High-temperature-resistant hyperbranched polymer tackifier for composite calcium salt water completion fluid as well as preparation method and application of high-temperature-resistant hyperbranched polymer tackifier

Abstract

The invention provides a high-temperature-resistant hyperbranched polymer tackifier for composite calcium salt water completion fluid as well as a preparation method and application of the high-temperature-resistant hyperbranched polymer tackifier. The preparation method of the tackifier comprises the following steps: mixing gamma-aminopropyltriethoxysilane, diethylene glycol and triethylene glycol, uniformly stirring, and reacting; after the reaction is finished, dialyzing and freeze-drying to obtain a branched monomer with high reaction activity; the preparation method comprises the following steps: adding a salt-resistant monomer and a branched monomer with high reaction activity into deionized water, and then adding an acrylamide monomer, a rigid cyclic monomer and a hydrophobic monomer to obtain a monomer solution; adjusting the pH value of the monomer solution, introducing nitrogen to remove oxygen, heating to a reaction temperature, adding an initiator, and thermally initiating a polymerization reaction; and after the reaction is finished, adding ethanol into the obtained reaction liquid for precipitation, filtering, drying in vacuum, and crushing to obtain the product. The tackifier disclosed by the invention is excellent in temperature resistance and salt resistance, and still has excellent tackifying performance after being aged in a composite calcium salt environment at a high temperature of 200 DEG C.

Description

Technical Field

[0001] The present invention relates to a high-temperature resistant hyperbranched polymer viscosifier for composite calcium salt water completion fluid, a preparation method thereof and an application thereof, belonging to the field of oilfield chemistry in the petroleum industry. Background Technique

[0002] During the drilling process of deep and ultra-deep oil and gas reservoirs, with the increase of well depth, the number of complex formations such as high temperature and high pressure is increasing continuously, the development difficulty is getting greater and greater, and new requirements are put forward for the performance of completion fluid. Under the action of high pressure difference, solid particles in the completion fluid are easy to invade the pores and fractures of the reservoir, block the oil and gas seepage channels, resulting in reservoir damage and reduction of production capacity. The solid-free completion fluid, with excellent lubricity and reservoir protection, is the mainstream development direction of completion fluid for deep and ultra-deep wells.

[0003] The viscosifier can increase the viscosity and shear force of the completion fluid and then suspend and carry the cuttings, and is the core additive of the solid-free completion fluid. However, in the high-temperature environment of deep and ultra-deep layers, the existing viscosifier molecules are extremely easy to undergo conformational transformations such as degradation and cross-viscosity, resulting in the failure of the viscosifier performance, causing a decrease in the viscosity of the solid-free completion fluid and an increase in the filtration loss. The formation pressure of deep and ultra-deep layers is high, and the solid-free completion fluid increases the density of the completion fluid through soluble salts (formates, inorganic salts) to balance the formation pressure. In a high-temperature environment, formates can enhance the temperature resistance performance of polymers, but their cost is too high to meet the requirements of large-scale popularization and application. Most of the existing linear polymer viscosifiers are extremely easy to curl and agglomerate in the water environment of high-concentration inorganic high-valent salts (such as CaCl 2 , CaBr 2 etc.), resulting in the precipitation of polymers and the failure of the completion fluid performance.

[0004] Chinese patent document CN104650827A developed a temperature-resistant micro-crosslinked tackifier through the reaction of alkenyl sulfonic acid, alkenyl amide and alkenyl benzene. It still has good tackifying effect after heat rolling aging at 165°C for 16h, which is better than the foreign similar product HE300. However, its temperature resistance still needs to be further improved (>200°C) to meet the requirements of well completion in deep and ultra-deep wells. Chinese patent document CN118459660A used 2-acrylamido-2-methylpropanesulfonic acid, dimethylaminopropyl acrylamide, sodium styrenesulfonate, hydrophobic monomer and micro-crosslinking agent as raw materials, and polymerized them into a linear copolymer through an initiator, and blended it with micron-sized inert bridging materials to develop a high-temperature-resistant polymer tackifier for calcium chloride brine completion fluid, which can resist temperature up to 170°C, and its temperature resistance still needs to be further improved. Chinese patent document CN114214049A disclosed a preparation method of a solid-free thickening and workover fluid for ultra-deep and ultra-high-temperature oil and gas wells. By adding an ultra-high-temperature polymer crosslinking agent, an ultra-high-temperature polymer stabilizer and an ultra-high-temperature heat stabilizer to the thickener solution, the use temperature of the thickener can reach 180°C, meeting the requirement of maintaining the stability of the thickener performance in high-temperature solid-free brine. However, the brine density used is only

[0005] 1.1 - 1.3 g / cm 3 , and it is a monovalent sodium salt, which does not meet the use conditions of high-density completion fluid.

