A polymer, a method for preparing the same, and a gelled composition containing the same

Abstract

The application provides a polymer, a preparation method thereof and a gelled composition containing the polymer. The monomers of the polymer include acrylamide, allyl-beta-cyclodextrin, (2-methyl-3-acrylamide propyl) butyl dimethyl ammonium chloride and styrene; the gelled composition includes the polymer provided by the application, a suspending agent, an activator, an emulsifier and a solvent, has high viscosity, good settling stability, good dispersibility in 20wt% hydrochloric acid, strong temperature resistance and strong shear resistance, and can meet the requirement of deep acidification at high temperature.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oilfield development, and particularly relates to a polymer, a preparation method thereof and a thickening composition containing the same. BACKGROUND

[0002] In the prior art, the viscosity of the high-temperature gel acid system decreases rapidly during the temperature rising process, and the shear resistance at high temperature is poor, so it is not suitable for being used as a high-temperature online viscosity-changing acid to perform acidizing construction on a marine oil and gas reservoir with a temperature exceeding 150 DEG C. In order to improve the temperature resistance of the acid liquid, it is necessary to improve the performance of the thickening agent. At present, most of the thickening agents used in the field for acidizing are prepared by using a powder, and the emulsion system is only simply emulsified on the basis of a conventional cationic polymer, so that the temperature resistance thereof cannot reach 150 DEG C.

[0003] Therefore, in view of the above problems, it is urgent to develop a new thickening agent for acidizing, so as to improve the stability and viscosity at high temperature of the thickening agent and realize the instant preparation of the acid liquid. SUMMARY

[0004] One of the present application provides a polymer, monomers of which include acrylamide, allyl-beta-cyclodextrin, (2-methyl-3-acrylamide propyl) butyl dimethyl ammonium chloride and styrene.

[0005] According to one specific embodiment of the present application, the total mass of the monomers is 100%, the content of the acrylamide is 0.75 to 1 wt%, the content of the allyl-beta-cyclodextrin is 68 to 69 wt%, the content of the (2-methyl-3-acrylamide propyl) butyl dimethyl ammonium chloride is 9 to 11.2 wt%, and the content of the styrene is 20 to 22 wt%.

[0006] According to one specific embodiment of the present application, the weight average molecular weight of the polymer is 2.698 x 10 6 to 2.989 x 10 6 ; and / or

[0007] The particle size of the polymer is 80 to 200 mesh.

[0008] Preferably, the weight average molecular weight of the polymer is 2.721 x 10 6 .

[0009] The second of the present application provides a method for preparing the polymer as described in one of the present application, which comprises the following steps:

[0010] The acrylamide, allyl-beta-cyclodextrin, (2-methyl-3-acrylamide propyl) butyl dimethyl ammonium chloride and styrene are allowed to react under the action of an initiator to obtain the polymer.

[0011] According to one embodiment of the present application, the total mass of the acrylamide, allyl-β-cyclodextrin, (2-methyl-3-acrylamidopropyl)butyldimethylammonium chloride and styrene is taken as 100%, the amount of the acrylamide is 0.75 to 1 wt%, the amount of the allyl-β-cyclodextrin is 68 to 69 wt%, the amount of the (2-methyl-3-acrylamidopropyl)butyldimethylammonium chloride is 9 to 11.2 wt% and the amount of the styrene is 20 to 22 wt%; and / or

[0012] The amount of the initiator is 0.4 wt% of the total mass of the acrylamide, allyl-β-cyclodextrin, (2-methyl-3-acrylamidopropyl)butyldimethylammonium chloride and styrene.

[0013] According to one embodiment of the present application, the initiator is a mixture of persulfate and bisulfite;

[0014] Preferably, the mass ratio of the persulfate to the bisulfite is 2:1;

[0015] Preferably, the persulfate is ammonium persulfate; and / or

[0016] The bisulfite is sodium bisulfite.

[0017] According to one embodiment of the present application, the reaction is carried out in water;

[0018] Preferably, the acrylamide, allyl-β-cyclodextrin, (2-methyl-3-acrylamidopropyl)butyldimethylammonium chloride and water are mixed, and then the initiator and styrene are added to carry out the reaction;

[0019] Preferably, the amount of the water is sufficient to dissolve the acrylamide, allyl-β-cyclodextrin and (2-methyl-3-acrylamidopropyl)butyldimethylammonium chloride;

[0020] Preferably, the conditions of the reaction are 10 h of reaction at 40°C; and / or

[0021] The reaction product obtained from the reaction is purified, dried, and crushed to obtain the polymer;

[0022] Preferably, the purification is washing with anhydrous ethanol; and / or

[0023] The conditions of the drying are 12 h of drying at 40°C.

[0024] According to one embodiment of the present application, the (2-methyl-3-acrylamidopropyl)butyldimethylammonium chloride is prepared by the following steps:

[0025] reacting methacrylamidopropyldimethylamine and chlorobutane to obtain the (2-methyl-3-acrylamidopropyl)butyldimethyl ammonium chloride;

[0026] Preferably, the methacrylamidopropyldimethylamine, chlorobutane and solvent are mixed before the reaction;

[0027] Preferably, the solvent is anhydrous ethanol and / or acetone; and / or

[0028] The amount of the solvent is sufficient to dissolve the methacrylamidopropyldimethylamine and chlorobutane;

[0029] Preferably, the molar ratio of the solvent, methacrylamidopropyldimethylamine and chlorobutane is 2.8:1.8:1;

[0030] Preferably, the reaction product obtained from the reaction is distilled to remove the solvent and unreacted chlorobutane to obtain the purified (2-methyl-3-acrylamidopropyl)butyldimethyl ammonium chloride;

[0031] Preferably, the reaction is carried out at 75°C for 6.5h.

