Multizone Openhole Gravel Packing with Enhanced Shunt Screens and Zonal Isolation in High-Rate Gas Wells

Abstract

A reliable single-trip openhole multizone completion can significantly lower capital expenditure (CAPEX) by reducing rig time and well count. Recent improvements in openhole packers and enhanced shunt screen technology have enabled multizone openhole gravel pack completions with complete zonal isolation. A multizone openhole gravel-pack completion was installed in the Julimar Field with an enhanced shunt screen system, shunted mechnaical packers (SMP) and shunt tube isolation valves (STIV), to provide improved operating pressure envelope and erosion tolerance. Well design was tailored to derisk the installation and optimize performance of the multizone completion. Extensive reliability testing was undertaken on all new technology for this project. Completions were installed as planned, and the main objectives of sand control integrity, production attainment, and complete zonal isolation with selective production were validated through post-job gravel-pack analysis and subsequent well unloading. The successful implementation of these technologies significantly reduced project CAPEX and enabled access to reserves that would otherwise have been uneconomical to recover. This paper discusses design, execution, and evaluation of the multizone openhole gravel pack (OHGP) completions installed in the Julimar Field. This includes methodology followed for multizone completion selection, development of a new high-temperature formate-based viscous gravel-pack carrier fluid, detailed completion equipment qualification tests, post-job gravel-pack evaluation, and initial well performance from well unload. It is the industry's first field case study of enhanced shunt screens with novel shunt tube isolation valves and high-temperature xanthan-based gravel-pack carrier fluid.