CN103509126A - Preparation method for high-substitution degree carboxymethyl starch used for drilling fluid - Google Patents

Abstract

The invention relates to the field of auxiliary agents for drilling fluids in the petroleum drilling industry, especially to a preparation method for high-substitution degree carboxymethyl starch used for a drilling fluid. The preparation method comprises the following steps: 1) placing 100 parts by mass of starch in the reaction vessel of a kneader; 2) adding 10 to 15 parts by mass of caustic soda, 5 to 10 parts by mass of water and 20 to 30 parts by mass of ethanol into the reaction vessel and carrying out an enclosed kneading reaction for 30 to 90 min to realize primary alkalization; 3) adding 15 to 20 parts by mass of caustic soda, 20 to 50 parts by mass of a carboxymethylation reagent and 20 to 30 parts by mass of ethanol into the reaction vessel and carrying out an enclosed kneading reaction at a temperature of 40 to 70 DGE C for 120 to 180 min to realize etherification; and 4) cooling to room temperature, carrying out blanking and carrying out drying at a temperature of 75 to 105 DEG C and crushing so as to obtain the high-substitution degree carboxymethyl starch. The method provided by the invention effectively makes use of the advantages of a dry process and a wet process, substantially reduces the application amounts of an organic solvent and water and lowers down production cost.

Description

The preparation method of carboxymethyl starch with high substitution degree for drilling fluid

Technical field

The present invention relates to the drilling fluid additive field of petroleum drilling industry, relate in particular to the preparation method of carboxymethyl starch with high substitution degree for a kind of drilling fluid.

Background technology

Drilling fluid needs good water-soluble, temperature resistance, filtration reduction and higher viscosity by carboxymethyl starch, in order to realize these performances, just needs carboxymethyl starch to have higher substitution value.Current carboxymethyl preparation method mainly contains: dry method or semidrying, wet method and solvent method, wherein: (1) dry method or semidrying: raw material is mixed in pulverizer, then putting into reactor adopts spray mode to react, the method sintetics substitution value is not high, substituting group is distributed in particle surface, and product solubility property is poor; (2) wet method: reaction homogeneity is higher than dry method and semidrying, but etherifying agent utilization ratio is low, the easy gelatinization of starch, and can produce a large amount of waste water, and causing environmental pollution, finished product is also difficult to purify; (3) solvent method: in the low-carbon (LC) organic solvent that contains certain water, add raw material reaction to form starch suspension, can improve reaction efficiency, product substitution value is high, uniform substituent distribution, but need to reclaim solvent, and also cost is very high.

Summary of the invention

For the deficiencies in the prior art, the invention provides a kind of kneading preparation method of carboxymethyl starch with high substitution degree, the method has been drawn the advantage of dry method and two kinds of methods of wet method effectively, has greatly reduced the usage quantity of organic solvent and water, has reduced production cost.

The technical solution used in the present invention:

1) starch of 100 mass parts is placed in kneader reactor;

2), to the ethanol that adds the caustic soda of 10-15 mass parts, the water of 5-10 mass parts and 20-30 mass parts in reactor, airtight kneading reaction is alkalized for 30-90 minute for the first time;

3) to adding the caustic soda of 15-20 mass parts in reactor, the ethanol of the carboxymethylation reagent of 20-50 mass parts, 20-30 mass parts, within the scope of 40～70 ℃ of temperature, etherification reaction is carried out in airtight kneading reaction for 120 ~ 180 minutes;

4) be cooled to room temperature, discharging, 75～105 ℃ of oven dry, pulverize and obtain product.

Described carboxymethylation reagent is one or both the mixture in ethyl chloroacetate, Mono Chloro Acetic Acid.

The present invention adopts semidrying and solvent method to combine, on the basis of semidrying reaction, by adding ethanol as dispersion agent, improve the efficiency of reaction, the acting in conjunction of dispersion agent second alcohol and water can make fully dispersion of reactant, reaches the reaction effect of solvent method.

The present invention compared with prior art has following advantage: (1) has kept the less feature of semidrying Water usage, with respect to wet method, has greatly reduced water consumption, has avoided the pollution of sewage to environment; (2) keep solvent method to make the starch feature in dispersion state all the time, guaranteed higher reaction efficiency, avoided the simple deficiency that dry process reaction efficiency is low, product substitution value is high, not poorly soluble; (3) the method, with respect to simple solvent method, has greatly reduced organic solvent usage quantity, has reduced production cost; (4) adopt kneader to synthesize, make reaction more evenly, more abundant, raw material availability is high, and single can carry out experiment more than 2kg, with respect to common lab method, has increased and has amplified the success ratio of producing; (5) through many experiments, finally synthesized substitution value DS up to 0.7, temperature resistance can reach 150 ℃, and water-soluble extraordinary carboxymethyl starch.

