CN107828015B

CN107828015B - Preparation method of high-temperature-resistant tackifier for drilling fluid

Info

Publication number: CN107828015B
Application number: CN201711124308.7A
Authority: CN
Inventors: 康建荣
Original assignee: Jiangsu Normal University
Current assignee: Jiangsu Normal University
Priority date: 2017-11-14
Filing date: 2017-11-14
Publication date: 2020-04-03
Anticipated expiration: 2037-11-14
Also published as: CN107828015A

Abstract

The invention discloses a preparation method of a high-temperature resistant tackifier for drilling fluid, which takes acrylamide, 2-acrylamide-2-methylpropanesulfonic acid, vinyl caprolactam and divinylbenzene as raw materials and prepares the tackifier by aqueous solution polymerization, wherein the raw materials are prepared according to the following weight parts: 28-36 parts of acrylamide, 20-28 parts of 2-acrylamide-2-methylpropanesulfonic acid, 16-32 parts of vinyl caprolactam and 0.6-1 part of divinylbenzene. The invention obtains a high molecular polymer by initiating the polymerization reaction of the monomer by the initiator, the product has outstanding tackifying performance and can resist high temperature of 240 ℃, and the viscosity of the drilling fluid can be effectively increased by adding a small amount of the product into the drilling fluid, and meanwhile, the product has certain filtration loss reduction.

Description

Preparation method of high-temperature-resistant tackifier for drilling fluid

Technical Field

The invention relates to the field of preparation of oilfield chemical additives, and in particular relates to a preparation method of a high-temperature-resistant tackifier for drilling fluid.

Background

The tackifier is one of core treating agents in reservoir protection drilling fluid, is always one of research hotspots of drilling fluid workers, and plays an important role in adjusting the rheological property of the drilling fluid. From the historical development of tackifiers, they can be divided into four broad categories: natural vegetable gum tackifiers, inorganic tackifiers, organic tackifiers, and synthetic polymer tackifiers. Since the 21 st century, with the development of oil exploration and development, oil field exploration and development have been developed towards oceans, complex formations, deep wells, medium-deep wells and ultra-deep wells, and higher requirements are provided for drilling fluid treatment agents. Practice has shown that, due to the performance limitations of conventional tackifiers, the requirements of more severe practical application conditions have not been met.

The conventional tackifier for reservoir protection drilling fluid mainly comprises a synthetic polymer represented by an acrylamide polymer and a biopolymer represented by xanthan gum, but the synthetic polymer and the biopolymer are difficult to overcome when the tackifier is used for high-temperature formations, the xanthan gum is easy to degrade at high temperature, relatively poor in stability, easy to degrade to block oil layers, and high in use cost, amide groups in molecules of the polyacrylamide polymer are easy to hydrolyze, the hydrolysis reaction speed is very high particularly under acidic and alkaline conditions, the hydrolysis rate is increased along with the increase of temperature, and when the hydrolysis degree of the amide groups exceeds a certain degree, the viscosity loss of a polymer solution can be caused. In view of this, it is necessary to improve the temperature resistance of acrylamide polymers, introduce functional groups with different structures and characteristics into the molecules of the acrylamide polymers, change the intramolecular or intermolecular action of the polymers, and develop a novel high temperature resistant tackifier for drilling fluids, so as to further improve the properties of the polymers and better adapt to the requirements of complex strata.

Disclosure of Invention

The invention aims to provide a preparation method of a high-temperature-resistant tackifier for drilling fluid, the high-temperature-resistant tackifier is a high-molecular polymer, the product has outstanding tackifying performance and can resist high temperature of 240 ℃, and the viscosity of the drilling fluid can be effectively increased by adding a small amount of the product into the drilling fluid, and meanwhile, the high-temperature-resistant tackifier has certain filtration loss reduction.

A preparation method of a high-temperature resistant tackifier for drilling fluid is characterized by comprising the following steps:

1) dissolving 28-36 parts of acrylamide and 20-28 parts of 2-acrylamido-2-methylpropanesulfonic acid in 108-148 parts of deionized water, adjusting the solution to be neutral by using an alkaline reagent, transferring the solution to a reaction kettle, adding 1.8-2.9 parts of a composite viscosity stabilizer and 3-5.5 parts of sodium dodecyl sulfate, and uniformly stirring;

2) heating the reaction kettle to 40 ℃, adding 16-32 parts of vinyl caprolactam dissolved with 0.13-0.19 part of azobisisobutyronitrile and 0.6-1 part of divinylbenzene, stirring uniformly, and introducing N₂Deoxidizing for 1h, continuously heating to 65 ℃, reacting for 6-7 h while stirring, discharging to obtain jelly, precipitating with acetone, drying in a 50 ℃ oven, and crushing to obtain the polymer high-temperature-resistant tackifier.

