CN108264890A - A kind of preparation method of micro-cross-linked water-base drilling fluid fluid loss additive - Google Patents

Abstract

The invention relates to a preparation method of a fluid loss control agent for branched water-based drilling fluid, and belongs to the technical field of oil field chemistry. Polyethylene polyamine compounds containing multiple double bonds are prepared by reacting polyethylene polyamines with halogenated hydrocarbons containing double bonds, which are used as crosslinking agents, and non-ionic water-soluble monomers such as acrylamide and vinylpyrrolidone, And anionic water-soluble monomers such as 2-acrylamide-2-methylpropanesulfonic acid and sodium styrenesulfonate are used as polymerization raw materials to synthesize polymers with micro-crosslinked structures. This kind of polymer has excellent heat resistance and salt resistance, and its molecular structure has a variety of functional groups, which can significantly improve the dispersion stability of clay particles, and is suitable as a fluid loss control agent for water-based drilling fluids under harsh conditions.

Description

Preparation method of a micro-crosslinked fluid loss reducer for water-based drilling fluid

technical field

The invention relates to a preparation method of a micro-crosslinked fluid loss reducer for water-based drilling fluid, and belongs to the technical field of oilfield chemistry.

Background technique

With the continuous development of modern industry and the continuous improvement of economic level, the demand for energy in human society is getting higher and higher. Petroleum is one of the most important energy supply resources at present, and its exploitation and utilization are of great significance to the development of national economy and the stability of national security. With the intensification of exploration and development of deep oil and gas, formations encountered by drilling are becoming more and more complex. Usually the deeper the well, the higher the temperature and the more difficult it will be to drill. There are high-temperature formations in many areas of the world, such as the North Sea of the United States and the United Kingdom, where the bottom temperature of many wells exceeds 200 °C. Drilling problems at different degrees of high temperature exist in Southwest Tarim, Northeast Sichuan, Xujiaweizi in Daqing and Yingqiong Basin in the South China Sea on land in my country. This puts forward higher requirements for drilling fluid technology, especially the control of drilling fluid rheology and fluid loss at high temperature has become the main factor restricting the development of drilling fluid technology. High-temperature drilling fluid treatment agent and drilling fluid system to meet the needs of deep and ultra-deep well drilling.

Polymer fluid loss additive molecules mainly interact with clay particles through the functional groups on the side chains to increase the zeta potential of clay particles, ensure the stability and multi-level dispersion of the drilling fluid, and enable the drilling fluid to form during the drilling process. Dense, low-permeability mud cake, thereby reducing the fluid loss of drilling fluid. The degradation of polymers at high temperatures mainly includes three aspects. The first aspect is the conformational change of polymer molecular chains; the second aspect is the hydrolysis of side groups in polymer molecules, such as amide groups and ester groups; the third aspect is the polymerization breakage of the main chain of the molecule. Therefore, to improve the performance of polymer fluid loss control agents at high temperatures, we can start by reducing the changes in the above three aspects.

Chinese patent document CN 106366243A discloses a preparation method of a betaine-type polymer fluid loss control agent. The preparation method is as follows: first, vinylimidazole and propane sultone are used as raw materials, and tetrahydrofuran is used as a solvent to synthesize a betaine Vinyl monomer, 3-(3-sulfopropyl)-1-vinylimidazole. Then take acrylamide, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), dimethyl diallyl ammonium chloride (DMDAAC) and synthesized monomers as raw materials, potassium persulfate as initiator, A betaine-type copolymer was synthesized by aqueous solution copolymerization as a fluid loss reducer for drilling fluid. The obtained polymer can be used to reduce the fluid loss of water-based drilling fluid.

Chinese patent document CN107365403A discloses a preparation method of a high-temperature fluid loss reducer for drilling fluids, using raw materials such as acrylamide, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrolidone, etc., through It is prepared by aqueous solution polymerization method, and the optimal conditions for synthesis are: acrylamide, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, and N-vinylpyrrolidone. Parts to 30 parts, 25 parts to 35 parts, 5 parts to 8 parts, 1 to 3 parts of chitosan-Mn-bentonite as an initiation aid, the reaction temperature is 30 to 40°C, the reaction time is 8 hours, oxidation/reduction initiation Agent ratio n sodium persulfate: n sodium sulfite = 1.2:1, the initiator is 0.3 parts by weight, the optimum pH value of the monomer solution is 7-8, and the obtained polymer can be used as a fluid loss control agent for high-temperature water-based drilling fluid.

