resin cementing fluid during displacement flow to form a suspension, thereby preventing resin droplets from aggregating and depositing, preventing the resin cementing fluid from aggregating, solidifying and leaving a plug, and ensuring the passage in the casing.

[0015] The amount of the anti-blocking liquid is 100-300m3 of the casing inner volume.

[0016] The beneficial effects of the present invention are: The anti-clogging liquid for resin cementing fluid provided by the present invention has the characteristics of low viscosity, good fluidity and easy solubility in water, and can reduce the viscosity of epoxy resin, so that the epoxy resin can easily form a suspension with the anti-clogging liquid during the displacement flow process. At the same time, the diluent and epoxy resin have good compatibility and can delay the curing time of the epoxy resin. The emulsifier can effectively reduce the interfacial tension of each component of the epoxy resin and the anti-clogging liquid aqueous phase mixed system, and form a relatively strong film on the surface of the epoxy resin droplets or form a double electric layer on the surface of the epoxy resin droplets to prevent the droplets from aggregating with each other, while maintaining a uniform emulsion to prevent the epoxy resin from aggregating and curing to leave a plug. The suspension stabilizer can increase the shear force, so that the anti-clogging liquid can better suspend the resin droplets, prevent the retained resin droplets from settling and aggregating, and hinder the epoxy resin from aggregating and curing. The epoxy resin diluent can significantly reduce the viscosity of the oily epoxy resin, improve the rheological properties of the epoxy resin-based cementing fluid, facilitate the mixing and pumping of the cementing fluid system, and enable the cementing fluid to meet the working performance requirements of the cementing fluid in the cementing of oil and gas wells.

[0017] The anti-clogging liquid of the present invention has good flowability and a density range of 1.0-1.20 g / cm 3 After the resin cementing fluid is pumped in, an anti-blocking liquid with a volume of 100-300m of casing is injected behind the rubber plug during displacement. When the rubber plug is worn and the force is uneven, the resin cementing fluid will flow into the groove and remain in the casing. The anti-blocking liquid system will mix with the resin cementing fluid during the displacement flow to form a suspension, which effectively prevents the aggregation and deposition of resin droplets and prevents the resin cementing fluid from agglomerating and solidifying to leave a blockage, thereby ensuring the passage in the casing and solving the problem of remaining blockage treatment. DETAILED DESCRIPTION

[0018] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0019] Now, exemplary embodiments of the present invention are introduced. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments are not intended to limit the present invention.

[0020] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0021] Example 1 This embodiment provides an anti-clogging liquid for resin cementing fluid, comprising the following components in parts by weight: 100 parts water; Epoxy resin diluent 15-100 parts; 5-15 parts of emulsifier; Suspension stabilizer 0-3 parts.

[0022] The epoxy resin diluent is one or more of polyol, N,N-dimethylformamide and acetone.

[0023] The emulsifier is one or more of Tween 60, emulsifier SR-10, and secondary alcohol AEO-9.

[0024] The suspension stabilizer is one or more of xanthan gum, carboxymethyl cellulose, hydroxyethyl cellulose and polyacrylamide.

[0025] The polyol is ethylene glycol or butanediol.

[0026] Principle of the invention: Epoxy resin diluent has good compatibility with epoxy resin and can delay the curing time of epoxy resin. Emulsifier can effectively reduce the interfacial tension of each component of epoxy resin and anti-blocking liquid aqueous mixed system, and form a relatively strong film or a double electric layer on the surface of epoxy resin droplets to prevent the droplets from aggregating with each other, while maintaining a uniform emulsion to prevent epoxy resin from aggregating and curing and leaving plugs. Suspension stabilizer can better suspend resin droplets in anti-blocking liquid, prevent the retained resin droplets from settling and aggregating, and hinder the aggregation and curing of epoxy resin.

[0027] The anti-blocking liquid has good flow properties. When the rubber plug is worn and the force is uneven, the resin cementing fluid will flow into the groove and remain in the casing. The anti-blocking liquid system mixes with the resin cementing fluid during the displacement flow to form a suspension, which effectively prevents the resin droplets from aggregating and depositing, and prevents the resin cementing fluid from aggregating and solidifying to leave a blockage. It can ensure the passage in the casing and solve the problem of difficult blockage treatment.

[0028] Example 2 Based on Example 1, this example provides an anti-clogging fluid for resin cementing fluid, comprising the following components in parts by weight: 100 parts water; Epoxy resin thinner 20 parts; Emulsifier 10 parts; 1.5 parts of suspension stabilizer.

[0029] Preparation process: Step 1) adding a formulated amount of suspension stabilizer to a formulated amount of water while stirring, stirring to dissolve evenly, and standing for 80 minutes to fully hydrate, to obtain a suspension stabilizer aqueous solution; Step 2) Add the epoxy resin diluent and emulsifier in the formula amount to the suspension stabilizer aqueous solution in sequence and stir for 30 minutes.