[0032] According to one specific embodiment of the present application, the allyl-β-cyclodextrin is prepared by the following method:

[0033] reacting β-cyclodextrin and bromopropylene in the presence of a catalyst to obtain the allyl-β-cyclodextrin;

[0034] Preferably, the mass ratio of the β-cyclodextrin and bromopropylene is 1:1.23; and / or

[0035] The amount of the catalyst is 35.2wt% based on 100% of the mass of the β-cyclodextrin;

[0036] Preferably, the reaction is carried out in a solvent;

[0037] Preferably, the β-cyclodextrin, catalyst and solvent are mixed before the bromopropylene is added dropwise to carry out the reaction;

[0038] Preferably, the solvent is dimethyl sulfoxide and / or N,N-dimethylformamide; and / or

[0039] The amount of the solvent is sufficient to dissolve the β-cyclodextrin;

[0040] Preferably, the catalyst is an inorganic base;

[0041] Preferably, the catalyst is sodium hydroxide;

[0042] Preferably, the reaction product obtained from the reaction is vacuum filtered, the filter residue is collected, washed with acetone, dried, and the purified allyl-β-cyclodextrin is obtained.

[0043] Preferably, the drying condition is 50℃ for 12h.

[0044] Preferably, the reaction condition is 1-8h under ice bath condition at 0-10℃.

[0045] The present application III provides a thickening composition comprising a polymer, a suspending agent, an activator, an emulsifier and a solvent.

[0046] The polymer is the polymer described in the present application I or the polymer prepared by the method described in the present application II.

[0047] According to one specific embodiment of the present application, the thickening composition comprises 39wt%-45wt% of the polymer, 1.5wt%-2.2wt% of the suspending agent, 0.5wt%-1.1wt% of the activator, 2.4wt%-2.8wt% of the emulsifier and 50wt%-55wt% of the solvent, based on the mass of the thickening composition as 100%.

[0048] According to one specific embodiment of the present application, the suspending agent is organic bentonite; and / or

[0049] The activator is a lower alcohol; and / or

[0050] The emulsifier is isomeric tridecanol nonionic surfactant; and / or

[0051] The solvent is white oil.

[0052] Preferably, the HLB value of the emulsifier is 7-13.

[0053] Preferably, the HLB value of the emulsifier is 9-12.

[0054] According to one specific embodiment of the present application, the organic bentonite is quaternary ammonium salt organic bentonite; and / or

[0055] The lower alcohol is methanol and / or ethanol; and / or

[0056] The emulsifier is selected from at least two of isomeric tridecanol polyoxyethylene ether 1303, isomeric tridecanol polyoxyethylene ether 1305 and isomeric tridecanol polyoxyethylene ether 1307; and / or

[0057] The white oil is selected from at least two of 3# white oil, 5# white oil and 26# white oil and / or 15# white oil.

[0058] Preferably, the white oil is a mixture of 3# white oil and 26# white oil or 15# white oil;

[0059] Preferably, the mass ratio of the 3# white oil and the 26# white oil is (25 to 31):(24 to 28);

[0060] Preferably, the white oil is 15# white oil.

[0061] According to one specific embodiment of the present application, the emulsifier is selected from any one of a mixture of isomeric tridecanol polyoxethylene ether 1303 and isomeric tridecanol polyoxethylene ether 1307 at a mass ratio of 0.7:2, a mixture of isomeric tridecanol polyoxethylene ether 1303, isomeric tridecanol polyoxethylene ether 1305, isomeric tridecanol polyoxethylene ether 1307 at a mass ratio of 0.9:0.2:1.7, a mixture of isomeric tridecanol polyoxethylene ether 1303 and isomeric tridecanol polyoxethylene ether 1305 at a mass ratio of 0.8:2, a mixture of isomeric tridecanol polyoxethylene ether 1303 and isomeric tridecanol polyoxethylene ether 1307 at a mass ratio of 0.7:1.9, and a mixture of isomeric tridecanol polyoxethylene ether 1303, isomeric tridecanol polyoxethylene ether 1305 and isomeric tridecanol polyoxethylene ether 1307 at a mass ratio of 0.6:1.2:0.6.

[0062] The fourth aspect of the present application provides a method for preparing the thickened composition as described in the second aspect of the present application, comprising the following steps:

[0063] 1) mixing the solvent and the suspending agent to obtain a first mixture;

[0064] 2) mixing the first mixture and the activating agent to obtain a second mixture;

[0065] 3) mixing the second mixture and the emulsifier to obtain a third mixture;

[0066] 4) mixing the polymer and the third mixture to obtain the thickened composition.

[0067] According to one specific embodiment of the present application, each of the steps 1) to 4) is mixed by stirring;

[0068] Preferably, the stirring speed in the step 1) and the step 2) is independently 8000 to 11000 rpm; and / or

[0069] The stirring speed in the step 3) and the step 4) is 400 to 600 rpm.

[0070] According to one specific embodiment of the present application, each of the steps 1) to 4) is performed at room temperature (i.e. ambient temperature without additional heating);

[0071] Preferably, in step 4), the polymer and the third mixture are mixed by stirring until no longer stratified, to obtain the thickened composition.

[0072] The polymer according to the first aspect of the present application, the polymer prepared by the method according to the second aspect of the present application, the thickened composition according to the third aspect of the present application and the thickened composition prepared by the method according to the fourth aspect of the present application are used in high-temperature carbonated reservoir acidification, in particular as a thickening agent for acidification.

[0073] Preferably, the high temperature is not less than 150℃.

