阅读说明：本技术 一种固井水泥浆用温敏增粘型悬浮剂的制备方法 (Preparation method of temperature-sensitive tackifying type suspending agent for well cementation cement slurry ) 是由 程小伟 罗敏 黄盛� 郑友志 辜涛 张占武 张春梅 高显束 刘开强 梅开元 于 2021-01-08 设计创作，主要内容包括：本发明涉及一种固井水泥浆用温敏增粘型悬浮剂的制备方法,包括：(1)将单体、引发剂加入去离子水中,水浴温度30-60℃,反应得到主链产物,单体为丙烯酰胺、2-丙烯酰胺基-2-甲基丙磺酸、丙烯酸、衣康酸；(2)将温敏性单体、亲水性单体、引发剂、链转移剂加入去离子水中,水浴温度40-80℃,反应得到侧链产物；温敏性单体为N-异丙基丙烯酰胺、N,N-二乙基丙烯酰胺、N,N-二甲基丙烯酰胺、N-叔丁基丙烯酰胺、N-乙基甲基丙烯酰胺、N-丙基丙烯酰胺,亲水性单体为对苯乙烯磺酸钠、N-乙烯基吡咯烷酮、丙烯酸、丙烯酰胺；(3)将主链产物、侧链产物、引发剂加入去离子水中,水浴温度20-50℃,反应得到温敏增粘型悬浮剂。该悬浮剂常温下泵送能力强,高温下增粘效果好。(The invention relates to a preparation method of a temperature-sensitive tackifying suspending agent for well cementation cement slurry, which comprises the following steps: (1) adding a monomer and an initiator into deionized water, reacting at the water bath temperature of 30-60 ℃ to obtain a main chain product, wherein the monomer is acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, acrylic acid and itaconic acid; (2) adding a temperature-sensitive monomer, a hydrophilic monomer, an initiator and a chain transfer agent into deionized water, and reacting at the water bath temperature of 40-80 ℃ to obtain a side chain product; the temperature-sensitive monomer is N-isopropyl acrylamide, N-diethyl acrylamide, N-dimethyl acrylamide, N-tert-butyl acrylamide, N-ethyl methacrylamide and N-propyl acrylamide, and the hydrophilic monomer is sodium p-styrene sulfonate, N-vinyl pyrrolidone, acrylic acid and acrylamide; (3) and adding the main chain product, the side chain product and the initiator into deionized water, and reacting at the water bath temperature of 20-50 ℃ to obtain the temperature-sensitive tackifying suspending agent. The suspending agent has strong pumping capacity at normal temperature and good tackifying effect at high temperature.)

1. A preparation method of a temperature-sensitive tackifying suspending agent for well cementation cement slurry sequentially comprises the following steps:

(1) adding 20-80g of monomer and 0.2-2.4g of initiator into 70-400ml of deionized water, placing the mixture into a three-neck flask, carrying out water bath at the temperature of 30-60 ℃ for 5-10h of reaction, washing and drying to obtain a main chain product ZL, wherein the monomer is one or a mixture of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, acrylic acid and itaconic acid which are mixed according to any proportion;

(2) adding 20-100g of temperature-sensitive monomer, 20-100g of hydrophilic monomer, 1-6g of initiator and 1-6g of chain transfer agent into 800ml of deionized water, placing the mixture into a three-neck flask, carrying out water bath at the temperature of 40-80 ℃ for 5-10h of reaction, washing and drying to obtain a temperature-sensitive side chain product CL, wherein the temperature-sensitive monomer is one or a mixture of N-isopropyl acrylamide, N-diethyl acrylamide, N-dimethyl acrylamide, N-tert-butyl acrylamide, N-ethyl methacrylamide and N-propyl acrylamide which are mixed according to any proportion; the hydrophilic monomer is one or a mixture of more of sodium p-styrene sulfonate, N-vinyl pyrrolidone, acrylic acid and acrylamide which are mixed according to any proportion;

(3) adding a main chain product ZL2-10g, a side chain product CL2-10g and an initiator 0.01-2g into 100-800ml deionized water, placing the mixture into a three-neck flask, carrying out water bath at the temperature of 20-50 ℃ for reaction for 1-2 days, washing and drying to obtain the temperature-sensitive tackifying suspending agent.

