Offshore Mature Fields in Deepwaters: The Final Challenge

Abstract

Abstract Increasing the recovery factor of a mature field should be a top goal for every petroleum engineer. Producing oil from mature fields is both strategic and necessary: ​​Necessary because we need to increase our efficiency and reduce our carbon footprint. And it is unreasonable to leave in the rock a resource that nature took millions of years to generate. And strategic because oil from a mature field is (or should be) cheaper and has very low risk: I know where it is, I know how to produce it and I know what not to repeat. However, producing onshore mature fields is much simpler than offshore. It is common to have onshore mature fields, which produce at marginal rates, for 80 years or more, which is rare offshore. Production costs require marginal wells to be closed. And the costs and difficulties are geometrically proportional to the water depth. Shallow water fields in Norway can reach an RF of 65%. In Brazil, recovery factors of up to 85% are expected in onshore fields, while modern and highly prolific pre-salt fields are expected to produce 16% of their oil il place. 84% of the oil will remain in the rock. The alternative is to apply technologies massively, and the sooner they are planned and implemented, the better. Among the possible strategies and lines of action applicable are: Water and gas management. Optimization of water injection using techniques such as: PWRI (produced water re-injection), IAFP (injection of water above fracture pressure), etc Reduction in well construction cost for infill drilling. Application of well slender architecture with one trip completion. Use of liner conveyed gravel pack for unconsolidadted sandstones. U-well planning and construction. Reduction of area and weight of production units: Use of technologies such as RWI (raw water injection), SSWO (Subsea Separation of Water and Oil), etc This paper aims to make an overview of the applied and applicable technologies for extending the useful life of offshore fields, trying to make viable also for high water depths a philosophy of a recognized mature field operator: "The last field to be explored must be the increase of the recovery factor "