[0074] Advantages of the present application:

[0075] In view of the poor stability and insufficient temperature resistance of the thickening agent for acidification in the prior art, the present application provides a polymer, a preparation method thereof and a thickened composition containing the same. The monomers of the polymer include acrylamide, allyl-β-cyclodextrin, (2-methyl-3-acrylamidopropyl) butyl dimethyl ammonium chloride and styrene; the thickened composition includes the polymer, a suspending agent, an activator, an emulsifier and a solvent. The performance of the thickened composition provided by the present application is as follows: at room temperature, the bulk viscosity is 369-414 mPa·s, the apparent viscosity is 51-58.5 mPa·s, the supernatant height after standing for 15 minutes is 0, no stratification phenomenon occurs, and the dispersion is good in 20wt% hydrochloric acid for 8 minutes, without obvious unsolved particles, precipitates or floaters; the gel acid prepared from the thickened composition, 20wt% hydrochloric acid and 5.5wt% imidazoline corrosion inhibitor has a viscosity of 17.98-20.35 mPa·s after shearing for 120 minutes at a constant shear rate, and the gel acid has a good dispersion in 20wt% hydrochloric acid at 150℃ for 8 minutes, without obvious unsolved particles, precipitates or floaters. -1 The viscosity after shearing for 120 minutes at a constant shear rate is 17.98-20.35 mPa·s. The above data prove that the thickened composition provided by the present application has a high viscosity, good sedimentation stability, good dispersion in 20wt% hydrochloric acid and strong temperature and shear resistance, and can meet the requirement of deep acidification at a high temperature of not less than 150℃. BRIEF DESCRIPTION OF DRAWINGS

[0076] Figure 1 The infrared spectrum of the polymer prepared in Example 1;

[0077] Figure 2 The reaction equation for preparing allyl-β-cyclodextrin;

[0078] Figure 3 The reaction equation for preparing (2-methyl-3-acrylamidopropyl) butyl dimethyl ammonium chloride. DETAILED DESCRIPTION

[0079] The application will be further described in connection with the following examples, which are merely exemplary and in no way limit the application.

[0080] Preparation of polymer

[0081] The β-cyclodextrin, dimethyl sulfoxide, sodium hydroxide, bromine propylene, acetone, anhydrous ethanol, methyl acrylamide propyl dimethyl amine, chlorobutane, acrylamide, styrene, ammonium persulfate and sodium bisulfite used in Example 1 are all of analytical purity.

[0082] The room temperature below refers to 25℃.

[0083] Example 1

[0084] According to the reaction equation shown in Figure 2 , allyl-β-cyclodextrin was prepared: β-cyclodextrin with a mass of 4.54 g was placed in a 150 mL beaker, then dimethyl sulfoxide was slowly added as a solvent until the β-cyclodextrin was completely dissolved, followed by the addition of sodium hydroxide with a mass of 1.60 g as a catalyst, and stirring was uniform; then 4 mL of bromine propylene (i.e. 5.592 g) was slowly added dropwise in two portions under an ice water bath (temperature 0-10℃) environment, and a large amount of yellow precipitate was obtained after 1 h of sufficient reaction; the solvent was removed by vacuum filtration, the filter residue was washed with acetone, and dried at 50℃ for 12 h to obtain white powder of allyl-β-cyclodextrin, which was stored in a sealed dry environment;

[0085] According to the reaction equation shown in Figure 3 , (2-methyl-3-acrylamide propyl) butyl dimethyl ammonium chloride was prepared: 5 mL of anhydrous ethanol was added as a solvent in a three-necked flask, then methyl acrylamide propyl dimethyl amine was added at room temperature, followed by the slow addition of chlorobutane under stirring (the molar ratio of anhydrous ethanol, methyl acrylamide propyl dimethyl amine and chlorobutane was 2.8:1.8:1); after uniform stirring, the system was heated to a temperature of 75℃, and constant temperature reaction was carried out for 6.5 h, then the solvent and unreacted chlorobutane were removed by distillation using a rotary evaporator, and a light yellow thick liquid, i.e. (2-methyl-3-acrylamide propyl) butyl dimethyl ammonium chloride, was prepared;

[0086] Preparation of polymer: the styrene product was first pretreated, specifically washed with 10 wt% sodium hydroxide aqueous solution for 3 times, washed with pure water several times until neutral, removed the polymerization inhibitor, dried, and distilled under reduced pressure, and the fraction at 59-60℃, 53.3 kPa was collected to obtain the pretreated styrene;

[0087] Then acrylamide 0.08 g, allyl-β-cyclodextrin 6.87 g and (2-methyl-3-acrylamidopropyl) butyldimethyl ammonium chloride 0.91 g were weighed into a beaker, 85 mL of deionized water was added and stirred, after the three monomers were completely dissolved, it was poured into a three-necked flask with a rotor, 0.04 g of initiator (a mixture of ammonium persulfate and sodium bisulfite with a mass ratio of 2:1) was added at one time, and 2.4 mL of styrene (2.1648 g) was added dropwise, and the reaction was carried out at 40°C for 10 h to obtain a transparent gel; the obtained gel was washed with anhydrous ethanol for 3 to 5 times, and after being cut into pieces, it was dried in an oven at 40°C for 12 h to obtain a purified polymer with a weight average molecular weight of 2.721×10 6 , which was a white solid, and after being crushed and sieved, a fine powder of the polymer with a particle size of 80 to 200 mesh was obtained.

[0088] Test Example 1 - Polymer structure characterization

[0089] The fine powder of the polymer prepared in Example 1 was pressed into a tablet with KBr as a sample, and Fourier infrared spectroscopy was performed on it with a Shimadzu IR Prestige-21 Fourier infrared spectrometer, and the infrared spectrum was measured as shown in Figure 1 .

