A suspension stabilizer for preventing abnormal high-temperature thickening of well cement and a preparation method thereof

Abstract

The application discloses a kind of anti-cementing cement high-temperature thickening abnormality suspension stabilizer and preparation method thereof, the suspension stabilizer includes 65~80 parts high-temperature suspension stabilizing main agent, 10~20 parts high-temperature suspending agent, 5~15 parts high-temperature thickening agent and 1~3 parts high-temperature thickening abnormality prevention agent;The high-temperature suspension stabilizing main agent is water-soluble hydrophobic association polymer, and is obtained by free radical micellar polymerization reaction.Compared with ordinary suspension stabilizer, the suspension stabilizer prepared in the application has no obvious thickening effect at room temperature, and has good suspension stabilizing effect;At high temperature, due to the sharp hydrophobic association of water-soluble hydrophobic association polymer, it can still maintain good suspension stability, thereby effectively guaranteeing the high-temperature working performance of high-density cementing slurry in deep well and ultra-deep well, improving the cementing quality of deep well and ultra-deep well, and guaranteeing the efficient and safe exploitation of oil and gas resources in deep well and ultra-deep well.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of additives for cementing slurry, and particularly relates to a suspension stabilizer for preventing abnormal high-temperature thickening of cementing cement and a preparation method thereof. BACKGROUND

[0002] The growing social economy has an increasingly great demand for energy, however, the shallow oil and gas resources on land in China have been almost exhausted, and the domestic major oilfield companies are increasing the exploration and development of deep and ultra-deep oil and gas resources, and therefore, the number of deep and ultra-deep wells is also increasing. In the cementing of deep and ultra-deep wells, the formation environment is high temperature and high pressure, and in order to stabilize the formation, a high-density cementing slurry needs to be used, and in order to ensure the uniformity and stability of the high-density cementing slurry weighting material and cementitious material under high temperature, a high-temperature suspension stabilizer also needs to be added.

[0003] At present, the high-temperature suspension stabilizer is mainly composed of high-molecular polymer and clay mineral, and has the following problems: first, the slurry is seriously thickened at room temperature, which affects the construction performance, and the pumping power needs to be increased for normal construction, but the structure of the high-molecular polymer is easily damaged under high shear and cannot be restored, and then the suspension performance of the high-temperature suspension stabilizer is affected; second, under high temperature, the adsorption of the polymer molecules is weakened, and in addition, due to the intensified thermal dilution effect of the cement slurry, the suspension stabilizing effect of the high-molecular polymer on each component of the cement, especially the weighting component, is greatly weakened. In addition, under high temperature, the water contained in each component of the high-density cement slurry is separated out, the cement slurry is seriously separated, the high-temperature stability is poor, and then the working performances of the cement slurry, such as high-temperature strength, high-temperature fluid loss, high-temperature thickening, etc., are difficult to meet the requirements of the cementing of deep and ultra-deep wells.

[0004] In order to ensure the fixing quality of the high-density cementing cement under the high-temperature and high-pressure environment of deep and ultra-deep layers, active admixtures such as quartz sand and metakaolin, and high-temperature fluid loss agents, high-temperature retarders and other additives need to be added, and therefore, the components of the high-density cement slurry are very complex. Under the comprehensive action of the admixtures, additives and cement in the high-temperature thickening process, the high-temperature thickening curve of the high-density cementing slurry is prone to abnormal phenomena such as "core wrapping" and "bulging".

[0005] The "core wrapping" phenomenon of cement slurry refers to the abnormal gelation of cement slurry in the slurry shaft part during the high-temperature thickening experiment, forming a gelatinous wrapping in the slurry shaft part, and forming a clear layer with the cement slurry close to the paddle outside the slurry shaft. The width of the cement channel in the cementing effect is only 3-5 cm, and if the abnormal gelation of cement slurry occurs, the gelatinous cement formed may block the channel, which will cause great harm to the cementing operation. The "bulging" of cement slurry refers to the process that the consistency of cement slurry abnormally increases during the high-temperature thickening experiment, and then returns to the normal level, which is manifested as bulging on the thickening curve. If the bulging is serious, it will lead to poor flowability of the cement slurry, increase the pumping pressure of the cement slurry, increase the cementing operation, and even lead to cementing failure. Therefore, in order to ensure the safe construction of cementing, the abnormal phenomena such as "core wrapping" and "bulging" should be avoided during the high-temperature thickening of high-density cement slurry. SUMMARY

[0006] In order to overcome the defects and deficiencies existing in the prior art, the present application provides a high-temperature suspension stabilizer capable of preventing high-temperature thickening abnormalities of cement slurry for well cementing. The purpose of the present application is to improve the deficiencies of the existing high-temperature suspension stabilizer, enhance the high-temperature settling stability of high-density cement slurry for well cementing, prevent high-temperature thickening abnormalities of high-density cement slurry for well cementing, ensure the cementing quality of deep and ultra-deep wells, and further improve the efficient and safe exploitation of oil and gas resources in deep and ultra-deep wells, thereby filling part of the gap in the demand for oil and gas resources for national economic development.