Has the advantages that: the invention provides a preparation method of a high-temperature resistant tackifier for drilling fluid, which has simple production flow and relatively easily obtained raw materials, and a compound viscosity stabilizer is added in the preparation process, can adjust the polymerization reaction speed, control the molecular weight, simultaneously remove oxygen dissolved in a polymer system, prevent the polymer from being degraded by the oxygen, complex high-valence metal ions and prevent the polymer from being curled by the high-valence metal ions. The product prepared by taking acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, vinyl caprolactam and divinylbenzene as main raw materials has outstanding tackifying performance and can resist high temperature of 240 ℃, and the viscosity of the drilling fluid can be effectively increased by adding a small amount of the product into the drilling fluid, and meanwhile, the product has certain filtration loss reduction.

Detailed Description

Example 1

Dissolving 32 parts of acrylamide and 24 parts of 2-acrylamido-2-methylpropanesulfonic acid in 128 parts of deionized water, adjusting the solution to be neutral by using an alkaline reagent, transferring the solution to a reaction kettle, adding 2.5 parts of a composite viscosity stabilizer and 5 parts of sodium dodecyl sulfate, and uniformly stirring; heating the reaction kettle to 40 ℃, adding 28 parts of vinyl caprolactam dissolved with 0.15 part of azobisisobutyronitrile and 0.8 part of divinylbenzene, stirring uniformly, and introducing N₂Deoxidizing for 1h, continuously heating to 65 ℃, reacting for 6-7 h while stirring, discharging to obtain jelly, precipitating with acetone, drying in a 50 ℃ oven, and crushing to obtain the polymer high-temperature-resistant tackifier.

The preparation method of the compound viscosity stabilizer comprises the following steps:

mixing 133 parts of vinyl acetate, 62 parts of thiourea, 7 parts of methanol and 2.7 parts of acetaldehyde, magnetically stirring for 2 hours, transferring into a reactor, and replacing the interior of the reactor with nitrogen through nitrogen bubbling; dissolving 2, 2' -azobisisobutyronitrile in methanol, preparing an initiator solution with the concentration of 0.8g/L, performing ultrasonic treatment for 30min, and performing nitrogen replacement on the initiator solution by nitrogen bubbling. The reactor was heated to 60 ℃ and 30 parts of the initiator solution was slowly added to the reactor to start the polymerization, and after 4 hours, the vessel was cooled to stop the polymerization. And when the temperature in the container reaches 30 ℃, reducing pressure, adding methanol into the reactor, removing unreacted vinyl acetate monomers from the reaction solution, drying, crushing, adding 6 parts of tetrapropyl thiuram disulfide, 20 parts of sodium sulfite, 12 parts of EDTA and 90 parts of sodium bentonite, and kneading to react to obtain the composite viscosity stabilizer.

Example 2

Exactly the same as example 1, except that: adding 28 parts of acrylamide, 20 parts of 2-acrylamide-2-methylpropanesulfonic acid, 108 parts of deionized water, 1.8 parts of composite viscosity stabilizer, 3 parts of sodium dodecyl sulfate, 0.13 part of azobisisobutyronitrile, 16 parts of vinyl caprolactam and 0.6 part of divinylbenzene.

Example 3

Exactly the same as example 1, except that: adding 28 parts of acrylamide, 20 parts of 2-acrylamide-2-methylpropanesulfonic acid, 108 parts of deionized water, 2 parts of a composite viscosity stabilizer, 3.5 parts of sodium dodecyl sulfate, 0.14 part of azobisisobutyronitrile, 20 parts of vinyl caprolactam and 0.6 part of divinylbenzene.

Example 4

Exactly the same as example 1, except that: adding 28 parts of acrylamide, 20 parts of 2-acrylamide-2-methylpropanesulfonic acid, 108 parts of deionized water, 2.2 parts of a composite viscosity stabilizer, 4 parts of sodium dodecyl sulfate, 0.15 part of azobisisobutyronitrile, 24 parts of vinyl caprolactam and 0.6 part of divinylbenzene.

Example 5

Exactly the same as example 1, except that: 2.3 parts of composite viscosity stabilizer, 3.5 parts of sodium dodecyl sulfate, 0.16 part of azobisisobutyronitrile and 20 parts of vinyl caprolactam are added.

Example 6

Exactly the same as example 1, except that: 2.4 parts of composite viscosity stabilizer, 4 parts of sodium dodecyl sulfate, 0.16 part of azobisisobutyronitrile and 24 parts of vinyl caprolactam are added.

Example 7

Exactly the same as example 1, except that: 36 parts of acrylamide, 28 parts of 2-acrylamido-2-methylpropanesulfonic acid, 148 parts of deionized water, 2.5 parts of a composite viscosity stabilizer, 4 parts of sodium dodecyl sulfate, 0.17 part of azobisisobutyronitrile, 24 parts of vinyl caprolactam and 1 part of divinylbenzene are added.

Example 8

Exactly the same as example 1, except that: 36 parts of acrylamide, 28 parts of 2-acrylamido-2-methylpropanesulfonic acid, 148 parts of deionized water, 2.8 parts of a composite viscosity stabilizer, 5 parts of sodium dodecyl sulfate, 0.18 part of azobisisobutyronitrile, 28 parts of vinyl caprolactam and 1 part of divinylbenzene are added.