[0006] Therefore, how to enhance the stability of the tackifier for solid-free completion fluid in high-temperature and high-valence salt (CaCl 2 , CaBr 2 ) environment and maintain the tackifying performance is of great significance for enriching the basic research of deep and ultra-deep solid-free completion fluid. Summary of the Invention

[0007] Aiming at the deficiencies of the prior art, especially the problems that linear polymer tackifiers are prone to degradation, crosslinking in high-temperature environments and curling, agglomeration in high-valence brine environments, the present invention provides a high-temperature-resistant hyperbranched polymer tackifier for composite calcium brine completion fluid, its preparation method and application. The tackifier of the present invention can resist high temperature (≥200°C), resist composite calcium salts (CaCl 2 and CaBr 2 ) and can achieve the effect of tackifying.

[0008] The technical solution of the present invention is as follows:

[0009] A preparation method of a high-temperature-resistant hyperbranched polymer tackifier for composite calcium brine completion fluid, including the following steps:

[0010] (1) Preparation of highly reactive branched monomers

[0011] Mix γ-aminopropyltriethoxysilane (KH550), diethylene glycol and triethylene glycol, stir evenly and then carry out the reaction; after the reaction is completed, carry out dialysis and freeze-drying to obtain a highly reactive branched monomer;

[0012] (2) Preparation of high-temperature resistant hyperbranched polymer viscosifier

[0013] Add the salt-resistant monomer and the highly reactive branched monomer prepared in step (1) into deionized water, and then add acrylamide monomers, rigid cyclic monomers and hydrophobic monomers to obtain a monomer solution; after adjusting the pH value of the monomer solution, pass nitrogen to remove oxygen, then raise the temperature to the reaction temperature, add an initiator, and carry out thermal-initiated polymerization reaction; after the reaction is completed, add ethanol to the obtained reaction solution for precipitation, and after filtration, vacuum drying and pulverization, obtain a high-temperature resistant hyperbranched polymer viscosifier for composite calcium salt completion fluid.

[0014] Preferably according to the present invention, the mass ratio of γ-aminopropyltriethoxysilane (KH550), diethylene glycol and triethylene glycol in step (1) is 1:3 - 5:1 - 3, and further preferably 1:4:2.

[0015] Preferably according to the present invention, the temperature of the reaction in step (1) is 150 - 200 °C, and the reaction time is 2 - 4 h.

[0016] Preferably according to the present invention, the dialysis step in step (1) is: put the product obtained after the reaction is completed into a dialysis bag and dialyze in deionized water for 24 - 48 h; the cut-off molecular weight of the dialysis bag is 3500 Da; the temperature of the freeze-drying is 0 - 5 °C, and the freeze-drying time is 10 - 15 h.

[0017] Preferably according to the present invention, the salt-resistant monomer in step (2) is 2-acrylamido-2-methylpropanesulfonic acid (AMPS), sodium p-styrenesulfonate (SSS) or sodium vinylsulfonate (VS).

[0018] Preferably according to the present invention, the acrylamide monomers in step (2) are acrylamide (AM), N,N-dimethylacrylamide (DMAA) or N-isopropylacrylamide (NIPAM).

[0019] Preferably according to the present invention, the rigid cyclic monomer in step (2) is N-vinylpyrrolidone (NVP).

[0020] Preferably according to the present invention, the hydrophobic monomer in step (2) is dimethylditetradecylammonium bromide (DTAB), allyl polyethylene glycol or dimethyldiallylammonium chloride (DMAAC16); the allyl polyethylene glycol is APEG-800, APEG-1000, APEG-1200, APEG-1300, APEG-2000 or APEG-2200.

[0021] Preferably according to the present invention, the mass ratio of the salt-resistant monomer, highly reactive branched monomer, acrylamide monomer, rigid cyclic monomer to the hydrophobic monomer in step (2) is 5-7:0.2:4:1:0.3, and more preferably 6:0.2:4:1:0.3.

[0022] Preferably according to the present invention, the mass ratio of the salt-resistant monomer to deionized water in step (2) is 1:4-10.

