Methylene Blue Test Kit (MBT)

MUD TESTING EQUIPMENT

For years, Inmotion Energy has supplied
precision instruments and drilling tools for
testing drilling fluids, well cements, and
completion fluids.

From our Bangalore facility, we provide
customers across India and the Middle East
with quality products and exceptional
service.

As an independent manufacturer, we have one priority: our customers.

INDUSTRIES WE SERVE

— Onshore & offshore drilling contractors
— National & independent oil companies
— Mud engineering & testing laboratories
— Well completion & workover operations

WHY CHOOSE US

— Rigorous quality control on every unit
— Fast turnaround on spares &
replacements
— Field-tested designs, built for uptime

INMOTION ENERGY (OPC) PRIVATE LIMITED

PRODUCT SPECIFICATION — Methylene Blue Test Kit (MBT)

Model: IM-MBT-RMBT Compliance / target standard: API RP 13B-1 Sec. 10

The methylene blue test (MBT) kit measures the cation exchange capacity of a drilling fluid, and thereby the amount of reactive clay (bentonite and drilled shale) it contains. Methylene blue solution of known strength is titrated into a treated mud sample until the clay is saturated; the end point is detected by spotting a drop on filter paper. The result, the methylene blue capacity (MBC), is used to estimate the bentonite-equivalent content of the mud.

Figure 9. Reference photograph of the Methylene Blue Test Kit (MBT) with labeled components and Inmotion part numbers. Components are listed on page 2.

Intended applications

• Estimating reactive-clay (bentonite-equivalent) content of water-based mud.
• Tracking build-up of low-gravity reactive solids and drilled shale.
• Deciding on dilution or solids-control action.
• Screening clays and shales by cation exchange capacity.

FEATURES

• Standard 0.01 meq/mL methylene blue solution in a dropper bottle.
• Reagents for oxidation of organics: hydrogen peroxide (3 %) and dilute sulfuric acid.
• Erlenmeyer flask, syringe, pipettes and stirring rod.
• Filter paper for spot testing.
• Portable case for laboratory or rig use.

TECHNICAL SPECIFICATIONS

Titrant	Methylene blue, 0.01 meq/mL (about 3.74 g/L as trihydrate)
Mud Sample	Typically 2 mL (water-based mud)
Pre-treatment	10 mL water, 15 mL 3 % H2O2, 0.5 mL 5 N H2SO4, boil gently 10 min
Titration Increment	0.5 mL of methylene blue solution
End Point	Light blue halo around the dyed solids spot on filter paper
Result	MBC = mL methylene blue / mL mud (meq/mL)
Bentonite Equivalent	lb/bbl = 5 x MBC (about 14.3 x MBC in kg/m3)

Values are typical for this equipment class based on API/ASTM practice and manufacturer literature (OFITE, Fann, Chandler); confirm against the Inmotion datasheet before use in a certificate or specification.

Main components (see Figure 9)

No.	Component
1	Hot plate, 120 V / 230 V option (Inmotion #168-03 / #168-03-1)
2	Retort stand with medium clip (#163-27L) and large clips, qty 2 (#163-28)
3	Red knob for bleeder valve (#134-36-1)
4	Graduated cylinder, 50 mL x 1 mL, glass (#153-14)
5	Methylene blue solution (#200-03)
6	Deionized water, 8 oz / 250 mL (#206-01)
7	Hydrogen peroxide, 3%, 8 oz / 250 mL (#200-11)
8	Erlenmeyer flask, 250 mL (#153-50)
9	Syringe, 2 cc, glass-tip (#153-29)
10	Pipet, 1 mL x 1/100 mL, glass (#153-34)
11	Pipet, 10 mL x 1/10 mL, glass (#153-40)
12	Pipet aid / safety bulb (#153-41)
13	Stirring rod, glass, 6 in, qty 2 (#168-04, #230-13)
14	Filter paper, Whatman Grade 1, 12.5 cm, pkg of 100 (#140-56)

Principle of operation

Clay minerals carry exchangeable cations that are replaced by the methylene blue cation, which is adsorbed onto the clay surface. While the clay is still adsorbing dye, a drop of suspension on filter paper shows only a dyed solids spot. Once the clay is saturated, excess dye stays in solution and appears as a blue-green halo around the spot. The titrated volume is proportional to the cation exchange capacity of the sample.

Basic operating procedure

1. Add 2 mL of mud to 10 mL of water in the flask; add 15 mL of 3 % hydrogen peroxide and 0.5 mL of 5 N sulfuric
acid.
2. Boil gently for 10 minutes; do not boil dry. Dilute to about 50 mL and cool.
3. Add methylene blue in 0.5 mL increments, swirling for about 30 seconds after each.
4. After each addition place a drop of suspension on filter paper.
5. Stop when a light blue halo appears around the solids spot and persists after 2 minutes.
6. Record total mL of methylene blue, calculate MBC and the bentonite equivalent.

Calibration and maintenance

• Store methylene blue solution in a closed, dark bottle; replace if precipitate forms.
• Use clean glassware; rinse immediately after tests to avoid staining.
• Check peroxide and acid strength; replace when out of date.
• Check the syringe and pipettes for accuracy.

Safety precautions

• Wear gloves and eye protection; sulfuric acid and hydrogen peroxide are corrosive and oxidising.
• Boil samples in a fume cupboard or ventilated space; avoid splashes.
• Methylene blue stains skin and clothing; dispose of waste per site rules.

Reference sources