[0090] Figure 1 It is shown that the N-H and C=O stretching vibration peaks of -CONH2 in acrylamide appear at 3350 cm -1 and 1645 cm -1 , respectively, indicating that the polymer contains an acrylamide structure; at the same time, the O-H stretching vibration peak of -OH in β-CD (i.e. β-cyclodextrin) appears at 3350 cm -1 , the skeletal vibration of β-CD appears at 560 cm -1 , indicating that the polymer contains an A-β-CD (i.e. allyl-β-cyclodextrin) structure; in addition, the C-H stretching vibration peaks of methyl and methylene in (2-methyl-3-acrylamidopropyl) butyldimethyl ammonium chloride appear at 2923 cm -1 , the stretching vibration peak of quaternary ammonium group (-(CH2)N(CH3)2Cl) in (2-methyl-3-acrylamidopropyl) butyldimethyl ammonium chloride appears at 948 cm -1 , the -CH=CH2 stretching vibration in benzene ring appears at 3092, 3027, 3005 cm -1 , and the -CH=CH- bending vibration peak in benzene ring appears at 1500, 1474, 1447, 1421 cm -1 . It is proved that allyl-β-cyclodextrin and (2-methyl-3-acrylamidopropyl) butyldimethyl ammonium chloride are first prepared in Example 1, and the final polymer prepared is a styrene-cyclodextrin type polyacrylamide polymer product.

[0091] Preparation of thickened composition

[0092] The HLB value of isomeric tridecanol polyoxyethylene ether 1303 used in the following examples and comparative examples is 9, the HLB value of isomeric tridecanol polyoxyethylene ether 1305 is 10, and the HLB value of isomeric tridecanol polyoxyethylene ether 1307 is 12;

[0093] The 806 organic bentonite rheological additive and the 801-B organic bentonite rheological additive used in the following examples and comparative examples are both purchased from Zhejiang Qinghong New Material Co., Ltd.

[0094] The following room temperature refers to the ambient temperature without additional heating.

[0095] Example 2

[0096] 1) 15# white oil 55 g was added to a reaction kettle with stirring device, and stirring was carried out at a speed of 11000 rpm. 2.2 g of suspending agent (i.e. 806 organic bentonite rheological additive) was added at a uniform speed to prevent the suspending agent from caking during stirring, and stirring was continued until uniform, to obtain a first mixture;

[0097] 2) 1.1 g of activating agent (i.e. ethanol) was added to the reaction kettle of step 1) at a stirring speed of 11000 rpm, and stirring was continued until uniform, to obtain a second mixture;

[0098] 3) 2.7 g of emulsifying agent (i.e. a mixture of 0.7 g of isomeric tridecanol polyoxyethylene ether 1303 and 2 g of isomeric tridecanol polyoxyethylene ether 1307) was added to the reaction kettle of step 2) at a stirring speed of 400 rpm, and stirring was continued until uniform, to obtain a third mixture;

[0099] 4) 39 g of the polymer prepared in Example 1 was added to the third mixture at a uniform speed, and stirring was continued until uniform and no longer stratified, to obtain a thickened composition.

[0100] Example 3

[0101] Preparation of thickened composition:

[0102] 1) 15# white oil 54 g was added to a reaction kettle with stirring device, and stirring was carried out at a speed of 10000 rpm. 1.5 g of suspending agent (i.e. 801-B organic bentonite rheological additive) was added at a uniform speed to prevent the suspending agent from caking during stirring, and stirring was continued until uniform, to obtain a first mixture;

[0103] 2) 0.7 g of activating agent (i.e. ethanol) was added to the reaction kettle of step 1) at a stirring speed of 8000 rpm, and stirring was continued until uniform, to obtain a second mixture;

[0104] 3) After the third mixture is stirred uniformly at 400 rpm, 2.8 g of emulsifier (i.e., a mixture of 0.9 g of isomeric tridecanol polyoxyethylene ether 1303 and 0.2 g of isomeric tridecanol polyoxyethylene ether 1305 and 1.7 g of isomeric tridecanol polyoxyethylene ether 1307) is added to the reaction kettle of step 2) to obtain a third mixture;

[0105] 4) The third mixture is uniformly added with 41 g of polymer prepared in Example 1 until it is stirred uniformly and no longer stratified, i.e., a thickened composition is obtained.

[0106] Example 4

[0107] Preparation of a thickened composition:

[0108] 1) 50 g of solvent 15# white oil is added to a reaction kettle with stirring device, and stirred at 10000 rpm, and 1.7 g of suspending agent (806 organic bentonite rheological additive) is uniformly added to prevent the suspending agent from caking during stirring, until it is stirred uniformly to obtain a first mixture;

[0109] 2) 0.5 g of activating agent (i.e., ethanol) is added to the reaction kettle of step 1) at 8000 rpm, and stirred uniformly to obtain a second mixture;

[0110] 3) After the third mixture is stirred uniformly at 400 rpm, 2.8 g of emulsifier (i.e., a mixture of 0.9 g of isomeric tridecanol polyoxyethylene ether 1303 and 0.2 g of isomeric tridecanol polyoxyethylene ether 1305 and 1.7 g of isomeric tridecanol polyoxyethylene ether 1307) is added to the reaction kettle of step 2) to obtain a third mixture;

[0111] 4) The third mixture is uniformly added with 41 g of polymer prepared in Example 1 until it is stirred uniformly and no longer stratified, i.e., a thickened composition is obtained.