[0023] Preferably according to the present invention, the pH value of the monomer solution in step (2) is adjusted to 5-8, and more preferably 6-7; the pH value of the monomer solution is adjusted using an aqueous sodium hydroxide solution with a mass fraction of 20-40%.

[0024] Preferably according to the present invention, the initiator in step (2) is potassium persulfate (KPS), ammonium persulfate (APS), azobisisobutyronitrile (AIBN) or azobis (2-amidinopropane) hydrochloride (V50); the mass of the initiator is 0.01-0.2% of the total mass of the salt-resistant monomer, highly reactive branched monomer, acrylamide monomer, rigid cyclic monomer and hydrophobic monomer, and more preferably 0.05-0.1%.

[0025] Preferably according to the present invention, the reaction temperature in step (2) is 55-65 °C, and the polymerization reaction time is 3-5 h.

[0026] Preferably according to the present invention, the volume ratio of ethanol to the mass of the salt-resistant monomer in step (2) is 15-50 mL:1 g.

[0027] Preferably according to the present invention, the temperature of the vacuum drying in step (2) is 70-80 °C, and the vacuum drying time is 8-10 h.

[0028] The present invention also provides a high-temperature resistant hyperbranched polymer viscosifier for composite calcium brine completion fluid, which is prepared by the above preparation method.

[0029] According to the present invention, the above-mentioned high-temperature-resistant hyperbranched polymer thickening agent for composite calcium brine completion fluid is used in the composite calcium brine completion fluid; preferably, the concentration of the high-temperature-resistant hyperbranched polymer thickening agent for composite calcium brine completion fluid in the composite calcium brine completion fluid is 10-15 g / L; the composite calcium salt includes calcium chloride and calcium bromide, and the density of the composite calcium brine completion fluid is preferably 1.70 g / cm 3 .

[0030] The technical features and beneficial effects of the present invention are as follows:

[0031] 1. The present invention first selects a specific silane coupling agent to react with a specific proportion and specific type of polyol to obtain a highly reactive branched monomer, and then introduces it into the thickening agent. By introducing active sites, it has groups that can further react and react with other functional monomers to generate high-temperature and high-salt-resistant products. However, if the proportion of the highly reactive branched monomer is too high or too low, the performance of the thickening agent will be reduced.

[0032] 2. Acrylamide monomers are introduced into the thickening agent of the present invention. It can not only improve the high-temperature hydrolysis resistance of the polymer but also increase the molecular weight of the polymer, further enhancing the temperature and viscosity resistance of the polymer; salt-resistant monomers are introduced, which can improve the salt resistance of the polymer; rigid cyclic monomers are introduced, and their unique five-membered ring structure can further enhance the stability of the polymer under high-temperature conditions; hydrophobic monomers are introduced. In the polymer aqueous solution, the hydrophobic groups aggregate with each other due to hydrophobic interaction, forming a spatial network structure, increasing the hydrodynamic volume, and showing good thickening properties; in the salt solution, due to the increase in the polarity of the solution, the hydrophobic association effect is enhanced, making the polymer show an obvious salt thickening effect and having good salt resistance.

[0033] 3. The polymer thickening agent synthesized by the present invention has excellent temperature and salt resistance. After aging in a high-temperature environment of 200 °C and a composite calcium salt environment, it still has excellent thickening performance and has broad application prospects in solids-free completion fluids. Specific embodiments

[0034] The following further illustrates the present invention with specific embodiments, but is not limited thereto.

[0035] Meanwhile, in the following embodiments, the experimental methods are all conventional methods unless otherwise specified; the reagents, materials, and equipment can all be obtained from commercial channels unless otherwise specified.

[0036] Example 1

[0037] A preparation method of a high-temperature-resistant hyperbranched polymer thickening agent for composite calcium brine completion fluid includes the following steps:

[0038] (1) Preparation of highly reactive branched monomer

[0039] Mix 1 g of γ-aminopropyltriethoxysilane (KH550), 4 g of diethylene glycol (CAS No. 111-46-6), and 2 g of triethylene glycol (CAS No. 112-27-6). After stirring evenly, react at 180 °C for 3 h. After the reaction is completed, put the obtained product into a dialysis bag with a molecular weight cut-off of 3500 Da and dialyze in deionized water for 48 h. Then freeze-dry at 4 °C for 10 h to obtain the highly reactive branched monomer.