Embodiment

Below in conjunction with specific embodiment, the present invention will be further described.

Embodiment 1

[1] take 1000g common starch raw material and put into kneader reactor;

[2] in reactor, add caustic soda 100g, water 50g, dehydrated alcohol 250mL;

[3] natural reaction is approximately 30 minutes, without carrying out temperature control;

[4] in reactor, add caustic soda 150g, ethyl chloroacetate 400g, dehydrated alcohol 250mL again, 40 ℃ are reacted 120 minutes;

[5] be cooled to room temperature, discharging, 75～105 ℃ of oven dry, pulverize and obtain product.

Embodiment 2

[1] take 1000g common starch raw material and put into kneader reactor;

[2] in reactor, add caustic soda 100g, water 100g, dehydrated alcohol 300mL;

[3] natural reaction is approximately 90 minutes, without carrying out temperature control;

[4] in reactor, add caustic soda 150g, Mono Chloro Acetic Acid 400g, dehydrated alcohol 300mL again, 75 ℃ are reacted 120 minutes;

[5] be cooled to room temperature, discharging, 75～105 ℃ of oven dry, pulverize and obtain product.

Embodiment 3

[1] take 1000g common starch raw material and put into kneader reactor;

[2] in reactor, add caustic soda 150, water 75g, dehydrated alcohol 200mL;

[3] natural reaction is approximately 60 minutes, without carrying out temperature control;

[4] again to adding in caustic soda 150g, Mono Chloro Acetic Acid in reactor and mixture 500g, the dehydrated alcohol 300mL of ethyl chloroacetate, 40 ℃ of reactions 180 minutes;

[5] be cooled to room temperature, discharging, 75～105 ℃ of oven dry, pulverize and obtain product.

Embodiment 4

[1] take 1000g common starch raw material and put into kneader reactor;

[2] in reactor, add caustic soda 100g, water 75g, dehydrated alcohol 300mL;

[3] natural reaction is approximately 30 minutes, without carrying out temperature control;

[4] again to caustic soda 200g in reactor, add in Mono Chloro Acetic Acid and mixture 400g, the dehydrated alcohol 200mL of ethyl chloroacetate, 75 ℃ of reactions 180 minutes;

[5] be cooled to room temperature, discharging, 75～105 ℃ of oven dry, pulverize and obtain product.

Through many experiments checking, the substitution value of the carboxymethyl starch that embodiment 1-4 is synthetic is up to 0.7, and temperature resistance can reach 150 ℃.And found through experiments, take 1000g starch material as example, Water usage of the present invention is minimum is only 50g (such as embodiment 1), and the people such as black clouds adopt the under equal conditions quick Study on Preparation [J] of Water usage 15kg(carboxymethyl starch of wet method. Inner Mongol petrochemical complex, 2001,17 (11): 46-47), be 300 times of water consumption of the present invention; Using amount of alcohol minimum is only 500mL-600mL, and Cao Kai gloss with solvent method, under equal conditions to use amount of alcohol be the research [J] that 4260mL(sweet potato powder is prepared high viscosity carboxymethyl starch technique. foodstuffs industry science and technology, 2002,23 (9): 73-74), be the more than 7 times of ethanol consumption of the present invention.By above contrast, proved, the present invention can greatly reduce the generation of waste water, has also greatly reduced the pressure that reclaims solvent simultaneously, has economic benefit and the social benefit of energy-saving and emission-reduction.

Claims (2)

1. the preparation method of carboxymethyl starch with high substitution degree for drilling fluid, is characterized in that:

1) starch of 100 mass parts is placed in kneader reactor;

2), to the ethanol that adds the caustic soda of 10-15 mass parts, the water of 5-10 mass parts and 20-30 mass parts in reactor, airtight kneading reaction is alkalized for 30-90 minute for the first time;

3) to adding the caustic soda of 15-20 mass parts in reactor, the ethanol of the carboxymethylation reagent of 20-50 mass parts, 20-30 mass parts, within the scope of 40～70 ℃ of temperature, etherification reaction is carried out in airtight kneading reaction for 120 ~ 180 minutes;

4) be cooled to room temperature, discharging, 75～105 ℃ of oven dry, pulverize and obtain product.

2. the preparation method of carboxymethyl starch with high substitution degree for drilling fluid according to claim 1, is characterized in that: described carboxymethylation reagent is one or both the mixture in ethyl chloroacetate, Mono Chloro Acetic Acid.