2. The method for preparing the temperature-sensitive tackifying type suspending agent for the well cementing cement slurry according to claim 1, wherein the initiator in the step (1) and the step (2) is azobisisobutyronitrile, dibenzoyl peroxide or ammonium persulfate/sodium bisulfite.

3. The method for preparing the temperature-sensitive tackifying type suspending agent for the well cementation cement slurry as claimed in claim 1, wherein the chain transfer agent in the step (2) is mercaptoethylamine hydrochloride.

4. The method for preparing the temperature-sensitive tackifying type suspending agent for the well cementation cement slurry as claimed in claim 1, wherein the initiator in the step (3) is 1-ethyl- (3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide.

Technical Field

The invention relates to a preparation method of a suspending agent for cement slurry in the well cementation process in the field of petroleum and natural gas exploration and development, in particular to a preparation method of a temperature-sensitive tackifying type suspending agent, which is used for improving the suspension stability of oil and gas well cementing cement slurry at high temperature.

Background

In the process of oil exploitation, well cementation is the last process of drilling engineering and is a key engineering for connecting drilling and oil production. In the well cementation process, cement slurry is injected from a ground wellhead, pumped to an annular space between the casing and the stratum through the casing, and forms a cement sheath after solidification, thereby playing the roles of supporting and protecting the casing and sealing and isolating oil, gas and water layers. In the well cementation of deep wells and ultra-deep wells, the static temperature at the bottom of the well is higher and higher along with the continuous increase of the well depth. In the waiting setting process of cement paste after the completion of the injection, the Brownian motion of solid-phase particles in the cement paste is accelerated due to the overhigh temperature, and the original viscous force in the cement paste is damaged. Meanwhile, the polymer suspending agent in the cement paste becomes thin at high temperature, the stability of the cement paste becomes poor, solid-phase particles settle, and even solid-phase and liquid-phase separation occurs, so that the interlayer packing capacity of the cement sheath is reduced. Therefore, the suspension stability of the cement slurry under the high-temperature condition is ensured, and the method has important significance for improving the well cementation quality and ensuring the safety of well cementation construction.

Common suspending agents include natural vegetable gum-modified species (e.g., highly viscous polyanionic cellulose, hydroxyethyl cellulose, etc.), organic polysaccharide-modified derivatives (e.g., xanthan gum), and synthetic polymers (mainly acrylamide-based polymers). The first two kinds of tackifier are easy to degrade at high temperature, and the synthetic polymer has introduced functional groups, so that it has high heat and salt resistance and molecular weight designed based on requirement, and may be used as well cementing slurry suspending agent for deep well and superdeep well. However, these suspensions all exhibit low temperature thickening. In a deep well, in order to improve the suspension stability of cement slurry under high temperature conditions, the addition amount of a suspending agent is increased, so that the slurry preparation on the site and the ground is difficult. Therefore, in order to overcome the defects of low-temperature thickening and high-temperature thinning of the existing cement slurry suspending agent, the synthesis of the suspending agent with high-temperature tackifying and low-temperature insignificant thickening is particularly important.

Disclosure of Invention

The invention aims to provide a preparation method of a temperature-sensitive tackifying type suspending agent for well cementation cement slurry, which has reliable principle and simple and convenient operation, and the temperature-sensitive tackifying type suspending agent prepared by the method has good chemical stability, good pumping capacity at normal temperature and good tackifying effect at high temperature, overcomes the problems of low-temperature thickening and high-temperature thinning of the existing suspending agent, and has wide market application prospect.

