一种强抑制低活度卤水基钻井液体系OA北大核心

As a new type of drilling fluid,bring-based drilling fluid manifests its significance in replacing oil-based and conventional water-based drilling fluids.To deal with the serious borehole wall collapse and reservoir protection problems encountered in drilling the Permian system reservoir in Tuha oilfield,a chloride brine was chosen as the base fluid for drilling fluid development.By selecting high efficiency drilling fluid additives,a highly inhibitive low solids low activity brine-based drilling fluid was formulated.This drilling fluid has simple composition and strong inhibitive capacity.Laboratory researches show that this drilling fluid has good high temperature stability and contamination resistance,and results of corrosion test with steel plate and rubber satisfy the standard requirements.This drilling fluid was successfully used in the Qitan-1 block in Tuha oilfield,the average percent hole enlargement of the target zone sections was 3.44%,and no downhole troubles were encountered during drilling,demonstrating that the highly inhibitive low solids low activity brine-based drilling fluid can satisfy the requirements of drilling in the Permian basin.The application of the chloride brine-based drilling fluid is the first in China,and is worth further optimization and promotion.