Development of Non-damaging and Inhibitive Water Based Oil Well Drilling Fluids

The bridging agent plays very important role in the development of nondamaging water-based drilling fluid systems as it controls the water loss and the formation of filter cake thickness, which is desirable for the prevention of formation damage. These drilling fluids are inhibited with potassium or sodium chloride to increase the well bore stability during drilling operations. Keeping the previous in view, experimental studies have been carried out to study the new generation nondamaging and inhibitive drilling fluid system using xanthan gum, polyanionic cellulose, starch, calcium carbonate, and fly ash. It was observed that drilling fluids developed using fly ash as bridging agent have maintained good rheological properties and have better control on fluid loss and filter cake thickness than the calcium carbonate.