A preparation method of a temperature-sensitive tackifying suspending agent for well cementation cement slurry sequentially comprises the following steps:

(1) adding 20-80g of monomer and 0.2-2.4g of initiator into 70-400ml of deionized water, placing the mixture into a three-neck flask, carrying out water bath at the temperature of 30-60 ℃ for 5-10h of reaction, washing and drying to obtain a main chain product ZL, wherein the monomer is one or a mixture of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, acrylic acid and itaconic acid which are mixed according to any proportion;

(2) adding 20-100g of temperature-sensitive monomer, 20-100g of hydrophilic monomer, 1-6g of initiator and 1-6g of chain transfer agent into 800ml of deionized water, placing the mixture into a three-neck flask, carrying out water bath at the temperature of 40-80 ℃ for 5-10h of reaction, washing and drying to obtain a temperature-sensitive side chain product CL, wherein the temperature-sensitive monomer is one or a mixture of N-isopropyl acrylamide, N-diethyl acrylamide, N-dimethyl acrylamide, N-tert-butyl acrylamide, N-ethyl methacrylamide and N-propyl acrylamide which are mixed according to any proportion; the hydrophilic monomer is one or a mixture of more of sodium p-styrene sulfonate, N-vinyl pyrrolidone, acrylic acid and acrylamide which are mixed according to any proportion;

(3) adding a main chain product ZL2-10g, a side chain product CL2-10g and an initiator 0.01-2g into 100-800ml deionized water, placing the mixture into a three-neck flask, carrying out water bath at the temperature of 20-50 ℃ for reaction for 1-2 days, washing and drying to obtain the temperature-sensitive tackifying suspending agent.

In the step (1) and the step (2), the initiator is Azobisisobutyronitrile (AIBN), dibenzoyl peroxide (BPO) or ammonium persulfate ((NH)₄)₂S₂O₈) Sodium bisulfite (NaHSO)₃)。

The chain transfer agent in the step (2) is mercaptoethylamine hydrochloride (AET. HCl).

The initiator in the step (3) is 1-ethyl- (3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS).

The synthesis process of the temperature-sensitive tackifying suspending agent is as follows:

the synthesis process of the main chain ZL (taking the reaction of acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid as an example):

the synthesis process of the side chain CL (taking the reaction of sodium p-styrene sulfonate and N-isopropyl acrylamide as an example):

the synthesis process of the temperature-sensitive tackifying type suspending agent (taking the main chain ZL and the side chain CL synthesized as examples) is as follows:

the mechanism of the invention is analyzed as follows:

the temperature-sensitive tackifying type suspending agent has a thermal tackifying behavior, small molecular polymers (temperature-sensitive side chains) with Low Critical Solution Temperature (LCST) are grafted to a main chain of a water-soluble polymer, when the temperature is below the LCST of the side chain polymers, the interaction of hydrogen bonds existing between water molecules and side chain molecules is strong, the side chains at the moment show strong hydrophilicity, and the water solubility of the temperature-sensitive tackifying type suspending agent is good. When the temperature is higher than the LCST of the side chain polymer, the temperature-sensitive side chain forms an associated hydrophobic domain due to the phase transition, the intermolecular association promotes the formation of a physical network structure, the hydrodynamic volume of the polymer is greatly increased, and the unique high-temperature tackifying performance is endowed to the polymer. Hydrophobic association is favored by the addition of electrolyte or by a suitable increase in temperature, which can result in the hydrophobic association increasing in viscosity with increasing electrolyte concentration and temperature.

Compared with the prior art, the invention has the following beneficial effects:

(1) the temperature-sensitive tackifying type suspending agent prepared by the method has wide application temperature range, has a thermal tackifying effect at high temperature, can overcome the defect that the existing polymer suspending agent becomes thinner at high temperature, and has an obvious suspending effect;

(2) the method adopts an aqueous solution free radical polymerization method for preparation, avoids introducing new impurities in the synthesis process through chemical synthesis, and the prepared temperature-sensitive tackifying suspending agent has high purity and good chemical stability;

(3) the method has the advantages of wide sources of various raw materials, low price and low cost;

(4) the method has simple operation and high yield, and can be applied in large scale.