The above-mentioned patents all realize the improvement of the temperature and salt resistance of the fluid loss control agent by introducing functional units. In the process, there are often the following shortcomings: the preparation process of the functional monomer is cumbersome, and there are follow-up operations such as purification, which increases the product cost; and Compared with acrylamide monomers, the polymerization activity of functional monomers is poor, and the molecular weight of fluid loss control agents is not high. During use, the performance of fluid loss control is not good.

The required fluid loss control agent concentration is high; the introduction of hydrophobic functional monomers and internal salt functional monomers reduces the solubility of the polymer. During use, the dissolution time of the polymer increases and the proportion of insolubles increases, which affects the product. use and promotion.

Contents of the invention

Aiming at the deficiencies of the prior art, the invention provides a preparation method of a micro-crosslinked fluid loss control agent for water-based drilling fluid.

Summary of the invention

The present invention utilizes polyvinylpolyamine compounds containing polyallyl functional groups as crosslinking agents, and water-soluble monomers such as acrylamide, vinylpyrrolidone, acrylic acid, 2-acrylamide-2-methylpropanesulfonic acid as raw materials , to prepare a water-soluble polymer with a slightly cross-linked structure by aqueous solution polymerization. After testing, the product has good solubility in the solution, and when added to water-based drilling fluid, it can significantly reduce its fluid loss at high temperature and high salinity.

Detailed description of the invention

Technical scheme of the present invention is as follows:

A preparation method of micro-crosslinked fluid loss control agent for water-based drilling fluid:

(1) Preparation of crosslinking agent

Add polyethylene polyamine, compounds containing halogen atoms and allyl groups, alkali, and acetone into a single-necked flask with magnetic stirring and a spherical condenser, stir to mix the raw materials evenly, control the temperature at 30-60°C, and magnetically stir React for 6 to 48 hours, filter the product, and distill the volatile components under reduced pressure at 50°C to obtain a viscous liquid that is the crosslinking agent; the concentration of polyethylene polyamine in acetone is 10 to 200 g/L; The mass ratio of polyethylene polyamine, halogen atom and allyl group-containing compound to base is 1:(0.5～5):(1～8);

(2) Preparation of fluid loss reducer

Add the cross-linking agent, non-ionic water-soluble monomer, anionic water-soluble monomer, and deionized water into a three-necked glass bottle equipped with a stirrer, nitrogen pipe and thermometer, stir until all raw materials are dissolved, and then pass nitrogen gas 30min, the pH is controlled at 6-11, the temperature is controlled at 10-60°C, then sodium sulfite, ammonium persulfate, and hydrogen peroxide are added, and the reaction is 1-10h, then the temperature is raised to 80°C, and the reaction is 1h, and the product is dried and Pulverize, to get final product; The mass ratio of cross-linking agent and non-ionic water-soluble monomer is 1:(500～4000), the mass ratio of non-ionic water-soluble monomer, anionic water-soluble monomer and deionized water is 1:( 0.4～2.5):(5～20), the mass ratio of non-ionic water-soluble monomer, sodium sulfite, ammonium persulfate and hydrogen peroxide is 1:(0.0006～0.008):(0.001～0.01):(0.0001～0.0005) .

According to the present invention, preferably, the polyethylene polyamine described in step (1) is diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctamine a kind of

Preferably, the compound containing a halogen atom and an allyl group is one of allyl chloride and allyl bromide;

Preferably, the alkali is one of sodium carbonate and potassium carbonate;

Preferably, the concentration of polyethylene polyamine in acetone is 50-150g/L, and the mass ratio of polyethylene polyamine, halogen atom and allyl group-containing compound to base is 1:(1-4):(1.5- 5);

Preferably, the reaction temperature in the preparation of the crosslinking agent is 40-60° C., and the reaction time is 6-24 hours.