[0112] Example 5

[0113] Preparation of a thickened composition:

[0114] 1) 53 g of solvent 15# white oil is added to a reaction kettle with stirring device, and stirred at 10000 rpm, and 1.8 g of suspending agent (806 organic bentonite rheological additive) is uniformly added to prevent the suspending agent from caking during stirring, until it is stirred uniformly to obtain a first mixture;

[0115] 2) 0.6 g of activating agent (i.e., ethanol) is added to the reaction kettle of step 1) at 8000 rpm, and stirred uniformly to obtain a second mixture;

[0116] 3) After the third mixture was stirred uniformly at 400 rpm, 2.6 g of emulsifier (i.e., a mixture of 0.7 g of isomeric tridecanol polyoxyethylene ether 1303 and 1.9 g of isomeric tridecanol polyoxyethylene ether 1307) was added to the reaction kettle of step 2) to obtain a fourth mixture;

[0117] 4) The fourth mixture was stirred uniformly until it was no longer layered, and 42 g of the polymer prepared in Example 1 was added thereto to obtain a thickened composition.

[0118] Example 6

[0119] Preparation of a thickened composition:

[0120] 1) 52 g of solvent 15# white oil was added to a reaction kettle equipped with a stirring device, and 1.7 g of suspending agent (i.e., 806 organobentonite rheological additive) was added thereto at a stirring speed of 10,000 rpm to prevent the suspending agent from caking during stirring, until the first mixture was stirred uniformly;

[0121] 2) 0.9 g of activating agent (i.e., ethanol) was added to the reaction kettle of step 1) at a stirring speed of 8,000 rpm, and the second mixture was stirred uniformly;

[0122] 3) After the third mixture was stirred uniformly at 400 rpm, 2.4 g of emulsifier (i.e., a mixture of 0.6 g of isomeric tridecanol polyoxyethylene ether 1303, 0.6 g of isomeric tridecanol polyoxyethylene ether 1305, and 1.2 g of isomeric tridecanol polyoxyethylene ether 1307) was added to the reaction kettle of step 2) to obtain a fourth mixture;

[0123] 4) The fourth mixture was stirred uniformly until it was no longer layered, and 43 g of the polymer prepared in Example 1 was added thereto to obtain a thickened composition.

[0124] Example 7

[0125] Preparation of a thickened composition:

[0126] 1) 25 g of solvent 3# white oil and 28 g of 26# white oil were added to a reaction kettle equipped with a stirring device, and 1.6 g of suspending agent (i.e., 801-B organobentonite rheological additive) was added thereto at a stirring speed of 10,000 rpm to prevent the suspending agent from caking during stirring, until the first mixture was stirred uniformly;

[0127] 2) 0.8 g of activating agent (i.e., ethanol) was added to the reaction kettle of step 1) at a stirring speed of 8,000 rpm, and the second mixture was stirred uniformly;

[0128] 3) After the 2.6 g emulsifier (i.e. a mixture of 0.7 g isomeric tridecyl alcohol polyox- ethylene ether 1303 and 1.9 g isomeric tridecyl alcohol polyox-ethylene ether 1307) was added into the reactor of step 2) and stirred uniformly, a third mixture was obtained;

[0129] 4) The 42 g polymer prepared in Example 1 was added into the third mixture at a uniform speed until it was stirred uniformly and no longer stratified, i.e. a thickened composition was obtained.

[0130] Example 8

[0131] Preparation of a thickened composition:

[0132] 1) The 31 g of solvent 3# white oil and 24 g of 26# white oil were added into a reactor with stirring device, and stirred at a speed of 10000 rpm. The 1.6 g suspending agent (i.e. 806 organobentonite rheological additive) was added at a uniform speed to prevent the suspending agent from caking during stirring, until it was stirred uniformly, and a first mixture was obtained;

[0133] 2) The 0.8 g activating agent (i.e. ethanol) was added into the reactor of step 1) at a speed of 8000 rpm, and stirred uniformly, and a second mixture was obtained;

[0134] 3) The 2.7 g emulsifier (i.e. a mixture of 0.7 g isomeric tridecyl alcohol polyox- ethylene ether 1303 and 2 g isomeric tridecyl alcohol polyox-ethylene ether 1307) was added into the reactor of step 2) at a speed of 400 rpm and stirred uniformly, and a third mixture was obtained;

[0135] 4) The 40 g polymer prepared in Example 1 was added into the third mixture at a uniform speed until it was stirred uniformly and no longer stratified, i.e. a thickened composition was obtained.

[0136] Comparative Example 1

[0137] Preparation of a thickened composition:

[0138] 1) The 53 g of solvent 15# white oil was added into a reactor with stirring device, and stirred at a speed of 10000 rpm. The 1.8 g suspending agent (i.e. 806 organobentonite rheological additive) was added at a uniform speed to prevent the suspending agent from caking during stirring, until it was stirred uniformly, and a first mixture was obtained;

[0139] 2) The 0.6 g activating agent (i.e. ethanol) was added into the reactor of step 1) at a speed of 8000 rpm, and stirred uniformly, and a second mixture was obtained;

[0140] 3) The 2.6 g emulsifier (i.e. a mixture of 0.7 g isomeric tridecyl alcohol polyox- ethylene ether 1303 and 1.9 g isomeric tridecyl alcohol polyox-ethylene ether 1307) was added into the reactor of step 2) at a speed of 400 rpm and stirred uniformly, and a third mixture was obtained;

[0141] 4) To the third mixture, cationic polyacrylamide 42 g was added at a uniform rate until the stirring was uniform and no longer layered, i.e. a thickened composition was obtained.

