Bentonite

Bentonite is a clay material that is quite abundant on Earth. It is formed from weathering of volcanic ash and subsequent sedimentation. Bentonite is a highly absorbent, viscous plastic clay that is a valuable binding, sealing, absorbing, and lubricating agent in a huge variety of industries and applications. It has some exceptional properties: when stirred into water, it demonstrates thixotropic behaviour in which it becomes thinner and less viscous. It therefore acts as a fluid when mechanically stressed, for example when shaken or stirred, yet it hardens in static conditions.
The most common use of bentonite is in drilling fluids for viscosity and filtration control. The bentonite in the flush fluid lubricates and cools the cutting tools while protecting against corrosion.
As a flushing fluid, bentonite seals the drilled shaft from water ingress downwards and at the sides of the shaft. The mineral forms a firm sludge cake on the bore wall, which provides the borehole with additional stability. The fine bentonite particles enter into the bore wall where they swell and harden.

Bentonite

Important Characteristics

  • Large surface area
  • High swelling and thixotropic properties
  • Good plasticity and lubricity
  • High shear and compressive strength
  • Low filter loss
  • High viscosity
  • Impermeability
  • Low compressibility
  • High Water Absorption
  • Excellent gel strength properties
  • Fluid Loss is at rest
  • Delivery

Key Benefits

  • High Cuttings Suspension capability
  • Low Depth of Slurry Penetration
  • Fast development of Rheological properties
  • Advanced Lubrication ability
  • Creation of Thin Filtrate Cake with Low Permeability
  • Products specification as per customer requirement can be designed to achieve
  • It Act as Viscosifier and fluid reducing Agent.

Typical Properties Of Various Grades As Per Api 13a Specification

  • Large surface area
  • High swelling and thixotropic properties
  • Good plasticity and lubricity
  • High shear and compressive strength
  • Low filter loss
  • High viscosity
  • Impermeability
  • Low compressibility
  • High Water Absorption
  • Excellent gel strength properties
  • Fluid Loss is at rest
  • Delivery
Sr.no Parameters API-9(Section-9)
1. Viscometer dial reading 600 rpm 30 Min
2. Yield Point/ Plastic Viscosity Ratio 3 Max
3. API Fluid Loss 15 Ml Max
4. Residue of diameter > 75 ?m 4% Max
Sr.no Parameters API-10(Section-10
1. Yield Point/ Plastic Viscosity Ratio 1.5 max
2. Dispersed Plastic Viscosity, millipascal- seconds 10 min
3. Dispersed Fluid Loss 12.5 ml max.
Sr.no Parameters API-10(Section-10
1. Viscometer dial reading 600 rpm >30 min
2. Yield Point / Plastic Viscosity Ratio >6 MAX
3. API Fluid Loss 16 ml max
4. Residue > 75 ?m 2.5 % max
5. Moisture Content 13 % max