This work presents the lessons learned from the studies carried out to understand the non-fulfillment of the hydraulic isolation required during the liner 10 ¾" cement job. Analyzing the drilling parameters performed and the events of cementing, it is possible that the stationary solids bed and the consequent poor conditioning of the well were probably responsibles for the failure to obtain the hydraulic isolation required for the cementing operation. The investigation report recommends some good practices for avoiding and/or removing the cuttings-bed. The results of some simulations carried out during the investigation studies showed that drillpipe rotation speed contributes significantly to reduce the cuttings-bed height. Additionally to the extended reach, the well studied is a design well, has a complex trajectory, and the computer simulations revealed that ROP control is mandatory to obtain a proper hole cleaning and well conditioning. It was identified that the reduction of the hole diameter has a huge impact on well conditioning, drilling fluid displacement and cement slurry displacement. At last, the paper presents some recommendations for backreaming, mainly for evaluation of ideal operational parameters; adjust the drilling rates according to the hydraulic simulation, to ensure the hole cleaning and optimize the total time of the drilling intervention.