Chemical Washes

Chemical washes are fluids containing surfactants and mud thinners, designed to thin and disperse the drilling fluid so that it can be removed from the casing and borehole. Washes are available for water-based and oil-based drilling fluids. They are designed to be used in turbulent flow conditions.

Spacers are fluids of controlled viscosity, density and gel strength used to form a buffer between the cement and drilling fluid. They also help in the removal of drilling fluid during cementing.

An accelerator is a chemical additive used to speed up the normal rate of reaction between cement and water which shortens the thickening time of the cement, increase the early strength of cement, and saves time on the drilling rig. Cement slurries used opposite shallow, low-temperature formations require accelerators to shorten the time for "waiting-on-cement". Most operators wait on cement to reach a minimum compressive strength of 500 psi before resuming drilling operations. When using accelerators, this strength can be developed in 4 hours. It is a good practice to use accelerators with basic cements because at temperatures below 100oF, neat cement may require 1 or 2 days to develop a 500 psi compressive strength.

Common accelerators are sodium metasilicate, sodium chloride, sea water, anhydrous calcium chloride, potassium chloride and gypsum.

Was this article helpful?

0 0
Helping Your Child Learn To Read

Helping Your Child Learn To Read

When parents help their children learn to read, they help open the door to a new world. As a parent, you can begin an endless learning chain: You read to your children, they develop a love of stories and poems, they want to read on their own, they practice reading, and finally they read for their own information or pleasure. They become readers, and their world is forever expanded and enriched.

Get My Free Ebook


Post a comment