[0142] Comparative Example 2

[0143] A thickened composition was prepared:

[0144] 1) Solvent 15# white oil 52 g was added to a reaction kettle with stirring means, stirred at 10000 rpm, and suspending agent (i.e. 806 organobentonite rheological additive) 1.7 g was added at a uniform rate to prevent the suspending agent from caking during stirring, until the stirring was uniform, to obtain a first mixture;

[0145] 2) 0.9 g of activating agent (i.e. ethanol) was added to the reaction kettle of step 1) at 8000 rpm, and stirred until uniform, to obtain a second mixture;

[0146] 3) 2.4 g of emulsifying agent (i.e. a mixture of 0.6 g of isomeric tridecanol polyoxyethylene ether 1303, 0.6 g of isomeric tridecanol polyoxyethylene ether 1305, and 1.2 g of isomeric tridecanol polyoxyethylene ether 1307) was added to the reaction kettle of step 2) at 400 rpm, and stirred until uniform, to obtain a third mixture;

[0147] 4) To the third mixture, cationic polyacrylamide 43 g was added at a uniform rate until the stirring was uniform and no longer layered, i.e. a thickened composition was obtained.

[0148] Comparative Example 3

[0149] A thickened composition was prepared:

[0150] 1) Solvent 15# white oil 53 g was added to a reaction kettle with stirring means, stirred at 10000 rpm, and suspending agent (806 organobentonite rheological additive) 1.8 g was added at a uniform rate to prevent the suspending agent from caking during stirring, until the stirring was uniform, to obtain a first mixture;

[0151] 2) 0.6 g of activating agent (i.e. ethanol) was added to the reaction kettle of step 1) at 8000 rpm, and stirred until uniform, to obtain a second mixture;

[0152] 3) 2.6 g of emulsifying agent (i.e. isomeric tridecanol polyoxyethylene ether 1307) was added to the reaction kettle of step 2) at 400 rpm, and stirred until uniform, to obtain a third mixture;

[0153] 4) To the third mixture, the polymer prepared in Example 1 42 g was added at a uniform rate until the stirring was uniform and no longer layered, i.e. a thickened composition was obtained.

[0154] Comparative Example 4

[0155] Preparation of the thickened composition:

[0156] 1) 53 g of solvent 3# white oil was added into a reaction kettle with stirring device, stirring at 10000 rpm, and 1.6 g of suspending agent (801-B organic bentonite rheological additive) was added at a uniform speed to prevent the agglomeration of the suspending agent during stirring, until the stirring was uniform, to obtain a first mixture;

[0157] 2) 0.8 g of activating agent (i.e. ethanol) was added into the reaction kettle of step 1) at a stirring speed of 8000 rpm, and stirring was uniform to obtain a second mixture;

[0158] 3) After 2.6 g of emulsifier (i.e. a mixture of 0.7 g of isomeric tridecanol polyoxyethylene ether 1303 and 1.9 g of isomeric tridecanol polyoxyethylene ether 1307) was added into the reaction kettle of step 2) at a stirring speed of 400 rpm and stirring was uniform, a third mixture was obtained;

[0159] 4) The polymer prepared in Example 1 was added into the third mixture at a uniform speed, until the stirring was uniform and there was no more layering, to obtain the thickened composition.

[0160] Comparative Example 5

[0161] Preparation of the thickened composition:

[0162] 1) 53 g of solvent 15# white oil was added into a reaction kettle with stirring device, stirring at 10000 rpm, and 1.8 g of suspending agent (806 organic bentonite rheological additive) was added at a uniform speed to prevent the agglomeration of the suspending agent during stirring, until the stirring was uniform, to obtain a first mixture;

[0163] 2) 0.6 g of activating agent (i.e. ethylene glycol) was added into the reaction kettle of step 1) at a stirring speed of 8000 rpm, and stirring was uniform to obtain a second mixture;

[0164] 3) After 2.6 g of emulsifier (i.e. a mixture of 0.7 g of isomeric tridecanol polyoxyethylene ether 1303 and 1.9 g of isomeric tridecanol polyoxyethylene ether 1307) was added into the reaction kettle of step 2) at a stirring speed of 400 rpm and stirring was uniform, a third mixture was obtained;

[0165] 4) The polymer prepared in Example 1 was added into the third mixture at a uniform speed, until the stirring was uniform and there was no more layering, to obtain the thickened composition.

[0166] Test Example 2

[0167] The thickened compositions prepared in Examples 2 to 8 and Comparative Examples 1 to 5 were subjected to viscosity determination, sedimentation stability determination, dispersion in acid at 8 min determination, apparent viscosity determination, and temperature and shear resistance determination, and the specific determination methods of the various indexes were as follows:

[0168] A. Determination of the bulk viscosity of the thickened composition

[0169] The bulk viscosity of the thickened compositions prepared in Examples 2 to 8 and Comparative Examples 1 to 5 was measured using a six-speed rotational viscometer, reading the viscometer pointer reading θ at a rotational speed of 100 r / min 100 .

[0170] The bulk viscosity (AV 本体 ) was calculated according to the following equation (1):

[0171] AV 本体 = θ 100 × 3 (1)

[0172] The results of the bulk viscosity determination are shown in Table 1.

[0173] B. Determination of the settling stability of the thickened composition

[0174] At room temperature (25°C), all the thickened compositions prepared in Examples 2 to 8 and Comparative Examples 1 to 5 were directly poured into 12 50 mL graduated cylinders, respectively, and left to stand for 15 min, the height of the supernatant liquid in each graduated cylinder being recorded, the lower the height of the supernatant liquid, the better the settling stability, the results being shown in Table 1.