[0007] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0008] A suspension stabilizer for preventing high-temperature thickening abnormalities of cement for well cementing, comprising the following components by weight fraction:

[0009]

[0010] The high-temperature suspension stabilizing main agent is a water-soluble hydrophobic associated polymer, which comprises 30-50 parts of alkenyl sulfonic acid monomer, 30-45 parts of alkenyl carboxylic acid monomer, 10-25 parts of alkenyl cation monomer, and 1-3 parts of alkenyl hydrophobic monomer by weight fraction, and 2-4 parts of ammonium persulfate as initiator, 3-5 parts of isopropyl alcohol as chain transfer agent, and 0.3-0.5 parts of dodecyl ammonium sulfate as surfactant, which is obtained by free radical micellar polymerization reaction.

[0011] The suspension stabilizer for preventing abnormal high-temperature thickening of cementing cement provided by the application uses a water-soluble hydrophobic association polymer as a high-temperature suspension stabilizing main agent. The water-soluble hydrophobic association polymer is a kind of heat-thickening water-soluble polymer, which has a relatively small solubility in water at normal temperature, and the solubility is accelerated with the increase of the temperature of the water solution, and the solubility is obviously accelerated at 90 DEG C, and the water-soluble hydrophobic association polymer can be completely dissolved at 120 DEG C. The heat dilution effect is intensified at high temperature, and it is difficult for common suspension stabilizers to guarantee the high-temperature sedimentation stability of high-density cement slurry. A large amount of free water is released from the flocculation structure of the cement slurry, the compatibility of the components is poor, it is difficult to suspend the weighting material, the cement slurry is seriously settled, the comprehensive working performance is poor, and it is difficult to guarantee the cementing quality of deep wells and ultra-deep wells, and even the cementing fails. The addition of the water-soluble hydrophobic association polymer can not affect the working performance of the high-density cementing cement slurry, and on the other hand, the hydrophobic association effect of the water-soluble hydrophobic association polymer is strengthened at high temperature, the suspension stability is enhanced, and the high-temperature stability of the high-density cement slurry is effectively enhanced.

[0012] In the technical scheme of the application, the high-temperature suspension stabilizing main agent is 65-80 parts; for example, 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, 70 parts, 71 parts, 72 parts, 73 parts, 74 parts, 75 parts, 76 parts, 77 parts, 78 parts, 79 parts, or 80 parts.

[0013] The high-temperature suspension agent is 10-20 parts; for example, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, or 20 parts.

[0014] The high-temperature thickening agent is 5-15 parts; for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, or 15 parts.

[0015] The high-temperature thickening abnormality preventing agent is 1-3 parts; for example, 1 part, 1.5 parts, 2 parts, 2.5 parts, or 3 parts.

[0016] In some embodiments of the application, the water-soluble hydrophobic association polymer includes 30-50 parts of an alkenyl sulfonic acid monomer by weight; for example, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 parts, 49 parts, or 50 parts.

[0017] The water-soluble hydrophobic association polymer includes 30-45 parts of an alkenyl carboxylic acid monomer; for example, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, or 45 parts.

[0018] The alkylene group-containing cationic monomer comprises 10-25 parts, for example, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts.

[0019] The alkylene group-containing hydrophobic monomer comprises 1-3 parts, for example, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts.

[0020] In some embodiments of the present application, the water-soluble hydrophobic associating polymer is obtained by a free radical micellar polymerization reaction with ammonium persulfate as an initiator, isopropanol as a chain transfer agent, and ammonium lauryl sulfate as a surfactant.

[0021] The ammonium persulfate comprises 2-4 parts, for example, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts.

[0022] The isopropanol comprises 3-5 parts, for example, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts.

[0023] The ammonium lauryl sulfate comprises 0.3-0.5 parts, for example, 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts, 0.5 parts.

[0024] In some embodiments of the present application, the suspension stabilizer for preventing abnormal thickening of the cement at high temperature comprises the following components by weight:

[0025]

[0026] Preferably, the high-temperature suspension stabilizer comprises a water-soluble hydrophobic associating polymer, which comprises at least 35-45 parts of an alkylene group-containing sulfonic acid monomer, 30-40 parts of an alkylene group-containing carboxylic acid monomer, 10-20 parts of an alkylene group-containing cationic monomer, and 2-3 parts of an alkylene group-containing hydrophobic monomer by weight, and is obtained by a free radical micellar polymerization reaction with 2-3 parts of ammonium persulfate as an initiator, 4-5 parts of isopropanol as a chain transfer agent, and 0.3-0.4 parts of ammonium lauryl sulfate as a surfactant.

[0027] Further, the alkylene group-containing sulfonic acid monomer comprises one or more of sodium methylallyl sulfonate, sodium vinyl sulfonate, and 2-acrylamido-2-methylpropane sulfonic acid (AMPS).

[0028] The alkylene group-containing carboxylic acid monomer comprises one or more of acrylic acid (AA), maleic anhydride (MA), and methacrylic acid (MAA).

[0029] The alkylene group-containing cationic monomer comprises one or more of dimethyldiallylammonium chloride (DMDAAC), acryloyloxyethyltrimethylammonium chloride (DAC), and trimethylallylammonium chloride (TAC).

[0030] The alkenyl-containing hydrophobic monomer includes but is not limited to one or more of octadecyl acrylate, dodecyl acrylate, nonyl acrylate, and the like.

[0031] Each component of the alkenyl sulfonic acid monomer, the alkenyl carboxylic acid monomer, the alkenyl-containing cationic monomer, and the alkenyl-containing hydrophobic monomer is of analytical purity.

[0032] Further, the high-temperature suspending agent includes one or more of polyethylene glycol 2000, polyvinyl alcohol 1788, and hydroxypropyl distarch phosphate.