According to the present invention, preferably, the nonionic water-soluble monomer described in step (2) is acrylamide, vinylpyrrolidone, vinylcaprolactam, acrylonitrile, methacrylamide, N-methylolacrylamide, N - One or a mixture of two or more of ethylacrylamide, N,N-dimethylacrylamide, N-isopropylacrylamide, hydroxyethyl acrylate, and hydroxypropyl acrylate;

Preferably, the anionic water-soluble monomer is acrylic acid, methacrylic acid, maleic acid, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, sodium vinylsulfonate, styrenesulfonic acid One or more mixtures of sodium and allyl sodium sulfonate;

Preferably, the mass ratio of crosslinking agent and nonionic water-soluble monomer is 1:(500～2000), and the mass ratio of nonionic water-soluble monomer, anionic water-soluble monomer and deionized water is 1:(0.6～2000). 1.5): (10～20);

Preferably, the mass ratio of nonionic water-soluble monomer, sodium sulfite, ammonium persulfate and hydrogen peroxide is 1:(0.001～0.005):(0.001～0.008):(0.0001～0.0003);

Preferably, in the preparation of the fluid loss control agent, the pH is 7-9, the reaction temperature is 30-50° C., and the reaction time is 2-6 hours.

Principle of the present invention:

The branched structure formed by the cross-linking agent with multiple double bonds in the polymer can increase the molecular weight of the product on the one hand, and on the other hand can increase the rigidity of the polymer molecule, thereby improving its temperature resistance and salt resistance; The prepared cross-linking agent does not contain amide groups, ether groups, ester groups and other functional groups, it is not easy to degrade at high temperature, and has excellent stability; the amino group can be partially cationized in the drilling fluid system, therefore, the polyethylene polyamine in the polymer The unit can increase the interaction strength between the polymer and the clay, thereby improving the stabilization effect of the polymer on the clay colloidal system.

The excellent effects of the present invention are as follows:

1. The raw materials of the present invention are easy to obtain, the process is simple and safe, and the production cost is low.

2. The polymer molecule has a micro-crosslinked structure, which has strong rigidity, and the molecular volume changes little under high temperature or high salt, and the product has excellent temperature and salt resistance.

3. The polyethylene polyamine segment in the polymer molecule can enhance the interaction between the polymer and the clay, and improve the rubber protection effect of the product.

4. The present invention uses conventional monomers as polymerization raw materials, and the molecular weight of the product is high.

5. The follow-up treatment of the product of the present invention is simple, and it is easy to realize continuous production.

6. The product prepared by the present invention has good compatibility with conventional water-based drilling fluid systems.

Detailed ways

The experimental methods used in the following examples are conventional methods unless otherwise specified.

The materials and reagents used in the following examples can be obtained from commercial sources unless otherwise specified.

The present invention will be further described below in conjunction with specific examples, but the protection scope of the present invention is not limited thereto.

Example 1:

(1) Preparation of crosslinking agent

Add 10g of tetraethylenepentamine, 22g of allyl chloride, 30g of sodium carbonate, and 100mL of acetone into a single-necked flask with magnetic stirring and a spherical condenser, stir to mix the raw materials evenly, control the temperature at 50°C, and react under magnetic stirring After 18 hours, the product was filtered, and the volatile components were distilled off under reduced pressure at 50°C, and the obtained viscous liquid was the crosslinking agent.

(2) Preparation of fluid loss reducer

Add 10 mg of crosslinking agent, 10 g of vinylpyrrolidone, 10 g of 2-acrylamido-2-methylpropanesulfonic acid, and 120 g of deionized water into a three-necked glass bottle equipped with a stirrer, a nitrogen pipe and a thermometer, and stir After all the raw materials are dissolved, nitrogen gas is introduced for 30 minutes, the pH is controlled at 8.5, and the temperature is controlled at 35°C, then 20 mg of sodium sulfite, 25 mg of ammonium persulfate, and 2 mg of hydrogen peroxide are added to react for 3 hours, then the temperature is raised to 80°C, and the reaction After 1 hour, the product is dried and pulverized to obtain a micro-crosslinked polymer fluid loss control agent product.

Example 2:

As described in Example 1, the difference is that the addition of allyl chloride is 30g.

