The high risk of RIH Φ177.8mm liner has long been recognized as a difficult problem in the drilling industry.Until recent years, the development of rotating liner running technology improves the success rate of RIH to target depth.However, the torsion strength of common casing thread cannot meet the requirements of rotating liner while RIH operation.If high torque resistant casing is used, the operation cost will be greatly increased.This paper introduces the structure, working principle and advantages of torque ring, and verifies the rationality of several parameters of torque ring in the laboratory.To save operating costs, the torque ring is introduced into the domestic offshore oilfield for the first time,and has been successfully applied to three extended-reach wells in Kenli oilfield,which achieved satisfying results.The torque ring not only solves the problem that common casing thread cannot meet requirements of rotating liner while RIH operation, but also saves nearly 60 % of the casing costs, and provides a powerful guarantee for the safe and efficient operation on site,which contributes to reduce the cost and improve the benefit for Bohai oilfield. It has a good application prospect and deserves further promotion.