Drawings

FIG. 1 is a Fourier infrared spectrum of the temperature sensitive tackified suspending agent prepared in example 2.

FIG. 2 is a NMR chart of the temperature-sensitive viscosity-increasing suspending agent prepared in example 2.

FIG. 3 shows the transmittance of the temperature-sensitive viscosity-increasing suspension concentrate prepared in example 4 at different concentrations at a wavelength of light λ 962nm as a function of temperature.

FIG. 4 shows the apparent viscosity of the temperature-sensitive viscosity-increasing suspending agent prepared in example 4 at different concentrations as a function of temperature.

Detailed description of the invention

The invention is further illustrated below with reference to the figures and examples in order to facilitate the understanding of the invention by a person skilled in the art. It is to be understood that the invention is not limited in scope to the specific embodiments, but is intended to cover various modifications within the spirit and scope of the invention as defined and defined by the appended claims, as would be apparent to one of ordinary skill in the art.

Preparation of temperature-sensitive tackifying suspending agent

Example 1

A preparation method of a temperature-sensitive tackifying suspending agent for well cementation cement slurry specifically comprises the following steps:

10g of acrylic acid and 10g of 2-acrylamide-2-methylpropanesulfonic acid are sequentially weighed and added into 120ml of deionized water, then the aqueous solution is added into a three-neck flask which is provided with a stirring device and is placed in a water bath kettle at 40 ℃, after nitrogen is introduced for a period of time, 0.9g of ammonium persulfate/sodium bisulfite is added, the experiment is finished after 8 hours of reaction, and the solid main chain ZL is obtained after washing and drying.

20g of N-isopropylacrylamide and 20g of sodium p-styrenesulfonate are sequentially weighed and added into 220ml of deionized water, then the aqueous solution is added into a three-neck flask which is provided with a stirring device and is placed in a 50 ℃ water bath kettle, after nitrogen is introduced for a period of time, 1.2g of azobisisobutyronitrile and 1.2g of mercaptoethylamine hydrochloride are added, the experiment is finished after 10 hours of reaction, and the solid side chain CL is obtained after washing and drying.

Sequentially weighing a main chain ZL2g and a side chain CL2g, adding the main chain ZL2g and the side chain CL2g into 220ml of deionized water, then adding the aqueous solution into a three-neck flask which is provided with a stirring device and is placed in a water bath kettle at 25 ℃, introducing nitrogen for a period of time, adding 0.02g of 1-ethyl- (3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide, reacting for 24 hours, finishing the experiment, washing and drying to obtain a solid product, namely the temperature-sensitive tackifying type suspending agent.

Example 2

A preparation method of a temperature-sensitive tackifying suspending agent for well cementation cement slurry specifically comprises the following steps:

weighing 5g of 2-acrylamide-2-methylpropanesulfonic acid, 5g of acrylamide and 5g of acrylic acid in sequence, adding the weighed materials into 100ml of deionized water, adding the aqueous solution into a three-neck flask which is provided with a stirring device and is placed in a 43 ℃ water bath kettle, introducing nitrogen for a period of time, adding 0.6g of ammonium persulfate/sodium bisulfite, reacting for 8 hours, ending the experiment, washing and drying to obtain the solid main chain ZL.

30g of N, N-diethylacrylamide and 20g of N-vinyl pyrrolidone are weighed in sequence, added into 270ml of deionized water, then the aqueous solution is added into a three-neck flask which is provided with a stirring device and is placed in a water bath kettle at 53 ℃, after nitrogen is introduced for a period of time, 1.5g of ammonium persulfate/sodium bisulfite and 1.5g of mercaptoethylamine hydrochloride are added, the experiment is finished after 10 hours of reaction, and the solid side chain CL is obtained after washing and drying.

