The invention provides a
drilling fluid for improving the sliding efficiency of highly-deviated large cluster wells and a construction method. The
drilling fluid is composed of the following substances in percentage by
mass: 5-10% of an inhibitor; 12-17% of a soluble weighting agent; 1.3%-1.85% of a tackifying fluid loss agent; and 0.1%-0.5% of a flow pattern
regulator, with the balance being water. Non-soluble
solid phase such as
bentonite, limestone and barite is not added into the
drilling fluid, and the density is increased through soluble composite salt; inorganic salt KCl is added into the drilling fluid to inhibit hydration of
clay minerals so that rock debris particles are complete, and the sieving rate is high; as the drilling fluid has no
solid phase, the friction resistance is lower than that of other drilling fluid systems, and sliding drilling is facilitated; a sliding drilling tool face is in place, a sliding drilling
machine speed is high, and the sliding efficiency is high. The drilling fluid is recyclable, easy to control performance, free of
solid phase, high in inhibiting performance, low in friction resistance, free of sticky support during sliding, effectivelyimproves the sliding efficiency of highly-deviated large cluster wells, and has extremely high applicability to field production.