The placement of cement plugs in extended-reach drilling (ERD) wells is a challenging task. Poor hole cleaning, insufficient mud displacement, incomplete centralization, and tight ECD management are some of the more common risks. Mud displacement efficiency and accurate cement placement is notably more complicated in ERD wells due high deviation angles and asymmetrical fluid velocities; problems which are compounded in presence of Synthetic Based Mud (SBM). In fact, the industry standard for setting and successfully testing cement plugs in highly deviated wells is 2.4x per successful attempt. For deepwater projects, these risks must be mitigated to ensure timely operations as the financial implications of failed cement plugs are vast.

Adopting best cementing practices in job planning and execution are beneficial elements to overcome the challenges; however even with excellent operational guidelines cement plug failures are common. A properly designed job should consider appropriate selection of equipment and materials, tailored properties of slurry and spacer systems, accurate down-hole pressure and temperature simulation, extensive laboratory testing, and identification and management of key risks.

This paper will discuss the various operational, engineering, and unique design techniques for setting horizontal cement plugs in a SBM environment on a project in deep waters offshore Indonesia. To date, four kick off plugs have been set successfully in the first attempt on four consecutive ERD wells. Conservative cost savings for achieving first attempt kick-off is 1.2 MM USD, applying 12 hours per well (48 hours total) with a daily rig rate of 600K USD.

The achievement is owing to application of best cementing practices in job design and execution, along with use of a unique cement system and innovative spacer. Techniques used in placing challenging kick off plugs are discussed followed by discussion on how the trouble-free operation has created value for both the client and service provider. Multiple case histories will be presented, along with specifics of the unique slurry and spacer system.

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