Sequentially weighing a main chain ZL2g and a side chain CL3g, adding the main chain ZL2g and the side chain CL3g into 190ml of deionized water, then adding an aqueous solution into a three-neck flask which is provided with a stirring device and is placed in a 28 ℃ water bath kettle, introducing nitrogen for a period of time, adding 0.02g of 1-ethyl- (3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide, reacting for 24 hours, finishing the experiment, washing and drying to obtain a solid product, namely the temperature-sensitive tackifying type suspending agent.

Example 3

A preparation method of a temperature-sensitive tackifying suspending agent for well cementation cement slurry specifically comprises the following steps:

sequentially weighing 5g of itaconic acid, 10g of 2-acrylamide-2-methylpropanesulfonic acid and 5g of acrylamide, adding the itaconic acid, the 2-acrylamide-2-methylpropanesulfonic acid and the acrylamide into 120ml of deionized water, adding the aqueous solution into a three-neck flask which is provided with a stirring device and is placed in a water bath kettle at 48 ℃, introducing nitrogen for a period of time, adding 0.6g of dibenzoyl peroxide, reacting for 8 hours, ending the experiment, washing and drying to obtain the solid main chain ZL.

Sequentially weighing 20g of N, N-dimethylacrylamide, 20g of N-ethylmethacrylamide and 30g of N-vinyl pyrrolidone, adding the weighed materials into 370ml of deionized water, adding the aqueous solution into a three-neck flask which is provided with a stirring device and is placed in a water bath kettle at 57 ℃, introducing nitrogen for a period of time, adding 2.1g of ammonium persulfate/sodium bisulfite and 2.1g of mercaptoethylamine hydrochloride, reacting for 10 hours, finishing the experiment, and washing and drying to obtain a solid side chain CL.

Sequentially weighing a main chain ZL3g and a side chain CL2g, adding the main chain ZL3g and the side chain CL2g into 260ml of deionized water, then adding an aqueous solution into a three-neck flask which is provided with a stirring device and is placed in a water bath kettle at 31 ℃, introducing nitrogen for a period of time, adding 0.02g of 1-ethyl- (3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide, reacting for 24 hours, finishing the experiment, washing and drying to obtain a solid product, namely the temperature-sensitive tackifying type suspending agent.

Example 4

A preparation method of a temperature-sensitive tackifying suspending agent for well cementation cement slurry specifically comprises the following steps:

sequentially weighing 5g of itaconic acid and 5g of 2-acrylamide-2-methylpropanesulfonic acid, adding the itaconic acid and the 2-acrylamide-2-methylpropanesulfonic acid into 80ml of deionized water, adding an aqueous solution into a three-neck flask which is provided with a stirring device and is placed in a water bath kettle at 53 ℃, introducing nitrogen for a period of time, adding 0.6g of ammonium persulfate/sodium bisulfite, reacting for 8 hours, ending the experiment, and washing and drying to obtain the solid main chain ZL.

40g of N-tert-butyl acrylamide, 10g of acrylic acid and 20g of N-vinyl pyrrolidone are sequentially weighed and added into 370ml of deionized water, then the aqueous solution is added into a three-neck flask which is provided with a stirring device and is placed in a water bath kettle at 62 ℃, after nitrogen is introduced for a period of time, 2.1g of azobisisobutyronitrile and 2.1g of mercaptoethylamine hydrochloride are added, the experiment is finished after 10 hours of reaction, and the solid side chain CL is obtained after washing and drying.

Sequentially weighing a main chain ZL2g and a side chain CL4g, adding the main chain ZL2g and the side chain CL4g into 230ml of deionized water, then adding the aqueous solution into a three-neck flask which is provided with a stirring device and is placed in a 34 ℃ water bath kettle, introducing nitrogen for a period of time, adding 0.02g of 1-ethyl- (3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide, reacting for 24 hours, finishing the experiment, washing and drying to obtain a solid product, namely the temperature-sensitive tackifying type suspending agent.