[0033] Each component of the high-temperature suspending agent is of analytical purity.

[0034] The high-temperature suspending agent added in the present application mainly includes inorganic salts and mineral suspending materials, and has good compatibility with cement, admixtures, and weighting materials; in addition, the high-temperature suspending agent has good high-temperature resistance and salt resistance, and can effectively prevent the sinking of the weighting material under high-temperature conditions, thereby ensuring the high-temperature stability of the high-density cement slurry.

[0035] Further, the high-temperature thickening agent includes one or more of magnesium lithium silicate, sepiolite powder, and mica stone powder; the specific surface area of the high-temperature thickening agent is greater than or equal to 500 m 2 / kg.

[0036] The high-temperature thickening agent added in the present application has good thickening effect at 20℃ to 120℃, can effectively prevent the sinking of the weighting material in the high-density cement slurry, and ensures the uniformity and stability of the high-density cement slurry.

[0037] Further, the high-temperature thickening abnormality prevention agent includes one or more of borax, borate, and fluoroborate.

[0038] Each component of the high-temperature thickening abnormality prevention agent is of analytical purity.

[0039] Since many admixtures and additives are added in the high-density cement slurry, the composition is extremely complex, the hydration speeds of the cementitious components are different, and under the action of the non-cementitious components, weighting agents, and other additives, the cement slurry is prone to have adverse phenomena such as "core wrapping" and "bulging" during high-temperature thickening. The high-temperature thickening abnormality prevention agent added in the present application effectively prevents these abnormal adverse phenomena, and ensures the good working performance of the cement slurry.

[0040] The application further provides a preparation method of the suspension stabilizer for preventing abnormal high-temperature thickening of the cementing cement, which comprises the following steps: weighing high-temperature suspension stabilizing main agents, high-temperature suspending agents, high-temperature thickening agents and high-temperature thickening abnormality preventing agents according to the weight parts, and mixing them uniformly to obtain the suspension stabilizer for preventing abnormal high-temperature thickening of the cementing cement slurry.

[0041] Further, the preparation method of the high-temperature suspension stabilizing main agent of the water-soluble hydrophobic association polymer comprises the following steps:

[0042] In step A, the olefinic sulfonic acid monomer, the olefinic carboxylic acid monomer and the olefinic cation-containing monomer are added into water to be dissolved and mixed to form a first mixed solution; preferably, 30-50 parts of the olefinic sulfonic acid monomer, 30-45 parts of the olefinic carboxylic acid monomer and 10-25 parts of the olefinic cation-containing monomer are weighed according to the weight parts, and then added into 100 parts of water to be dissolved and mixed to form the first mixed solution;

[0043] In step B, the olefinic hydrophobic monomer and sodium dodecyl sulfate are added into water to be stirred to form a second mixed solution; preferably, 1-3 parts of the olefinic hydrophobic monomer and 0.3-0.5 parts of the sodium dodecyl sulfate are weighed according to the weight parts, and then added into 46.7-48.5 parts of water to be stirred at high speed to form the second mixed solution;

[0044] In step C, the ammonium persulfate and isopropyl alcohol are added into water to be stirred, dissolved and mixed to form a third mixed solution; preferably, 2-4 parts of the ammonium persulfate and 3-5 parts of the isopropyl alcohol are weighed according to the weight parts, and then added into 43 parts of water to be stirred at high speed, dissolved and mixed to form the third mixed solution;

[0045] In step D, preferably, the first mixed solution and the second mixed solution are mixed, the pH of the mixed solution is adjusted to 6-7, and then a fourth mixed solution is formed;

[0046] In step E, the third mixed solution is added dropwise into the fourth mixed solution to perform constant-temperature reaction, and a reaction solution is obtained;

[0047] In step F, the reaction solution is purified and dried in sequence, and the water-soluble hydrophobic association polymer is obtained.

[0048] In step D, preferably, a lye is added to adjust the pH value, more preferably, the lye is a sodium hydroxide solution, further preferably, the concentration of the sodium hydroxide solution is 15-25 wt.%, and more preferably, the concentration is 20 wt.%.

[0049] Further, in step E, the fourth mixed solution is moved into a reaction kettle, the third mixed solution is added dropwise into the reaction kettle to perform constant-temperature stirring reaction with the fourth mixed solution after the reaction kettle is heated to a preset temperature under a protective atmosphere; the protective gas is inert gas or nitrogen;

[0050] Preferably, the preset temperature of the temperature rise is 60-80 DEG C, more preferably 70 DEG C;

[0051] Preferably, the stirring reaction time of the constant temperature is 3-5h, more preferably 4.5h; the stirring speed of the constant temperature is 300-500r / min, more preferably 400r / min;

[0052] Preferably, the dropping speed of the third mixed solution is 8-15 drops / min, more preferably 10 drops / min.

[0053] Further, the step F is to purify the reaction solution by using anhydrous propanol for multiple times to obtain a white and viscous purified product, and the purified product is subjected to vacuum freeze-drying to obtain the water-soluble hydrophobic associated polymer.

[0054] Preferably, the adding amount of the anhydrous propanol is 80-90ml, more preferably 90ml.

[0055] Preferably, the temperature of the vacuum freeze-drying is -5--15 DEG C, more preferably -10 DEG C; the time of the vacuum freeze-drying is 6-18h, more preferably 12h.

