Structured Approach in Qualifying Cement Isolation Through the Use of Cementing Scorecard and Post-Job Execution Data

Conventional ‘textbook’ primary cement job execution has always been associated with the combination of bumping top wiper plug, successful casing pressure test and/or no losses during the job. These criteria have been referenced by the general industry as positive indications and conveniently adopted as qualification for a successful cement job without considering other key parameters that contributes to proper cement isolation behind casing. In a deepwater development campaign offshore Malaysia, cement isolation behind the 9-5/8" production casing serves as critical barrier to ensure well integrity throughout the production lifecycle. To achieve this, the authors have deployed a structured approach focused on designing for success and optimizing a set of key performance indicators (KPIs) with pre- and post-drilled hole conditions. This paper outlines the approach based on the experience from the drilling campaign of nine oil producer wells.