DESCRIPTION
Clay Doctor is a versatile modified encapsulating polymer used in water based drilling fluid systems to provide stability
when encountering reactive clay and shale formations. Clay Doctor’s charge density and molecular weight are uniquely
adjusted to maximise encapsulation with only a minimal increase in viscosity. Clay Doctor will disperse quickly into
solution with minimal shear to produce a highly effective manageable fluid that will prevent swelling, sloughing and
dispersion, also enhance down-hole lubrication and improve sample recovery.
APPLICATION
Clay Doctor forms a protective film over the surfaces of the bore hole reducing water invasion into the hydratable clays
and shale while also providing excellent cuttings encapsulation and borehole stability. Clay Doctor acts as a superior
friction reducer, is a mild flocculant and when used in high concentrations causes no appreciable increase in viscosity
thus maintaining low circulation pressures. Clay Doctor is ideal for highly dispersible fragile clays where K+ inhibition
is often not required or where the conventional use of conventional PHPA-type polymers can result in excessively high
viscosities. Clay Doctor is tolerant to saline environments however to achieve maximum potential from the products the
total hardness values should be maintained below 400 milligrams per litre and a pH range of 8.5 – 9.5.
ADVANTAGES
- Versatile product
- Readily dispersed and does not form fish-eyes
- Low viscosity when mixed at higher concentrations
- Effective at low and high concentrations
- Very stable, non-fermenting polymer
- Provide excellent cuttings encapsulation to control dispersion
- Highly efficient clay and shale stabiliser
- Prevents bit balling and collaring
- Improves borehole stability
- Improves lubrication
- Improves core recovery and penetration rates
- Stable in saturated salt environments
- Compatible with most water based drilling fluid systems, polymers and lubricants
TYPICAL PROPERTIES
- Appearance: White, free flowing granular powder
- pH (1% solution): 7.0 – 8.0
- Specific gravity: 0.55 +/- 0.15
- Shelf life: 24 months
RECOMMENDED TREATMENT
Clay Doctor can be mixed directly into the active mud system or premixed at higher concentrations separately and blended
into the active system. For best result it can be slowly introduced into mechanical agitation, through a mud hopper or a
high shear mixing device.
| APPLICATION |
KG/m3 |
| Under Normal Drilling Conditions |
0.5 - 2.5 |
| To Stabilise Swelling Clays & Shales |
2.0 - 8.0 |
| To Improve Foam Performance Properties |
1.0 - 2.5 |
Liquid Sodium Hypochlorite can be used to accelerate the breakdown of Clay Doctor after use.