[0056] Compared with the prior art, the present application has the following beneficial effects:

[0057] The ordinary suspension stabilizer is mainly composed of high molecular polymer and clay mineral, which causes the cement slurry to be seriously thickened at normal temperature, and affects the working performance of the cement slurry; under the action of high temperature, the suspension stability of the ordinary suspension stabilizer is poor, and it is difficult to effectively suspend the weighting material, so that the working performance of the cement slurry is rapidly deteriorated, and the cementing quality of the deep well and the ultra-deep well cannot be guaranteed. Compared with the ordinary suspension stabilizer, the suspension stabilizer prepared by the present application has no obvious thickening effect at normal temperature, and has good suspension stability; under high temperature, due to the rapid hydrophobic association of the water-soluble hydrophobic associated polymer, the suspension stabilizer still has good suspension stability, thereby effectively guaranteeing the high-temperature working performance of the high-density cementing slurry of the deep well and the ultra-deep well, improving the cementing quality of the deep well and the ultra-deep well, and guaranteeing the efficient and safe exploitation of the oil and gas resources of the deep well and the ultra-deep well.

[0058] The high-temperature suspension stabilizer prepared by the present application has good compatibility with the additives, and has wide applicability. According to the site conditions, the high-temperature fluid loss additive, the high-temperature retarder and other additives can be added to adjust the properties such as the fluid loss and the thickening time of the cement slurry, so as to form a high-density cementing slurry system with good rheological property, no free liquid, good settlement stability and other comprehensive working performances, which can completely meet the cementing construction requirements of the deep well and the ultra-deep well. BRIEF DESCRIPTION OF DRAWINGS

[0059] Figure 1 It is the high-temperature thickening curve of the high-density cement slurry prepared by the suspension stabilizer of Example 1.

[0060] Figure 2 High temperature thickening curve of high density cement slurry prepared by the suspension stabilizer of Example 1.

[0061] Figure 3 High temperature thickening curve of high density cement slurry prepared by the suspension stabilizer of Example 2.

[0062] Figure 4 High temperature thickening curve of high density cement slurry prepared by the suspension stabilizer of Example 3.

[0063] Figure 5 High temperature thickening curve of high density cement slurry prepared by the suspension stabilizer of Example 4.

[0064] Figure 6 High temperature thickening curve of high density cement slurry prepared by the suspension stabilizer of Example 5. DETAILED DESCRIPTION

[0065] In order to better understand the technical scheme of the present application, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0066] Example 1

[0067] As a preferred embodiment of the present application, the present embodiment discloses a suspension stabilizer for preventing high temperature thickening anomaly of cement for well cementation, which comprises the following components in parts by weight:

[0068]

[0069] In the present embodiment, the high temperature suspension stabilizer comprises 30 parts of alkenyl sulfonic acid monomer, 45 parts of alkenyl carboxylic acid monomer, 15 parts of alkenyl cation monomer and 2 parts of alkenyl hydrophobic monomer, and 3 parts of ammonium persulfate as initiator, 3 parts of isopropyl alcohol as chain transfer agent and 0.4 parts of dodecyl ammonium sulfate as surfactant, which are obtained by free radical micellar polymerization reaction.

[0070] In the present embodiment, the alkenyl sulfonic acid monomer comprises sodium methylallyl sulfonate and sodium vinyl sulfonate; the alkenyl sulfonic acid monomer comprises sodium methylallyl sulfonate, sodium vinyl sulfonate and 2-acrylamide-2-methylpropane sulfonic acid;

[0071] The alkenyl sulfonic acid monomer includes sodium methyl allyl sulfonate, sodium vinyl sulfonate and 2-acrylamide-2-methylpropane sulfonic acid;

[0072] The alkenyl-containing hydrophobic monomer includes octadecyl acrylate and dodecyl acrylate.

[0073] In this embodiment, the preparation of the high-temperature suspension stabilizing main agent of the water-soluble hydrophobic association polymer is as follows:

[0074] Step A: 30 parts of alkenyl sulfonic acid monomer, 45 parts of alkenyl carboxylic acid monomer and 15 parts of alkenyl-containing cationic monomer are weighed in parts by weight, added into 100 parts of water, dissolved and mixed to form a first mixed solution;

[0075] Step B: 2 parts of alkenyl-containing hydrophobic monomer and 0.4 parts of sodium dodecyl sulfate are weighed in parts by weight, added into 46.7 parts of water and stirred at high speed to form a second mixed solution;

[0076] Step C: 3 parts of ammonium persulfate and 3 parts of isopropyl alcohol are weighed in parts by weight, added into 43 parts of water, dissolved and mixed at high speed to form a third mixed solution;

[0077] Step D: The first mixed solution and the second mixed solution are mixed well, and the pH of the mixed solution is adjusted to 6-7 with sodium hydroxide solution to form a fourth mixed solution;

[0078] Step E: The third mixed solution is added dropwise into the fourth mixed solution for constant temperature reaction to obtain a reaction solution;

[0079] Step F: The reaction solution is purified and dried in sequence to obtain the water-soluble hydrophobic association polymer.

[0080] In this embodiment, the high-temperature suspension agent includes polyethylene glycol 2000 and polyvinyl alcohol 1788.

[0081] In this embodiment, the high-temperature thickening agent includes magnesium lithium silicate and mica stone powder, and the specific surface area of the high-temperature thickening agent is ≥500 m 2 / kg.

[0082] In this embodiment, the high-temperature thickening abnormality preventing agent includes borax and borate.