[0175] C. Determination of the dispersibility of the thickened composition in acid at 8 min

[0176] i. Determination of the time of acid injection into the well:

[0177] The target well is a pipe column with a diameter of 76 mm and a depth of 5000 meters, the gelled acid (obtained by mixing the thickened composition and 20 wt% hydrochloric acid at a volume ratio of 0.009:1) being used as the main acid, the displacement being 4 m 3 / min, it being calculated that:

[0178] The wellbore volume is (76 mm / 1000 / 2) 2 × 3.14 x 5000 m = 22.67 m 3 ;

[0179] The gelled acid injection time into the well is 22.67 m 3 ÷ 4 m 3 / min = 5.67 min;

[0180] Because of the displacement speed-up process, the injection time is estimated to be 8 min;

[0181] ii. 500 mL of 20 wt% hydrochloric acid (i.e., an aqueous solution of HCl with a mass fraction of 20 wt%) was placed in a beaker and stirred at a speed of 400 r / min ± 5 r / min. 4.5 mL of the thickened composition prepared in any one of Examples 2 to 8 and Comparative Examples 1 to 5 was added to the beaker. The timer was started when stirring began and stirred for 8 min. The mixture was allowed to stand at room temperature (25°C) and the dispersion of the thickened composition in the acid solution was recorded. The presence of obvious undissolved particles, precipitates, or floating matter in the acid solution was observed.

[0182] Following the method in section II, the dispersibility of the thickened compositions prepared in Examples 2 to 8 and Comparative Examples 1 to 5 in hydrochloric acid for 8 minutes was determined, and the specific results are shown in Table 1.

[0183] D. Measurement of apparent viscosity of thickened compositions

[0184] The thickened compositions prepared in Examples 2 to 8 and Comparative Examples 1 to 5 were added to 300 mL of 20 wt% hydrochloric acid at a rate of 4.5 mL each, and the reading θ was measured at 100 r / min. 100 '.

[0185] Apparent viscosity (AV) 表观 Calculate according to the following formula (2):

[0186] AV 表观 =θ 100 '×3 (2)

[0187] The results of the apparent viscosity determination are shown in Table 1.

[0188] E. Determination of the temperature and shear resistance of thickened compositions

[0189] 300 mL of 20 wt% hydrochloric acid was prepared and placed in a beaker. The hydrochloric acid was stirred at a speed of 400 r / min ± 5 r / min. An imidazoline corrosion inhibitor (150℃ corrosion inhibitor purchased from Dongying Shipu Petroleum Engineering Technology Co., Ltd., at a dosage of 5.5 wt% of the 20% hydrochloric acid mass) was added and stirred evenly. Then, 4.5 mL of the thickening composition prepared in any one of Examples 2 to 8 and Comparative Examples 1 to 5 was added. After the thickening composition was completely dissolved, it was placed in a water bath at 25℃ ± 1℃ for 2 hours to obtain gel acid. 50 mL of the prepared gel acid was placed in an acid rheometer and pressurized to 0.7 MPa with nitrogen gas. The gel acid was tested at 150℃ for 170 seconds. -1 Viscosity after shearing at a constant shear rate for 120 min;

[0190] Following the above method, the temperature and shear resistance of the thickened compositions prepared in Examples 2 to 8 and Comparative Examples 1 to 5 were determined, and the specific results are shown in Table 1.

[0191] Table 1. Performance Evaluation of Thickened Compositions

[0192]

[0193] The data in Table 1 show that the thickened compositions prepared in Examples 2 to 8 have high viscosity, good sedimentation stability and good dispersibility in 20wt% hydrochloric acid at room temperature. Specifically, the bulk viscosity of the thickened compositions prepared in Examples 2 to 8 is 369 to 414 mPa·s, and the apparent viscosity is 51 to 58.5 mPa·s at room temperature; the height of supernatant liquid after standing for 15 minutes at room temperature is 0, and no stratification phenomenon occurs; and the dispersibility in 20wt% hydrochloric acid is good for 8 minutes, and no obvious unsolved particles, precipitates or floating substances occur. At a high temperature of 150℃, the thickened compositions prepared in Examples 2 to 8 have strong shear resistance: the gel acid prepared from the thickened composition, 20wt% hydrochloric acid and 5.5wt% imidazoline corrosion inhibitor has a viscosity of 17.98 to 20.35 mPa·s after shearing at a constant shear rate for 120 minutes, and no obvious stratification phenomenon occurs. -1 The viscosity after shearing at a constant shear rate for 120 minutes is 17.98 to 20.35 mPa·s. Compared with Example 5, the cationic polyacrylamide prepared in Example 1 is replaced with an equal amount of cationic polyacrylamide in Comparative Example 1, although the bulk viscosity of Comparative Example 1 is not much different from that of Example 5, the apparent viscosity of Comparative Example 1 is reduced to 61% of that of Example 5, and the temperature resistance and shear resistance are greatly reduced, which is reduced by 54% compared with Example 5; compared with Example 6, the cationic polyacrylamide prepared in Example 1 is also replaced with an equal amount of cationic polyacrylamide in Comparative Example 2, the bulk viscosity is reduced by 18.7% compared with Example 6, and the sedimentation stability at room temperature is also obviously poor (stratification phenomenon occurs after standing for 15 minutes at room temperature, and the height of supernatant liquid reaches 10 mL), the dispersibility in acid is poor, and the temperature resistance and shear resistance cannot be determined. Comparative Example 1 and Example 5, and Comparative Example 2 and Example 6, can prove that the thickened composition prepared from the polymer prepared by the present application has better high temperature resistance and shear resistance;

[0194] Compared with Example 5, the emulsifier (specifically, a mixture of isomeric tridecanol polyoxyethylene ether 1303 and isomeric tridecanol polyoxyethylene ether 1307) in Example 5 is replaced with an equal amount of isomeric tridecanol polyoxyethylene ether 1307 in Comparative Example 3, which shows that the bulk viscosity of Comparative Example 3 at room temperature is increased by 18.5% compared with that of Example 5, the sedimentation stability is reduced (specifically, stratification phenomenon occurs after standing for 15 minutes at room temperature, and the height of supernatant liquid reaches 5 mL), and the dispersibility in 20wt% hydrochloric acid is poor and easy to form a group, so the temperature resistance and shear resistance cannot be determined, which indicates that the type of emulsifier can affect the bulk viscosity, sedimentation stability and dispersibility in acid of the thickened composition, and ultimately affect the temperature resistance and shear resistance;

