DISADVANTAGES OF TREATED BENTONITE

HIGH COST

• If treated bentonite is used in hard drilling conditions like, high temperature, salt, bivalent cations and bacterial reproduction , the cost significantly increases because of following reasons.

• Polimers can’t adapt to additives or formation. Besides polymers disintegrate during the process. unexpected complications and dangerous reactions resulting by these disintegrations and/or incongruities ,causes drilling to interrupt.

• Because of the low montmorillonite content, treated bentonite does not form plasticity.

• Indefinite additives in treated bentonite, accelerate the bacteria production and causes surface equipments and drill string component to be damaged.

LESS YIELD

• Polimeric additives having high molecular weight, may increase the yield but they must be used rarely because there is an optimum point which we should never get over in the polymer concentration. If this optimum point is got over , the yield decreases so much that the yield becomes less than the yield of untreated state. Besides, if the polymer inside the treated bentonite in the mud system, is used together with another similar polymer, concentration becomes got over and again the yield decreases significantly.
  
  

FLOCCULATION

• Flocculation is definitely an undesired situation in mud system. There is no flocculation when natural bentonite is used because montmorillonite mineral in the natural bentonite is resistant to lump formation. On the other hand , additives like ( aggravating materials) are highly tend to flocculate so flocculation always occur in treated bentonite applications.
  
  

EXCESSIVE VISCOSITY

Adding treated bentonite to cement, causes unacceptable increases in viscosity.

FERMANTATION

While adding biopolymers like starch and xhantum gum to the bentonite, polymers ferment under the affect of bacteria depending the conditions. As a result , polymers loose their function and treated bentonite definitely can’t perform as desired. Furthermore by-products formed as result of fermentation , may negatively affect bentonite too.

In cases of long term stocking, depending the heat and moisture of environment, bacteria from surrounding infects the bentonite.

Moreover, there may be directly in the bentonite itself but because of the reason that bentonite is inorganic , these bacteria can’t directly affect bentonite on the other hand these bacteria may destroy the properties of bentonite thanks to existence of said additives in the bentonite. In conclusion, bacteria affect no bentonite but treated ones.

DISEASES AND ENVIRONMENTAL CORRUPTION

In the first stages of drilling especially in the levels, where surface water exists , the drilling mud being used is very important for human health and environment. Slurries being applied in these stages and levels, definitely mustn’t harm the human health and environment. If the drilling mud of these levels are prepared by treated bentonite chemical escapes in treated bentonite injects surface water by filtration and causes corruption . The chemical and / or biological corruption of surface water is a serious treat for human health and environment.

INCAPABILITY OF PLASTERING

During the drillings performed with soda – treated bentonite, when it is reached to aquifer, soda in the circulating mud melts , salinity of circulation fluid increases and plastering capability of mud decreases. Soda-activated bentonite can’t perform a normal plastering in drillings in brine zones.

LOW CARRYING CAPACITY

When treated bentonite is added to cement excessive gel formation occurs and this decreases the carrying capacity of.