First use worldwide of a conventional stage tool integrated with an inflatable packer element for casing while drilling

摘要

The sustained impact of low oil prices continues to keep pressure on drilling economics whereby well construction teams must combine techniques to decrease Non Productive Time (NPT) therefore reducing cost, and improve drilling performance. A casing while drilling approach was proposed in the top sections where borehole instability typically occurs after having a total loss circulation which increases the risk of mechanical stuck pipe. The presence of a water aquifer in the same section imposes the need for a cement stage tool and an isolation packer. A 9-5/8in trial job was planned and executed where drilling forces simulations were performed for the 9- 5/8in casing with buttress connections and conventional cement stage tools, packer elements and centralization to identify the maximum forces that could be experienced during the execution. A hazard analysis and risk control with a full contingency plan was performed. Three jobs were carried out after first trial with 13-3/8in casing buttress connections and conventional stage tool with successful results. This paper describes the methodology and the successful execution of incorporating a conventional cement stage tool and packer element for casing while drilling applications to reduce both NPT and drilling risks as well as maintaining well construction integrity.