[0040] (2) Preparation of high-temperature and high-salt resistant hyperbranched viscosifier

[0041] Weigh 18 g of sodium p-styrenesulfonate (SSS) and 0.6 g of the highly reactive branched monomer obtained in step (1), add them to 100 g of deionized water, then add 12 g of N,N-dimethylacrylamide (DMAA), 3 g of N-vinylpyrrolidone (NVP), and 0.9 g of dimethylditetradecylammonium bromide (DTAB) to the system, and stir evenly to obtain a monomer solution. Adjust the pH of the monomer solution to 6 with a 20% sodium hydroxide aqueous solution. Then deoxygenate by passing nitrogen for 30 min, raise the temperature to 60 °C, add 0.03 g of azodiisobutyramidine hydrochloride (V50), and react at 60 °C for 4 h. After the reaction is completed, add 500 mL of absolute ethanol to the obtained reaction solution for precipitation, then filter. The obtained solid is vacuum-dried at 70 °C for 10 h, and the dried product is crushed to obtain a high-temperature resistant hyperbranched polymer viscosifier for composite calcium brine completion fluid.

[0042] Example 2

[0043] A preparation method of a high-temperature resistant hyperbranched polymer viscosifier for composite calcium brine completion fluid is as described in Example 1, except that: the reaction temperature in step (2) is 55 °C.

[0044] Comparative Example 1

[0045] A preparation method of a polymer viscosifier for composite calcium brine completion fluid includes the following steps:

[0046] Weigh 18 g of sodium p-styrenesulfonate (SSS) and add it to 100 g of deionized water. Then, add 12 g of N,N-dimethylacrylamide (DMAA), 3 g of N-vinylpyrrolidone (NVP), and 0.9 g of dimethylditetradecylammonium bromide (DTAB) to the system, and stir evenly to obtain a monomer solution. Adjust the pH of the monomer solution to 6 using a 20% sodium hydroxide aqueous solution. Then, purge with nitrogen for 30 min, raise the temperature to 50 °C, add 0.03 g of 2,2'-azobis(2-methylpropionamidine) dihydrochloride (V50), and react at 60 °C for 4 h. After the reaction is completed, add 500 mL of absolute ethanol for precipitation, then filter. The obtained solid is vacuum dried at 70 °C for 10 h, and the dried product is crushed to obtain a polymer viscosifier for composite calcium brine completion fluid.

[0047] The viscosifier in this comparative example does not contain highly reactive branched monomers.

[0048] Comparative Example 2

[0049] A preparation method of a polymer viscosifier for composite calcium brine completion fluid is as described in Example 4, except that: in step (2), the salt-resistant monomer sodium p-styrenesulfonate (SSS) is not added.

[0050] Comparative Example 3

[0051] A preparation method of a polymer viscosifier for composite calcium brine completion fluid is as described in Example 4, except that: in step (2), the acrylamide monomer N,N-dimethylacrylamide (DMAA) is not added.

[0052] Comparative Example 4

[0053] A preparation method of a polymer viscosifier for composite calcium brine completion fluid is as described in Example 4, except that: in step (2), the rigid cyclic monomer N-vinylpyrrolidone (NVP) is not added.

[0054] Comparative Example 5

[0055] A preparation method of a polymer viscosifier for composite calcium brine completion fluid is as described in Example 4, except that: in step (2), the hydrophobic monomer dimethylditetradecylammonium bromide (DTAB) is not added.

[0056] Comparative Example 6

[0057] A preparation method of a polymer viscosifier for composite calcium brine completion fluid is as described in Example 4, except that: in step (2), an equal mass of KH550 is used instead of the highly reactive branched monomer.

[0058] Comparative Example 7

[0059] As described in Example 4 of the preparation method of a polymer viscosifier for a composite calcium salt water completion fluid, the difference is that in step (2), an equal mass of N,N-methylenebisacrylamide (MBA) is used instead of the highly reactive branched monomer.

[0060] Comparative Example 8

[0061] Purchase the viscosifier HE300 commercially.

[0062] Test Example

[0063] Perform the following tests on the polymer viscosifiers prepared in the examples and comparative examples.

[0064] 1. Determination of the viscosity-average molecular weight of the viscosifier

[0065] Referring to the national standard GBT 12005.10-1992 "Determination of Molecular Weight of Polyacrylamide - Viscosity Method", use an automatic capillary viscometer to measure the flow-through times of the solvent (1.0 mol / L NaCl solution) and the solution at 30 °C respectively. Combine the use of the Huggins formula and the Kraemer formula to calculate the intrinsic viscosity [η] of the viscosifier, and use the empirical formula Mη=(10000[η] / 3.73)^1.515 to calculate the viscosity-average molecular weight Mη of the viscosifier.