[0083] 65 parts of the high-temperature suspension stabilizing main agent, 20 parts of the high-temperature suspension agent, 12 parts of the high-temperature thickening agent and 3 parts of the high-temperature thickening abnormality preventing agent are weighed, mixed uniformly and then a high-temperature thickening abnormality preventing suspension stabilizing agent #1 for cement slurry is obtained.

[0084] Example 2

[0085] As a preferred embodiment of the present application, the embodiment discloses a kind of suspended stabilizer for preventing high-temperature thickening anomaly of well cementing cement, which comprises the following components by weight fraction:

[0086]

[0087] In the embodiment, the high-temperature suspended stabilizer is a water-soluble hydrophobic associating polymer, which comprises 38 parts of alkenyl sulfonic acid monomer, 30 parts of alkenyl carboxylic acid monomer, 20 parts of alkenyl cation-containing monomer and 3 parts of alkenyl hydrophobic monomer, and 4 parts of ammonium persulfate is used as initiator, 5 parts of isopropyl alcohol is used as chain transfer agent, and 0.3 parts of ammonium lauryl sulfate is used as surfactant, and the water-soluble hydrophobic associating polymer is obtained by free radical micellar polymerization reaction.

[0088] In the embodiment, the alkenyl sulfonic acid monomer comprises sodium vinyl sulfonate and 2-acrylamide-2-methylpropane sulfonic acid;

[0089] The carboxylic acid alkenyl monomer comprises maleic anhydride and methacrylic acid;

[0090] The alkenyl cation-containing monomer comprises dimethyldiallylammonium chloride and acryloyloxyethyl trimethyl ammonium chloride;

[0091] The alkenyl hydrophobic monomer comprises stearyl acrylate and dodecyl acrylate.

[0092] In the embodiment, the preparation of the high-temperature suspended stabilizer of the water-soluble hydrophobic associating polymer is as follows:

[0093] In step A, 38 parts of alkenyl sulfonic acid monomer, 30 parts of alkenyl carboxylic acid monomer and 20 parts of alkenyl cation-containing monomer are weighed by weight fraction, added into 100 parts of water, fully dissolved and mixed to form a first mixed solution;

[0094] In step B, 3 parts of alkenyl hydrophobic monomer and 0.3 parts of sodium dodecyl sulfate are weighed by weight fraction, added into 47 parts of water and stirred at high speed to form a second mixed solution;

[0095] In step C, 4 parts of ammonium persulfate and 5 parts of isopropyl alcohol are weighed by weight fraction, added into 43 parts of water, fully dissolved and mixed by high-speed stirring to form a third mixed solution;

[0096] In step D, the first mixed solution and the second mixed solution are fully mixed, and the pH of the mixed solution is adjusted to 6-7 by sodium hydroxide solution to form a fourth mixed solution;

[0097] In step E, the third mixed solution is added dropwise into the fourth mixed solution for constant-temperature reaction to obtain a reaction solution;

[0098] In step F, the reaction solution is purified and dried in sequence to obtain the water-soluble hydrophobic associating polymer.

[0099] In the embodiment, the high-temperature suspending agent comprises polyethylene glycol 2000 and hydroxypropyl distarch phosphate.

[0100] In the embodiment, the high-temperature thickening agent comprises magnesium lithium silicate and sepiolite powder, and the specific surface area of the high-temperature thickening agent is ≥500 m 2 / kg.

[0101] In the embodiment, the high-temperature thickening abnormality preventing agent comprises borax and fluoroborate.

[0102] 70 parts of the high-temperature suspending and stabilizing main agent, 13 parts of the high-temperature suspending agent, 15 parts of the high-temperature thickening agent, and 2 parts of the high-temperature thickening abnormality preventing agent are weighed, and after being fully mixed and uniformly mixed, the anti-cementing slurry high-temperature thickening abnormality suspending and stabilizing agent #2 is obtained.

[0103] Embodiment 3

[0104] As a preferred embodiment of the present application, the anti-cementing slurry high-temperature thickening abnormality suspending and stabilizing agent disclosed in the embodiment comprises the following components in parts by weight:

[0105]

[0106] In the embodiment, the high-temperature suspending and stabilizing main agent is a water-soluble hydrophobic associating polymer, which comprises 42 parts of an alkenyl sulfonic acid monomer, 36 parts of an alkenyl carboxylic acid monomer, 12 parts of an alkenyl cation-containing monomer, and 1 part of an alkenyl hydrophobic monomer, and is obtained by a free radical micellar polymerization reaction with 2 parts of ammonium persulfate as an initiator, 4 parts of isopropyl alcohol as a chain transfer agent, and 0.42 parts of ammonium lauryl sulfate as a surfactant.

[0107] In the embodiment, the alkenyl sulfonic acid monomer comprises sodium methylallyl sulfonate;

[0108] The carboxylic acid alkenyl monomer comprises one or more of maleic anhydride and methacrylic acid;

[0109] The alkenyl cation-containing monomer comprises dimethyldiallylammonium chloride and trimethylallyl ammonium chloride.

[0110] The alkenyl hydrophobic monomer comprises dodecyl acrylate.

