Well Accessibility Considerations in Well Completion Designs for Long-Reach and Deviated Offshore Wells

AA is a new gas field located offshore Sarawak currently under field development planning phase. The elongated field structure consists of multi-stack reservoirs that are located up to 15,000 ft tvdss. Two options for developing the shallow Phase 1 wells (down to AA300 reservoir) have been assessed; completing at either one or two wellhead platforms. To decide between the two options, the team needed to be confident about the ability to safely intervene these wells in the future, which triggered detailed accessibility analyses for all wells considering various intervention methods. Four main intervention methods assessed were slickline, braided line, electric line (E-line) and coiled tubing (CT). This paper provides the details of well accessibility analyses conducted during development planning stage. Sensitivities on the types of intervention activities, bottom-hole assemblies and friction factors are also studied. The findings from the study have significantly changed the well completion designs of the long reach deviated wells justifying use of smart wells. This systematic well accessibility approach was applied for the first time to replace the traditional rule of thumb of a simple 60 degree deviation used as a cut-off for well accessibility.