Example 3:

As described in Example 1, the difference is that the addition of allyl chloride is 18g.

Example 4:

As described in Example 1, the difference is that the polyethylene polyamine is 8 g of hexaethyleneheptamine.

Example 5:

As described in Example 1, the difference is that the polyethylene polyamine is 12 g of diethylene triamine.

Embodiment 6:

As described in Example 1, the difference is that the sodium carbonate addition is 20g.

Embodiment 7:

As described in Example 1, the difference is that the reaction temperature in the preparation of the crosslinking agent is 60°C.

Embodiment 8:

As described in Example 1, the difference is that the amount of crosslinking agent added in the polymerization reaction is 15 mg.

Embodiment 9:

As described in Example 1, the difference is that the dosage of the crosslinking agent in the polymerization reaction is 5 mg.

Example 10:

As described in Example 1, the difference is that the non-ionic water-soluble monomer is 6g of vinylpyrrolidone and 2g of N,N-dimethylacrylamide.

Example 11:

As described in Example 1, the difference is that the anionic water-soluble monomer is 8 g of sodium vinyl sulfonate and 4 g of sodium styrene sulfonate.

Example 12:

As described in Example 1, the difference is that the amount of deionized water added is 170g.

Example 13:

As described in Example 1, the difference is that the added amount of sodium sulfite is 35 mg, and the added amount of ammonium persulfate is 50 mg.

Example 14:

As described in Example 1, the difference is that in the polymerization reaction, the pH is 7.5, the temperature is 45° C., and the time is 5 h.

Comparative example 1:

Add 10g of vinylpyrrolidone, 10g of 2-acrylamido-2-methylpropanesulfonic acid, and 120g of deionized water into a three-necked glass bottle equipped with a stirrer, a nitrogen pipe and a thermometer, and stir until all the raw materials are dissolved , feed nitrogen for 30 minutes, control the pH at 8.5, and control the temperature at 35°C, then add 20 mg of sodium sulfite, 25 mg of ammonium persulfate, and 2 mg of hydrogen peroxide, react for 3 hours, then raise the temperature to 80°C, react for 1 hour, and dry the product , crushed, that is.

Comparative example 2:

Add 10mg of N,N'-methylenebisacrylamide, 10g of vinylpyrrolidone, 10g of 2-acrylamido-2-methylpropanesulfonic acid, and 120g of deionized water into a mixture equipped with a stirrer, nitrogen pipe and thermometer. In a three-neck glass bottle, stir until all the raw materials are dissolved, then pass nitrogen gas for 30 minutes, control the pH at 8.5, and control the temperature at 35°C, then add 20 mg of sodium sulfite, 25 mg of ammonium persulfate, and 2 mg of hydrogen peroxide, react for 3 hours, and then Raise the temperature to 80°C, react for 1 hour, dry and pulverize the product to obtain the product.

Comparative example 3:

Industrial product produced by Longquan Chemical Factory in Yanggu County, SMP-2.

Comparative example 4:

Industrial product produced by Renqiu Gaoke Chemical Materials Co., Ltd., SL-II.

performance evaluation

The fluid loss control performance of the comparative examples and the products of Examples 1 to 14 in water-based drilling fluids was evaluated. The evaluation of each sample was carried out in the composite brine-based slurry. Fluid Field Test” stipulates that medium pressure fluid loss is measured with ZNS-2 drilling fluid water loss instrument, and the aging temperature is 180°C, 200°C and 220°C respectively. The composition of the evaluation slurry is as follows, and the evaluation results are shown in Table 1. Show.

Composite brine-based slurry: 400mL water + 4.5% sodium chloride + 0.5% anhydrous calcium chloride + 1.3% magnesium chloride + 15% evaluation soil + 0.9% sodium carbonate + 1% fluid loss additive.

It can be seen from the data in the table that the introduction of synthetic cross-linking agent into the polymer fluid loss control agent can significantly improve the fluid loss control performance of the fluid loss control agent, and the improvement effect is more significant at high temperatures above 200°C.