[0030] In this embodiment, the suspension stabilizer is carboxymethyl cellulose; the emulsifier is Tween 60; and the epoxy resin diluent is N,N-dimethylformamide.

[0031] Example 3 Based on Example 1, this example provides an anti-clogging fluid for resin cementing fluid, comprising the following components in parts by weight: 100 parts water; Epoxy resin thinner 30 parts; Emulsifier 15 parts; 0.5 parts of suspension stabilizer.

[0032] Preparation process: Step 1) adding a formulated amount of suspension stabilizer to a formulated amount of water while stirring, stirring to dissolve evenly, and standing for 120 minutes to fully hydrate, to obtain a suspension stabilizer aqueous solution; Step 2) Add the epoxy resin diluent and emulsifier in the formula amount to the suspension stabilizer aqueous solution in sequence and stir for 50 minutes.

[0033] In this embodiment, the suspension stabilizer is anionic polyacrylamide; the emulsifier is emulsifier SR-10; and the epoxy resin diluent is a mixture of acetone and ethylene glycol, with a mass ratio of 2:1.

[0034] Example 4 Based on Example 1, this example provides an anti-clogging fluid for resin cementing fluid, comprising the following components in parts by weight: 100 parts water; Epoxy resin thinner 50 parts; 8 parts of emulsifier; 0.5 parts of suspension stabilizer.

[0035] Preparation process: Step 1) adding a formulated amount of suspension stabilizer to a formulated amount of water while stirring, stirring to dissolve evenly, and standing for 90 minutes to fully hydrate, to obtain a suspension stabilizer aqueous solution; Step 2) Add the epoxy resin diluent and emulsifier in the formula amount to the suspension stabilizer aqueous solution in sequence and stir for 70 minutes.

[0036] In this embodiment, the suspension stabilizer is a mixture of xanthan gum and hydroxyethyl cellulose in a mass ratio of 3:2; the emulsifier is a mixture of Tween 60 and secondary alcohol AEO-9 in a mass ratio of 1:1; and the epoxy resin diluent is a mixture of acetone and ethylene glycol in a mass ratio of 2:1.

[0037] In order to further illustrate the effect of the present invention, the following performance tests were performed on the anti-clogging liquids prepared in Examples 2-4.

[0038] 1) Thickening test According to the method in GB / T19139-2012 Oil Well Cement Test Method, a thickening test was carried out at 50°C and 25MPa to test the initial consistency and the consistency after 48 hours of the anti-plugging fluid. The test results are shown in Table 1.

[0039] The anti-blocking liquid prepared in Example 2 was mixed with epoxy resin E44 at a mass ratio of 50 / 50 and then subjected to a thickening test to obtain the initial consistency. Stir for 30 minutes at 50°C, remove the slurry cup, absorb the thickening oil on the top of the mixed liquid, pour the mixed liquid into a beaker and place it in a 50°C water area for 48 hours. After standing, pour the mixed liquid into a normal pressure thickener and stir to obtain the consistency after 48 hours.

[0040] The anti-blocking liquid prepared in Example 3 was mixed with epoxy resin E44 at a mass ratio of 60 / 40 and then subjected to a thickening test. The consistency test after 48 hours was the same as above.

[0041] The anti-blocking liquid prepared in Example 4 was mixed with epoxy resin E51 at a mass ratio of 70 / 30 and then subjected to a thickening test. The consistency test after 48 hours was the same as above.

[0042] 2) Viscosity test The viscosity was tested using a rotational viscometer. The results are shown in Table 1.

[0043] 3) Density test Measured with a digital liquid density meter. The results are shown in Table 1.

[0044] Table 1 Performance test results The test results show that after the anti-clogging liquid of the present invention is allowed to stand, the mixed liquid is poured into a normal pressure thickener for stirring, and the mixed liquid has a consistency of 20-22Bc and good fluidity, indicating that the anti-clogging liquid is pumpable.

[0045] 4) Comparative ratio The anti-plugging fluid for horizontal wells is a cement slurry anti-plugging fluid with good use effect, and the anti-plugging fluid for horizontal wells is used as a comparative example.

[0046] (1) First, prepare a carboxymethyl cellulose aqueous solution. First, weigh 5g of carboxymethyl cellulose and dissolve it in 85g of water according to the weight percentage. Stir it thoroughly to make it fully dissolved and evenly. After standing for 30 minutes, it is fully hydrated. Then weigh 3g of filtrate reducer, 5g of slow-release treatment agent EDTA, and 1g of particle dispersant in turn, pour them into the dissolved aqueous solution, and continue to stir for 20 minutes. The resulting liquid mixture is the horizontal well cementing anti-plugging fluid. The obtained horizontal well cementing anti-plugging fluid has a density of 1.09g / cm3 and a plastic viscosity of 32 mPa·s.