[0111] In the embodiment, the preparation of the high-temperature suspending and stabilizing main agent of the water-soluble hydrophobic associating polymer is as follows:

[0112] Step A, 42 parts of the alkenyl sulfonic acid monomer, 36 parts of the alkenyl carboxylic acid monomer, and 12 parts of the alkenyl cation-containing monomer are weighed in parts by weight, added to 100 parts of water to be fully dissolved and mixed to form a first mixed solution;

[0113] Step B, take 1 part of the alkenyl-containing hydrophobic monomer and 0.42 parts of sodium dodecyl sulfate, add 48.5 parts of water, and stir at high speed to form a second mixture;

[0114] Step C, take 2 parts of ammonium persulfate and 4 parts of isopropanol, add 43 parts of water, and stir at high speed to fully dissolve and mix to form a third mixture;

[0115] Step D, mix the first mixture and the second mixture, and adjust the pH of the mixture to 6-7 with sodium hydroxide solution, and then form a fourth mixture;

[0116] Step E, drop the third mixture into the fourth mixture for constant temperature reaction to obtain a reaction solution;

[0117] Step F, purify and dry the reaction solution in sequence to obtain the water-soluble hydrophobic associating polymer.

[0118] In this embodiment, the high-temperature suspending agent is polyethylene glycol 2000.

[0119] In this embodiment, the high-temperature thickening agent includes sepiolite powder and mica stone powder, and the specific surface area of the high-temperature thickening agent is ≥500 m 2 / kg.

[0120] In this embodiment, the high-temperature thickening agent includes sepiolite powder and mica stone powder, and the specific surface area of the high-temperature thickening agent is ≥500 m 2 / kg.

[0121] According to the weight ratio of each component in this embodiment, take 75 parts of the high-temperature suspending stabilizing main agent, 18.5 parts of the high-temperature suspending agent, 5 parts of the high-temperature thickening agent, and 1.5 parts of the high-temperature thickening abnormal agent, and mix them evenly to obtain the suspending stabilizing agent #3 for preventing high-temperature thickening abnormality of the cement slurry for well cementation.

[0122] Example 4

[0123] As a preferred embodiment of the present application, the suspending stabilizing agent for preventing high-temperature thickening abnormality of the cement for well cementation disclosed in this embodiment includes the following components by weight:

[0124]

[0125] In this embodiment, the high-temperature suspending stabilizing main agent is a water-soluble hydrophobic associating polymer, which includes 50 parts of alkenyl sulfonic acid monomer, 40 parts of alkenyl carboxylic acid monomer, 25 parts of alkenyl-containing cationic monomer, and 2.5 parts of alkenyl-containing hydrophobic monomer, and 3.2 parts of ammonium persulfate as an initiator, 4.2 parts of isopropanol as a chain transfer agent, and 0.5 parts of sodium dodecyl sulfate as a surfactant, which are obtained by free radical micellar polymerization reaction.

[0126] In the embodiment, the alkenyl sulfonic acid monomer includes sodium methylallyl sulfonate, sodium vinyl sulfonate, 2-acrylamido-2-methylpropane sulfonic acid;

[0127] The alkenyl carboxylic acid monomer includes acrylic acid;

[0128] The alkenyl cationic monomer includes dimethyldiallyl ammonium chloride, trimethylallyl ammonium chloride;

[0129] The alkenyl hydrophobic monomer includes stearyl acrylate, dodecyl acrylate, nonyl acrylate.

[0130] In the embodiment, the preparation of the high-temperature suspension stabilizing main agent of the water-soluble hydrophobic association polymer is as follows:

[0131] Step A, 50 parts of alkenyl sulfonic acid monomer, 40 parts of alkenyl carboxylic acid monomer, and 25 parts of alkenyl cationic monomer are weighed in parts by weight, added into 100 parts of water, dissolved and mixed to form a first mixed solution;

[0132] Step B, 2.5 parts of alkenyl hydrophobic monomer and 0.5 parts of sodium dodecyl sulfate are weighed in parts by weight, added into 48 parts of water, and stirred at high speed to form a second mixed solution;

[0133] Step C, 3.2 parts of ammonium persulfate and 4.2 parts of isopropyl alcohol are weighed in parts by weight, added into 43 parts of water, dissolved and mixed at high speed to form a third mixed solution;

[0134] Step D, the first mixed solution and the second mixed solution are mixed, and the pH of the mixed solution is adjusted to 6-7 with sodium hydroxide solution to form a fourth mixed solution;

[0135] Step E, the third mixed solution is added dropwise into the fourth mixed solution for constant temperature reaction to obtain a reaction solution;

[0136] Step F, the reaction solution is purified and dried in sequence to obtain the water-soluble hydrophobic association polymer.

[0137] In the embodiment, the high-temperature suspension agent includes polyvinyl alcohol 1788 and hydroxypropyl distarch phosphate.

[0138] In the embodiment, the high-temperature thickening agent is mica stone powder, and the specific surface area of the high-temperature thickening agent is ≥500 m 2 / kg.

[0139] In the embodiment, the high-temperature thickening abnormality prevention agent is fluoroborate.

[0140] According to the weight ratio of the components in this embodiment, 80 parts of high-temperature suspension stabilizing main agent, 10 parts of high-temperature suspending agent, 9 parts of high-temperature thickening agent and 1 part of high-temperature anti-thickening abnormality agent are weighed, and after being uniformly mixed, the suspension stabilizing agent #4 for preventing high-temperature thickening abnormality of cement slurry is obtained.

[0141] Test Example 1

[0142] The suspension stabilizing agents #1 to #4 obtained in Examples 1 to 4 are respectively added to cement slurries under the same conditions to obtain experimental groups corresponding to the respective examples, and 195℃ experiments are carried out according to the following formulation: Jiahua G-grade oil well cement (based on 100wt.% of G-grade oil well cement) + 60wt.% of quartz sand + 165wt.% of iron powder + 0.5wt.% of suspension stabilizing agent + 0.5wt.% of polycarboxylic acid dispersing agent + 3wt.% of AMPS copolymer high-temperature retarder (liquid) + 5wt.% of AMPS-AM high-temperature fluid loss additive + 70wt.% of tap water.

