Methylene Blue Test Kit

Methylene Blue Test Kit

1、 Overview:

The soil content testing box is an instrument box used to determine the active soil (clay) content in drilling fluid by methylene blue determination (MBT) method. The total cation exchange capacity (CEC) of the solid phase can be estimated using methylene blue capacity. The methylene blue capacity and cation exchange capacity do not necessarily have to be equal, usually the former is slightly smaller than the actual cation exchange capacity.

Add methylene blue solution to the drilling fluid sample (treated with hydrogen peroxide and acidified) until a dye "color ring" appears around the solid suspension droplets on the filter paper, indicating saturation. The measurement program used for drilling fluid can be modified to determine the content of each type of solid phase present in drilling fluid by measuring drilling cuttings and commercial soil.

Drilling fluid often contains substances that can adsorb methylene blue in addition to active soil. Pre treatment with hydrogen peroxide is an attempt to eliminate the influence of organic substances such as lignosulfonates, lignite, cellulose polymers, polyacrylic acid salts, etc. on paper.

2、 The instrument mainly consists of the following parts:

1. Box: Used to hold the necessary accessories for instruments.

2. Column: used to support butterfly clips.

3. Butterfly clip: used to secure a burette.

4. Heating plate: It is used to heat the experimental reagents during the testing process.

5. Cone shaped bottle: used to hold experimental drugs and then heat them up.

6. Pipette: Used for injection purposes.

7. Liquid bottle: used to hold liquids.

8. Burette: used according to the experiment.

3、Experimental operation

1. Add 2.0cm3 of drilling fluid sample to a conical flask already filled with 10cm3 of water. To accurately add the 2.0cm3 sample, take the following steps:

a. The capacity of the syringe used should be greater than 2.0 cm3, and using a larger syringe does not require removing the air entering the syringe.

b. Air or natural gas mixed into the drilling fluid sample must be removed. Stir the drilling fluid to destroy its gel, and quickly suck the sample into the syringe. Keep the syringe mouth submerged in the mud and slowly drain the mud from the syringe.

c. Inhale the drilling fluid sample into the syringe again until the top of the plunger reaches the back mark on the syringe.

d. The positioning ring of the rotary injector is positioned at 2.0 cm3, and the plunger is pushed from the rear scale until the 2.0cm3 drilling fluid sample is accurately added to the conical flask.

2. Add 15 cm of 33% hydrogen peroxide solution and 0.5 cm of sulfuric acid (5N). Boil slowly for 10 minutes, but do not steam dry. Dilute with water to about 50 cm3.

3. Add methylene blue into the conical flask in increments of 0.5cm3 each time. If the amount of methylene blue solution required to reach the endpoint is roughly known from previous experiments, 1-2 cm3 can be added each time at the beginning of titration. After each addition of methylene blue solution, shake the conical flask for 30 seconds. While keeping the solid particles suspended, use a stirring rod to take a drop of the suspension and place it on the filter paper. When a blue or green blue ring appears around the solid particles on the filter paper as shown in Figure 1, the titration endpoint has been reached.

4. After observing the blue ring around the solid particles, continue shaking the conical flask for 2 minutes and take another drop of suspension onto the filter paper. If the blue ring is still prominent, the titration endpoint has been reached. If no blue ring appears, continue to add methylene blue solution according to the above operation method until the suspension droplet taken after 2 nm shows a blue ring.

4. Equipment and reagents

1. Testing equipment:

a. Syringe (TD): 10cm3 e. Measuring cylinder: 50 cm3

b. Cone shaped bottle: 250cm3 f. stirring rod

c. Burette: 10cm3 g. heating plate

d. Pipette: 1 cm3 h. Filter paper

2. Test reagents:

a. Methylene Blue Solution: 3.2g/l concentration, reagent grade Methylene Blue (C16H18N3SCl) (1cm3=0.01 milliequivalents)

Attention: When preparing the solution each time, the water content of reagent grade methylene blue must be measured. Dry 1.000g methylene blue at 93 ℃ to a constant weight.

When configuring the solution, calibrate the sampling amount according to the following formula:

Sampling weight (g)=3.20/Dry sample weight g

b. Hydrogen peroxide: 3% solution

c. Dilute sulfuric acid: about 5N