Limbayong: Decoding Industry Top Decile Reservoir Complexity for Marginal Deepwater Development
Authors: Mohamed Najib Mohamed Aiman , Phoon Yong Ken , Wan Shamshudin Wan Fatimah , Mustapa Shazana Sofia , Khalid Aizuddin , Yusof Yunus Alwi 
Published: September 2022

PETRONAS Carigali (PCSB) has developed a solution to monetize industry top decile worth reservoir complexity in the deepwater environment via Limbayong field, Malaysia. The field complexity is acknowledged by Independent Project Analysis (IPA) as industry top decile reservoir complexity due to severe elongated structure (30km length, 2.5km width) with varying faults frequency, vertical intercalation of thin-bed, thick sand reservoir and lateral compartmentalization which impend effectiveness of well drainage and pressure maintenance. The four (4) appraisal wells result since 2002 give diverse subsurface understanding, indicated possible different depositional model and greater degree of complication. This paper describes the key development challenges and strategies that significantly improve the field value proposition for FID.

PCSB pivoted to focus assessment on low realization case for development. It generated advanced reservoir mapping to simulate sand distribution and concentration through incorporated faults re-interpretation, refined grid resolution, and change of facies prediction, increasing the stratigraphic compartments. The team performed integrated subsurface-surface flow assurance modeling and validated turndown limit for production and operation. Subsequently, iterated concepts for incremental reservoir recoverable by high-grading producer-injector pairing, wells-facilities design provision for a base, upgrade, or future tie-in. The team formulated industry collaboration (IC) studies in each FEL phase with drivers for deepwater technology enablers implementation in EPCIC primarily via concept selection, engineering standardization, and design competition. Each distinct concept is ratified with project economics group value chain evaluation and stakeholders’ alignment.

The breakthrough signifies merit in the key strategies and templates to overcome similar-scale project complexity with viable business cases. The IC affirmed cost proposition of 20 to 30% lower than industry average for deepwater wells and facilities, ensuring it to be positioned in top quartile project performance. It re-defined minimum technical design and demonstrated a prominent value trade-off for scaling-up concepts.

It drives momentum to monetize high complexity reservoirs even further in the deepwater environment, which otherwise remains undeveloped. There is potential for replication throughout nearly 800MMboe scattered fields within deepwater offshore Sabah, Malaysia. Deepwater offshore has a niche role in bridging global transition between energy mix offering and net-zero economy target. It produces among the industry's smallest carbon footprints yet with high economic efficiency. Consolidated and efficient development strategies accelerate the decarbonization pathway. It advocates a hybrid capital project management model to manage extreme uncertainties with design thinking, lean startup, and agile approach.