[0143] Meanwhile, a control group and a blank group are set. The suspension stabilizing agent of the present application is replaced by a commercially available ordinary suspension stabilizing agent xanthan gum in the control group, and no suspension stabilizing agent is added in the blank group. The rest of the formulation and conditions are the same as described above.

[0144] High-density high-temperature cementing slurry is prepared according to “GB / T19139-2012 Oil Well Cement Test Method”, and the engineering performance of the high-density high-temperature cementing slurry in the control group, the blank group and each experimental group is tested according to “SY / T6544-2017 Oil Well Cement Slurry Performance Requirement”. The experimental results are shown in Table 1.

[0145] Table 1 Comparison of experimental results

[0146]

[0147] Note: The densities of the cement slurries prepared in the above experimental groups, the control group and the blank group are all 2.50g / cm 3 .

[0148] As can be seen from Table 1, under high-temperature conditions, the density difference between the top and bottom of the high-density cement slurry prepared without adding a suspension stabilizing agent (blank group) is very large, the cement slurry is severely destabilized, the thickening time and curve are abnormal, the thickening time is 133min, i.e. no thickening occurs; at the same time, the high-temperature thickening shows serious adverse phenomena of “bulging” and “core wrapping” (see Figure 6 ), and the high-temperature strength of the cement stone decays seriously (especially for 7d), which is difficult to meet the requirements of normal cementing construction. After adding a commercially available high-temperature suspension stabilizing agent (control group), the high-temperature stability of the prepared high-density cementing slurry is obviously improved, but the thickening time and curve are abnormal, and the high-temperature thickening still shows the “bulging” phenomenon (see Figure 5), the upper and lower density difference of the cement slurry is also large, and the high-temperature stability of the high-density cement slurry still needs to be further improved.

[0149] It can be further known from Table 1 that the suspension stabilizer of Examples 1-4 can not only significantly improve the high-temperature stability of the high-density cement slurry, but also prevent the serious adverse phenomena such as "bulging" and "core wrapping" during the high-temperature thickening process of the cement slurry (see Figures 1-4 ), and can also reduce the decline of the high-temperature compressive strength to a certain extent. The experiment proves that the suspension stabilizer provided by the present application can effectively solve the high-temperature stability problem of the high-density cement slurry, still has good suspension capacity for the high-density cement slurry at 195 DEG C, and prevents the adverse phenomena such as "bulging" and "core wrapping" during the high-temperature thickening process. In addition, the suspension stabilizer has no adverse effect on other properties of the high-density cement slurry, has no obvious thickening effect at room temperature, and is a high-temperature resistant suspension agent with good comprehensive performance.

[0150] Finally, it should be pointed out that: the above embodiments are only the preferred embodiments of the present application for describing the technical solutions of the present application, but not limiting them, and of course, are not limiting the patent scope of the present application; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application; that is, any modification or polishing without substantial significance in the main design idea and spirit of the present application, and the technical problems solved are still consistent with the present application, and should be included in the protection scope of the present application; in addition, the technical solutions of the present application are directly or indirectly applied to other related technical fields, and are also included in the patent protection scope of the present application.

Claims

1. A suspension stabilizer for preventing abnormal thickening of cementing cement at high temperatures, characterized in that, It comprises the following components by weight parts: High temperature suspension stability main agent 65~80 parts; High temperature suspension agent 10~20 parts; High temperature thickening agent 5~15 parts; High temperature thickening abnormality prevention agent 1~3 parts; The high temperature suspension stability main agent is a water-soluble hydrophobic associated polymer, which comprises 30~50 parts of alkenyl sulfonic acid monomer, 30~45 parts of alkenyl carboxylic acid monomer, 10~25 parts of alkenyl cation-containing monomer and 1~3 parts of alkenyl hydrophobic monomer by weight parts, and 2~4 parts of ammonium persulfate as initiator, 3~5 parts of isopropyl alcohol as chain transfer agent, 0.3~0.5 parts of dodecyl ammonium sulfate as surfactant, obtained by free radical micellar polymerization reaction; The high temperature thickening abnormality prevention agent comprises one or more of borax, borate, fluoroborate; The high temperature suspension agent comprises one or more of polyethylene glycol 2000, polyvinyl alcohol 1788, hydroxypropyl distarch phosphate; The high temperature thickening agent comprises one or more of magnesium lithium silicate, sepiolite powder, mica stone powder; The preparation method of the high temperature suspension stability main agent comprises: Step A, take alkenyl sulfonic acid monomer, alkenyl carboxylic acid monomer and alkenyl cation-containing monomer, add water to dissolve and mix, form a first mixed solution; Step B, take alkenyl hydrophobic monomer and dodecyl ammonium sulfate, add water and stir, form a second mixed solution; Step C, take ammonium persulfate and isopropyl alcohol, add water, stir, dissolve and mix, form a third mixed solution; Step D, mix the first and second mixed solutions well, adjust the pH of the mixed solution to 6~7, and then form a fourth mixed solution; Step E, drop the third mixed solution into the fourth mixed solution for constant temperature reaction to obtain a reaction solution; Step F, purify and dry the reaction solution in sequence to obtain the water-soluble hydrophobic associated polymer.

