Definition - What does Attapulgite mean?
Attapulgite, chemically called magnesium aluminum phyllosilicate occurs in clay soil. This is also called Palygorskite. Attapulgite is processed to produce variety of clays having different physical properties. In the oil industry this materials is used as one of the component in preparing drilling fluid, i.e., mud.
Petropedia explains Attapulgite
The primary function of the mud circulation is to remove formation cuttings from the hole. Viscosity of the mud system is more important to carry the cuttings from the bottom of hole to the surface. For this purpose bentonites are widely used in mud system that improve or retain the viscosity of the mud. In presence of contaminants like calcium or magnesium sulfate, salts bentonite is quite ineffective in maintaining viscosity.
On the other hand these attapulgite, will maintain the viscosity even in the presence of these impurities. It shows chemical stability even at a high pressure and temperature conditions that exist in the bottom of the well. Additionally, attapulgite provides good dispersion, mud sealing, protect walls, prevent borehole collapse, etc.