Fishing of sampling tool and subsequent treatment of a well in South China Sea

With the extensive application of the Saturn sampling tool in high-temperature and high-pressure wells in Yinggehai Basin of South China Sea, while it ensures the acquisition of complete and accurate reservoir data, downhole complications such as sticking of the sampling tool also occur. A well in South China Sea is a high-temperature and high-pressure well, which encountered a stuck pipe incident with the Saturn sampling tool at 3 611 m during sampling operations after drilling completion and tool release. This paper analyzes the causes of the stuck sampling tool and the technical challenges involved in fishing the tool and subsequent borehole treatment. By implementing appropriate well control measures, selecting a suitable slip overshot, and implementing anti-sticking and wellbore cleaning measures during reaming, the Saturn sampling tool was successfully fished in one attempt. Despite numerous remnants in the borehole, wellbore treatment was successfully completed, creating favorable conditions for subsequent cementing and bottom hole assembly (BHA) running. The successful handling of this well can provide reference for the fishing of similar tools and bore treatments in high-temperature and high-pressure offshore wells.