2. The suspension stabilizer against abnormal high temperature thickening of cementing cement according to claim 1, characterized in that, The suspension stabilizer comprises the following components by weight parts: High temperature suspension stability main agent 68~78 parts; High temperature suspension agent 10~18 parts; High temperature thickening agent 8~15 parts; High temperature thickening abnormality prevention agent 1.5~2 parts; The high temperature suspension stability main agent is a water-soluble hydrophobic associated polymer, which comprises at least 35~45 parts of alkenyl sulfonic acid monomer, 30~40 parts of alkenyl carboxylic acid monomer, 10~20 parts of alkenyl cation-containing monomer and 2~3 parts of alkenyl hydrophobic monomer by weight parts, and 2~3 parts of ammonium persulfate as initiator, 4~5 parts of isopropyl alcohol as chain transfer agent, 0.3~0.4 parts of dodecyl ammonium sulfate as surfactant, obtained by free radical micellar polymerization reaction.

3. The suspension stabilizer for preventing abnormal high-temperature thickening of cementing cement according to claim 1 or 2, characterized in that, The alkenyl sulfonic acid monomer comprises one or more of sodium methylallyl sulfonate, sodium vinyl sulfonate and 2-acrylamide-2-methylpropane sulfonic acid; The alkenyl carboxylic acid monomer comprises one or more of acrylic acid, maleic anhydride and methacrylic acid; The alkenyl cation-containing monomer comprises one or more of dimethyl diallyl ammonium chloride, acryloyl ethyl trimethyl ammonium chloride and trimethyl allyl ammonium chloride; The alkenyl hydrophobic monomer comprises one or more of stearyl acrylate, dodecyl acrylate and nonyl acrylate.

4. The suspension stabilizer for preventing abnormal high-temperature thickening of cementing cement according to claim 1 or 2, characterized in that, The high temperature thickener has a specific surface area ≥ 500 m 2 / kg.

5. The method for preparing the suspension stabilizer for preventing abnormal thickening of cement at high temperature according to any one of claims 1 to 4, characterized in that, The method comprises the following steps: weighing high-temperature suspension stabilizing main agent, high-temperature suspending agent, high-temperature thickening agent and high-temperature thickening abnormality preventing agent according to weight parts, and mixing them uniformly to obtain the suspension stabilizing agent for preventing high-temperature thickening abnormality of the cement slurry for well cementation.

6. The preparation method of claim 5, wherein, The preparation method of the high-temperature suspension stabilizing main agent comprises: Step A, taking the alkenyl sulfonic acid monomer, the alkenyl carboxylic acid monomer and the alkenyl cation-containing monomer, adding them into water to dissolve and mix to form a first mixed solution; Step B, taking the alkenyl hydrophobic monomer and ammonium lauryl sulfate, adding them into water to stir to form a second mixed solution; Step C, taking ammonium persulfate and isopropyl alcohol, adding them into water to stir, dissolve and mix to form a third mixed solution; Step D, mixing the first mixed solution and the second mixed solution, adjusting the pH of the mixed solution to 6-7, and then forming a fourth mixed solution; Step E, dropping the third mixed solution into the fourth mixed solution to perform constant temperature reaction to obtain a reaction solution; Step F, purifying and drying the reaction solution in sequence to obtain the water-soluble hydrophobic association polymer. In step D, the pH value is adjusted by adding an alkali solution, and the alkali solution is a sodium hydroxide solution with a concentration of 15-25 wt.%.

7. The production method according to claim 6, characterized by, The concentration of the sodium hydroxide solution is 20 wt.%.

8. The preparation method according to claim 6, characterized in that, Step E is to move the fourth mixed solution into a reaction kettle, heat to a preset temperature under a protective atmosphere, and then drop the third mixed solution into the reaction kettle to perform constant temperature stirring reaction with the fourth mixed solution.

9. The production method according to claim 8, characterized by, The preset temperature of the heating is 60-80℃.

10. The preparation method according to claim 8, characterized in that, The preset temperature of the heating is 70℃.

11. The production method according to claim 8, characterized by, The constant temperature stirring reaction time is 3-5 h, and the constant temperature stirring speed is 300-500 r / min.

12. The production method according to claim 11, characterized by, The constant temperature stirring reaction time is 4.5 h.

13. The preparation method according to claim 11, characterized in that, The constant temperature stirring speed is 400 r / min.

14. The preparation method according to claim 8, characterized in that, The dropping speed of the third mixed solution is 8-15 drops / min.

15. The preparation method according to claim 14, characterized in that, The dropping speed of the third mixed solution is 10 drops / min.

16. The method of claim 6, wherein, Step F is to purify the reaction solution by using anhydrous propanol for multiple times to obtain a milky white viscous purified product, and then vacuum freeze-drying the purified product to obtain the water-soluble hydrophobic association polymer.

17. The preparation method according to claim 16, characterized in that, The amount of the anhydrous propanol added each time is 80-90 ml.

18. The method of claim 17, wherein, The amount of the anhydrous propanol added each time is 90 ml.

19. The method of claim 16, wherein, The temperature of the vacuum freeze-drying is -5 to -15℃, and the time of the vacuum freeze-drying is 6-18 h.

20. The method of claim 19, wherein, The temperature of the vacuum freeze-drying is -10℃.

21. The method of claim 19, wherein, The time of the vacuum freeze-drying is 12 h.

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