[0066] 2. Influence of the viscosifier on the rheological and filtration properties of the base slurry before and after aging

[0067] Preparation of the base fluid:

[0068] Preparation of the solid-free completion fluid sample: Take 400 mL of deionized water, add 2 g (0.5%) of the viscosifier samples of the examples and comparative examples respectively, and stir at a speed of 6000 r / min for 20 min at room temperature; subsequently, add 236 g of calcium chloride and 500 g of calcium bromide, and stir at a speed of 4000 r / min for 20 min at room temperature to obtain a solid-free completion fluid with a density of 1.70 g / cm 3 ;

[0069] Aging treatment of the completion fluid sample: Place the above-mentioned completion fluid sample in a roller heating furnace, set the aging temperature to 180 °C or 200 °C, and the aging time to 16 h.

[0070] Referring to GB16783.1-2014 "Petroleum and Natural Gas Industries - Drilling Fluids - Part 1: Water-Based Drilling Fluids", evaluate the rheological and filtration properties of the above-prepared solution.

[0071] 3. Performance test results

[0072] Table 1 Viscosity-average molecular weight of the viscosifier

[0073] Test sample Viscosity-average molecular weight (mPa·s) Example 1 <![CDATA[2.22×10 6 > Example 2 <![CDATA[2.08×10 6 > Comparative Example 1 <![CDATA[1.39×10 6 > Comparative Example 2 <![CDATA[1.25×10 6 > Comparative Example 3 <![CDATA[1.21×10 6 > Comparative Example 4 <![CDATA[1.33×10 6 > Comparative Example 5 <![CDATA[1.42×10 6 > Comparative Example 6 <![CDATA[1.68×10 6 > Comparative Example 7 <![CDATA[1.74×10 6 > Comparative Example 8 <![CDATA[2.02×10 6 >

[0074] Table 1 records the viscosity-average molecular weights of the samples of Examples 1-2 and Comparative Examples 1-8. It can be seen that among Examples 1-2, the sample prepared in Example 2 has a relatively large viscosity-average molecular weight; in Comparative Example 1, since the highly reactive branched monomer A was not introduced, the molecular weight of the thickener was small due to aqueous solution free radical polymerization; in Comparative Examples 2, 3, 4, and 6, the monomers SSS, DMAA, NVP, and DTAB were missing respectively. It can be seen that the absence of monomers led to a decrease in the molecular weight of the thickener, because these four monomers are all easy to polymerize and are likely to increase the molecular weight of the polymer. In Comparative Examples 6 and 7, two commercially available crosslinking agents were used instead of the highly reactive hyperbranched monomer, and the resulting polymer had a relatively low molecular weight. Comparative Example 8 is a commercially available thickener HE300, and its viscosity-average molecular weight is relatively large.

[0075] Table 2 Density 1.70 g / cm 3 Viscosity increasing performance of calcium chloride / calcium bromide brine after aging at 180 °C / 200 °C

[0076]

[0077]

[0078] From the test results in Table 2, it can be seen that compared with the composite brine completion fluid without adding a thickener, after adding the thickeners prepared in Examples 1-2, the apparent viscosity (AV), plastic viscosity (PV), and yield point (YP) of the completion fluid have been significantly improved. Even after aging at 180 °C and 200 °C, the viscosity increasing performance of the Examples can still be maintained. It can be seen that the thickeners prepared in the Examples have excellent high temperature resistance. Among them, after adding the thickener of Example 2, the viscosity of the completion fluid sample is the largest and the performance is the most excellent.

[0079] In summary, the thickener prepared by the present invention still has excellent viscosity increasing performance after aging in a high temperature (200 °C) composite calcium salt (calcium chloride / calcium bromide) environment, which can enrich the development of the technology of high temperature resistant and high density solids-free completion fluid.

Claims

1. A method for preparing a high temperature resistant hyperbranched polymer tackifier for composite calcium salt water completion fluid, comprising the following steps: (1) Preparation of highly reactive branched monomers γ-aminopropyltriethoxysilane, diethylene glycol and triethylene glycol are mixed, stirred evenly and reacted; after the reaction is completed, dialyzed and freeze-dried to obtain a branched monomer with high reactivity; (2) Preparation of high temperature resistant hyperbranched polymer thickener The salt-resistant monomer and the highly reactive branched monomer prepared in step (1) are added to deionized water, and then acrylamide monomers, rigid cyclic monomers and hydrophobic monomers are added to obtain a monomer solution; after adjusting the pH value of the monomer solution, nitrogen is introduced to deoxygenate, and then the temperature is raised to the reaction temperature, an initiator is added, and a thermal polymerization reaction is initiated; after the reaction is completed, ethanol is added to the obtained reaction solution for precipitation, and the reaction solution is filtered, vacuum dried and crushed to obtain a high-temperature resistant hyperbranched polymer thickener for a composite calcium salt water completion fluid.

