Drilling Execution and Completion Advancements Continue to Deliver for Guyana
Authors: Adeola Olatunji , Burmaster Kolby , Phi Michael , Arnold Shaun , Robinson Alexander , Klein Jackson 
Published: August 2021

The ExxonMobil Wells organization, along with Hess Guyana Exploration Limited and CNOOC Petroleum Guyana Limited, executed a successful multi-rig campaign to achieve First Oil on the Liza Phase 1 project ahead of schedule, utilizing advanced deepwater completion technologies to deliver highly productive wells. Considering the sizable resource offshore Guyana, strategic partnerships have been established with drilling contractors and other service providers to build economies-of-scale.

ExxonMobil's prior global experience is actively being leveraged in rig selection and well design. Standardization, both above and below the rotary, has allowed for increased flexibility on current and future well execution, maintaining optionality to rapidly adjust project pace. A deliberate contracting strategy with established rig providers has also opened access to top tier rigs with reduced procurement timelines, providing flexibility with total rig count and capability. With an integrated team approach focused on simulataneous operations (SIMOPS) mitigation, rig movements have been optimized within the field to prioritize the highest value work and streamline project delivery. Effective schedule integration with multiple drilling rigs and installation vessels has reduced SIMOPS downtime during Phase 1 project execution. Additionally, batch rig operations have allowed the team to capitalize on operational efficiencies. A combination of these factors led to on-time well delivery and helped the project achieve aggressive First Oil milestones.

The team has implemented innovative technologies to maximize value and well reliability, including the following: integrated geosteering workflows, with Azimuthal Ultra-Deep Resistivity (AUDR), enabling maximum reservoir penetrations; a suite of low equivalent circulating density (ECD) drilling fluids that enable the drilling of narrow-margin, highly deviated wells; ExxonMobil's patented NAFPac™ openhole gravel pack technology and autonomous inflow control devices (AICDs) on stand-alone-screen completions to increase well life and reliability; and remotely operated vehicle (ROV) based tree intervention control systems and ROV actuated suspension valves allowing for offline installation of subsea trees. Additionally, the team implemented the first floating application of the NOVOS™ automated slip-to-slip drilling system. NOVOS™ has been coupled with an automated drilling advisory system (AutoDAS) and data analytics environments for continuous performance improvement.

The production wells that were delivered for Liza Phase 1 have highly productive, low-skin completions averaging over 900 m in length and production rates in excess of 30 kbd/well. Advancements in completion technology and efficiency proven on Liza Phase 1 are being extended into Phase 2 development and beyond, providing additional reservoir management capability.

Lastly, ExxonMobil's commitment to Guyana extends to its people. Guyanese personnel have benefitted from significant training provided by ExxonMobil and sub-contractors, and Guyanese Nationals represented approximately 40% of the workforce involved in Wells-related activities at the end of 2020.