Publications

Primary cementing process is established as the single most important factor in Well Integrity. Cement slurry contamination risk is one of the factors that will lead to a poor primary cement job and failure to achieve zonal isolation. The cement slurry contamination risk happens inside the casing and in the annulus. To prevent the contamination risk inside casing, wiper plug as a mechanical separator can be used to physically separate the interface between other fluids and the cement slurry, stopping contamination. In the 3 ½ inch Monobore well, previously the single wiper plug system was used. There was a history of the plug not bumping, mud left inside tubing and wet shoe. Therefore, the dual wiper plug system was brought as a solution. There are numbers of challenges associated with the 3 ½ inch wiper plug design. The main challenge is the wiper plug need to pass the 2.75 inch ID of X-Nipple in the monobore completion. To compensate the size, it will also need to be effective to wipe the tubing to clean the mud. An Innovative wiper plug has been designed to meet the challenges related to the 3 ½ inch monobore completion. The entire test associated to the challenges has been performed in the design of the wiper plug. The dual wiper plug was tested to be able to pass the 2.75 inch ID X-Nipple. An erosion test was performed to ensure the effectiveness of the wiper plug to wipe down the remaining mud in the tubing. The bump plug test also performed to ensure the latch in design wiper plug worked as per expected. To be compliant, the new design has been validated as per API. The dual wiper plug system has been implemented, and brings a good result in the cementing process. This paper discusses the design, the entire test that have been performed, and the implementation of the system.