Example 9

Exactly the same as example 1, except that: 36 parts of acrylamide, 28 parts of 2-acrylamido-2-methylpropanesulfonic acid, 148 parts of deionized water, 2.9 parts of a composite viscosity stabilizer, 5.5 parts of sodium dodecyl sulfate, 0.19 part of azobisisobutyronitrile, 32 parts of vinyl caprolactam and 1 part of divinylbenzene are added.

Comparative example 1

Exactly the same as example 1, except that: except that no complex viscosity stabilizer was added.

Comparative example 2

Exactly the same as example 1, except that: except that the viscosity stabilizer added was thiourea.

Comparative example 3

Exactly the same as example 1, except that: except that thiourea was not added in the preparation of the composite viscosity stabilizer.

Comparative example 4

Exactly the same as example 1, except that: except that 90 parts by weight of vinyl acetate was added when the composite viscosity stabilizer was prepared.

Comparative example 5

Exactly the same as example 1, except that: the pH value is not adjusted when the high-temperature resistant tackifier is prepared.

Comparative example 6

Exactly the same as example 1, except that: except that 2-acrylamido-2-methylpropanesulfonic acid was replaced by dimethyldiallylammonium chloride.

The performance of the high temperature resistant tackifiers prepared in examples 1 to 9 of the present invention and comparative examples 1 to 6 was tested by the following methods:

1. adhesion promotion Performance test

Accurately weighing 2.00g of dry polymer tackifier powder, adding the powder into 400ml of deionized water under the stirring condition, stirring the mixture at a low speed for 6 hours, and standing the mixture overnight to completely dissolve the powder so as to obtain a polymer deionized water solution with the mass concentration of 0.5%. The apparent viscosity of the aqueous polymer solution was measured with a Brookfield DV-III ULTRA type viscometer with a temperature control accuracy of. + -. 0.1 ℃ and a measurement temperature of 20 ℃ and the measurement data are shown in Table 1.

TABLE 1 tackifying Performance test

As can be seen from Table 1, the viscosity of water increased after different samples were added to the water, and the apparent viscosity generally increased from 1.06 mPas to 202.34-298.20 mPas. The tackifying effect of the tackifier in example 1 is outstanding, and the apparent viscosity is increased to 320.90mPa · s, so that the ratio of the raw materials in the process of synthesizing the tackifier sample has great influence on the tackifying performance of the tackifier, and the tackifying effect is best when the ratio of the raw materials in example 1 reaches the optimal combination. In addition, comparative examples 1 to 4 show that the addition of the composite viscosity stabilizer and the proportion of the formula have large influence on the tackifying performance of the tackifier, and comparative examples 5 to 6 show that the selection of raw materials and synthesis conditions during preparation of the tackifier has a prominent influence on the performance of the tackifier.

2. Evaluation results of tackifier temperature resistance

The formula A comprises 4 percent of bentonite, 0.2 percent of NaOH and 0.1 percent of Na₂CO₃+0.6% SPNH +0.3% LV-Pac +3% SMP + barite (drilling fluid density ρ =1.2 g/cm)³) As a blank sample, 0.2% of the sample in example 1 was added to the blank sample as a test sample, and the rheological property, the medium-pressure water loss and the high-temperature high-pressure water loss were measured after hot rolling at 200 ℃, 220 ℃ and 240 ℃ for 16 hours, respectively, and the high-temperature high-pressure water loss was measured at the hot rolling temperature.

TABLE 2 Effect of hot roll temperature on drilling fluid Performance

As can be seen from Table 2, the viscosity and shear force of the drilling fluid added with the tackifier are both increased, the dynamic-plastic ratio is increased, and the filtration loss is reduced. The drilling fluid shows a descending trend of viscosity, shearing force and dynamic-plastic ratio along with the rise of the hot rolling temperature, after the drilling fluid is hot rolled at 240 ℃, the apparent viscosity and the dynamic-plastic ratio of the drilling fluid are greatly reduced, but the tackifier is not completely degraded, the drilling fluid still meets the field drilling requirement, and the tackifier agent has excellent temperature resistance and still has certain temperature resistance at 240 ℃.

Claims

1. A preparation method of a high-temperature resistant tackifier for drilling fluid is characterized by comprising the following steps:

dissolving 32 parts of acrylamide and 24 parts of 2-acrylamido-2-methylpropanesulfonic acid in 128 parts of deionized water, adjusting the solution to be neutral by using an alkaline reagent, transferring the solution to a reaction kettle, adding 2.5 parts of a composite viscosity stabilizer and 5 parts of sodium dodecyl sulfate, and uniformly stirring; heating the reaction kettle to 40 ℃, adding 28 parts of vinyl caprolactam dissolved with 0.15 part of azobisisobutyronitrile and 0.8 part of divinylbenzene, stirring uniformly, and introducing N₂Deoxidizing for 1h, continuously heating to 65 ℃, reacting for 6-7 h while stirring, discharging to obtain a jelly, precipitating with acetone, drying in a 50 ℃ oven, and crushing to obtain the polymer high-temperature-resistant tackifier;