No abstract

A block of Liaohe Oilfield was taken as research object, based on geological condition of the block and performance parameter of coiled-tubing drilling rig, the pressure loss of different sections was calculated in coiled-tubing drilling(CT) including pressure loss of CT twisting in reel, downhole CT, annulus and total circulating. Especially, the effect of some important factors on total circulating pressure loss was discussed such as flow rate Q, consistency index K and rheological index n. Rheological properties parameter for coiled drilling fluid was determined by combining calculation results and practical experience. The calculation results show that it was desirable that Q is selected at 0.01 m 3 /s, n is at 0.4-0.5 and K is at 0.7-1.0 Pa•s n in the water-based solid-free drilling fluid. Certain theoretical basis is provided for the design of fluids used in coiled-tubing drilling.