[0195] Compared with Example 5, the activated agent ethanol in Comparative Example 5 is replaced with an equal mass of ethylene glycol, so that the bulk viscosity of the thickening composition is greatly increased, specifically 1.4 times the bulk viscosity of Example 5, the settlement stability is also poor, and stratification occurs after standing at room temperature for 15 min, the height of the supernatant is 7 mL, and the dispersibility in acid is poor and easy to form a mass, indicating that the activated agent can affect the bulk viscosity, settlement stability and dispersibility in acid of the thickening composition, and ultimately affect the temperature resistance and shear resistance;

[0196] Compared with Example 7, the solvent (specifically 26# white oil and 3# white oil) in Example 7 is replaced with an equal mass of 3# white oil in Comparative Example 4, although the dispersibility in acid is good, the bulk viscosity of the thickening composition is reduced to below 100 mPa·s, and the settlement stability is also poor (stratification occurs after standing at room temperature for 15 min, and the height of the supernatant is 12 mL);

[0197] In summary, the types of polymer, solvent, activated agent and emulsifier can all affect the viscosity, settlement stability, acid dispersibility and temperature resistance and shear resistance of the thickening composition, and the thickening composition prepared by using the formulation provided by the present application can maintain a stable dispersed state for a long time, can be quickly dispersed in acid, is not easy to form a mass, and has good temperature resistance and shear resistance, and can meet the requirements of deep acidification.

[0198] Although the present application has been described with reference to specific embodiments, it is understood by those skilled in the art that various changes can be made without departing from the true spirit and scope of the present application. In addition, various changes can be made to the subject matter, spirit and scope of the present application to adapt to specific circumstances, materials, material compositions and methods. All of these changes are included in the scope of the claims of the present application.

Claims

1. A thickening composition comprising a polymer, a suspending agent, an activator, an emulsifier, and a solvent; The monomers of the polymer include acrylamide, allyl-β-cyclodextrin, (2-methyl-3-acrylamidopropyl)butyldimethylammonium chloride, and styrene; The total mass of the monomers is 100%, the content of acrylamide is 0.75 to 1 wt%, the content of allyl-β-cyclodextrin is 68 to 69 wt%, the content of (2-methyl-3-acrylamidopropyl)butyldimethylammonium chloride is 9 to 11.2 wt%, and the content of styrene is 20 to 22 wt%. The activator is ethanol; The emulsifier is selected from at least two of isotridecyl alcohol polyoxyethylene ether 1303, isotridecyl alcohol polyoxyethylene ether 1305 and isotridecyl alcohol polyoxyethylene ether 1307; The solvent is white oil, which is selected from at least two of the following: No. 3 white oil, No. 5 white oil and No. 26 white oil, and / or No. 15 white oil; The thickened composition, by weight of 100%, comprises 39 wt% to 45 wt% of the polymer, 1.5 wt% to 2.2 wt% of the suspending agent, 0.5 wt% to 1.1 wt% of the activator, 2.4 wt% to 2.8 wt% of the emulsifier, and 50 wt% to 55 wt% of the solvent.

2. The thickening composition according to claim 1, characterized in that, The polymer has a weight-average molecular weight of 2.698 × 10⁻⁶. 6 Up to 2.989×10 6 ; and / or The polymer has a particle size of 80 to 200 mesh.

3. The thickening composition according to claim 1, characterized in that, The polymer is prepared according to the following steps: The polymer is obtained by reacting the acrylamide, allyl-β-cyclodextrin, (2-methyl-3-acrylamidopropyl)butyldimethylammonium chloride and styrene in the presence of an initiator.

4. The thickening composition according to claim 3, characterized in that, The amount of the initiator is 0.4 wt% of the total mass of the acrylamide, allyl-β-cyclodextrin, (2-methyl-3-acrylamidopropyl)butyldimethylammonium chloride, and styrene.

5. The thickening composition according to claim 3, characterized in that, The initiator is a mixture of persulfate and bisulfite; The mass ratio of the persulfate to the bisulfite is 2:

1.

6. The thickening composition according to claim 3, characterized in that, The reaction is carried out in water; and / or The reaction conditions are: reaction at 40°C for 10 hours; and / or The reaction product obtained from the reaction is purified, dried, and pulverized to obtain the polymer.

7. The thickening composition according to claim 1, characterized in that, The suspending agent is organic bentonite.

8. The thickening composition according to claim 7, characterized in that, The organic bentonite is a quaternary ammonium salt organic bentonite; and / or The white oil is a mixture of No. 3 white oil and No. 26 white oil, or No. 15 white oil.

9. A method for preparing the thickened composition according to any one of claims 1 to 8, comprising the following steps: 1) The solvent and suspending agent are mixed to obtain a first mixture; 2) Mix the first mixture and the activator to obtain a second mixture; 3) Mix the second mixture and the emulsifier to obtain a third mixture; 4) Mix the polymer and the third mixture to obtain the thickened composition.

10. The application of the thickening composition according to any one of claims 1 to 8 or the thickening composition prepared by the method of claim 9 in the acidizing of high-temperature carbonate reservoirs.

11. The application according to claim 10, characterized in that, The high temperature is not lower than 150°C.

12. The use of the thickening composition according to any one of claims 1 to 8 or the thickening composition prepared by the method of claim 9 as a thickener for acidification.

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