These starches are used as viscosifiers in oil well drilling and are exported 100% to the Middle East.  These are also one of the key ingredients of a mud chemical system. 

DRILLING STARCH (DS) and HIGH THERMAL STABLE DRILLING STARCH (HTDS) are used to provide filtration control and rheology stability in all types of waterbase drilling fluids. HTDS is stable upto 135 °C (275 °F) temperature.  CARBOXYMETHYL STARCH (CMS) is a non-ionic material especially suited for fluids containing salts or ion sensitive additives.