Table 1 performance evaluation results

Claims (6)

1. a kind of preparation method of micro-cross-linked water-base drilling fluid fluid loss additive, as follows including step：

(1) preparation of crosslinking agent

The compound of polyethylene polyamine, halogen atom and pi-allyl, alkali, acetone magnetic agitation and spherical condensation tube have been added to Single-necked flask in, stir and be uniformly mixed raw material, by temperature control at 30~60 DEG C, under magnetic agitation react 6~48h, will Product filters, and the vacuum distillation removing volatile component at 50 DEG C, gained viscous liquid is crosslinking agent；Polyethylene polyamine exists A concentration of 10~200g/L in acetone；The mass ratio of polyethylene polyamine, the compound of halogen atom and pi-allyl and alkali is 1: (0.5~5):(1~8)；

The polyethylene polyamine is diethylenetriamine, triethylene tetramine, tetraethylenepentamine, in pentaethylene hexamine, six ethylene seven One kind of amine, seven ethylene, eight amine；

The halogen atom and the compound of pi-allyl are allyl chloride, one kind in allyl bromide, bromoallylene；

The alkali is sodium carbonate, one kind in potassium carbonate；

(2) preparation of fluid loss additive

Crosslinking agent, nonionic water-soluble monomers, anionic water-soluble monomer, deionized water are added to equipped with blender, logical nitrogen It in the wolf bottle of pipe and thermometer, stirs after all dissolution of raw material, is passed through nitrogen 30min, pH controls are 6~11, temperature Then degree control adds in sodium sulfite, ammonium persulfate, hydrogen peroxide at 10~60 DEG C, react 1~10h, then raise the temperature to 80 DEG C, react 1h, by product it is dry, crush to get；The mass ratio of crosslinking agent and nonionic water-soluble monomers is 1:(500~ 4000), the mass ratio of nonionic water-soluble monomers, anionic water-soluble monomer and deionized water is 1:(0.4~2.5):(5~ 20), the mass ratio of nonionic water-soluble monomers, sodium sulfite, ammonium persulfate and hydrogen peroxide is 1:(0.0006~0.008): (0.001~0.01):(0.0001~0.0005)；

The nonionic water-soluble monomers are acrylamide, vinyl pyrrolidone, caprolactam, acrylonitrile, first Base acrylamide, N hydroxymethyl acrylamide, N- ethyl acrylamides, N, N- dimethacrylamide, N- isopropyl acrylamides One or two kinds of object mixed above in amine, hydroxy-ethyl acrylate, hydroxypropyl acrylate；

The anionic water-soluble monomer is acrylic acid, methacrylic acid, maleic acid, itaconic acid, 2- acrylamido -2- first One or two kinds of object mixed above in base propane sulfonic acid, sodium vinyl sulfonate, sodium styrene sulfonate, Sodium Allyl Sulfonate.

2. the preparation method of micro-cross-linked water-base drilling fluid fluid loss additive according to claim 1, which is characterized in that step Suddenly a concentration of 50~150g/L of polyethylene polyamine in acetone, the chemical combination of polyethylene polyamine, halogen atom and pi-allyl in (1) The mass ratio of object and alkali is 1:(1~4):(1.5~5).

3. the preparation method of micro-cross-linked water-base drilling fluid fluid loss additive according to claim 1, which is characterized in that step Suddenly reaction temperature is 40~60 DEG C in (1), the reaction time for 6~for 24 hours.

4. the preparation method of micro-cross-linked water-base drilling fluid fluid loss additive according to claim 1, which is characterized in that step Suddenly the mass ratio of crosslinking agent and nonionic water-soluble monomers is 1 in (2):(500~2000), nonionic water-soluble monomers, it is cloudy from Sub- water-soluble monomer and the mass ratio of deionized water are 1:(0.6~1.5):(10~20).

5. the preparation method of micro-cross-linked water-base drilling fluid fluid loss additive according to claim 1, which is characterized in that step Suddenly the mass ratio of nonionic water-soluble monomers in (2), sodium sulfite, ammonium persulfate and hydrogen peroxide is 1:(0.001~ 0.005):(0.001~0.008):(0.0001~0.0003).

6. the preparation method of micro-cross-linked water-base drilling fluid fluid loss additive according to claim 1, which is characterized in that step Suddenly pH is 7~9 in (2), and reaction temperature is 30~50 DEG C, and the reaction time is 2~6h.