Page 169 - Drilling Technology in Nontechnical Language

160 Drilling Technology in Nontechnical Language Second Edition

2. Increase gelation properties. When the fluid becomes stationary,

it forms a gel. This allows solids in the mud, including drilled
rock cuttings, to be suspended within the gel so that they do not
fall down through the mud.

3. Decrease fluid loss into the formation. A mud containing solids
that is in contact with a permeable formation will lose water and
dissolved chemicals into the formation. As this happens, solids in
the mud will form a plaster or cake on the face of the formation.

This loss of liquid, or filtrate, into the formation is called fluid

loss. Some chemicals can reduce the amount of fluid lost to the

formation in this way. A low fluid loss is sometimes desired in
a mud.
4. Act as a surfactant. This will allow oil and water to mix together
in an emulsion.

Fig. 7–3. Using polymers to bind clay platelets

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