Fit-for-Purpose Development Planning for Greenfield Aims To Deliver Early Monetization

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 226390, “Fit-for-Purpose Development Planning for Oil Greenfield To Deliver Early Monetization: A Case Study From Sarawak (Malaysia),” by Ankaj Kumar Sinha, SPE, Nur Hazwani Izyan bt Hashim, and Kamilla Majid, Petronas, et al. The paper has not been peer-reviewed. _ An efficient resource-maturation funnel ensures seamless transition of fields from the exploration to the development phase, leading to an optimal pace of field development while yielding value transformation through early monetization. The complete paper illustrates a case study from a greenfield oil asset in Sarawak planned for a fit-for-purpose development scope to create value for stakeholders and develop oil resources in a phased manner within 4 years of project framing. Field Background Field X is a recently discovered oil field in West Balingian province offshore Sarawak, Malaysia. The field is strategically surrounded by several producing oil and gas fields, and presents a viable opportunity for greenfield development through nearby evacuation routes. First oil delivery is targeted within 4 years of project framing for accelerated monetization. The productive reservoirs comprise Early Miocene Cycle II sediments transported from the nearby Penian High and deposited in a braided delta system that provides good reservoir quality and continuity. The discovered field has oil accumulations along with gas cap in all reservoirs. Gas/oil contact has been observed in the RA and RC reservoirs, but oil/water contact has not been observed. Based on fluid samples, the fluid is low-contaminant (no hydrogen sulfide and less than 8% CO2) with 33° API and a primary recovery mechanism expected to be gas-cap drive with weak to moderate aquifer drive. An integrated project team was constituted to prepare the project-maturation roadmap, and four key enablers were identified: a phased-development approach, fit-for-purpose reservoir modeling, early screening of scopes, and a simplified governance process. Phased Development Strategy To allow for potential uncertainties and future upside in this greenfield development, a phased approach was planned to realize the full potential of Field X. Phase I Scope. Modeling studies for Phase I development were focused on primary recovery mechanisms in major oil reservoirs that constituted approximately 60% of field in-place volumes. Five-well development was identified as the most optimal for this greenfield. Initially, all five wells were planned as deviated wells. Subsequently, the plan was revised from all deviated wells to a combination of four deviated and one horizontal well to achieve higher recovery in Phase I. With Phase I development and a potential Phase II focus on secondary recovery, current estimates for field oil-recovery factors are within the benchmark range. In the absence of well-testing data from the discovery wells, production rates from proposed development wells also were benchmarked to nearby field performance. The trends of reservoir-pressure decline for each reservoir (from the simulation model) also were analyzed with type curves to assess aquifer strength. All reservoirs exhibited weak to moderate aquifer support, as expected, during Phase I development. Evidently, secondary recovery will be required to improve the field recovery in subsequent phases.