Strategic Value Framing for Brownfield Redevelopment
Authors: Ab Razak Norsyuhada , Kerya Normawani , Hendrawati May Sari , Nordin Syarah Syazana , Abd Rahman Noor Shakila , Strobech Poul Gustav , Amsidom Amirul Adha , Ho Yeek Huey 
Published: March 2021

Abstract

Objectives/Scope
Field A is a brownfield that has been produced for 52 years under natural depletion via a total of 207 strings. The field comprises 7000 ft of reservoir section, multiple fault blocks and over 200 separate reservoir units has been produced to date. Despite the long period of production, the field recovery factor (RF) to date is only 29%. To improve the RF, a strategic assest value framing exercise was carried out to identify the additional subsurface opportunities i.e. infill well drilling, secondary recovery, late field life appraisal in underdeveloped fault blocks as well as adopting standardized low well concepts and the design one build many facility design concept to reduce cost and accelerate development. The main purpose of the exercise was to capture the overall opportunities for the field, outline the roadmap and phase out the project with suitable wells and facilities design to bring down the cost for project commerciality.

Methods, Procedures, Process
The integrated workflow of the exercise involved subsurface, drilling, facilities, operations and economist and took a total of 3 months to complete. The process started off with a RF benchmarking exercise utilizing a newly developed inhouse RF benchmarking tool to compare the current attained vs the attainable RF(EUR) and identify incremental reserves. The number of new wells required to develop the incremental reserves was estimated by analyzing EUR per well trends over time. This analysis indicated that on a campaign basis the current realistic average EUR per well is in the order of 0.7-1.0 MMstb per well. The preliminary well placements are guided by bubble maps of all reservoirs, in a top to bottom & block by block approach, to identify underdeveloped areas and combining these areas into stacks of reservoirs that can be combined and developed with simpler wells from existing or future facilities. The drilling team has designed a few simple trajectories to penetrate shallower to deeper reservoirs and proposed the drilling center within a radius of 2 km from the targets. This approach differs from the object-based approach where individual high EUR targets are chased with more complex wells drilled from a specific location during a platform campaign.

Result, Observations, Conclusions
Potential additional reserves and 6 new projects have been identified which would result in a field recovery factor increase of 11%, of which 2 projects are being accelerated to realize early first oil. Timelines for all the projects have been mapped out with the aim of completing all within the next 10 years. A dedicated project management team has been formed to support the project from the initial stage. Detail Full Field Review study will be conducted to mature all the opportunities up to development stage. The listed projects will follow the low cost well guideline established in the framing as well as fast track facility design concept.

Novel/added value
The strategic value framing exercise is a systematic approach that provide a total picture of the future opportunities to optimize field production/EUR and maximize commercial value of brownfield redevelopment.