[0047] (2) After the anti-plugging fluid and epoxy resin E44 were mixed in a 50 / 50 ratio, a thickening test was conducted at 50°C and 25MPa according to the method in GB / T19139-2012 Oil Well Cement Test Method. The initial consistency of the mixed liquid was 14Bc. After stirring at 50°C for 30 minutes, the slurry cup was removed, the thickened oil on the top of the mixed liquid was sucked off, and the mixed liquid was poured into a beaker and placed in a 50°C water area for 48 hours. The epoxy resin settled and stratified, and was easily solidified, indicating that the anti-plugging fluid for horizontal wells cannot meet the anti-plugging requirements of resin cementing fluids.

[0048] Example 5 The present embodiment provides a method for using an anti-blocking liquid for resin cementing fluid. After the resin cementing fluid is pumped, the anti-blocking liquid is injected into the casing behind the rubber plug during displacement. The anti-blocking liquid is mixed with the resin cementing fluid during the displacement flow process to form a suspension, thereby preventing the resin droplets from aggregating and depositing, and preventing the resin cementing fluid from aggregating and solidifying to form a blockage, thereby ensuring the passage in the casing.

[0049] The amount of the anti-blocking liquid is 100-300m3 of the casing inner volume.

[0050] The anti-clogging liquid of the present invention has good flowability and a density range of 1.0-1.20 g / cm3. After the resin cementing fluid is pumped, the anti-clogging liquid with a volume of 100-300 m2 of the casing is followed by the rubber plug during displacement. When the rubber plug is worn and unevenly stressed, the resin cementing fluid will flow into the groove and remain in the casing. The anti-clogging liquid system is mixed with the resin cementing fluid during the displacement flow process to form a suspension, which effectively prevents the aggregation and deposition of resin droplets and prevents the resin cementing fluid from aggregating and solidifying to leave a blockage, thereby ensuring the passage in the casing and solving the problem of difficult blockage treatment.

[0051] The above examples are merely illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. All designs that are the same or similar to the present invention fall within the protection scope of the present invention.

Claims

1. An anti-clogging liquid for resin cementing fluid, characterized in that: The composition comprises the following components in parts by weight: 100 parts water; Epoxy resin diluent 15-100 parts; 5-15 parts of emulsifier; Suspension stabilizer 0-3 parts.

2. The anti-clogging liquid for resin cementing fluid according to claim 1, characterized in that: The epoxy resin diluent is one or more of polyol, N,N-dimethylformamide and acetone.

3. The anti-clogging liquid for resin cementing fluid according to claim 1, characterized in that: The emulsifier is one or more of Tween 60, emulsifier SR-10, and secondary alcohol AEO-9.

4. The anti-clogging liquid for resin cementing fluid according to claim 1, characterized in that: The suspension stabilizer is one or more of xanthan gum, carboxymethyl cellulose, hydroxyethyl cellulose and anionic polyacrylamide.

5. The anti-clogging liquid for resin cementing fluid according to claim 2, characterized in that: The polyol is ethylene glycol or butanediol.

6. The anti-clogging liquid for resin cementing fluid according to claim 4, characterized in that: The relative molecular weight of the carboxymethyl cellulose is 20,000-80,000, the relative molecular weight of the hydroxyethyl cellulose is 30,000-100,000, and the relative molecular weight of the anionic polyacrylamide is 3 million-6 million.

7. The method for preparing an anti-clogging liquid for resin cementing fluid according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1) adding a formulated amount of suspension stabilizer to a formulated amount of water while stirring, stirring to dissolve evenly, and standing for 60-120 minutes to fully hydrate, to obtain a suspension stabilizer aqueous solution; Step 2) Add the epoxy resin diluent and emulsifier in the formula amount to the suspension stabilizer aqueous solution in sequence and stir for 30-60 minutes.

8. The method for using the anti-clogging liquid for resin cementing fluid according to any one of claims 1 to 6, characterized in that: After the resin cementing fluid is pumped in, anti-blocking liquid is injected into the casing behind the rubber plug during displacement. The anti-blocking liquid mixes with the resin cementing fluid during displacement flow to form a suspension, which prevents the resin droplets from aggregating and depositing, and prevents the resin cementing fluid from aggregating and solidifying to leave a blockage, thereby ensuring the passage in the casing.

9. The method for using the anti-clogging liquid for resin cementing fluid according to claim 8, characterized in that: The amount of the anti-blocking liquid is 100-300m3 of the casing inner volume.

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