Addressing Challenging Well Conditions: Optimized Cementing Approaches for Achieving Zonal Isolation in Intermediate and Deep Liners

Abstract Addressing challenging well conditions to achieve zonal isolation during primary cementing operations is a top priority for ensuring cementing success, well integrity, and maintaining safety, as well as regulatory and environmental compliance. This case study presents two successful field applications of liner cementing operations conducted within a narrow operating window (between formation pore and fracture pressures) across challenging formations. To address these conditions, a managed pressure cementing (MPC) technique was implemented to overcome challenges posed by the narrow operating window. The approach also incorporated engineered heavy-weight slurries, a wellbore shielding spacer combined with an environmentally friendly lost circulation material (LCM), and an expandable liner hanger system. Extensive placement simulations and meticulously designed fluid properties helped optimize cement placement accuracy. The case studies involved 9 5/8-in and 7-in liners, where the deviated sections were drilled using the Managed Pressure Drilling (MPD) technique from the preceding 13 3/8-in and 9 5/8-in casings, respectively, through weak formations intersecting high-pressure zones. Although the well conditions were complex, zonal isolation was achieved in both cases by incorporating pioneering cementing techniques. The use of MPC, along with wellbore shielding spacer system helped mitigate potential losses within the narrow operating window and ensured effective zonal isolation. Extensive placement simulations contributed to maintaining well stability throughout the execution. The use of expandable liner hanger systems, combined with detailed engineering procedures and meticulously designed fluid properties, was essential in overcoming operational complexities and achieving the cementing objectives. This study highlights the importance of innovative solutions and a tunable engineering approach to achieve zonal isolation in complex and challenging cementing environments. This paper presents insights into the design, execution, and evaluation of cementing operations through the effective use of innovative techniques. The novel integration of MPC, expandable liner hangers, and environmentally friendly lost circulation spacers contributed to ensuring well integrity. Furthermore, the paper offers valuable perspectives on how the integration of advanced methods and technologies can enhance operational excellence in cementing applications.