Structural representation of temperature-sensitive tackifying suspending agent

FIG. 1 shows a Fourier infrared spectrum of the temperature-sensitive tackified suspending agent prepared in example 2.

FIG. 2 shows the NMR spectrum of the temperature-sensitive viscosity-increasing suspending agent prepared in example 2.

As can be seen from FIG. 1, 1778.90cm^-1Is the absorption peak of lactam in the pyrrole ring, 1642.24cm^-1Is the absorption peak of-CO-in the amide at 1560.80cm^-1In-plane vibration absorption peak of N-H in the secondary amide at 1091.95cm^-1And 1041.70cm^-1Is SO₃Absorption Peak of H, 630.61cm^-1Is the out-of-plane vibration absorption peak of N-H in the amide.

As can be seen from fig. 2, δ -8.0653 ppm is the chemical shift of the hydrogen atom on-CONH-formed by dehydration condensation of the carboxyl group in acrylic acid and the terminal amino group on the side chain, and δ -7.7224 ppm is-CONH-in acrylamide₂Chemical shift of the hydrogen atom in (b), delta-3.3786 ppm being the CH of N, N-diethylacrylamide to which N is attached₂Chemical shift of hydrogen atoms.

Infrared spectroscopic analysis shows that the synthesized polymer contains N-vinyl pyrrolidone and 2-acrylamide-2-methyl propanesulfonic acid; the hydrogen nuclear magnetic resonance spectrum analysis shows that the synthesized polymer contains acrylamide, acrylic acid and N, N-diethylacrylamide. Therefore, comprehensive infrared spectrum and nuclear magnetic resonance hydrogen spectrum analysis show that the main chain ZL containing acrylamide, acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid and the side chain CL containing N-vinyl pyrrolidone and N, N-diethyl acrylamide are successfully synthesized, and the main chain ZL and the side chain CL are successfully coupled and grafted to synthesize the temperature-sensitive tackifying type suspending agent.

Third, performance analysis of temperature-sensitive tackifying type suspending agent

FIG. 3 shows the transmittance of different concentrations of the temperature-sensitive viscosity-increasing suspension concentrate prepared in example 4 as a function of temperature, measured at a wavelength λ of 962 nm.

FIG. 4 shows the apparent viscosity of different concentrations of the temperature-sensitive viscosity-increasing suspending agent prepared in example 4 as a function of temperature.

As can be seen from fig. 3, the transmittance of the synthesized temperature-sensitive thickening-type suspending agent at different concentrations tends to decrease with the increase of temperature, and as can be seen from fig. 4, the solution viscosity of the temperature-sensitive thickening-type suspending agent is low at low temperature, but the apparent viscosity increases significantly with the increase of temperature. The following conclusions can be drawn in conjunction with fig. 3 and 4: the apparent viscosity of the synthesized suspending agent aqueous solution is not obviously associated among molecules at a lower temperature, the light transmittance is better, the intermolecular association begins to form along with the temperature rise to 60 ℃, the light transmittance of the solution is reduced, the light transmittance approaches 0 at about 80 ℃, and the light transmittance is consistent with the apparent viscosity which begins to obviously rise at about 60-80 ℃. When molecules are further associated, the light transmittance is close to 0, so that the light transmittance does not change along with the increase of the association degree, which shows that the temperature-sensitive tackifying type suspending agent has obvious temperature-sensitive effect and thermal tackifying effect.

Tables 1-3 show the results of the suspension stability of the cement paste containing the suspending agent of the invention under high temperature conditions, and the difference between the upper and lower densities of the cement paste after the cement paste is maintained at different temperatures by standing is less than or equal to 0.02g/cm³All have better stability.

TABLE 1 p 1.90g/cm³Cement slurry suspension stability test results

TABLE 2 p 2.10g/cm³Cement slurry suspension stability test results

TABLE 3p 2.30g/cm³Cement slurry suspension stability test results

Although the present invention has been described in detail with reference to examples, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims.