CN105175628A - Oil well cement water-loss control agent compatible with AMPS (2-acrylamido-methylpropanesulfonic acid)-IA retarder and preparation method thereof - Google Patents

Abstract

The invention provides an oil well cement fluid loss reducer compatible with AMPS-IA retarder and its preparation method. The fluid loss reducer prepared by the method is used to reduce the water loss of cement slurry in the process of oil and natural gas drilling and cementing . The fluid loss reducer prepared by this method is a tetrapolymer, and the comonomers are 2-acrylamido-2-methylpropanesulfonic acid (AMPS), N, N'-dimethylacrylamide (DMAA ), acrylamide (AM), maleic anhydride (MA), and the initiator is a mixture of ammonium persulfate and sodium bisulfite. The fluid loss reducer provided by the invention has good ability to control water loss and improve the rheology of cement slurry, and has good compatibility with retarder AMPS-IA.

Description

A kind of oil well cement fluid loss reducer compatible with AMPS-IA retarder and preparation method

Inventors: Guo Shenglai, Bu Yuhuan, Guo Xinyang, Wang Chengwen

technical field

The invention relates to an oil well cement fluid loss reducing agent for oil field cementing and a preparation method thereof, belonging to the fields of oil field chemistry and oil gas well cementing. The fluid loss reducing agent prepared by the method is used for reducing the fluid loss of cement slurry in the cementing process of oil and gas wells.

Background technique

After oil and gas well drilling is completed, it is necessary to run casing and pump cement slurry to seal the annular space between the casing and the formation. Typically, the cement slurry is pumped downhole through the casing and back up the annulus. Due to the complex formation conditions and harsh downhole conditions, the free water in the cement slurry will filter out from the cement slurry and enter the formation under the action of the pressure difference during cementing. This process is usually called the loss of cement slurry. water. If the dehydration of the cement slurry is not well controlled, as the liquid phase content of the cement slurry decreases, the fluidity of the cement slurry will become worse, and the thickening time will be shortened. In severe cases, the cement slurry will lose its flow ability and become unpumpable If a large amount of cement slurry filtrate enters the oil and gas layer, it will cause damage to the oil and gas layer, which is not conducive to the protection of the oil and gas layer; in the waiting stage of cementing, if the water loss of the cement slurry is not controlled, it will cause Severe cement slurry loses weight, which causes annular air channeling. Therefore, it is necessary to add a fluid loss reducer to the cement slurry to ensure the safety of cementing and improve the quality of cementing.

In the field of oil and gas well cementing, the cementing technology with large temperature difference and long sealing section is a hot spot in current research. The core content of this technology is 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and itaconic acid (IA ) is the development of a large temperature difference retarder as the main functional monomer. However, most fluid loss reducers on the market (including the fluid loss reducer invented by the inventor in the invention patent ZL201110063542.X) have poor compatibility with the AMPS-IA retarder, and the addition of the AMPS-IA retarder It will seriously affect the water loss of cement slurry, and the existence of this problem also limits the application of AMPS-IA retarder. In view of this problem, on the basis of the patent ZL201110063542.X, the inventor found that when the pH value of the synthetic solution was less than 5, the synthesized fluid loss reducer and retarder AMPS-IA Has good compatibility.

At present, when the oil well cement fluid loss reducing agent containing maleic anhydride monomer is synthesized, the selected pH value is 6-8 (CN200810226689.4, CN200910076431.5, CN201010143591.X, CN201010591637.4, CN201110063542.X, CN201110072174 .5), the pH value mainly affects the reactivity ratio and the form of the carboxylic acid group, and the fluid loss reducer synthesized under the pH value (6-8) synthesis condition has strong dehydration control ability and little retarding side effect, which is similar to When the non-AMPS-IA retarder is used in combination, the water loss of the cement slurry can be easily controlled, but the compatibility with the retarder AMPS-IA is poor. Therefore, compared with the existing fluid loss reducer, the present invention has obvious advantages, and the patent of the present invention has the excellent dispersion performance of the patent (ZL201110063542.X).

Contents of the invention

The object of the present invention is to provide an oil well cement fluid loss reducer compatible with retarder AMPS-IA and a preparation method thereof. The fluid loss reducer synthesized by this method has good compatibility with the setting retarder AMPS-IA, which can solve the problem of poor compatibility between the conventional fluid loss reducer and the setting retarder AMPS-IA, and the fluid loss reducer has good Dispersion properties can improve the rheological properties of cement slurry while reducing the water loss of cement slurry, and solve the problem of high cement slurry consistency caused by conventional fluid loss reducers. In actual construction, it can meet the construction requirements without using dispersants.

In order to achieve the above object, the present invention provides a kind of oil well cement fluid loss reducer compatible with retarder AMPS-IA and its preparation method, the preparation method comprising:

a) Prepare raw material aqueous solution, described raw material aqueous solution comprises four kinds of monomers: 2-acrylamido-2-methylpropanesulfonic acid (AMPS), N, N'-dimethylacrylamide (DMAA), acrylamide ( AM), maleic anhydride (MA), wherein the parts by weight of the four monomers are: 50 parts to 65 parts of 2-acrylamido-2-methylpropanesulfonic acid (AMPS), N, N'-dimethyl 8 to 25 parts of DMAA, 10 to 15 parts of acrylamide (AM), and 5 to 10 parts of maleic anhydride (MA).

b) reacting the raw material aqueous solution by adjusting the solution polymerization conditions such as the concentration of the solution, the pH value of the solution, the reaction temperature, and the amount of the initiator added.

c) The initiator is ammonium persulfate and sodium bisulfite (mass ratio 1:1).

The total concentration of reacting monomers affects the polymerization rate and the water loss performance of the product. If the total concentration of monomers is too high, violent polymerization or excessive viscosity of the product will easily occur; on the contrary, if the total concentration of monomers is too small, the reaction rate will be too low and the effective concentration of the product will decrease. Therefore, the preferred total weight of the monomers in the present invention accounts for 25% to 35% of the weight of deionized water.

The synthesis method of the oil well cement fluid loss reducer compatible with the setting retarder AMPS-IA is an aqueous solution polymerization method. A typical polymerization method is: dissolve all the monomers in deionized water, adjust the pH value of the monomer solution to 1-5 with sodium hydroxide solution, add the solution into a three-necked flask, and put the three-necked flask at 40°C In a constant temperature water bath at ~60°C, pass nitrogen into the three-necked flask to exclude oxygen. After the temperature of the aqueous solution in the three-necked flask reaches the set temperature, add ammonium persulfate and hydrogen sulfite accounting for 0.2% to 1.5% of the total monomer mass Sodium (mass ratio 1:1) is used to initiate the reaction, and the reaction lasts for 2-5 hours to make a tetrapolymer solution, which is dried and pulverized to make a powder to obtain oil well cement that is compatible with the retarder AMPS-IA. Dehydration agent.

Compared with the prior art, the oil well cement fluid loss reducer prepared by the present invention has good compatibility with the setting retarder AMPS-IA, and the water loss of cement slurry can be controlled at a low level without adding other auxiliary admixtures. level.

Detailed ways

Example 1

Weigh 61.4 parts of 2-acrylamido-2-methylpropanesulfonic acid (AMPS), 18.3 parts of N, N'-dimethylacrylamide (DMAA), 13.07 parts of acrylamide (AM), maleic anhydride (MA ) 7.23 copies. Dissolve in 308 parts of deionized water, add an appropriate amount of sodium hydroxide solution, and adjust the pH value to 5. Add the solution into the three-necked flask, put the three-necked flask into a constant temperature water bath at 60°C, start stirring, and pass nitrogen gas into the three-necked flask to remove oxygen. After the temperature of the aqueous solution in the three-necked flask reaches 60°C, add 4 parts of The mass concentration of ammonium sulfate and sodium bisulfite is 10% of the mixed solution to initiate the reaction, and the reaction lasts for 5 hours to make a tetrapolymer solution, which is dried and pulverized to obtain oil well cement compatible with the retarder AMPS-IA Dehydration reducer powder. Code-named as sample 1.

Example 2

Weigh 61.4 parts of 2-acrylamido-2-methylpropanesulfonic acid (AMPS), 18.3 parts of N, N'-dimethylacrylamide (DMAA), 13.07 parts of acrylamide (AM), maleic anhydride (MA ) 7.23 copies. Dissolve in 308 parts of deionized water, add an appropriate amount of sodium hydroxide solution, and adjust the pH value to 2. Add the solution into the three-necked flask, put the three-necked flask into a constant temperature water bath at 60°C, start stirring, and pass nitrogen gas into the three-necked flask to remove oxygen. After the temperature of the aqueous solution in the three-necked flask reaches 60°C, add 4 parts of The mass concentration of ammonium sulfate and sodium bisulfite is 10% of the mixed solution to initiate the reaction, and the reaction lasts for 5 hours to make a tetrapolymer solution, which is dried and pulverized to obtain oil well cement compatible with the retarder AMPS-IA Dehydration reducer powder. Code-named sample 2.

Comparative example 1

Weigh 61.4 parts of 2-acrylamido-2-methylpropanesulfonic acid (AMPS), 18.3 parts of N, N'-dimethylacrylamide (DMAA), 13.07 parts of acrylamide (AM), maleic anhydride (MA ) 7.23 copies. Dissolve in 308 parts of deionized water, add an appropriate amount of sodium hydroxide solution, and adjust the pH value to 7. Add the solution into the three-necked flask, put the three-necked flask into a constant temperature water bath at 60°C, start stirring, and pass nitrogen gas into the three-necked flask to remove oxygen. After the temperature of the aqueous solution in the three-necked flask reaches 60°C, add 4 parts of A mixed solution with a mass concentration of 10% of ammonium sulfate and sodium bisulfite initiates a reaction, and the reaction lasts for 5 hours to prepare a tetrapolymer solution, which is dried and pulverized to obtain an oil well cement fluid loss reducer powder. Code-named sample 3.

Comprehensive performance evaluation of embodiment 1, embodiment 2 and comparative example 1

The cement slurry was prepared according to the standard GB10238-88, and the thickening time, water loss, rheological properties, and compressive strength were evaluated according to the standard SY/T5960-94 "Evaluation method of oil well cement fluid loss reducer", and the experimental condition was 75°C.

Cement slurry formula 1: 100 parts of Shengwei G grade cement + 1 part of sample 1 + 44 parts of water, the density is 1.9g/cm ³ .

Cement slurry formula 2: 100 parts of Shengwei G grade cement + 1 part of sample 1 + 0.5 parts of retarder AMPS-IA + 44 parts of water, the density is 1.9g/cm ³ .

Cement slurry formula 3: 100 parts of Shengwei G grade cement + 1 part of sample 2 + 44 parts of water, the density is 1.9g/cm ³ .

Cement slurry formula 4: 100 parts of Shengwei G grade cement + 1 part of sample 2 + 0.5 parts of retarder AMPS-IA + 44 parts of water, with a density of 1.9 g/cm ³ .

Cement slurry formula 5: 100 parts of Shengwei G grade cement + 1 part of sample 3 + 44 parts of water, the density is 1.9g/cm ³ .

Cement slurry formula 6: 100 parts of Shengwei G grade cement + 1 part of sample 3 + 0.5 parts of retarder AMPS-IA + 44 parts of water, with a density of 1.9 g/cm ³ .

Table 1 cement slurry properties

The experimental results show that when no retarder AMPS-IA is added, the water loss of the cement slurry with sample 1, sample 2, and sample 3 is lower, the rheological properties are better, and the 24h cement stone compressive strength is better; The thickening time of the cement slurry with sample 1 and sample 2 is slightly longer than that of the cement slurry with sample 3, which is mainly because the adsorption capacity of sample 1 and sample 2 on the surface of cement particles is greater than that of sample 3. When the retarder AMPS-IA was added, the water loss of the cement slurry with sample 1 and sample 2 was not much different from that without the retarder AMPS-IA, and the sample was added after the retarder AMPS-IA was added The water loss of the cement slurry of 3 was increased to 200mL. By comparison with sample 3, the compatibility of sample 1 and sample 2 with retarder AMPS-IA is obviously better than that of sample 3.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and modifications can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the invention is defined by the claims and their equivalents.

Claims (8)

1. one kind and AMPS-IA retardant compatibility type oil-well cement filtrate reducer preparation method, it is characterized in that, take four kinds of monomers according to quality proportioning and be respectively 50 parts ~ 65 parts 2-acrylamide-2-methylpro panesulfonic acids (AMPS), 8 parts ~ 25 parts N, N '-dimethyl acrylamide (DMAA), 10 parts ~ 15 parts acrylamides (AM), 5 parts ~ 10 parts maleic anhydrides (MA), four kinds of monomers are all dissolved in deionized water, stir formation mixed solution, under 20 ~ 25 DEG C of conditions, regulate mixed solution pH value, the mixed solution mixing up pH value is placed in reaction vessel, reaction vessel is placed in water bath with thermostatic control, get rid of the oxygen in reaction vessel simultaneously and stir with agitator, the temperature of question response intra-tank mixed liquor reaches constant temperature, drip initiator solution, after isothermal reaction, obtain thick liquid, drying obtains oil-well cement filtrate reducer.

2. one according to claim 1 and AMPS-IA retardant compatibility type oil-well cement filtrate reducer preparation method, it is characterized in that, four kinds of described monomer total masses are 25% ~ 35% of deionized water quality.

3. one according to claim 1 and AMPS-IA retardant compatibility type oil-well cement filtrate reducer preparation method, is characterized in that, described adjustment mixed solution pH value is for regulating mixed solution pH value to be 1 ~ 5 with sodium hydroxide.

4. one according to claim 1 and AMPS-IA retardant compatibility type oil-well cement filtrate reducer preparation method, is characterized in that, the oxygen in described eliminating reaction vessel is got rid of for being filled with nitrogen in reaction vessel.

5. one according to claim 1 and AMPS-IA retardant compatibility type oil-well cement filtrate reducer preparation method, is characterized in that, described isothermal reaction is react 2 ~ 5h under 40 ~ 60 DEG C of conditions.

6. one according to claim 1 and AMPS-IA retardant compatibility type oil-well cement filtrate reducer preparation method, it is characterized in that, described initiator solution is be the aqueous solution that the ammonium persulphate of 1:1 and sodium bisulfite dissolve by quality proportioning, and its massfraction is 10%.

7. one according to claim 1 and AMPS-IA retardant compatibility type oil-well cement filtrate reducer preparation method, it is characterized in that, described dropping initiator solution is in described mixed solution, add the ammonium persulphate and sodium bisulfite that total mass is 0.2% ~ 1.5% of described four kinds of monomer total masses.

8. a kind of oil-well cement filtrate reducer prepared with AMPS-IA retardant compatibility type oil-well cement filtrate reducer preparation method described in any one of claim 1-7.