2. The method for preparing the high temperature resistant hyperbranched polymer tackifier for composite calcium salt water completion fluid according to claim 1, characterized in that: The mass ratio of γ-aminopropyltriethoxysilane, diethylene glycol and triethylene glycol in step (1) is 1:3-5:1-3, preferably 1:4:

2.

3. The method for preparing the high temperature resistant hyperbranched polymer tackifier for composite calcium salt water completion fluid according to claim 1, characterized in that: The reaction temperature in step (1) is 150-200° C. and the reaction time is 2-4 h. The dialysis step is: putting the product obtained after the reaction into a dialysis bag and dialyzing it in deionized water for 24-48 hours; the molecular weight cutoff of the dialysis bag is 3500Da; the freeze-drying temperature is 0-5°C, and the freeze-drying time is 10-15 hours.

4. The method for preparing the high temperature resistant hyperbranched polymer tackifier for composite calcium salt water completion fluid according to claim 1, characterized in that: The salt-resistant monomer in step (2) is 2-acrylamido-2-methylpropanesulfonic acid, sodium p-styrenesulfonate or sodium vinylsulfonate; the acrylamide monomer is acrylamide, N,N-dimethylacrylamide or N-isopropylacrylamide; the rigid cyclic monomer is N-vinylpyrrolidone; the hydrophobic monomer is dimethylditetradecylammonium bromide, allyl polyethylene glycol or hexadecyldimethylallylammonium chloride; the allyl polyethylene glycol is APEG-800, APEG-1000, APEG-1200, APEG-1300, APEG-2000 or APEG-2200.

5. The method for preparing the high temperature resistant hyperbranched polymer tackifier for composite calcium salt water completion fluid according to claim 1, characterized in that: In step (2), the mass ratio of the salt-resistant monomer, the highly reactive branched monomer, the acrylamide monomer, the rigid cyclic monomer and the hydrophobic monomer is 5-7:0.2:4:1:0.3, preferably 6:0.2:4:1:0.

3.

6. The method for preparing the high temperature resistant hyperbranched polymer tackifier for composite calcium salt water completion fluid according to claim 1, characterized in that: The mass ratio of the salt-resistant monomer to deionized water in step (2) is 1:4-10; In step (2), the pH value of the monomer solution is adjusted to 5-8, preferably 6-7; the pH value of the monomer solution is adjusted using a sodium hydroxide aqueous solution with a mass fraction of 20-40%.

7. The method for preparing the high temperature resistant hyperbranched polymer tackifier for composite calcium salt water completion fluid according to claim 1, characterized in that: The initiator in step (2) is potassium persulfate, ammonium persulfate, azobisisobutyronitrile, azobisisobutyramidine hydrochloride; the mass of the initiator is 0.01-0.2% of the total mass of the salt-resistant monomer, the highly reactive branched monomer, the acrylamide monomer, the rigid cyclic monomer and the hydrophobic monomer, preferably 0.05-0.1%.

8. The method for preparing the high temperature resistant hyperbranched polymer tackifier for composite calcium salt water completion fluid according to claim 1, characterized in that: In step (2), the reaction temperature is 55-65° C., and the polymerization reaction time is 3-5 h; The volume ratio of the ethanol to the mass ratio of the salt-resistant monomer is 15-50 mL:1 g; the vacuum drying temperature is 70-80° C., and the vacuum drying time is 8-10 h.

9. A high temperature resistant hyperbranched polymer tackifier for composite calcium salt water completion fluid, characterized in that: The preparation method is described in any one of claims 1 to 8.

10. Use of the high temperature resistant hyperbranched polymer tackifier for composite calcium brine completion fluid according to claim 9 in composite calcium brine completion fluid; preferably, the concentration of the high temperature resistant hyperbranched polymer tackifier for composite calcium brine completion fluid in the composite calcium brine completion fluid is 10-15 g / L; the composite calcium salt comprises calcium chloride and calcium bromide.

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